Research On Microwave Bidirectional Amplifier And Low Noise Amplifier Chip

As the core module of the RF front-end,the microwave amplifier chip has application scenarios covering radar,communication,Internet of Things and other fields.Bidirectional amplifiers(BDAs)can be used in time division duplex system,which can share the up/down converter module in the transmitting and receiving channel.It realizes low cost,miniaturization and high integration of the system.With the advantage of high data transfer rate of millimeter wave and the miniaturization of millimeter wave circuit,millimeter wave technology is used more widely.Firstly,the research status of bidirectional amplifiers and Ka band low noise amplifiers are investigated and analyzed to provide guidance for the research of this thesis.Then the structure of p HEMT and the equivalent models of transistor,capacitor,resistor and inductor are studied.Finally,the gain,stability and efficiency of the amplifier are introduced and studied.The main contributions of this thesis are as follows:This thesis presents a Ku-band 14-18GHz BDA in 0.25um GaAs pHEMT technology.The BDA integrates in/output single-pole double-throw switches,a power amplifier in transmitting channel,and a low-noise power amplifier in receiving channel.The transceiving amplifiers all adopt a self-biased structure to realize single power supply.The result of measurement shows,the BDA has a small signal gain of 24.2±0.8d B in the transmitting mode.The saturated output power is 23.6d Bm with a power added efficiency(PAE)of 28.3%at 16GHz.In the receiving mode,the small signal gain is 13.1±0.7d B,and the noise figure is 4.2-4.7d B.The input and output 1d B compression point are10.3d Bm and 22.8d Bm at 16GHz,respectively.The chip size is 2.15mm×1.55mm.To the author's knowledge,this BDA has higher PAE in the transmitting mode and higher in/output P_{1d B} in the receiving mode,compared with other BDAs with the same frequency band.A Ka-band LNA is also presented in 0.15um p HEMT process.The LNA combines current-reused technique and self-biased structure to realize single power supply.This thesis analyzes the current"limiting"effect in current-reused technique,and selects the transistor size to meet the output P_{1d B} requirement,reasonably.The simulation results show that the LNA achieves a flat gain of 18-18.7d B at 32-36GHz.The input and output return loss are almost above 10d B.The noise figure is about 2.15d B,and the output P_{1d B}is 4.3-5.4d Bm.The quiescent current is 7.9m A from a 5.5V single power supply,and the DC power consumption is 43.5m W.The chip size is 1.5mm×0.8mm.The LNA is suitable for high-voltage single-power supply scenarios and achieves low power consumption.Compared with the reported Ka-band LNA using GaAs pHEMT technology,the LNA has a more compact size and lower power consumption.