W-Band Injection-Locked Frequency Octupler Using a Push-Push Output Structure

This letter presents an injection-locked frequency octupler (ILFO) fabricated using a 100-nm GaAs pHEMT. A frequency quadrupler, followed by an injection-locked push–push oscillator, is employed to achieve a high multiplication factor of eight with a simple structure. Compared to conventional amplifier-multiplier chains, the proposed structure is advantageous for dc power and chip area consumption, phase noise, and circuit stability. The high multiplication factor allows the use of a low-frequency, high-performance, phase-locked-loop (PLL) as input. The ILFO achieves a locking range from 90.5 to 95.2 with 1-dBm input power. The output power is measured to be −0.4 dBm at 91.2 GHz. The phase-noise degradation from the input source to the output is 19.7 dB at 100-kHz offset.