Opening the terahertz window with integrated diode circuits

Abstract

The terahertz region of the electromagnetic spectrum, spanning from 100 GHz through 10 THz, is of increasing importance for a wide range of scientific, military and commercial applications. This interest is spurred by the unique properties of this spectral band and the very recent development of convenient terahertz sources and detectors. However, the terahertz band is also extremely challenging, in large part because it spans the transition from traditional electronics to photonics. This paper reviews the importance of this frequency band and summarizes the efforts of scientists and engineers to span the "terahertz technology gap." The emphasis is on solid-state circuits that use nonlinear diodes to translate the functionality of microwave technology to much higher frequencies.

THz radiation sensors

“…SBDs are used either as direct detection detectors, and as nonlinear elements in heterodyne receiver mixers at the temperatures T~4-300 K [3,8,75]. The mixing process in SBDs is due to the rectification of the electromagnetic waveform because of nonlinear behaviour of its current− −voltage characteristic [see Fig.…”

“…Even wider region n »0.1-10 THz [3,4] is treated as THz band overlapping thus with sub−mm wavelength band. As a result, frequently, both these notions are used as equal ones (see, e.g., Ref.…”

“…1). Around n~1 THz one can see that there exist the so cold "THz gap" [3,15]. The pixels quantities for different variety of mixer arrays, that can drive single− −source solid−state LOs in sub−mm spectral range, are listed in Table 1.…”

380 GHZ Sub-Harmonically Pumped Mixer Based on Anti-Parallel Planar Schottky Diode

“…Between the atmosphere THz wave absorption lines, there are some relatively minor atmospheric absorption bands, and these minimum value attenuation peaks are called transparent window regions (atmospheric window) [6,7]. In the millimeter/THz band, several atmospheric windows distribute at the center frequencies of 118 GHz, 140 GHz, 183 GHz, 225 GHz, 380 GHz, 425 GHz, etc., and the relative bandwidth reaches about 20%, even 70% [8]. These bands will make great potential applications in THz atmosphere transmission.…”

Design of a low noise 190–240 GHz subharmonic mixer based on 3D geometric modeling of Schottky diodes and CAD load-pull techniques

“…The progress of device fabrication process and the emergence of planar GaAs Schottky diodes make devices' physical and geometrical structures stable and reliable. The Schottky contact in a planar diode is formed lithographically rather than manually achieved as whisker-contacted diodes require [5]. Since the planar diode process brings the merits in terms of device geometrical ruggedness and electrical performance repeatability and thanks to the emergence of commercial three-dimensional (3D) full-wave electromagnetic (EM) simulation software (e.g.…”