Study On Key Technologies Of W Band Solid State Power Combiner

Solid state devices have ideal size,weight and reliability,and are now widely used in the design of microwave and millimeter wave circuits.The output power of W-band solid state power amplifiers is low at the present stage.Although the development of third-generation wide bandgap semiconductors has greatly improved the power level of power amplifier chips,a single MMIC still fails to meet the power requirements of the system,and power combining technology can solve this problem.This project uses a transmission line in the form of a low loss metal waveguide to study the multi-branch low loss power combining network in the W band,and has made important breakthroughs in the number of its combining ways,combining efficiency,output power,and operating bandwidth.The main results are:1.Based on theoretical analysis,the basic unit structure of power combining network commonly used in W-band is studied.The commonly used wave splitter power splitters were analyzed,and the W-band magic-T network and the waveguide to microstrip transition structure were processed and tested.The low-loss,high-amplitude and phase-consistency magic T and broadband waveguide to microstrip conversion structure with low loss were successfully achieved.2.A W-band radial waveguide power combiner was developed.The network uses the symmetry of the radial waveguide to achieve a direct twelve-channel power combining network design with good amplitude and phase consistency.Including waveguide-coaxial transition,coaxial-radial waveguide transition,radial waveguide-multiple rectangular waveguide transition structures,electromagnetic simulation results show good return loss and good amplitude and phase consistency.The test results show that within the bandwidth of 80-100 GHz,the single-channel insertion loss is about 0.5dB,and the amplitude consistency is less than ?0.5 dB.Due to the limitation of test conditions,the phase test is not referenced.3.A W-band four-way power combining amplifier was developed.Using two-stage cascaded binary power combiner,four-way power combining networks with two-stage rat-race,rat-race-T junction,two-level magic T,and magic T-T junction were developed,and two-stage rat-race were selected.As a combining network of amplifiers,using gallium arsenide power amplifier chip as a branch power amplifier,and its output power reaches 16 dBm.The final amplifier realizes the combining amplification of each unit's MMIC,and the output power is higher than 22 dBm in the range of 89 GHz to 95 GHz.The combining efficiency is greater than 88%,the highest point of efficiency reaches 95%.4.A W-band 48-way power combiner amplifier was developed.The amplifier adopts a 12-way radial power combiner and a two-stage ring bridge cascaded to realize a multi-way and high combining efficiency power combining amplifier.Each branch MMIC uses a GaAs power amplifier chip.Test results show that the output power of the amplifier is higher than 30 dBm,and the total 48-channel combining efficiency is greater than 53%.