A 60 GHz Injection-Locked Frequency Tripler With Spur Suppression

A 60 GHz injection-locked frequency tripler is designed to improve spectral purity with spur suppression of the fundamental and the even-order harmonics. Several circuit designs are utilized in the harmonic current injection circuit to maximize the third-order harmonic and minimize the undesired harmonic current outputs, including notch filters and a capacitive cross-coupled transistor pair. With the input signal of 0.5 dBm at 19.7 GHz, the harmonic rejection ratios of the fundamental, and the second-order achieve 31.3 dBc, and 45.8 dBc, respectively. Implemented in 0.13 m CMOS technology, the core circuit consumes power of 9.96 mW with 1.2 V supply voltage. The entire die occupies an area of 985 × 866 μm
²
.