Research On The Key Technology Of Millimeter-wave And Terahertz Integrated Transceiver System

Millimeter-wave(MMW)and terahertz(THz)band are rich in spectrum resources,and have the characteristics of transient,perspective and security.Therefore,MMW and THz technology have great application prospects in high-speed communication,radio astronomy,radar,security,life sciences,etc.The integrated transceiver front-end is the core of the MMW and the THz system,which consists of transmitters and receivers for the frequency conversion from the low frequency signals to MMW and THz signals and vice versa.The MMW and THz mixer is the key device of the integrated transceiver front-end,and have important research value.Noise performance is an essential factor affecting the overall performance of MMW and THz integrated transceiver front-end,and a high-performance noise source is needed to value the system noise performance.In this paper,two MMW single-balanced mixers with high intermediate frequency(IF),a 220 GHz planar sub-harmonic mixer and a 220 GHz receiving front-end are developed respectively,and the measurement method of noise figure of 220 GHz receiver front-end is preliminarily explored.Specific research work includes:(1)Research on MMW single-balanced mixers with high IF.In this paper,a 66～86GHz 180°single-balanced mixer and a 66～86GHz 90° single-balanced mixer are developed.For the receiver of the super-heterodyne structure,the mixer with high IF greatly reduces the requirement of the image rejection filter.Both mixers use multiple local oscillator(LO)signals for frequency conversion,covering the radio frequency(RF)frequency of 66～86GHz in several segments,overlapping 2GHz between each segment to ensure the demand for 2GHz instantaneous bandwidth.The 180° single-balanced mixer adopts finline and suspended microstrip line structure as 180° hybrid coupler.Under the excitation of four LO signals,the IF signals are up-converted to 66～72.5GHz,70.5～77GHz,75～81.5GHz and 79.5-86 GHz respectively,with the maximum conversion loss of 15.5d B.At the LO frequency of 57.6GHz and the RF frequency of75 GHz,the best conversion loss is 9.2d B;The 90° single-balanced mixer adopts 90° waveguide hybrid coupler.Under the excitation of three LO signals,the RF signals of 66～74GHz,72～80GHz and 78～86GHz are down-converted to IF frequency respectively,with the maximum conversion loss of 8.9d B.At the LO frequency of 57.6GHz and the RF frequency of 75 GHz,the best conversion loss is 5.84 d B.(2)Research on 220 GHz sub-harmonic mixers.In this paper,an easy-to-integrate 220 GHz sub-harmonic mixer is developed.The mixer does not use waveguide port,the entire circuit is designed based on planar microstrip structure.In order to facilitate the test,a 220 GHz sub-harmonic mixer module integrating the waveguide-microstrip transition structures is designed and manufactured.The test results show that,the frequency conversion loss of the mixer is less than 16.9d B in the RF frequency range of210～230GHz,and the optimum conversion loss is 11.78 d B at 220 GHz.(3)Research on the 220 GHz receiver front-end.Based on the 220 GHz sub-harmonic mixer module,a 220 GHz receiver front-end is developed.The front-end adopts the super-heterodyne structure,including a 220 GHz low-noise amplifier module,a 220 GHz image suppression filter module,220 GHz sub-harmonic mixer module,LO frequency multiplier module,LO filter module and IF amplifier module.The test results show that,the conversion gain of the receiver is more than 31 d B and the image rejection is higher than 44 d B in the range of 215-225 GHz.(4)Research on the measurement method of noise figure of 220 GHz receiver front-end.In this paper,the cold noise source method is used to measure the noise figure of the 220 GHz receiver front-end,and the test results are further analyzed.The noise sources needed for Y-factor test method are studied,and two solid-state noise sources are developed.The same Schottky barrier diode is used in these two noise sources,and two grounding schemes are adopted respectively.A noise test platform is built of a spectrum analyzer and a 220 GHz receiving front-end.The corresponding test results and analysis are given.