Rotary traveling wave oscillators (RTWOs) with distributed stubs are provided. In certain embodiments, an RTWO includes segments that are implemented using distributed stubs to mitigate flicker noise upconversion arising from transmission line dispersion. For example, a distance between the distributed stubs can be selected to intentionally generate a phase difference between transmission line modes, thereby cancelling out phase shifts due to transmission line dispersion. In particular, each segment is subdivided into multiple transmission line sections with a maintaining amplifier electrically connected to one of the sections and a tuning capacitor array connected to adjacent transmission line sections.

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.

Certain aspects of the present disclosure generally relate to a voltage-controlled oscillator (VCO) that is configurable (e.g., in a dynamic manner) in multiple modes of operation (e.g., low/high-band modes). The VCO may include a resonant circuit coupled to a plurality of switches that may be used to adjust current flow within one or more inductive elements of the resonant circuit. By adjusting the current flow within the inductive elements, an inductance of the resonant circuit may be adjusted, which in turn adjusts a band of the VCO.

There is disclosed herein clock generation circuitry, in particular rotary travelling wave oscillator circuitry. Such circuitry comprises a pair of signal lines connected together to form a dosed loop and arranged such that they define at least one transition section where both said lines in a first portion of the pair cross from one lateral side of both said lines in a second portion of the pair to the other lateral side of both said lines in the second portion of the pair.

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.

Rotary traveling wave oscillator-based (RTWO-based) frequency multipliers are provided herein. In certain embodiments, an RTWO-based frequency multiplier includes an RTWO that generates a plurality of clock signal phases of a first frequency, and an edge combiner that processes the clock signal phases to generate an output clock signal having a second frequency that is a multiple of the first frequency. The edge combiner can be implemented as a logic-based combining circuit that combines the clock signal phases from the RTWO. For example, the edge combiner can include parallel stacks of transistors operating on different clock signal phases, with the stacks selectively activating based on timing of the clock signal phases to generate the output clock signal of multiplied frequency.

Rotary traveling wave oscillator-based (RTWO-based) frequency multipliers are provided herein. In certain embodiments, an RTWO-based frequency multiplier includes an RTWO that generates a plurality of clock signal phases of a first frequency, and an edge combiner that processes the clock signal phases to generate an output clock signal having a second frequency that is a multiple of the first frequency. The edge combiner can be implemented as a logic-based combining circuit that combines the clock signal phases from the RTWO. For example, the edge combiner can include parallel stacks of transistors operating on different clock signal phases, with the stacks selectively activating based on timing of the clock signal phases to generate the output clock signal of multiplied frequency.

In example embodiments, an RF-to-DC converter includes one or more unit cells that integrate a spintronic element (e.g., a magnetic tunnel junction (MTJ)) into a conductor ring RF energy absorber (e.g., a split-ring resonator (SRR)). A RF-to-DC converter that includes one or more MTJ-integrated SRR unit cells may provide compactness, as each unit cell includes its own independent SRR and integrated MTJ; scalability, as multiple unit cells may be connected into an array to increase DC power output; and energy harvesting efficiency, as a MTJ may be much more sensitive than a Schottky diode and the SRR of each unit cell may directly feed energy to a MTJ without impedance matching circuits.

The present invention relates to a radiofrequency oscillator comprising an optical resonator being a ring waveguide allowing the propagation of a first wave in a first direction and of a second wave in a second direction, the second direction being opposite to the first direction, and the resonator comprising an active optical medium generating a first optical line from the first wave and a second optical line from the second wave, the resonator being in contact with a part made of a material featuring a magneto-optic effect, an applier of external magnetic field of adjustable intensity on the resonator generating a frequency offset between the first wave and the second wave, and a processing circuit converting the beat between the two optical lines in a radiofrequency signal.

Rotary traveling wave oscillators (RTWOs) with distributed stubs are provided. In certain embodiments, an RTWO includes segments that are implemented using distributed stubs to mitigate flicker noise upconversion arising from transmission line dispersion. For example, a distance between the distributed stubs can be selected to intentionally generate a phase difference between transmission line modes, thereby cancelling out phase shifts due to transmission line dispersion. In particular, each segment is subdivided into multiple transmission line sections with a maintaining amplifier electrically connected to one of the sections and a tuning capacitor array connected to adjacent transmission line sections.