Terahertz frequency multiplier

The invention provides a terahertz frequency multiplier, and belongs to the field of terahertz devices. The frequency multiplier comprises a metal shell, a circuit substrate arranged in an inner cavity of the metal shell, and an input waveguide structure, a filter circuit structure, a first matching circuit structure, a frequency multiplication chip, a second matching circuit structure and an output waveguide structure which are arranged on the circuit substrate and are connected in sequence; a second thermal expansion adaptation layer is arranged at a second pressure point, corresponding to the circuit substrate, on the metal shell; the second thermal expansion adaptation layer comprises an adaptation substrate integrally arranged with the metal shell and a plurality of adaptation throughholes formed in the adaptation substrate, the opening direction of the adaptation through holes is parallel to the surface of the circuit substrate, and the adaptation substrate is further connectedwith the circuit substrate