SKA Dish Array Elements

SKA Dish Array Elements Eduardo Artal (1) Francisco Casas (2) (1) Departamento de Ingeniería de Comunicaciones (DICOM) Universidad de Cantabria. Santander. (2) Instituto de Física de Cantabria (IFCA). CSIC-Universidad de Cantabria. Santander. Workshop SKA: Strategic Position and Future Opportunities for Spanish Industry Madrid, 23 November 2012, Instituto Rocasolano 1

Summary! SKA Dish Array! Description! Our projects in radio astronomy! ESA Planck mission! Microwave polarimeters in El Teide! Low noise receivers for radio astronomy! Cryogenic Low Noise Amplifiers (LNA)! Feed-horns, polarizers, Orthomode Transducers (OMT)! Microwave correlators and detectors! Conclusions 2

SKA Dish Array - Description Dishes: Receptors of the astronomical signal for frequencies from 450 MHz to 10 GHz Feeds and Low Noise Amplifiers (LNAs): Single Pixel Feeds (part of the SKA1)" " Phased Array Feeds (part of Advanced Instrumentation) Receivers: Receive amplified RF from the feed/lnas 3

SKA Dish Array - Description SKA phases SKA1 250 antennas (15 m) Single-pixel feeds Frequency range of 0.45-3 GHz SKA2 Depending on the Advanced Instrumentation Program results Inclusion of Phased Array or Ultra-Wide Band Feeds on the dishes Frequency range up to 10 GHz Proposed work on Feed antennas and Receivers Wideband single-pixel feeds Octave-band single-pixel feeds (current default) Phased-array feeds 4

Our projects in radio astronomy ESA Planck-LFI radiometers (30 and 44 GHz) 4 K load reference Feed-horn Feed-horn 20K WG Radiometer metro 300K Channel 4 Channel 3 OMT FEM BEM to DAE 20K WG 300K Channel 2 Channel 1 Radiometer 4 K load reference Feed-horn Back End Module: BEM 5

One branch of the 30 GHz BEM EBB L 50 mm LNA (MMIC) Detector output Filter Detector DC amplifier 6

MMIC amplifiers (LNA) at 44 GHz Two LNA (Low Noise Amplifier): same topology PHEMT LNA (HEMT-Depletion) OMMIC ED02AH Gate Width : 90 µm (6x15µm) Gate Length : 0.18 µm LNA (HEMT-Enhancement) Size: 3x1 mm 2 7

30 GHz BEM. Qualification Model (QM) RF channels 8

30 GHz BEM. Flight Model (FM) Size: 60 x 65 x 39 mm 3 DC amplifiers 9

Planck - LFI integration in the satellite 3 Back End Modules at 44 GHz 2 Back End Modules at 30 GHz 10

Microwave polarimeters in El Teide Observatorio de El Teide Izaña site, 2.390 m First telescope installation at the observatory (QUIJOTE 1st instrument) 11

QUIJOTE 1st Instrument 30 GHz pixel Frontal panel of 30 GHz BEM rack 12

Polarimeter receiver (26-36 GHz) (2nd instrument) Feedhorn Polarizer OMT Cryo-LNA LNA LNA FEM Gain&Filtering Modules LNA LNA Phase Switches Module F Ph.Switch 180º F Ph.Switch 180º F Ph.Switch 90º F Ph.Switch 90º 180º Hybrid 0º Ph.Shift φ φ 90º Ph.Shift Correlation&Detection Module DC DC V d1 180º Hybrid V d2 DC DC V d3 V d4 Cryostat (T = 20 K) Back-End Module (Room Temperature, T = 298 K) Receiver test bench 13

Cryogenic Low Noise Amplifiers 4-12 GHz MMIC LNA 100 nm mhemt (IAF-Fraunhofer) 3-stage (Gate width: 4 30 µm) Chip size: 3 x 1 mm 2 Collaboration: Centro Astronómico de Yebes Fraunhofer - UC 14

Cryogenic Low Noise Amplifiers 4-12 GHz MMIC LNA @ 15K Gain = 31.5 ± 1.8 db Te average = 5.3 K ± 1.4 K DC Pd= 8 mw 15

Feed-horns Feedhorn measurements 26 36 GHz band (db) 50 40 30 20 10 0-10 -20-30 -40 Directivity -50 25 26 27 28 29 30 31 32 33 34 35 36 37 Frecuencia (GHz) Input Matching X-polarization (db) 30 20 10 0-10 -20-30 -40-50 φ = 0º φ = 90º -60-180 -135-90 -45 0 45 90 135 180 θ (deg) Radiation pattern at f = 32 GHz θ -3dB ~ 13º 16

Polarizer Measured performance 26 36 GHz band Reflexión (db) 0-5 -10-15 -20-25 -30-35 -40-45 -50-55 -86-88 -90-92 -94-96 -98-100 -102-104 -106-108 -60-110 24 26 28 30 32 34 36 38 40 Frecuencia (GHz) Diferencia de Fase (deg) Transmisión (db) 0-0.1-0.2-0.3-0.4-0.5-0.6-0.7 24 26 28 30 32 34 36 38 40 Frecuencia (GHz) Phase Imbalance: 90º ± 1º Matching > 25 db Insertion Losses ~ 0.18 db 17

Orthomode Transducer (OMT) Units: 10-14 GHz 14-22 GHz 26-36 GHz 18

Facilities at Universidad de Cantabria Test equipment from DC to 50 GHz: Gain, Noise temperature, Signal analysis, Spectrum analysis, 1/f noise, at Room temperature (300 K) and at cryogenic temperature (20 K) Cryostats general view Two LNA units installed inside 19

Conclusions - Expertise in broadband low noise receivers for radio astronomy - We are able to contribute to SKA preconstruction phase in collaboration with the industry Acknowledgment: QUIJOTE receivers are funded by the Ministerio de Ciencia e Innovación under Astronomy and Astrophysics research program, reference AYA2010-21766-C03-03. 20