Wideband Fourth-Harmonic Mixer Operated at 325–500 GHz

Wang

et al. 2020

IEEE Access

In this paper, the influence of the silver glue on circuit performance and the reasons for its formation are analyzed in a terahertz hybrid integrated mixer. A validation analysis was carried out in the 600-700 GHz band with the aid of simulation software. Then a terahertz hybrid integrated mixing circuit with large pads was proposed in order to reduce the influence of the silver glue. Through the comparison of simulation results, it can be seen that after using large pads, the silver glue used for connection mainly concentrated on pads, which cannot have a significant impact on the matching of the circuits. The use of large pads also to a certain extent eliminates the resonance effect caused by silver glue. A terahertz hybrid integrated mixer with large pads was processed, assembled and tested. The test results show that the conversion loss is less than 14 dB under an RF frequency of 600-667 GHz. The experiments prove good consistency between measured and predicted conversion loss of the mixer using large pads. The difference between the measured and predicted conversion loss is only within 1.8 dB.

Section: Mixer Designmentioning

confidence: 99%

Analysis of Welding Pad for Terahertz Hybrid Integrated Mixer

Wang

et al. 2020

IEEE Access

“…Subharmonic mixers are preferred due to their excellent performances referring to noise temperature and conversion loss . High harmonic submillimeter wave and terahertz mixers are also researched to reduce the LO frequency . However, the high harmonic mixers have worse conversion loss and noise temperature compared with subharmonic mixers, thus they cannot meet the requirement of high sensitivity imaging systems.…”

Section: Introductionmentioning

confidence: 99%

220 GHz wideband integrated receiver front end based on planar Schottky diodes

Yang

Micro & Optical Tech Letters

Zhao

et al. 2020

In this article, a 220 GHz wideband receiver front end is proposed, featuring a 220 GHz subharmonic mixer and a 110 GHz wideband tripler integrated in one single block. The 220 GHz subharmonic mixer and 110 GHz tripler are firstly developed separately with proper planar Schottky diodes. According to the simulated and experimental results, the direct combination of independent mixer and tripler will lead to deterioration of the front end's performances, especially for wideband receivers. This indicates the necessity of building matching network between the cascade circuits in wideband submillimeter receivers. To improve the integral performances of the receiver front end and reduce its size, the combination of the subharmonic mixer and the tripler was optimized with load‐pull techniques and realized in one block. Measured results reveal that the single sideband (SSB) conversion loss of the integrated receiver front end is 7.5‐11 dB from 185 to 250 GHz, while the double sideband (DSB) noise temperature is 750‐1600 K within this frequency range. The integrated front end features half size of the combination of independent modules and better performances. Good agreement between the simulated and measured results shows that the integration and optimization techniques can be applied to realize compact terahertz systems in the future.

“…A single-stage reduced matching technology and Subdivision Design Method (SDM) are generally used to design terahertz harmonically mixers. [6][7][8][9][10][11][12][13] The regular single-stage reduced matching process is that the same size chamfering or filleting is performed on both sides of LO waveguide and RF waveguide. [6][7][8][9] The key of terahertz harmonically mixers using regular SDM is required to design function units individually, including Direct Current (DC) grounded in RF port, RF/LO reducing waveguide, LO Low-Pass Filter (LPF), IF LPF, and so on.…”

Section: Introductionmentioning

confidence: 99%

“…Because of the fewer number of matching variables, the simulation optimization space of terahertz harmonically mixer with a single-stage reduced waveguide matching technology and SDM is limited and increases circuit size inevitability. 12,13 In the study of Siegel et al, 10 a 215 GHz subharmonic mixer based on SDM is presented. Two high-low impedance filters are adopted to LO LPF and IF LPF of mixer with overall circuit size 8.51 mm.…”

Section: Introductionmentioning

confidence: 99%

“…Terahertz mixer is one of the core components of terahertz solid transceiver system. A single‐stage reduced matching technology and Subdivision Design Method (SDM) are generally used to design terahertz harmonically mixers . The regular single‐stage reduced matching process is that the same size chamfering or filleting is performed on both sides of LO waveguide and RF waveguide .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Cui

Int J Numerical Modelling

Liu

et al. 2019

Terahertz 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 singlesideband (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.