Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are disclosed. In certain embodiments, an RTWO system include an RTWO ring that carries a traveling wave, a plurality of selectable capacitors distributed around the RTWO ring and each operable in a selected state and an unselected state, and a decoder system that controls selection of the plurality of selectable capacitors based on a frequency tuning code. The frequency tuning code includes a fine tuning code and a coarse tuning code, and the decoder system is operable to maintain a constant number of capacitors that toggle state for each value of the fine tuning code.

Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are disclosed. In certain embodiments, an RTWO system include an RTWO ring that carries a traveling wave, a plurality of selectable capacitors distributed around the RTWO ring and each operable in a selected state and an unselected state, and a decoder system that controls selection of the plurality of selectable capacitors based on a frequency tuning code. The frequency tuning code includes a fine tuning code and a coarse tuning code, and the decoder system is operable to maintain a constant number of capacitors that toggle state for each value of the fine tuning code.

Abstract: A phase-locked loop (PLL) comprising a multi-band oscillator and a memory configured to store control input for the oscillator. The PLL is operable in a calibration mode in which the PLL is configured to acquire a frequency controlled word (FCW) for the PLL corresponding to a frequency generated by the oscillator in response to a first control input threshold on a first band of the oscillator; generate a frequency corresponding to said FCW on a second band of the oscillator adjacent to said first band; identify a second control input causing the oscillator to generate said frequency corresponding to said FCW and store said second control input in memory.