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

Abstract

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.

Roadmap of Terahertz Imaging 2021

“…As a classical example of diodes, one can underline Schottky diodes, which have already long been and continue to be one of the most useful THz devices both in detection and THz emission schemes as high as 3 THz frequencies [87]. The identification of CMOS technology as a promising platform for the development of THz devices [168] suggested different ways to make THz chips, as well as Schottky diodes [169], enabling reliable and circuits-friendly solutions. Concerning materials choice, GaAs [170] and GaN-based structures [171] remain as the main platforms for sensor development.…”

MeSat Mission: Revolutionizing Mars Exploration with THz Radiometer Payload and Optimal Trajectory

“…Additionally, subharmonic mixers simplify the circuitry and improve the receiver's noise figure, enhancing the overall functionality of the system. One of the most prevalent types of subharmonic mixers is the anti-parallel diode pair (APDP) [45][46][47]. In this study, we propose an optimized CubeSat THz subharmonic mixer specifically designed for water detection on Mars [48].…”

“…Instead, it simply involves the insertion of two neighboring rectangular sheets into the gap, situated between the anode and the buffer layer. These sheets are designated as lumped ports, each aligned with the other, enhancing the design's efficiency [53].…”

220 GHz Multi Circuit Integrated Front End Based on Solid‐State Circuits for High Speed Communication System

“…Therefore, a branch waveguide hybrid coupler is integrated to couple a small part of the power of the multiplier as a test port to check the performance of the frequency multiplier. Meanwhile, in order to solve the problem of double sideband (DSB) interference caused by RF front-end up conversion in the process of terahertz high-speed communication [21] , the front-end presented in this paper also integrates a waveguide bandpass filter, which can effectively suppress one sideband and SSB communication. The front-end integrates a 110 GHz tripler, a 110 GHz 8 dB branch waveguide hybrid coupler, a 220 GHz subharmonic mixer and a 220 GHz waveguide BPF in one single block.…”

“…In addition, according to the research of Ref. [22], the performance of the cascade circuits will deteriorate, which is mainly caused by the mismatch between the mixer and the multiplier. The coupler is a four‐port matching circuit, and the standing wave coefficients of each port are better than 20 dB.…”