Research On Ultra Wideband Microwave Power Amplifier

With the development of the integrated electronic theory,the integrated electronic system is the inevitable trend of the development of the wireless electronic system.Ultra wide band?UWB?power amplifier is an important part of the integrated electronic system,and it is the channel of signal transmission.In order to achieve the higher performance of the integrated electronic system for the RF front end,UWB and high-gain power amplifiers have great value for research.At the same time,GaN HEMT semiconductor with the characteristics of wide band gap and high frequency,and microwave monolithic integrated circuit?MMIC?technology have been developing rapidly,and they have been widely used in the latest design of UWB power amplifier circuit.The different broadband amplification technologies are compared and analyzed,the distributed amplifier structure?DPA?is selected according to the requirement of design bandwidth.And based on the OMMIC D01GH Si-based GaN HEMT process,MMIC is designed.Considering the contraction of the total gate width of the signal transistor between the output and bandwidth of the traditional distributed amplifier,a coupling capacitor is in series with the gate to increase the output power and bandwidth.M derived section is connected in series on the drain line,which can balance the phase velocity of gate line and drain line.The appropriate gate width of transistor and the best bias condition are decided,the optimal sections of the distributed amplifier can be acquired,three UWB power amplifier chips have been designed.The first chip is a 5sections distributed amplifier with single tube size of 30?m×4,the simulation results show that the gain is 11dB at 0.5-18GHz,and the output power reaches 30dBm.The second chip is a 6 sections DPA with single tube size of 60?m×2,also,the simulation results show that the gain is 12dB at 0.5-18GHz,and the output power reaches 30dBm.Clearly,the added sections does not improve the gain of DPA significantly,and the two chips both are 3mm×1mm.In order to acquire higher gain,two distributed amplifiers are cascaded,with single size of 15?m×4 and 60?m×2 respectively.The simulation results show that,the small signal gain is 26dB at 2-18GHz,the input S₁₁ is less than-10dB,the output S₂₂ is less than-7.6dB,the saturated output power reaches 30dBm,and the chip area is 2.3mm×3mm.The amplifier chip has the advantages of wider bandwidth,higher gain,smaller size,and it reachs a relatively advanced level.Based on the requirements of electronic war project,the 6-18GHz drive module with two power amplification and 2-18GHz drive module with three power amplification are accomplished,the output power of 33dBm and 30dBm have been achieved respectively,and the test results satisfy the project indicators.