LAUSR

A reconfigurable injection-locked frequency multiplier (RE-ILFM) with both frequency $\times 2$ doubler mode (DM) and $\times 3$ tripler mode (TM) is proposed to increase both the operation frequency range and power efficiency. The proposed wideband RE-ILFM has common input and output ports by switching the working DM and TM without any calibration. For TM, harmonic suppression technology (HST) composed of notch filtering and transformer injection-coupling network is presented to optimize the harmonic rejection. For DM, an injection device composed of push-push pair operates in class-C to reduce power consumption and improve second-order harmonic current. Moreover, the concept of a dual core with multiple tanks is first introduced into ILFM, which can effectively improve the magnitude of output signal compared with traditional methods. The proposed RE-ILFM is designed and fabricated in a 55-nm CMOS process. The measurement results show that under a 0-dBm differential injection power, the RE-ILFM can achieve the bandwidth from 20.7 to 43.8 GHz, i.e., 71.6% with a good harmonic rejection of better than 27-dB using HST. From 22 to 30 GHz and 35.4 to 42 GHz for 28 and 39-GHz mm-wave fifth-generation bands, the RE-ILFM can achieve a differential output power of −5.9 to −14.06 dBm and −9.38 to −13.48 dBm with a low power consumption of 12 and 9.6 mW, respectively. The measured phase noise degradation is around 9.5 and 6 dB, which is close to the theoretical value.