A millimeter-wave, third-harmonic, Gunn VCO with ultra-wideband tuning

State-of-the-art ultra-wideband tuning (69 to 91 GHz) has been demonstrated with a third-harmonic, varactor-tuned, GaAs Gunn oscillator. The 22 GHz wide tuning band was obtained by tuning the voltage-controlled oscillator (VCO) at the fundamental frequency and using the in-situ generated Gunn-diode third harmonic for output. Lumped-element VCO circuit refinements have resulted in the frequency extension of the use of lumped-element VCO circuit technology to 91 GHz in W-band (WR-10) from the previously reported maximum frequency of 66 GHz in V-band (WR-15).<>