A 3.5-THz, x6-Harmonic, Single-Ended Schottky Diode Mixer for Frequency Stabilization of Quantum-Cascade Lasers

Abstract

Efficient and compact frequency converters are essential for frequency stabilization of terahertz sources. In this paper, we present a 3.5-THz, x6-harmonic, integrated Schottky diode mixer operating at room temperature. The designed frequency converter is based on a single-ended, planar Schottky diode with a sub-micron anode contact area defined on a suspended 2-um ultra-thin GaAs substrate. The dc-grounded anode pad was combined with the radio frequency E-plane probe, which resulted in an electrically compact circuit. At 200 MHz intermediate frequency, a mixer conversion loss of about 59 dB is measured resulting in a 40 dB signal-to-noise ratio in a phase-locking application. Using a quasi-static diode model combined with electromagnetic simulations, good agreement with the measured results was obtained. Harmonic frequency converters without the need of cryogenic cooling will help in the realization of highly sensitive space and air-borne heterodyne receivers.<br>

Phase Locking of 3.5-THz and 4.7-THz Quantum-Cascade Lasers Using a Schottky Diode Harmonic Mixer

“…The Schottky diode harmonic mixer generates the sixth and eighth harmonic for phase locking of a 3.5-THz and a 4.7-THz QCL, respectively. Details of the design of the harmonic mixer are described in [5,6]. With this setup, phase locking was achieved for both frequencies [Fig.…”

Optimal design ofCMOSmixer: A research review

“…As a result, a lot of circuit designs are built on Ân harmonic Schottky diode mixers in the III-V process. 83,84 High-performance mixer must satisfy a number of requirements, including low power consumption, low cost, high integration, multiband, and so forth. But it is difficult to satisfy all of the demanding stringent design requirements.…”