Hetero-integrated terahertz low-noise miniaturized image frequency rejection transceiver front-end

A hetero-integrated terahertz low-noise miniaturized image frequency rejection transceiver front-end, comprising an intermediate frequency circuit and a terahertz circuit arranged up and down, wherein the terahertz circuit comprises a local oscillator frequency tripler, a 135° 3 dB filter coupler, a first quartz hetero-integrated subharmonic mixer, a second quartz hetero-integrated subharmonic mixer, and a radio frequency waveguide power divider;

• the 135° 3 dB filter coupler comprises an input unit, a first output unit, a second output unit, and an isolation unit each of which is composed of a resonant cavity and a waveguide, and the resonant cavities of the input unit, the first output unit, the isolation unit, and the second output unit are sequentially coupled through resonant grooves to form a ring structure;
• a cavity length of the resonant cavity of the input unit is twice that of the resonant cavities of the other three units, and an electrical length of the waveguide of the first output unit is 45° different from that of the waveguide of the second output unit;
• a radio frequency signal is divided by the radio frequency waveguide power divider into two signals, which respectively enter the first quartz hetero-integrated subharmonic mixer and the second quartz hetero-integrated subharmonic mixer;
• a local oscillator signal is tripled by the local oscillator frequency tripler, then filtered and coupled by the 135° 3 dB filter coupler into two local oscillator drive signals, which respectively enter the first quartz hetero-integrated subharmonic mixer and the second quartz hetero-integrated subharmonic mixer to drive frequency mixing;
• and intermediate frequency components generated after the frequency mixing by the first quartz hetero-integrated subharmonic mixer and the second quartz hetero-integrated subharmonic mixer are respectively inputted to the intermediate frequency circuit, 90° coupled and amplified, to output an upper side band (USB) signal and a lower side band (LSB) signal.