A Novel Four-Port Configuration With Improved Efficiency and Power-Handling Capability for Diode-Based Doublers in Submillimeter Waves

Abstract

We present a novel four-port balanced configuration for Schottky diode-based doublers featuring improved power-handling capability and conversion efficiency. The circuit design includes two frequency doubler cells associated with compact functional networks, which provides unique phase differences for those generated harmonic currents. So, this circuit could achieve the inherent suppressions on odd-order harmonics as well as the fourth harmonic without any filter, which guarantees the efficient frequency multiplying and overcomes the efficiency degradations exists in conventional power-combined multipliers. Example of the diode-based frequency doubler, operating up to 115 GHz, has been demonstrated based on this prototype. At room temperature, the fabricated doubler exhibits a 13.6% 3-dB bandwidth and a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim $ </tex-math></inline-formula> 46.1% peak conversion efficiency (at 105 GHz) for a nominal input power of 240–360 mW. At the same time, this module could deliver maximum power over 230 mW with the maximum achievable input power level.