Compact type low-temperature second harmonic mixer base

A compact type low-temperature second harmonic mixer base comprises a heat conduction support and a base body, the base body comprises a signal input waveguiding structure, a reference signal input waveguiding structure, a frequency mixing chip slot, a high-frequency switching cavity and an output signal port, wherein the L-shaped heat conduction support comprises a horizontal contact surface, a vertical contact surface and a hollowed-out structure on the vertical contact surface, the base body is fixed together with the heat conduction support, the signal input waveguiding structure is internally provided with a to-be-measured signal input port, a to-be-measured signal input waveguide, a reference signal input waveguide transition segment and a to-be-measured signal input half-height waveguide, the reference signal input waveguiding structure is also internally provided with a reference signal input port, a reference signal input waveguide, a reference signal input waveguide transition segment and a referenc