Research On Microwave And Millimeter Wave Mixer And Amplifier Based On MMIC Circuit

The microwave and millimeter wave Monolithic Microwave Integrated Circuit(MMIC)fabricated based on the GaAs PHEMT process has been widely used in civil communications and electronic countermeasure systems due to its small area,small parasitic parameters,good consistency,excellent performance,and high integration.Mixers and amplifiers are key components of microwave millimeter wave transceiver,radar,communications systems,and electronic warfare systems.This article analyzes the urgent needs of modern wireless communication systems for mixers and amplifiers,summarizes the implementation methods of mixers and amplifiers in transceiver chips in China and abroad in recent years,and illustrates the technical difficulties of high-performance broadband mixers and amplifiers as well as the way to design them.In the end,two mixers and one amplifier are designed based on GaAs MMIC.In the design of distributed cascode mixers,this article based on the design theory of distributed circuits,combined with the theory of characteristic impedance of artificial transmission line,analyzed the influence of inductive components on the artificial transmission line,and an artificial transmission line with high cutoff frequency was constructed.The number of distributed mixer cells is optimized for the compromise of circuit size and conversion loss performance.In order to improve the port isolation in high frequency,a cascode mixer cell is used instead of the traditional common source mixer cell.A resistor and inductor in parallel with the output port to increase the flatness of the IF signal.In addition,realize a 4~64 GHz wideband mixer design with dual-mode operation,high isolation,and low conversion loss.The mixer conversion loss is less than 10 dB,and the isolation between LO and RF is greater than 14 dB,the input 1 dB compression point is-2 dBm.In the design of the V-band sub-harmonic mixer,the on-chip balun can convert the single-ended signal to a differential signal.The balun introduces capacitive loading technology to reduce the size of the coupled line successfully,this article analyzes the influence of three stub lines to the RF and local oscillator signals.The on-chip integrated low-pass filter in the IF output port reduces the difficulty of implementation of the off-chip filter.The frequency of the local oscillator used in sub-harmonic mixer is half of the frequency of the fundamental mixer,which greatly reduces the difficulty of the realization of the transceiver system and easier to design a local oscillator.In addition,this article realizes a passive mixer with high isolation and low conversion loss.The frequency conversion loss of the mixer is less than 5 dB,isolation of LO to RF and isolation of LO to IF are both greater than 50 dB.The medium power gain block amplifier designed in this paper is usually used between the module circuits of a transceiver.The input and output stages of the two stages amplifier both adopts negative feedback and self-bias technology to expand bandwidth and achieve flat gain,the input impedance of the amplifier is matched to the best noise,and the output impedance of the amplifier is matched to the highest power.The amplifier is single power supply.The choke inductors and the DC blocking capacitors are part of the matching,which effectively reduces the amount of passive components used.In addition,this article completes a broadband amplifier design with low power consumption,high integration,and gain flatness.In the bandwidth of 6~20 GHz,this amplifier implement the gain of 15~18 dB,the input and output reflection coefficient are below-10 dB,the noise figure is less than 4.4 dB,the reverse isolation is greater than 35 dB,and the output 1 dB compression point is about 12 dBm.