A Method for Measuring Amplitude and Phase of Each Radiating Element of a Phased Array Antenna


 Homer O’Brien’
 3 years ago
 Views:
Transcription
1 Electronics and Communications in Japan, Vol. 65B, No. 5, 1982 A Method for Measuring Amplitude and Phase of Each Radiating Element of a Phased Array Antenna Seiji Mano and Takashi Katagi, Regular Members Information Systems and Electronics Development Laboratory, Mitsubishi Electric Corp., Kamakura, Japan 247 SUMMARY In the phased array system, excitation amplitudes and phases based on the design are specified for each antenna element in order to synthesize desired beam scannings and radiation patterns. However, due to fluctuations of antenna and feed network characteristics, the amplitude and phase of each antenna element deviate from the desired values. To correct these deviations, the amplitude and phase of each antenna element must be accurately measured under specific operating conditions. In this paper, we employ variable phase shifters connected to the antenna elements and measure only the amplitude variation of the composite electric field of the entire array when the phase of each element is modified. The rotating element electric field vector method in which the measured amplitude variation is numerically processed for obtaining the amplitude and phase of the particular element is theoretically discussed and experimentally tested for its usefulness. The present method can be easily attained by simply adding software to the computercontrolled phased array system. 1. Introduction In a phased array system consisting of many antenna elements (henceforth referred to simply as elements), the radiating beam is controlled by means of variable phase shifters. To realize desired radiation characteristics such as beam scanning, low side amplitude and phase must be established for each element. However, in general, the amplitude and phase of each element deviate from the desired values in the array environment due to characteristic fluctuations caused by mechanical errors and ambient effects. Therefore, these deviations must be compensated for. To this end, it is necessary to know accurate values of the amplitude and phase of each element in the array operation. Although the conventional nearfield measurement of the antenna by means of a field probe [l] can be used for amplitude and phase measurement of the element, measurement errors by the probe itself can be generated and a complicated mechanism for precise scanning of the probe is needed [2]. Another method in which correct phases are established by a microcomputer with detector circuits for the interelement phase difference of elements installed in the feed network cannot be used for an array consisting of more than ten elements because analog phase shifters are used and control is done with a closed circuit [3]. Yet another scheme operates on each bit of the phase shifters in the operating condition of the array and monitors bit errors by evaluating the signal received by a test antenna placed near the array [4]. In this scheme, both the amplitude and phase of the received signal need to be measured and the detected phase must be compared with the known reference phase. In this paper, we present a new method which does not require extra equipment or reflobe pattern and pattern synthesis, appropriate erence values. We employ variable phase 58
2 2.2 Expressions for the amplitude and phase of the element In Fig. 1, the amplitude and phase of the composite field vector in the initial state are denoted by EO and $ and those of the nth element by En and Qn. When the phase of this nth element is varied by A, the composite field is ;= (Eo el'o  E,,&'n ) +En &('m+d) (1) Fig. 1. Vectors of radiated field of each element and array. shifters connected to each element of the phased array. We measure only the amplitude variation of the composite electric field of the array when the phase of one of the elements is changed under the operating condition. By numerically processing the results, we obtain the amplitude and phase of this particular element [5]. The present method can be realized by adding sogtware to the phased array system controlled by a computer. Since only the amplitude variation of the composite electric field is measured, the accuracy is better than that for the method requiring phase measurement. In the sequel we discuss the theory of the present method and investigate its usefulness by comparison of experimental results with those of the directcoupled pickup method. 2. Measurement Theory 2.1 Measurement principle As shown in Fig. 1, the composite field vector of an array in a specific direction is given by superposition of the field vectors of the elements. When the phase of an element is changed by means of a phase shifter, the composite vector varies as the element field vector rotates. We measure the amplitude variation of the composite vector and determine the amplitude and phase of the element from the measured results. This is the principle of the present method. Note that Fig. 1 exhibits the situation in a specific observation direction. The element field vector is proportional to the product of the radiated field in such a direction and the excitation amplitude and phase of the element. Hence, in the present method, we take into account the fluctuation of radiation characteristics of the element 3s well as the excitation amplitude and phase. The aperture phase setting is disturbed appropriately from the cophasal condition in the observation direction so that the contribution of each element to the field variation is sufficiently large for measurement. We now define the relative amplitude and relative phase of the nth element as k =  En EO x = #n#o (3) We modify (1) so that the relative power expression of k is (see Appendix 1) where sinx tando = COSX  k Equation (4) indicates that the composite power Q varies cosinusoidally as the phase of one of the elements changes. From (4), it is seen that 6 is the phase making Q the maximum. From (4), the ratio of the maximum and minimum of Q is given as Hence, (Yfk r2 = (Yk)2 r=*(jq) From these r and Ao, the relative amplitude k and the relative phase X of the nth element are obtained as follows depending on the sign of r in (8) (see Appendix 2). (i) For the positive sign in (8) (the first solution) kk  1 JT+2r cos A, +r2 (ii) For the negative sign in (8) (second solution) r 59
3 where Therefore, if we measure the change in the composite power Q of the array as the phase of the nth element is changed and obtain (1) Ao: the phase making Q maximum and (2) r: the ratio of the maximum and minimum of Q, then the relative amplitude and the relative phase of the element are given by (9) and (1) or (11) and (12). Fig. 2. Relation between k and Y. 2.3 Interpretation of the two solut ions Due to different signs in (8), two sets of solutions are obtained for the relative amplitude and phase, k and X, of the element. Figure 2 shows the relation between the element field vector (amplitude k) normalized by the composite field amplitude Eg and the composite field vector (unit amplitude). Y in the figure is clearly the difference between the composite and element vectors. Since r in (7) is the ratio of the maximum and minimum levels of the power, always r > 1. Then, from the inequality relations between Y and k,rtakesoneof the signs in (8). For k < Y, r= (14) Yk In this case, the varying vector k added to the consant vector Y provides the maximumtominimum ratio of the composite vector. On the other hand, if k > Y, we obtain from (8) k +Y r=  k Y This case is in effect a superposition of the varying vector Y on the constant vector k so that the maximumtominimum ratio is expressed. For Fig. 2(b), kl is Y and k2 is k and, hence, the correct solution is k2. It is necessary to obtain both kl and k2 and to select the correct solution by the method described later. This is because, in general, inequality of k and Y is not known. We now study the relation of three vectors having amplitudes kl, k2 and Y for the case of k < Y. Let the three vectors be f, = kl ejx1 (16) f, = k, (17) Y = YeJ3 (18) Fig. 3. Relation between kl, k2 and Y (for the case of k = kl < Y). Then, from (9), (lo), (11) and (12), where * r K, =  { (cosdo+r) + j sin do 1 R2 (19) R = dl+v cos A, +f2 (21) Hence, with * as the symbol for complex conjugate quantities, we obtain i, +&*=I (22) On the other hand, as shown in Fig. 2(a), Therefore, from (22) and (23) we get *. y = K,* = k2 e ixa (24) The relation of the three vectors with amplitudes kl, k2 and Y is as shown in Fig. 3. In the case of k > Y, we get k = k2 [Eq. (ll)] and a similar vector relation is satisfied. 2.4 Discrimination of the solution The following three methods are conceivable for discriminating two sets of solutions. (a) The element vector is rotated once by changing the element phase. If the phase change of the composite field is less than 18, we choose kl. Otherwise, k2 is chosen. 6
4 (b) Obtain two sets of soiutions in the two states with different initial phase distributions. Choose as the solution the set for which values of kejx remain identical. (c) By adjusting the phase of each element, set the initial composite vector EO such that k < Y always holds. Choose the set for kl. Fig. 4. Case that only El is too large. Of these three, (a) is relatively simple for discrimination. However, it requires both the amplitude and the phase of the composite field. Although there is a possibility of erroneous discrimination in method (b) due to measurement errors, correct discrimination can be attained if the number of initial settings is increased. Method (c) cannot be applied to the cases in which the amplitude of one particular element En is extremely large, as in Fig. 4, and k < Y cannot be attained even when all the remaining elements are adjusted in phase. However, this method is applicable to the cases in which none of the elements has an extremely large amplitude. 2.5 Leastsquare approximation of measured values Theoretically, the composite field amplitude (power) versus the element phase changes in a cosinusoidal manner. In practice, however, the measured values fluctuate due to measurement errors in the maximumtominimum ratio r and the phase A giving the maximum, which are needed for computing the amplitude and phase of the element. Therefore, more accurate values may result if a cosinusoidal curve (4) that fits the measured values best is derived and r and A are obtained from such a curve. This procedure also makes numerical processing easier via computer. Such curves may be derived by means of the leastsquare approximations (LSA). 3. Experimental Discussion 3.1 Comparison with pickup method We use a 32element linear array operated in the X band (~OGHZ range). Experimental results are shown for the case where the phase is adjusted so that cophasal excitation occurs in the broadside direction. Also given are the results by the conventional pickup probe method for detecting the amplitude and phase of the element. The designed amplitude distribution is 32dB linear taper and is fixed. Analoglphase shifters are connected to each element. In the pickup method, an antenna identical to the element (circular horn) is used as the probe and the amplitude is detected by contacting the probe with the aperture of the element in order to obtain mechanical accuracy. This mechanism is for avoidance of positional irregularity in the nearfield measurement. In the new method, the observation point is in the broadside direction of the array and the aperture initial phase was appropriately disturbed from the cophasal condition. Hybrid circuits and circulators have been used in the feed network of the array to eliminate the effect of the circuit. Figure 5(a) shows the measured radiation pattern in the plane containing the array axis when the phases are set by the pickup method. Figure 5(b) is the corresponding result based on the new method. In both parts of this figure the dashed lines indicate the computed values when ideal amplitude and phase distributions are given. In the pickup method shown in Fig. 5(a), the sidelobe level is 22 db, which is substantially higher than the computed db. On the other hand, in Fig. 5(b) based on the new method, the sidelobe level is improved to db. The difference in the phase shift set by the two methods is shown in Fig. 6. The phase shift set has a maximum of 22' difference. Although the sidelobe level in Fig. 5(b) is still higher than the computed value, this difference is considered to be caused by poor reproducibility of the phase shift set in the analog phase shifters used for six elements each at both ends of the 32element linear array. It is clear, however, in parts (a) and (b) of Fig. 5 that the phase set accuracy is better in the new method than in the pickup method. 3.2 Experiments with a lowsidelobe antenna Here we report the results of experiments conducted with an antenna system in which the linear array described in the previous section is used as the feed array (primary radiator) of a 1.8 m x 1.8 m reflector. The antenna is oriented into the boresight and the aperture initial phase distribution is disturbed from the cophasal condition. A uniform phase distribution is realized by the new 61
5 mea cal. Observ. angle (deg) Observ. angle (deg) (a) Pickup method (b) This paper's method Fig. 5. Radiation patterns due to two phase setting methods, pickup method and this paper's method. 3 *O = 1 r 5  % 1 r a 2 j\. /,\,./\,  to'/ 25. $ CI Element number meas.  LSA Fig. 6. Difference of phase shift set by this paper's method and pickup method. I I I I A (deg) Fig. 7. Amplitude variation of array field by varying phase shift of one element. method. Such operating conditions as the fre cussed in 2.5. The standard deviation of the quency and array amplitude distribution error between the approximate curve and the (lowsidelobe distribution) are kept identical measured values at all points is.6 db in to those in 3.1. the case of Fig. 7. For all 32 elements, the maximum is.25 db and the average is (1) Element phase change and composite.6 db. Within the range of experiment, amplitude change the variation of the composite amplitude due to the element phase agrees well with the Figure 7 is an example of the measured theoretical curve given by [6]. variation of the composite amplitude when the phase of one of the elements is changed. The (2) Element amplitude solid line is a cosinusoidal curve approximated in the leastsquare sense (LSA) dis The composite amplitude variations described above were measured for all 32 62
6 1  m v al U 7.z 1 s a. al. w c) a a 2c (3) Radiation pattern Let us fix the amplitude distribution and set the phase based on the related phase Xi corresponding to kl in Fig. 8. The radiation pattern measured in the plane containing the array axis is shown in Fig. 9 for this case. The dashed lines in the figure show the computed values. In the angular range on the left of the main beam, the pattern is not shown because the effect of the ground reflection prevented measurement. Figure 9 shows that the sidelobe level of db agrees well with the designed value and the phase shift set on the aperture is accurately realized although the sidelobe structures are somehwat different. Fig. 8. I I I I Element number Distribution of amplitude kl and k2 of element. 1bII 2oc I it1 i 9 4. Conclusion A theoretical discussion was conducted and experimental verification was given for the usefulness of a new element method called the element fieldvector rotation method. In this method, the composite field amplitude of a phased array due to variation of the element phase shift was measured and the result was used for identifying the amplitude and phase of the element. The present method can be adapted by the addition of software to the phased array system with computercontrolled phase shifters. It can also be used for diagnosis of defects of elements and phase shifters as well as for checking wiring errors in the feed network. Acknowledgement. The authors thank Mr. T. Tsutsumi of the Communication Equipment Division of Mitsubishi Electric Company for his experimental assistance. REFERENCES Fig. 9. Low sidelobe pattern by uniform phasesetting due to this paper's method. 2. elements under the array condition. The distributions of the two solutions kl and k2 of the relative amplitude obtained numerically in the leastsquare approximation are shown in Fig. 8. The o symbols in this figure are the products of the measured amplitude of the element radiation field in the boresight direction and the designed excitation amplitude of that element. These o symbols and kl are well correlated, and hence kl is the correct solution in this case J.D. Dyson. Measurement of near field of antennas and scatters, I.E.E.E., Trans. Antennas and Propag., E, pp (July 1973). W.A. Harmening. Implementing a nearfield antenna test facility, Microwave J., 22, 9. pp (Sept. 1979). A.R. Skatvold, Jr. Beam steering antenna control technique, 1981 I.E.E.E. MTTS Internat. Microwave Symp. Digest, pp (June 1981). J.F. White. Phased array technology workshop, Microwave J., 3, 2, pp (Feb. 1981). Mano and Katagi. A method for measuring amplitude and phase of phase array antenna elements in the operating condition, Natl. Conv. Record of I.E.C.E., Japan, 69 (1981).
7 APPENDIX Hence, 1. Derivation of (4) From (1) clr (3), i = {E,eJX+E, (el  1) 1 el '(x+&) (Al) I h I = (Eo cosx+e, cos A  E,, ) +(E,sinXE,,sind)' NOW, we obtain where = (E,COSXE,)~ +Eo2 sin2x+e,2 +2E,{(~ocosXE,)cos~EosinXsind~ (A21 substituting Y2 = (cosx k +sin2x (5) sinx sind ) =Y2+kz+2kY cos (A+do) (4) we get (A4 1 From (5), (6) and (A4) we eliminate Y and obtain the following simultaneous equations for k and X: r+l sinx= (7) k sindo r (z) cosx= k (1+ cos do} (A6) Solution of the above results in (9) and (1). since we get (ii) When the sign in (8) is negative,?= (yk) Y= ( 2 ) k Eliminating Y from (5), (6) and (A8), we get the following simultaneous equations for k and X: sid= ( s+l e ) k sindo 2. Derivation of (9) Q (12) since (i) When the sign in (8) is positive, 7 G Yk Solution of the above results in (11) and (12). 64
Performance of Thinned Antenna Arrays using Nonlinear Processing in DBF Radar Applications
0 Annual report 1999/2000 Performance of Thinned Antenna Arrays using Nonlinear Processing in DBF Radar Applications Carsten Metz, Leif C. Stange, Arne F. Jacob and Ernst Lissel Efficient thinning techniques
More informationAntennas and Propagation. Chapter 3: Antenna Parameters
Antennas and Propagation : Antenna Parameters Introduction Purpose Introduce standard terms and definitions for antennas Need a common language to specify performance Two types of parameters 1. Radiation
More informationDetailed simulation of mass spectra for quadrupole mass spectrometer systems
Detailed simulation of mass spectra for quadrupole mass spectrometer systems J. R. Gibson, a) S. Taylor, and J. H. Leck Department of Electrical Engineering and Electronics, The University of Liverpool,
More informationProposal for a Slot Pair Array Having an Invariant Main Beam Direction with a Cosecant Radiation Pattern Using a PostWall Waveguide
176 IEICE TRANS. ELECTRON., VOL.E86 C, NO.2 FEBRUARY 2003 PAPER Special Issue on Circuit and Device Technology for HighSpeed Wireless Communication Proposal for a Slot Pair Array Having an Invariant Main
More informationAUTOMATED THREEANTENNA POLARIZATION MEASUREMENTS USING DIGITAL SIGNAL PROCESSING
AUTOMATED THREEANTENNA POLARIZATION MEASUREMENTS USING DIGITAL SIGNAL PROCESSING John R. Jones and Doren W. Hess Abstract In this paper we present a threeantenna measurement procedure which yields the
More informationA DualBand BeamSwitched Slot Array for GSM 900/1800MHz
Proceedings of AsiaPacific Microwave Conference 2006 A DualBand BeamSwitched Slot Array for GSM 900/1800MHz Yijun Liu, Zhongxiang Shen, Boyu Zheng and Weihua Tan School of Electrical and Electronic
More informationAnalysis of Electromagnetic Propulsion on a TwoElectricDipole System
Electronics and Communications in Japan, Part 2, Vol. 83, No. 4, 2000 Translated from Denshi Joho Tsushin Gakkai Ronbunshi, Vol. J82CI, No. 6, June 1999, pp. 310 317 Analysis of Electromagnetic Propulsion
More informationAntennas. Antenna Design Kit. M. Kesteven ATNF 25/September/2001. The primary elements of a synthesis array. The Antenna Structure
Antennas The Antenna Structure The primary elements of a synthesis array M. Kesteven ATNF 25/September/2001 * Backup structure * Reflector surface(s) shape accuracy construction * Two axis Mount Antenna
More informationHigh performance horn antenna design (II) Dr. Carlos del Río Bocio Antenna Group Public University of Navarra
High performance horn antenna design (II) Dr. Carlos del Río Bocio Antenna Group Public University of Navarra Feedhorns Feedhorns Feedhorns are widely used in microwave and millimeter wave bands because
More informationREPORT ITUR BO.2029. Broadcastingsatellite service earth station antenna pattern measurements and related analyses
Rep. ITUR BO.229 1 REPORT ITUR BO.229 Broadcastingsatellite service earth station antenna pattern measurements and related analyses (Question ITUR 93/11) (22) 1 Introduction Recommendation ITUR BO.1443
More informationPrinted Dipole Array Fed with Parallel Stripline for Kuband Applications
Printed Dipole Array Fed with Parallel Stripline for Kuband Applications M. Dogan 1, 3,K. Özsoy 1, 2, and I.Tekin 1, 1 Electronics Engineering, Sabanci University, Istanbul, Turkey 2 Vestek Electronic
More informationDevelopment of Optical Wave Microphone Measuring Sound Waves with No Diaphragm
Progress In Electromagnetics Research Symposium Proceedings, Taipei, March 5 8, 3 359 Development of Optical Wave Microphone Measuring Sound Waves with No Diaphragm Yoshito Sonoda, Takashi Samatsu, and
More informationWeighted Thinned Arrays by Almost Difference Sets and Convex Programming
Guidelines for Student Reports Weighted Thinned Arrays by Almost Difference Sets and Convex Programming V. Depau Abstract The design of thinned arrays can be carried out with several techniques, including
More informationSynthesis Of Polarization Agile Interleaved Arrays Based On Linear And Planar ADS And DS.
Guidelines for Student Reports Synthesis Of Polarization Agile Interleaved Arrays Based On Linear And Planar ADS And DS. A. Shariful Abstract The design of large arrays for radar applications require the
More informationG(θ) = max{g 1 (θ), G 2 (θ)}
Rec. ITUR F.1336 1 RECOMMENDATION ITUR F.1336* Rec. ITUR F.1336 REFERENCE RADIATION PATTERNS OF OMNIDIRECTIONAL AND OTHER ANTENNAS IN POINTTOMULTIPOINT SYSTEMS FOR USE IN SHARING STUDIES (Question
More informationASTRA 3B HORN ANTENNA DESIGN
ASTRA 3B HORN ANTENNA DESIGN Jorge Teniente and Carlos delrío Grupo de Antenas, Universidad Pública de Navarra, Campus Arrosadía s/n, 31006 Spain, Email: jorge.teniente@unavarra.es, carlos@unavarra.es
More informationA New Active Phased Array Antenna for Mobile Direct Broadcasting Satellite Reception
34 IEEE TRANSACTIONS ON BROADCASTING, VOL. 46, NO. 1, MARCH 2000 A New Active Phased Array Antenna for Mobile Direct Broadcasting Satellite Reception SoonIk Jeon, YoungWan Kim, and DeogGil Oh Abstract
More informationDESIGNER POLARIZATION
DESIGNER POLARIZATION (for magazine publication) INTRODUCTION istorically, Radar Warning Receivers (RWR) employ cavity backed spiral antennas to detect and classify threats to the aircraft and to determine
More informationEffect of Antenna Performance on the GPS Signal Accuracy
Effect of Antenna Performance on the GPS Signal Accuracy Waldemar Kunysz, NovAtel Inc. BIOGRAPHY Waldemar Kunysz received a Master of Nautical Science Degree from the Merchant Marine Academy, Gdynia, Poland
More informationTwo primary advantages of radars: allweather and day /night imaging
Lecture 0 Principles of active remote sensing: Radars. Objectives: 1. Radar basics. Main types of radars.. Basic antenna parameters. Required reading: G: 8.1, p.40140 dditional/advanced reading: Online
More informationExperiment 7: Familiarization with the Network Analyzer
Experiment 7: Familiarization with the Network Analyzer Measurements to characterize networks at high frequencies (RF and microwave frequencies) are usually done in terms of scattering parameters (S parameters).
More informationNew Modelling Capabilities in Commercial Software for HighGain Antennas
New Modelling Capabilities in Commercial Software for HighGain Antennas Erik Jørgensen, Michael Lumholt, Peter Meincke, Min Zhou, Stig B. Sørensen, Oscar Borries, Cecilia Cappellin, and Poul Erik Frandsen
More informationSIW 2D PLANAR ARRAY WITH FOUR CROSS SLOTS RADIATOR AND TUNING VIAS
Progress In Electromagnetics Research C, Vol. 40, 83 92, 2013 SIW 2D PLANAR ARRAY WITH FOUR CROSS SLOTS RADIATOR AND TUNING VIAS P. SanchezOlivares, J. L. MasaCampos *, J. A. RuizCruz, and B. TahaAhmed
More informationNew Method for Optimum Design of Pyramidal Horn Antennas
66 New Method for Optimum Design of Pyramidal Horn Antennas Leandro de Paula Santos Pereira, Marco Antonio Brasil Terada Antenna Group, Electrical Engineering Dept., University of Brasilia  DF terada@unb.br
More informationMITSUBISHI ELECTRIC ANNOUNCES THE SUCCESSFUL DEVELOPMENT OF AN AIRBORNE KuBAND ANTENNA SUBSYSTEM FOR SATELLITE COMMUNICATIONS
FOR IMMEDIATE RELEASE No. 2330 Product Inquiries: Media Contact: Yutaka Kamada Oliver Cox Mitsubishi Electric Corporation Mitsubishi Electric Corporation Tel: +81332182391 Tel: +81332182346 Yutaka.Kamada@hq.melco.co.jp
More informationCompact Tunable and Dual band Circular Microstrip Antenna for GSM and Bluetooth Applications
205 Compact Tunable and Dual band Circular Microstrip Antenna for GSM and Bluetooth Applications *K. P. Ray 1, S. Nikhil 2 and A. Nair 2 1 SAMEER, IIT Campus, Powai, Mumbai 400 076, India 2 K.J.Somaiya
More informationVarious Technics of Liquids and Solids Level Measurements. (Part 3)
(Part 3) In part one of this series of articles, level measurement using a floating system was discusses and the instruments were recommended for each application. In the second part of these articles,
More informationPreCompliance Test Method for Radiated Emissions of Automotive Components Using Scattering Parameter Transfer Functions
PreCompliance Test Method for Radiated Emissions of Automotive Components Using Scattering Parameter Transfer Functions D. Schneider 1*, S. Tenbohlen 1, W. Köhler 1 1 Institute of Power Transmission and
More informationBy Sayan Roy Major Advisor: Dr. Benjamin D. Braaten Dept. of ECE, NDSU, Fargo, ND, USA
By Sayan Roy Major Advisor: Dr. Benjamin D. Braaten Dept. of ECE, NDSU, Fargo, ND, USA Contents Introduction Defining the Problem Phased Array Antenna Realization of Conformal Phased Array Antenna Designing
More informationEnhanced Stripline Scanning Array B.M. Cahill and J.C. Batchelor
Enhanced Stripline Scanning Array B.M. Cahill and J.C. Batchelor This paper is a postprint of a paper submitted to and accepted for publication in IET Microwaves, Antennas and Propagation and is subject
More informationFind all of the real numbers x that satisfy the algebraic equation:
Appendix C: Factoring Algebraic Expressions Factoring algebraic equations is the reverse of expanding algebraic expressions discussed in Appendix B. Factoring algebraic equations can be a great help when
More informationAntenna Measurements
Antenna Measurements Antenna Measurements Introduction Antenna range Radiation patterns Amplitude Phase Gain measurements Antenna polarization Scale model measurements Introduction Most of the methodology
More informationGPR Polarization Simulation with 3D HO FDTD
Progress In Electromagnetics Research Symposium Proceedings, Xi an, China, March 6, 00 999 GPR Polarization Simulation with 3D HO FDTD Jing Li, ZhaoFa Zeng,, Ling Huang, and Fengshan Liu College of Geoexploration
More informationA ReflectionType Vector Modulator with Balanced Loads
45 A ReflectionType Vector Modulator with Balanced Loads Franco Di Paolo, Mauro Ferrari, Franco Giannini, Ernesto Limiti Department of Electronic Engineering, University of Rome Tor Vergata Via del Politecnico
More informationAre you. you should from your
Are you gaining what you should from your antenna? An overview of antenna design considerations is presented. The design considerations include system requirements, antenna selection, antenna placement,
More informationOverview of Antennas. Muhammad Dawood Research Assistant Professor. The Information and Telecommunication Technology Center
Overview of Antennas Muhammad Dawood Research Assistant Professor The Information and Telecommunication Technology Center Outline What is an Antenna? Historical Background Antenna Radiation Mechanism Antenna
More informationRec. ITUR F.6995 1 RECOMMENDATION ITUR F.6995 *
Rec. ITUR F.6995 1 RECOMMENATION ITUR F.6995 * REFERENCE RAIATION PATTERNS FOR LINEOFSIGHT RAIORELAY SYSTEM ANTENNAS FOR USE IN COORINATION STUIES AN INTERFERENCE ASSESSMENT IN THE FREQUENCY RANGE
More information2. Do Not use the laser without getting instructions from the demonstrator.
EXPERIMENT 3 Diffraction Pattern Measurements using a Laser Laser Safety The Helium Neon lasers used in this experiment and are of low power (0.5 milliwatts) but the narrow beam of light is still of high
More informationTRIPLE BAND GPS TRAP LOADED INVERTED L ANTENNA ARRAY
TRIPLE BAND GPS TRAP LOADED INVERTED L ANTENNA ARRAY B. Rama Rao, M. A. Smolinski, Cuong C. Quach, E. N. Rosario The MITRE Corporation Bedford, Massachusetts 17142 Email: brrao@mitre.org, FAX: (781)
More informationSynthetic Aperture Radar: Principles and Applications of AI in Automatic Target Recognition
Synthetic Aperture Radar: Principles and Applications of AI in Automatic Target Recognition Paulo Marques 1 Instituto Superior de Engenharia de Lisboa / Instituto de Telecomunicações R. Conselheiro Emídio
More informationSimplified procedure for evaluating the coverage area of a multifeed shaped antenna Application to the planning of a broadcasting satellite system
Simplified procedure for evaluating the coverage area of a multifeed shaped antenna Application to the planning of a broadcasting satellite system L. Tomati (RAI) M. D Onofrio (RAI) G. Carere (RAI) Shaped
More informationA Novel GPS Survey Antenna
A Novel GPS Survey Antenna Waldemar Kunysz, NovAtel Inc. BIOGRAPHY Waldemar Kunysz obtained a BSEE from the Technical University of Nova Scotia in 1989. From 1991 to 1995 he worked on phased array antennas
More informationDielectric Definition
RADIO FREQUENCY DIELECTRIC MEASUREMENT Dielectric Definition Electric field interaction with an atom under the classical dielectric model In the classical approach to the dielectric model a material is
More informationAntenna Measurement 1 Antenna Ranges antenna range
Antenna Measurement 1 Antenna Ranges An antenna range is a facility where antenna radiation characteristics are measured. An antenna range includes the following typical components: 1. A substantial space
More informationANALYSIS OF ELEMENT SHAPE IN THE DESIGN FOR MULTIBAND APPLICATIONS
ANALYSIS OF ELEMENT SHAPE IN THE DESIGN FOR MULTIBAND APPLICATIONS Pidugu Prasad 1, D Vakula 2 1 M.Tech, Dept. of Electronics and Communication Engineering, NIT Warangal, A.P, India 2 Assistant Professor,
More informationElectromagnetic radiation exposure: assessment against ACA mandated limits
Electromagnetic radiation exposure: assessment against ACA mandated limits Paging services (Edition May 2002) Disclaimer Unless otherwise specified, the information contained in these guidelines is intended
More informationCopyright 1996 IEEE. Reprinted from IEEE MTTS International Microwave Symposium 1996
Copyright 1996 IEEE Reprinted from IEEE MTTS International Microwave Symposium 1996 This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE
More informationReflectivity of Reflectarrays Based on Dielectric Substrates
American J. of Engineering and Applied Sciences 3 (1): 180185, 2010 ISSN 19417020 2010 Science Publications Reflectivity of Reflectarrays Based on Dielectric Substrates 1 M.Y. Ismail, 1 M. Inam and 2
More informationElectromagnetic Induction
Electromagnetic Induction "Concepts without factual content are empty; sense data without concepts are blind... The understanding cannot see. The senses cannot think. By their union only can knowledge
More informationRADIATION PATTERNS. The halfpower (3 db) beamwidth is a measure of the directivity of the antenna.
RADIATION PATTERNS The radiation pattern is a graphical depiction of the relative field strength transmitted from or received by the antenna. Antenna radiation patterns are taken at one frequency, one
More informationALMA Memo No. 519 An alternative scheme of roundtrip phase correction
ALMA Memo No. 519 An alternative scheme of roundtrip phase correction Hitoshi KIUCHIa and Masoto ISHIGUROa anational Astronomical Observatory of Japan, 2211 Osawa, Mitaka, Tokyo 1818588, Japan, hitoshi.kiuchi@nao.ac.jp,
More informationPillbox Antenna for 5.6 GHz Band Dragoslav Dobričić, YU1AW dragan@antennex.com
Pillbox Antenna for 5.6 GHz Band Dragoslav Dobričić, YU1AW dragan@antennex.com Introduction The pillbox or cheese antenna is made of two parallel plates which are connected to the narrow strip of parabolic
More informationCHAPTER4 GENERAL ASPECTS OF MUTUAL
CHAPTER4 GENERAL ASPECTS OF MUTUAL ADMITTANCE OF CPWFED TWIN SLOTS ON CONDUCTORBACKED TWOLAYER SUBSTRATES 4.1 INTRODUCTORY REMARKS The present chapter is concerned with an exploratory investigation
More informationMicrowave Antennas and Radar. Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8
Microwave Antennas and Radar Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8 G P P directional isotropic Antenna Basics Isotropic Dipole High gain directional 0 db i 2.2 db i 14 db i Antenna performance
More informationA PRACTICAL MINIATURIZED USLOT PATCH ANTENNA WITH ENHANCED BANDWIDTH
Progress In Electromagnetics Research B, Vol. 3, 47 62, 2008 A PRACTICAL MINIATURIZED USLOT PATCH ANTENNA WITH ENHANCED BANDWIDTH G. F. Khodaei, J. Nourinia, and C. Ghobadi Electrical Engineering Department
More informationEXPERIMENT 4. Microwave Experiments. Introduction. Experimental Procedure. Part 1 : Double Slit
EXPERIMENT 4 Microwave Experiments Introduction Microwaves are electromagnetic radiation in the centimeter range of wavelengths. As such, they, like light, will exhibit typical wave properties like interference
More informationInternational Journal of Computer Trends and Technology (IJCTT) volume 4 Issue 9 Sep 2013
Design and Development of Tapered Spiral Helix Antenna B.Sai Yashodha #1, J.Ravindranadh *2 1 # Mtech Student, ECE Department, RVR&JCCE, GUNTUR 2 # Associate Professor, ECE Department, RVR&JCCE, GUNTUR
More informationSound Power Measurement
Sound Power Measurement A sound source will radiate different sound powers in different environments, especially at low frequencies when the wavelength is comparable to the size of the room 1. Fortunately
More informationVolts/m For EMC and Antenna Measurement
Application Note #0430 September 2012 Revised: Volts/m For EMC and Antenna Measurement Application Note Image courtesy of Wikipedia Commons This note describes the concept of electric field strength in
More informationEE 321 Analog Electronics, Fall 2013 Homework #5 solution
EE 321 Analog Electronics, Fall 2013 Homework #5 solution 3.26. For the circuit shown in Fig. P3.26, both diodes are identical, conducting 10mA at 0.7V, and 100mA at 0.8V. Find the value of for which V
More informationEnhancing the SNR of the Fiber Optic Rotation Sensor using the LMS Algorithm
1 Enhancing the SNR of the Fiber Optic Rotation Sensor using the LMS Algorithm Hani Mehrpouyan, Student Member, IEEE, Department of Electrical and Computer Engineering Queen s University, Kingston, Ontario,
More informationENGR 210 Lab 11 Frequency Response of Passive RC Filters
ENGR 210 Lab 11 Response of Passive RC Filters The objective of this lab is to introduce you to the frequencydependent nature of the impedance of a capacitor and the impact of that frequency dependence
More information102 26m Antenna Subnet Telecommunications Interfaces
DSMS Telecommunications Link Design Handbook 26m Antenna Subnet Telecommunications Interfaces Effective November 30, 2000 Document Owner: Approved by: Released by: [Signature on file in TMOD Library]
More informationSPINDLE ERROR MOVEMENTS MEASUREMENT ALGORITHM AND A NEW METHOD OF RESULTS ANALYSIS 1. INTRODUCTION
Journal of Machine Engineering, Vol. 15, No.1, 2015 machine tool accuracy, metrology, spindle error motions Krzysztof JEMIELNIAK 1* Jaroslaw CHRZANOWSKI 1 SPINDLE ERROR MOVEMENTS MEASUREMENT ALGORITHM
More informationSentinel Antennas Address Growing Capacity Challenge in Today s Microwave Backhaul Network
White Paper Sentinel Antennas Address Growing Capacity Challenge in Today s Microwave Backhaul Network Dipesh Rattan, Product Line Manager, CommScope www.commscope.com Contents Introduction 3 Role of antenna
More informationPolarization of Light
Polarization of Light References Halliday/Resnick/Walker Fundamentals of Physics, Chapter 33, 7 th ed. Wiley 005 PASCO EX997A and EX999 guide sheets (written by Ann Hanks) weight Exercises and weights
More informationDesign and Electromagnetic Modeling of EPlane Sectoral Horn Antenna For Ultra Wide Band Applications On WR137 & WR 62 Waveguides
International Journal of Engineering Science Invention ISSN (Online): 2319 6734, ISSN (Print): 2319 6726 Volume 3 Issue 7ǁ July 2014 ǁ PP.1117 Design and Electromagnetic Modeling of EPlane Sectoral Horn
More informationCHAPTER 5 PREDICTIVE MODELING STUDIES TO DETERMINE THE CONVEYING VELOCITY OF PARTS ON VIBRATORY FEEDER
93 CHAPTER 5 PREDICTIVE MODELING STUDIES TO DETERMINE THE CONVEYING VELOCITY OF PARTS ON VIBRATORY FEEDER 5.1 INTRODUCTION The development of an active trap based feeder for handling brakeliners was discussed
More informationDOLPHChebyshev linear arrays [1] are ideal in the sense
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. XX, NO. X, FEBRUARY 0XX 1 On the Generalization of Taylor and Bayliss nbar Array Distributions Srinivasa Rao Zinka and Jeong Phill Kim, Member, IEEE
More informationAccuracy assessment of the scalar network analyzer using sliding termination techniques
Downloaded from orbit.dtu.dk on: Jan 04, 2016 Accuracy assessment of the scalar network analyzer using sliding termination techniques Knudsen, Bent; Engen, Glenn F.; Guldbrsen, Birthe Published in: I E
More informationPATTERN SYNTHESIS OF NONUNIFORM AMPLITUDE EQUALLY SPACED MICROSTRIP ARRAY ANTENNA USING GA, PSO AND DE ALGORITHMS
International Journal of Advanced Research in Engineering and Technology (IJARET) Volume 7, Issue 2, MarchApril 2016, pp. 132 147, Article ID: IJARET_07_02_013 Available online at http://www.iaeme.com/ijaret/issues.asp?jtype=ijaret&vtype=7&itype=2
More informationDETERMINING THE POLARIZATION STATE OF THE RADIATION CROSSING THROUGH AN ANISOTROPIC POLY (VINYL ALCOHOL) FILM
DETERMINING THE POLARIZATION STATE OF THE RADIATION CROSSING THROUGH AN ANISOTROPIC POLY (VINYL ALCOHOL) FILM ECATERINA AURICA ANGHELUTA Faculty of Physics,,,Al.I. Cuza University, 11 Carol I Bd., RO700506,
More informationElectromagnetic radiation exposure: assessment against ACA mandated limits
Electromagnetic radiation exposure: assessment against ACA mandated limits General radio services (operating above 0 MHz) (Edition May 0) Disclaimer Unless otherwise specified, the information contained
More informationChapter 11 PARABOLIC DISH FEEDS PERFORMANCE ANALYSIS Paul Wade N1BWT 1997,1998
Chapter 11 PARABOLIC DISH FEEDS PERFORMANCE ANALYSIS Paul Wade N1BWT 1997,1998 Achieving optimum performance from a microwave dish antenna requires that the feed antenna be matched to the parabolic reflector.
More informationNational Laboratory of Antennas and Microwave Technology Xidian University Xi an, Shaanxi 710071, China
Progress In Electromagnetics Research, PIER 76, 237 242, 2007 A BROADBAND CPWFED TSHAPE SLOT ANTENNA J.J. Jiao, G. Zhao, F.S. Zhang, H.W. Yuan, and Y.C. Jiao National Laboratory of Antennas and Microwave
More information* Biot Savart s Law Statement, Proof Applications of Biot Savart s Law * Magnetic Field Intensity H * Divergence of B * Curl of B. PPT No.
* Biot Savart s Law Statement, Proof Applications of Biot Savart s Law * Magnetic Field Intensity H * Divergence of B * Curl of B PPT No. 17 Biot Savart s Law A straight infinitely long wire is carrying
More informationAntenna A mean for radiating and receiving radio waves Transitional structure between freespace and a guiding device. Application: Radiation
Antenna A mean for radiating and receiving radio waves Transitional structure between freespace and a guiding device Application: adiation Introduction An antenna is designed to radiate or receive electromagnetic
More informationAPPENDIX D: SOLAR RADIATION
APPENDIX D: SOLAR RADIATION The sun is the source of most energy on the earth and is a primary factor in determining the thermal environment of a locality. It is important for engineers to have a working
More informationNational Centre for Radio Astrophysics. Fitting Beamwidths for Broadband Feeds
National Centre for Radio Astrophysics Internal Technical Report GMRT/AST/001Sep2012 Fitting Beamwidths for Broadband Feeds Authors Manisha S. Samble, Divya Oberoi Email:manisha@ncra.tifr.res.in, div@ncra.tifr.res.in
More informationMonochromatic electromagnetic fields with maximum focal energy density
Moore et al. Vol. 4, No. 10 /October 007 /J. Opt. Soc. Am. A 3115 Monochromatic electromagnetic fields with maximum focal energy density Nicole J. Moore, 1, * Miguel A. Alonso, 1 and Colin J. R. Sheppard,3
More informationALLEN Mouse Brain Atlas
TECHNICAL WHITE PAPER: QUALITY CONTROL STANDARDS FOR HIGHTHROUGHPUT RNA IN SITU HYBRIDIZATION DATA GENERATION Consistent data quality and internal reproducibility are critical concerns for highthroughput
More informationA Note on the Effects of Broadcast Antenna Gain, Beam Width and Height Above Average Terrain
A Note on the Effects of Broadcast Antenna Gain, Beam Width and Height Above Average Terrain John L. Schadler  Director of Antenna Development Dielectric L.L.C. Raymond, ME 30 September 2014 Abstract
More informationThe accurate calibration of all detectors is crucial for the subsequent data
Chapter 4 Calibration The accurate calibration of all detectors is crucial for the subsequent data analysis. The stability of the gain and offset for energy and time calibration of all detectors involved
More information2 Absorbing Solar Energy
2 Absorbing Solar Energy 2.1 Air Mass and the Solar Spectrum Now that we have introduced the solar cell, it is time to introduce the source of the energy the sun. The sun has many properties that could
More information7. DYNAMIC LIGHT SCATTERING 7.1 First order temporal autocorrelation function.
7. DYNAMIC LIGHT SCATTERING 7. First order temporal autocorrelation function. Dynamic light scattering (DLS) studies the properties of inhomogeneous and dynamic media. A generic situation is illustrated
More informationAntenna Measurements Using the Mirror Method with Gating in a Time Domain
58 H. BÁTÍK, MEASUEMENTS USING THE MIO METHOD WITH GATING IN A TIME DOMAIN Antenna Measurements Using the Mirror Method with Gating in a Time Domain Hynek BÁTÍK Dept. of Electromagnetic Field, Czech Technical
More informationSensor and Simulation Notes. Note 479. October 2003. A DualPolarity Impulse Radiating Antenna
Sensor and Simulation Notes Note 479 October 2003 A DualPolarity Impulse Radiating Antenna Leland H. Bowen and Everett G. Farr Farr Research, Inc. Dean I. Lawry Air Force Research Laboratory, Directed
More informationRadiated emission measurement of a cell phone processor module using TEM cell
, pp.4853 http://dx.doi.org/10.14257/astl.2013.28.09 Radiated emission measurement of a cell phone processor module using TEM cell Fayu Wan 1,2*, Qi Liu 3, Jian Shen 3, Jin Wang 3 and Nigel Linge 4 1
More informationCS647: Advanced Topics in Wireless Networks Basics of Wireless Transmission
CS647: Advanced Topics in Wireless Networks Basics of Wireless Transmission CS 647 2.1 Outline Frequencies Signals Antennas Signal propagation Multiplexing Spread spectrum Modulation CS 647 2.2 Types of
More informationReprint (R22) Avoiding Errors in UV Radiation Measurements. By Thomas C. Larason July 2001. Reprinted from Photonics Spectra, Laurin Publishing
Reprint (R22) Avoiding Errors in UV Radiation Measurements By Thomas C. Larason July 2001 Reprinted from Photonics Spectra, Laurin Publishing Gooch & Housego 4632 36 th Street, Orlando, FL 32811 Tel: 1
More informationSMART ANTENNA BEAMFORMING NETWORK Sharul Kamal Abdul Rahim Peter Gardner
Smart Antena Beamforming Network 23 3 SMART ANTENNA BEAMFORMING NETWORK Sharul Kamal Abdul Rahim Peter Gardner 3.1 INTRODUCTION Smart Antenna with RF beamforming capability can greatly improve the performance
More informationCHAPTER 7 PHASED ARRAY RADAR ANTENNAS. Theodore C. Cheston Naval Research Laboratory. Joe Frank Technology Service Corporation
CHAPTER 7 PHASED ARRAY RADAR ANTENNAS Theodore C. Cheston Naval Research Laboratory Joe Frank Technology Service Corporation 7.1 INTRODUCTION Phased Array Radars Multifunction Radar. Early radar systems
More informationELECTROMAGNETIC ANALYSIS AND COLD TEST OF A DISTRIBUTED WINDOW FOR A HIGH POWER GYROTRON
ELECTROMAGNETIC ANALYSIS AND COLD TEST OF A DISTRIBUTED WINDOW FOR A HIGH POWER GYROTRON M.A.Shapiro, C.P.Moeller, and R.J.Temkin Plasma Science and Fusion Ceer, Massachusetts Institute of Technology,
More informationUsing a Modified Hewlett Packard 8410 Network Analyzer as an Automated FarField Antenna Range Receiver
/h' 3...3 NASA Technical Memorandum ]03700._. Using a Modified Hewlett Packard 8410 Network Analyzer as an Automated FarField Antenna Range Receiver (NASATMI03700) USING A MOUIFIED HEWLETT NqIIC_349
More informationModel Based Control of a Moving Solar Roof for a Solar Vehicle
Model Based Control of a Moving Solar Roof for a Solar Vehicle G.Coraggio*, C.Pisanti*, G.Rizzo*, A.Senatore* *Dept. Of Mechanical Engineering, University of Salerno, 8484 Fisciano (SA), Italy Email: gcoraggio
More informationE190Q Lecture 5 Autonomous Robot Navigation
E190Q Lecture 5 Autonomous Robot Navigation Instructor: Chris Clark Semester: Spring 2014 1 Figures courtesy of Siegwart & Nourbakhsh Control Structures Planning Based Control Prior Knowledge Operator
More informationPower Electronics. Prof. K. Gopakumar. Centre for Electronics Design and Technology. Indian Institute of Science, Bangalore.
Power Electronics Prof. K. Gopakumar Centre for Electronics Design and Technology Indian Institute of Science, Bangalore Lecture  1 Electric Drive Today, we will start with the topic on industrial drive
More informationANTENNA THEORY ANALYSIS AND DESIGN THIRD EDITION T WILEY INTERSCIENCE A JOHN WILEY & SONS, INC., PUBLICATION
ANTENNA THEORY ANALYSIS AND DESIGN THIRD EDITION Constantine A. Balanis T WILEY INTERSCIENCE A JOHN WILEY & SONS, INC., PUBLICATION Contents Preface 1 Antennas 1.1 Introduction 1.2 Types of Antennas 1.3
More informationTWODIMENSIONAL XRAY DIFFRACTION
TWODIMENSIONAL XRAY DIFFRACTION BOB B. HE GQ WILEY ,. "'! :~! CONTENTS~\..~..). Preface 1. Introduction 1.1 XRay Technology and Its Brief History, 1.2 Geometry of Crystals, 2 1.2.1 Crystal Lattice
More informationBiological TissueEquivalent Phantoms Usable in Broadband Frequency Range
Biological TissueEquivalent Phantoms Usable in Broadband Frequency Range Phantoms, which are models simulating various electrical constants of biological tissues, are used to evaluate antenna characteristics
More information