High-Performance 76-GHz Planar Gunn VCO

A 76-GHz Gunn voltage-controlled oscillator (VCO) with a high output power and a wide tuning-frequency range was fabricated by optimizing VCO circuits and using laser micromachining. The tuning-frequency range of the fabricated Gunn VCO was more than two times higher than that attained in our previous experiments by optimizing VCO circuits. The VCO attained a tuning-frequency range of 493MHz, out-put power variation of 1.0dB, and tuning-frequency linearity of 6.1% over a tuning-voltage range from 0 to 10V. Its power consumption was 2.0W at operation voltage of 3.6V. And it measured out-put power was 13.3dBm with DC-RF conversion efficiency of 1.0% at 76.5GHz. Moreover, under fundamental-mode operation, it achieved low phase noise of -107.8dBc/Hz at an offset frequency of 1MHz. Since laser micromachining was used in fabricating the Gunn VCO, the reproducibility of its RF performance was improved.