An ILFT with Input Selector for 5G Transceiver

This article reports an injection-locked frequency tripler (ILFT) as the local oscillators for the fifth-generation communication. This tripler features two sets of input selectors. It adopts a differential injection pair tailed with an inductor at the common source node to generate the third harmonic injection current to lock the core oscillator, resulting in a large locking range. The input selector can choose whether the input signal is from an on-chip PLL or off-chip signal source, providing flexibility during the transceiver testing. Fabricated in the 65 nm CMOS technology, the ILFT consumes a total power of 56 m W under a 1.2-V power supply. The measurement result shows that the locking range of the ILFT is 20.04-27.69 GHz (32.1%).