Research And Design On Terahertz Harmonic Mixer

Terahertz has many unique advantage,which makes it has important academic values and the prospects for 6G communications,biomonitoring,high-definition imaging and other fields,the research in this field has become a hot spot and.The mixer is an indispensable and important device in the application of solid-state terahertz technology,and its performance determines the overall performance of the terahertz system.Domestic monolithic integrated mixers are relatively mature in low frequency bands,but hybrid integration technologies are mostly used in terahertz bands,and monolithic integration is in the initial stage.In addition,harmonic mixing is a better choice for terahertz mixer due to the expensive price and limited performance of the solid-state terahertz local oscillator for fundamental mixing.Based on the proposed novel method of circuit modeling and circuit matching,this dissertation presents two terahertz monolithic harmonic mixer integrations using anti-parallel diode topology in a Wins PIH0-03(0.1μm InGaAs pHEMT)technology: 220 GHz harmonic mixer and 235 GHz harmonic mixer.The proposed 220 GHz monolithic integrated harmonic mixer adopts a duplex tube pair parallel structure and achieves excellent circuit isolation.The mixer covers a radio frequency(RF),intermediate frequency(IF),local oscillator frequency(LO)range of 200-220 GHz,DC-20 GHz,95-105 GHz,respectively.The conversion loss is better than 17 dB and the isolation between ports is better than 37 dB across the frequency band.The proposed 235 GHz monolithic integrated harmonic mixer adopts a microstrip branch structure and a series-parallel structure of λ/4 RF frequency stub in the IF port.The conversion loss and the isolation between ports are better than 17 dB and 27 dB across the RF range of 225-235 GHz.The LO and IF frequency are 105-115 GHz and DC-20 GHz,respectively.The presented two monolithic integrated solid-state terahertz harmonic mixers demonstrate state-of-the-art performance based on monolithic integrated technology.Wins PIH0-03 technology used in this dissertation is less studied and adopted.The research results of this dissertation will provide references for future research on monolithic integrated terahertz harmonic mixers with better performance and higher frequencies.