Generation of Second and Fourth Harmonic Signals Using a Balanced Colpitts Oscillator With a Patch Antenna

A Colpitts oscillator that generates signal at 589 GHz using both phase superposition and nonlinearities of components is demonstrated in a 0.12 m SiGe BiCMOS process. This approach increases the ratio between fourth and second order harmonic power levels by more than 2 dB compared to that obtained using only linear phase superposition. The output power of this circuit with the highest operating frequency for transistor based signal generators is -37.7 dBm.