Comparison of a sub-harmonic and a fourth-harmonic mixer working at 440 GHz

A comparison between two mixer designs is presented in this paper. The electromagnetic performances of fourth-harmonic mixer are compared with the ones of a sub-harmonic mixer both working at an RF frequency of 440 GHz. The best results in terms of noise temperature and conversion loss values are obtained for the sub-harmonic mixer; however, a higher local oscillator frequency is required to pump the mixer. On the other hand, the fourth-harmonic design exhibits a lower operational bandwidth and higher noise temperature. The final selection will depend on the requirements of the application.