A monolithic integrated mixer based on InP material Schottky diodes is introduced, and its operating frequency is 560 GHz. The mixer uses a new type of thin-film hybrid transmission structure, and the transmission loss of a passive structure based on a polymer material is reduced to 14.4-15.5 Np/m. Compared with the transmission line based on traditional quartz dielectric substrate and semiconductor dielectric substrate, the transmission loss is reduced by more than half. At the same time, in order to reduce high-frequency losses and improve circuit efficiency, the diode needs to use a sub-micron structure with a junction radius of 0.5 μm and a junction capacitance of 1.5 fF. The simultaneous optimization of the passive structure and the active structure makes the frequency multiplier operating in the 540-580 GHz band, with the conversion loss better than -8 dB, and the return loss better than 10 dB. And because the passive part adopts an innovative hybrid transmission structure, the overall physical size of the mixer circuit is increased under the condition of ensuring single-mode transmission, and the process difficulty of cavity processing is reduced, which makes the low loss plane transmission of THz signal above 1THz becomes possible in the future.