The Design Of Millimeter-Wave Broadband Mixer Chip Based On The GaAs PHEMT Technology

2019 is the year when ‘5G commercial use' began.At the same time,the 6G has also been put on the research agenda by the researchers all over the world.The wireless communication will surpass the traditional communication type and turn to ‘the everything communication' and ‘the man-machine communication' in a broad sense.Under this background,the development of wireless communication transceiver system with high transmission rate and large signal capacity has become one of the hotspots.The research,development,debugging and maintenance of wireless communication transceiver systems require the corresponding electronic test instruments to provide accurate and reliable test data.The thesis is writed based on the background of millimeter wave electronic testinstruments and systems.The design of millimeter-wave broadband mixer chip is the major theme of the thesis.The circuit topologies and the design methods of the broadband mixer chip have discussed deeply.In the circuit design,we adapted the 0.1 ?m GaAs pHEMT process provided by Taiwan's win semiconductors corporation to design four different topologies of broadband mixer chip,the main research works are as follows:(1)The balanced mixer based on Marchand balun has the potential to realize the ultrawide bandwidth.Therefore,the basic theory of Marchand balun is deeply researched in this thesis.The three-coupled-line Marchand balun is proposed to expand the bandwidth of mixer and makes an appropriate chip area.The three-coupled-line Marchand balun has many design parameters and is hard to be designed.In order to simplify the design process of three-coupledline Marchand balun,the S parameter matrix model of balun is constructed by the theory of matrix cascade and odd-even mode analysis.In addition,resulting from the continuity of impedance curve and the concept of no singularity on a continuous curve,a multi-frequency broadband matching method based on the Smith circle graph is proposed.The method is simple to operate and has a broad application prospect in the design of broadband chip.(2)This thesis proposes a fast design method of three-coupled-line Marchand balun based on the S parameter matrix model.The design method effectively reduces the iterative design of balun,in which takes up a large amount of time and computer resources.Resulting from the model and method mentioned above,a full W-band single balanced mixer chip based on the miniaturized three-coupled-line Marchand balun is proposed.The test results show that the conversion loss of the mixer chip is 8.8-12.5 dB for the frequency range of 75-110 GHz.The isolation between the LO(local oscillator)port and the RF(radio frequency)port is above 20 dB and the chip area is only 0.53 mm × 0.56 mm.This work has been published in the Chinese core journal ‘Telecommunication Engineering'.(3)In order to expand the IF bandwidth of double balanced mixer structure,a novel IF extraction structure is proposed.An ultra-wideband double balanced fundamental mixer is designed based on the novel IF extraction structure and the three-coupled-line Marchand balun.The IF extraction structure of the mixer can be reused with the partial microstrip lines of the RF balun.Compared with the traditional double balanced mixer chip,the chip area is reduced by 20-30%.The test results show that the double balanced fundamental mixer chip has realized the RF working frequency of 35-95 GHz and the IF working frequency of DC-30 GHz.The conversion loss within the range of RF bandwidth is 7.2-11.9 dB and the typical isolation between the LO and the RF port is above 30 dB.This circuit is one of millimeter-wave broadband mixer chips with the best bandwidth performance published before.The circuit had been published in the SCI journal ‘IEICE Electronics Express'.(4)In order to improve the bandwidth and isolation of the subharmonic mixer based on the traditional structure of anti-parallel parallel pair(APDP),a new high-isolation balanced subharmonic mixer topology is proposed.At the level of theory,the feasibility,design idea and circuit theory were analyzed in detail.At the level of circuit design,a full E-band balanced subharmonic mixer chip with broad bandwidth and high isolation is designed based on the balanced subharmonic mixer topology.The simulation results show that the conversion loss of the mixer is 10-13 dB for the RF frequency range of 55-95 GHz.The typical isolation of LO to the RF port is 50 dB.The isolation of other ports performs well(Due to the limitation of time,the chip has not been tested in practice).(5)The single open/short stub of traditional APDP subharmonic mixer based on a quarter wavelength microstrip line limits working bandwidth of the mixer chip.This thesis puts forward a broadband matching network based on the multiple parallel open/short stubs.The structure of matching network is simple and easy to design.The matching network expands the bandwidth of the traditional mixer up to the 2-3 times which mentioned above.In this thesis,a full W-band subharmonic mixer is designed by using the broadband matching network.The simulation results show that the conversion loss of the mixer chip is 9.7-12.5 dB for the RF frequency of 75-125 GHz.The typical LO-to-RF isolation is 25 dB.The typical isolation of the second harmonic of the LO frequency to the RF port is 30 dB(Due to the limitation of time,the chip has not been tested in practice).