Low-noise integrated balanced-mixer for 300-GHz band based on Fermi-level managed barrier diode on Si platform

A balanced mixer module for operation in the J-band was developed based on Fermi-level managed barrier (FMB) diodes using epi-layer-transfer technique on a Si substrate. Deep dry etching of the Si substrate enabled an arbitrary chip shape to monolithically integrate FMB diodes, waveguide couplers, a 90-degree hybrid circuit, and low-pass filters with better design flexibility. The fabricated module integrated with a transimpedance amplifier, exhibited a double-side intermediate frequency bandwidth of about 43GHz. The lowest noise-equivalent-power obtained was as low as 5×10-20W/Hz for a local oscillator power of 400µW at a signal frequency of 300GHz.