The invention discloses a 
millimeter wave frequency quadrupler with a 
broadband high-fundamental-wave suppression double-balance self-mixing structure. The 
millimeter wave quadrupler comprises a 
third harmonic frequency multiplication unit, a double-balance 
ring type mixing unit and three transformers. An input 
signal is converted into a differential 
signal by the first-stage 
transformer, the differential 
signal is injected into the frequency multiplication unit, and one path of signal is divided as a 
local oscillator of the 
frequency mixing unit. And the frequency multiplication unit outputs a differential signal, and third 
harmonics are injected into a source 
electrode of the 
frequency mixing unit as 
intermediate frequency by a second-stage 
transformer in a differential-to-differential manner. And the 
frequency mixing unit mixes the fundamental wave and the 
third harmonic wave to generate a 
fourth harmonic wave, the 
fourth harmonic wave is led out by a drain 
electrode of the frequency mixing unit in a differential mode, and the third-stage 
transformer outputs the 
fourth harmonic wave by a differential-to-single end. According to the invention, the double-balance 
ring type frequency mixing unit is adopted, the unit has good inhibition degree on local oscillation and 
intermediate frequency leakage, a fundamental wave and 
third harmonic wave mixing scheme is adopted, the problem that the frequency tripler with the self-mixing structure generates 
fundamental frequency mixing products is solved, and the fundamental wave inhibition degree of the frequency tripler with the self-mixing structure is greatly improved.