A 4–15-GHz ring oscillator based injection-locked frequency multiplier with built-in harmonic generation

This paper presents a new injection-locked frequency multiplier (ILFM) designed to achieve wide locking range and low power dissipation. The ILFM is constructed using an injection-locked ring oscillator (ILRO) without any inductors. It is injection-locked at each ILRO stage by an injection signal, which is generated by the harmonic generation integrated in each stage from the input signal, with a progressive phase shift. The multiphase injection locking scheme and built-in harmonic generation improve the injection efficiency, increase the locking range, and reduce the power consumption. A multiply-by-2 ILFM prototype is implemented on a test chip using 130-nm CMOS. The measured locking range is 116% (4-15 GHz) with 0.3-V input amplitude. The ILFM prototype consumes 8 mW at 1.8 V, and occupies a chip area less than 0.01 mm².