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ÇÒÃÊÒÃÇÔªÒ ÒþÃÐ ÍÁà ÅéÒ¾Ãй Ãà˹ Í»Õ Õè ºÑº Õè -  5 The Junal f KMTNB Vl N Jul - Sep The Fg hw the geet f a ngle ffet c lt n the bawall f ectangula wavegue wth fnte length t cnt f the upeptn f lt # (length l an wth w an lt # (length l an wth w wth the cn geet cente equal ffet p an cng angle b Befe analzng the fllwng auptn wee ae: (a the wavegue wall pefectl cnuctng (b an nfnte plane f pefect electc cnuct place at the extenal uface f the wavegue wall an (c all ectangula lt ae ve naw that the electcal fel n each lt apetue ha nl a cpnent n the ectn f the lt wth The anal el ve nt fu egn; the wavegue egn (egn the wall-thcne egn (egn an an the half-pace egn (egn V a hwn n Fg Accng t the fel equvalent thee all c lt apetue can be eplace b unnwn equvalent agnetc cuent M whee f the c lt apetue between wavegue an wall-thcne egn f the lt # an # ae ente b S an S epectvel an that between the half-pace an wall-thcne egn ae ente b S an S epectvel the cntnut cntn f the tangental agnetc fel n the apetue can be wtten nt ntegal equatn a On S On S On S On S H H G S n n ( G( M ( ( G S ( ( M ( V ( M ( G ( ( M ( G ( S V ( M ( G ( G ( S S G ( M G ( M S G S S S ( M ( M ( G ( G ( S S ( M ( ( G ( M S S ( ( M ( M ( ( V ( M ( G ( ( M ( G ( S ( V S G ( M S ( ( ( ( ( whee M ( the agnetc cuent at a uce pnt ( vect G when V the ac Geen functn f the agnetc fel puce b a unt agnetc cuent n the egn ( an nfntel lng wavegue an a cavt V a half fee pace an an bevatn pnt vect an H n ( the cattee agnetc fel b the lt apetue Thee equatn can be euce t lnea equatn b applng the Galen eth f ent [6] wth M ( A ( whee A the unnwn expann ceffcent ( the ba functn an ( the weghtng functn Theefe the lnea equatn can be btane a the fllwng ( A A A B (5 5
ÇÒÃÊÒÃÇÔªÒ ÒþÃÐ ÍÁà ÅéÒ¾Ãй Ãà˹ Í»Õ Õè ºÑº Õè -  5 The Junal f KMTNB Vl N Jul - Sep A ( A A B V V A ( A A (6 (7 whee f xl xl w exp( exp( n( πl π ( l w x (6 V V A A ( A (8 x nθ c( φ φ (7 Thee can be wtten n a atx f a whee A B A B A A (9 ( ( Slvng equatn (9 wll pve the unnwn expann ceffcent A the ueful value f etenng the electc fel an eflectn ceffcent f the antenna The electc fel can be etene a On lt# V V V V ( G ( ( θ φ S S B ( H n ( S exp( A exp[ nθ π ( p cφ q nφ ] f n( φ φ ( exp( A exp[ nθ π ( p cφ q nφ ] f cθ c( φ φ ( (8 B ung upeptn thee electc fel paaete can be wtten a Theefe the axal at (AR can be expee a whee nθ n( φ ( θ φ l θ θ θ φ φ φ AR ( (9 ( ( ( ( The eflectn ceffcent (S an the tann ceffcent (S can be fun a S S θ l l φ ( A ( H A ( S S ( A ( H A ( S S φ H H ( ( ( (5 On lt# A π exp( exp[ θ nθ ( p cφ q nφ ] f n( φ φ exp( A exp[ π nθ φ ( p cφ q n φ ] f cθ c( φ φ ( (5 whee H ( ± the cattee agnetc fel n ± z ectn at T e The atnal aatn pwe f c lt epeente a S S (6 The nput chaactetc peance (Z n can be calculate f 6
ÇÒÃÊÒÃÇÔªÒ ÒþÃÐ ÍÁà ÅéÒ¾Ãй Ãà˹ Í»Õ Õè ºÑº Õè -  5 The Junal f KMTNB Vl N Jul - Sep Z n ( S ( S (7 whee Z the te chaactetc peance (5 W an S the eflectn ceffcent Nuecal an xpeental Reult n th eeach the chen ba functn wa Z Axal Rat 9 8 7 6 5 p -6 p - p - p -8 π w l ( n x x l (8 9 5 5 Cng Angle (egee Fg Calculate axal at wth l l 5 an w w 5 B ung the ac Geen functn n the vtual cavt [7] t analze equatn (9 the unnwn expann ceffcent wee btane A tana X-ban wavegue wa ue a a el antenna MATLAB â pga wa utlze t lve the ptze c lt paaete f the nu axal at an VSWR at peatng fequenc aun 87 GHz Fg an hw the calculate axal at an the eflectn ceffcent a functn f ffet (p p -6 - - an -8 an cng angle value (b t n Fg the nu axal at value ae fun at ffeent cng angle cepnng t each ffet The ptze c lt paaete f antenna wee fun t be l l 5 w w 5 p p -8 an b The antenna wa then cntucte an tenate wth a atche wavegue la at ne en The axal at wa caefull eaue t be 9 The VSWR an chaactetc peance f the antenna wee al tete at the fequenc ange f 7 t GHz b ung a netw analze a the eult hwn n Fg 5 an 6 The eaue VSWR an chaactetc peance at fequenc f 87 GHz wee bvul btane t be an 57 57 W epectvel Fnall the pecent f aatn pwe f the ncent pwe a a functn f lt length wa calculate an eaue a eult hwn n Fg 7 ncatng a ve g ageeent VSWR 5 5 5 5 Fg Fg 5 5 5 Cng Angle (egee p -6 p - p - p -8 Calculate VSWR wth l l 5 an w w 5 Meaue VSWR at fequenc ange f 7 t GHz 7
ÇÒÃÊÒÃÇÔªÒ ÒþÃÐ ÍÁà ÅéÒ¾Ãй Ãà˹ Í»Õ Õè ºÑº Õè -  5 The Junal f KMTNB Vl N Jul - Sep Cnclun The eth f ent wa ue t analze the antenna f the ptze c ltte paaete Wth thee paaete the antenna wa bult an tete The eult f calculatn ae n g ageeent wth eal expeent at the peatng fequenc aun 87 GHz whch vefe the accuac f th eth The nu axal at f 9 an VSWR f wee epte The cntucte antenna entate a ba peatng fequenc ban (³ GHz an hgh effcenc (³ % aatn pwe The antenna effcenc expecte t be atcall pve b nceang a nube f c lt a an antenna aa Fg 6 Raatn Pwe (% 8 6 Fg 7 Meaue chaactetc peance at fequenc ange f 7 t GHz Calculate Meaue 8 6 8 6 Slt Length ( Calculate an eaue aatn pwe a a functn f lt length 5 Acnwlegent Th w ha been uppte b the Japan Scet f Ptn f Scence (JSPS an the Thalan Natnal Scence an Technlg Develpent Agenc (NSTDA The auth wul le t expe ncee gattue t PfD J Hawa an PfD Mat An at T nttute f Technlg f the nvaluable avce an uggetn n th eeach Refeence Khac T V an Can C T peance ppete f a lngtunal lt antenna n the ba face f a ectangula wavegue Tan Antenna Ppagat 9 (Sep 97: 78-7 Ln R W an Sangte A J ffcent ent eth anal f aatng lt n a thc-walle ectangula wavegue Pc Pat H 8 (Aug 98: 97-5 Sten G J an lltt R S Renant length f lngtunal lt an valt f ccut epeentatn: the an expeent Tan Antenna Ppagat (Nv985: 6-7 Rengaaan S R Cpun aatng lt n a ba wall f a ectangula wavegue Tan Antenna Ppagat 7 (Sep 989: 6-5 Hngu L Zhenghe F an Q Anal f an ffet c lt n the bawall f ectangula wavegue ung the Galen eth Tan Antenna Ppagat nt Sp l ( Jun 998: 7-75 6 Hangtn R F Fel Cputatn b Ment Meth Rbet ege Publhng 98 7 Hawa J et al Matchng lt pa f a cculal plaze ltte wavegue aa Pc Pat H 7 6 (Dec 99 8