A Ka-band quadruple-push oscillator

In this paper, a quadruple-push oscillator is proposed for the first time. The quadruple-push oscillator consists of four identical sub-circuits and a microstrip ring resonator. By using the ring resonator as common resonator, the four identical sub-circuits oscillate in the same fundamental frequency f/sub 0/, and the fundamental oscillating signal of each sub-circuit has a phase difference of 90/spl deg/, 180/spl deg/ and 270/spl deg/ to that of the others. Therefore, the undesired fundamental signals (f/sub 0/), the second harmonic signals (2f/sub 0/), the third harmonic signals (3f/sub 0/) and so on can be suppressed in principle and the desired fourth harmonic signal (4f/sub 0/) is obtained when all the signals are combined. A Ka-band quadruple-push oscillator was designed and fabricated. The measured output power of the desired fourth harmonic signal (4f/sub 0/) was +1.67 dBm at the frequency of 35.8 GHz. The measured suppression of the undesired signals of the fundamental signal (f/sub 0/), the second harmonic signal (2f/sub 0/), the third harmonic signal (3f/sub 0/) and the fifth harmonic signal (5f/sub 0/) were -18.0 dBc, -17.9 dBc, -17.8 dBc and -35.5 dBc, respectively. The measured phase noise performance at 35.8 GHz was -104.0 dBc/Hz at an offset frequency of 1 MHz.