Local oscillator chain for 1.55 to 1.75THz with 100-/spl mu/W peak power

Abstract

We report on the design and performance of a fix-tuned 2 3 3 frequency multiplier chain that covers 1.55-1.75 THz. The chain is nominally pumped with 100 mW at W-band. At 120 K the measured output power is larger than 4 W across the band with a peak power of 100 W at 1.665 THz. A similar chain operated at room temperature produced a peak power of 21 W. These power levels now make it possible to deploy multipixel heterodyne imaging arrays in this frequency range.Index Terms-Frequency multiplier, frequency tripler, local oscillator (LO), Schottky diode, submillimeter wavelength, THz technology, varactor.

Terahertz Frequency Metrology for Spectroscopic Applications: a Review

“…These chains produce from several to tens of microwatts at room temperature but, as reported in an earlier work [41], they greatly improve upon cooling at 120-150 K and in 2005, a 2 × 3 × 3 multiplier chain reached a record 100 μW at 1.665 THz [42]. Moreover, they are electronically and continuously tunable over 10-15% of their bandwidth, and they are intrinsically easy to be referenced to primary frequency standards, in order to precisely know their emission frequency.…”

A Frequency-Multiplied Source With More Than 1 mW of Power Across the 840–900-GHz Band

“…With current terahertz frequency multipliers, power is measured in microwatts rather than milliwatts. The current state-of-the-art at room temperature is 3 W at 1.9 THz [12], 15-20 W at 1.5-1.6 THz [13], [14], and 100 W at 1.2 THz [15]. As predicted in [16], these powers improve dramatically upon cooling: the same sources produce, respectively, 30, 100, and 200 W at 120 K.…”

Technology for Submillimeter Astronomy

“…Fueled by advances in computational electromagnetics, precision machining techniques, and especially device fabrication, frequency multipliers using GaAs diodes are now available to at least 2 THz [38], [39]. These multipliers are driven either by phaselocked Gunn oscillators around 100 GHz, or in a more modern approach, by a microwave synthesizer multiplied up to -100 GHz.…”

“…For instance, a beamsplitter serves as a directional coupler. For fabricating waveguide structures, standard metal machining remains dominant even above 1 THz [39] although micromachining techniques have attracted interest [42], [43].…”