A Broadband 630-720 GHz Schottky Based Sub-Harmonic Mixer Using Intrinsic Resonances of Hammer-Head Filter

摘要

An room temperature low noise an-ti-parallel Schottky diode based 630-720GHz sub-harmonic mixer (SHM) is designed, built and measured. Intrinsic resonances in low-pass hammer-head filter have been adopted to prevent the LO and RF power leak from the IF channel, while greatly minimizing the trans-mission line size. The mixer consists of 15um quartz terahertz circuit and 127um Al2O3 IF transformer circuit. An improved lumped ele-ment equivalent noise model of SBDs guaran-tees the accuracy of simulation. The measure-ment indicates that with local oscillating (LO) signal of 2-8 mW, the lowest double sideband (DSB) conversion loss is 8.2 dB at 645 GHz, and the best DSB noise temperature is 2800 K at 657GHz. The 3 dB bandwidth of conver-sion loss is 75 GHz from 638 to 715 GHz. The work IF frequency band is above 20GHz rang-ing from 1 to 20 GHz with -10dB return loss.