Design of 199 to 238 GHz broadband subharmonic mixer combining two‐stage reduced matching technology with Global Design Method

Abstract

AbstractTerahertz technology is widely used in communications, radar, electronic countermeasures, precision guidance, and biomedical applications. In this paper, a 199 to 238 GHz broadband subharmonic mixer combining two‐stage reduced matching technology with Global Design Method is designed, fabricated, measured, and analysed successfully. Compared with traditional single‐stage reduced matching technology and Subdivision Design Method, the two‐stage reduced matching technology is applied for terahertz mixer's Radio Frequency (RF) waveguide and Local Frequency (LO) waveguide, while the LO/Intermediate Frequency (IF) Low‐Pass Filter of terahertz mixers is not necessary to design separately. The core of Global Design Method is that the whole mixer circuit, including LO/RF waveguide, is divided into basic transmission units, which match and filter circuit simultaneously with more optimization variables. When LO driven power is 3.1 mW, LO frequency is 108, 112 GHz. The measured single‐sideband (SSB) conversion loss ranges from 7.84 to 12.4 dB with RF frequency 199 to 238 GHz. The measured double‐sideband (DSB) noise temperature varies between 580 and 1059 K with LO driven power 2 to 5 mW. The multi‐stage reduced matching technology and Global Design Method is general, effective, accurate, can reduce circuit size, simplify circuit structure, broaden frequency band, and can be applied for terahertz harmonically mixers.