Study On Key Technologies Of 3-mm Solid State Power Combiner

W band,as one of the atmospheric windows in millimeter wave,has been widely applied in the fields of radar,guidance,remote sensing,electronic countermeasures and denial system.Being the core of these systems,the power level of the amplifiers has an important impact on the system performance.Compared with vacuum tube devices,solidstate devices have advantages in size,reliability and yield.With the help of power combining technology,the solid-state amplifiers are able to improve their power level,which make them another important power source.In this paper,studies have been made on W-band solid-state power combining technology.Here are the main contents:1.Studying the factors on the power combining efficiency.By the knowledge of microwave network,analysis on amplitude and phase consistency,network loss and network isolation has been done and it shows that high consistency and low loss are important to acquire high combining efficiency.The isolation of the combining network is helpful to reduce the effects of the differences in channels on the signals and thus improves the power combining efficiency.2.Studying the design of the key passive structures.This paper has designed wide band low loss waveguide-to-microstrip transition structure,T-junction,rat-race,magic T,planar magic T and the combined multi-channel networks.The simulation results show that the transition structure performs well with return loss better than 20 dB and insertion loss less than 0.1dB over 75-110 GHz.All the power combining units work well with good consistency and low loss in 91-95 GHz.The multi-channel networks composed of magic Ts and planar magic Ts have good consistency,low loss and high isolation.After removing the loss of microstrip line,the insertion loss of the transition structure is tested to be around 0.2dB.The insertion loss of magic T and planar magic T is 0.26 dB and 0.14 dB respectively.3.Studying the realization of the multi-channel amplifiers.This paper has fabricated modules of single channel amplifier,4-channel amplifier,8-channel amplifier,16-channel amplifier and 32-channel amplifier.To make sure all the amplifiers working normally,heat removing systems are carefully designed on the basis of the heat dissipation.The simulation results show that the highest temperature of single channel,4-channel,8-channel,16-channel and 32 channel amplifiers are 25.2?,38.4?,56.5?,63.5? and 70? when the ambient temperature is 20?.The differences between the chips are less than 2?.The test results show that the single channel amplifier gives an output power level of over 2W.The highest power level of 4-channel,8-chanel,16-channel amplifiers are 11.43W@93GHz,20W@93GHz and 37.2W@92GHz.In 91-94.5GHz,the output power level of the 32-channel amplifier is over 50 W.And at 95 GHz,the output power level is over 40 W.The highest combining efficiency of the 32-channel network is 73.1%@92GHz.