Balanced active frequency multipliers for W-band signal sources

The design and performance of millimeter-wave monolithic integrated circuits implementing active balanced frequency multipliers for the W-band (75-110 GHz) is presented. The multipliers by eight and twelve are realized in a 100 nm gatelength metamorphic high electron mobility transistor technology. A novel circuit architecture using a cascade of active balanced frequency doubler and tripler stages in combination with active unbalanced-to-balanced converters is adopted in order to combine very broadband operation with high spectral purity of the output signal. On the module level, the multiplier by twelve achieves an output power of -1.5 dBm and associated conversion gain of 2.5 dB in the frequency range from 78 to 100 GHz, corresponding to a relative bandwidth of 24.7%. Within this frequency range, unwanted harmonics are suppressed by at least 12 dB with respect to the twelfth harmonic. The multiplier by eight achieves an output power of 6.9 dBm, associated conversion gain of 8.9 dB and harmonic suppression of 13 dBc in the frequency range from 84 to 101 GHz.