Low-power Ka band injection-locked frequency dividers using distributed LC tanks

This article presents low-power injection-locked frequency dividers (ILFD) operating in the Ka band. To achieve low-power operation, we use two circuit techniques to reduce the effects of the capacitance and resistance. To achieve a high oscillation frequency by reducing the effective capacitance, a distributed LC tank with a split auxiliary negative-g_m cell is used. To achieve a high loop gain for a given power, we reduce the gate resistance by modifying the foundry-provided transistor layout. Two versions of the divider, which have different inductor implementations, are fabricated in 1-poly 9-metal 65-nm low-power RFCMOS. When biased at 1 V and 1 mA, the ILFD shows successful injection locking at 34 GHz with -35 dBm input power. When biased at 1.2 V and 3 mA, the input frequency ranges from 32.3 to 34.6 GHz at 5 dBm input power. Good phase noise spectral density of -126.6 and -132.0 dBc/Hz at a 1-MHz offset is achieved.