No abstract

In this letter, a dual-mode rotary traveling-wave oscillator (RTWO) is proposed to achieve wide operation bandwidth and multiple phases. Two twisted differential transmission lines are coupled together to form the dual-mode traveling-wave resonator. Sixteen pairs of back-to-back inverters and capacitors are connected to the resonators to introduce the multicore multiphase operation. The mode switches are used to control the coupling direction and select the desired mode without degrading the quality factor. Verified in a 40-nm CMOS process, the proposed dual-mode RTWO exhibits a dual-mode frequency range from 19.1 to 25.5 GHz with the core size of 0.08 mm 2 . The measured 10-MHz phase noise at 25.30 and 22.12 GHz is −129.6 and −131.5 dBc/Hz, respectively. The best FoM and FoM T are 186.2 and 195.4 dBc/Hz, respectively.