Dielectric Rod Waveguide Antenna as THz Emitter for Photomixing Devices

Abstract

We propose a dielectric rod waveguide antenna (DRW) integrated with a photomixer as a THz emitter. This represents a different approach as opposed to the classical solution of a substrate lens. Main goals are an inexpensive alternative to substrate lenses, reduction of both reflections on the semiconductor-air interface and scattering of terahertz-generated power into the substrate. A radiation pattern measured at 137 GHz is shown as a proof-of-concept. In order to increase radiated power, the improvement of the rod antenna is discussed. Finally, as an application example, evanescent coupling of the DRW into a high index whispering gallery mode resonator is shown

Vivaldi End-Fire Antenna for THz Photomixers

“…Rivera-Lavado et al proposed a dielectric rod waveguide antenna at the backside of substrate as an alternative to the hyper-hemispherical Si-lens for THz photomixing devices. The waveguide antenna is cost-effective and avoids power scattering in the substrate [15]. Holdengreber et al presented another antenna system based on a Josephson junction as a detecting element for 0.20-THz detection [16,17].…”

Single-walled carbon nanotube layers for millimeter-wave beam steering

“…[19][20][21][22] DRWs can be fabricated with standard micromachining techniques in the form of photonic crystal waveguides or silicon-on-glass devices, 23,24 and several passive and active devices have already been demonstrated, such as phase shifters, antennas, amplifiers, and power sensors. [25][26][27][28] In this work, we show how thin SWCNT layers can be used as a reconfigurable impedance surface for beam-steerable antenna components in the millimeter-wave range. The impedance of SWCNTs is tuned by light illumination.…”

Theory and measurements of harmonic generation in semiconductor superlattices with applications in the 100 GHz to 1 THz range

“…Furthermore, efficient devices have only been demonstrated for frequencies between 2 and 4 THz, while the realization of 1-THz QCL required magnetic fields of tens of teslas [11]. Recent photomixer concepts can reach this range, but emitted powers fall drastically with increasing frequency [12]. Difference frequency generation via resonant optical nonlinearities pumped by a mid-infrared (MIR) QCL [13] is a promising approach for on-chip simultaneous emission from the MIR to the THz range but would require GHz resonances, which are not easily achievable per design.…”