Development Of Millimeter-wave Waveguide Power Combiner Amplifier

The output power of millimeter-wave source is one of the main indicators in millimeter-wave system.The limited output power of solid power devices is the bottleneck of millimeter wave system.In order to improve the output power,the power combination technique is an effective method.In this thesis,various solid-state power combining techniques have been studied and analyzed,Then the waveguide power combining structutes are exploerd and implenmented according to domestic assembly techniques.the detailed work includes:1.Analyze the impact of amplitude and phase in power combination technique.T- he waveguide to microstrip transition is designed and used in the power divider/combi- ner structure.2.We have designed three kinds of millimeter-wave waveguide power divider/ combiners divider/combiners: magic tee power divider/combiner; T-junction power divider/ combiner, two coppers waveguide to microstrip transition power divider/Com- biner, their main features are as belows:(1) Magic tee power divider/combiner: between 32GHz~38GHz,the return loss is between 20dB and 50dB, The isolation is between 32dB and 50dB, The output amplitude and phase is uniform at output port.(2) T-junction power divider/combiner: between 31GHz~39GHz,the return loss is between 20dB and 40dB, The isolation is between 5.25dB and 6.25dB. The output amplitude and phase is uniform at output port.(3) Two coppers waveguide to microstrip transition power divider/combiner: in ka band, the return loss is between 20dB and 30dB, The isolation is between 5.3dB and 6.5dB. The output amplitude and phase is uniform at output port.4.Using AMMC 5040s fabricated by Agilent company as single-way amplifiers, we have designed a four-way power combing circuit with a waveguide as interface ports. Between 33GHz~37GHz, the combining efficiency estimated is more than 72%, the most measured saturated output power is about 328.85mW and the most combining efficiency estimated is 82.2% at 35GHz. The result indicate that our scheme is practic- al and feasible and it will obtain efficiency greater with the improvement of fabricating technology.