Abstract: Apparatus and methods for control and calibration of external oscillators are provided herein. In certain embodiments, an electronic oscillator system includes a semiconductor die and a controllable oscillator that is external to the semiconductor die. The oscillation frequency of the controllable oscillator is tuned by a first varactor and a second varactor. The semiconductor die includes a phase-locked loop (PLL) that provides fine tuning to the controllable oscillator by controlling the first varactor, and a calibration circuit that provides coarse tuning to the controllable oscillator by controlling the second varactor.

Abstract: Aspects of this disclosure relate to a segmented receiver for a wireless communication system. The segmented receiver includes a first receiver segment and a second receiver segment configured to receive respective radio frequency signals. The radio frequency signals can be orthogonally polarized. Branch circuits in each receiver segment can provide a radio frequency signal to different mixers. The different mixers can be included in different receiver segments and receive local oscillator signals from independent local oscillators. Each receiver segment can process a different bandwidth of the radio frequency signal. Two different bandwidths of the radio frequency signal can be processed concurrently by different receiver segments.

Abstract: 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.

Abstract: 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.

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: Aspects of this disclosure relate to a segmented receiver for a wireless communication system. The segmented receiver includes a first receiver segment and a second receiver segment configured to receive respective radio frequency signals. The radio frequency signals can be orthogonally polarized. Branch circuits in each receiver segment can provide a radio frequency signal to different mixers. The different mixers can be included in different receiver segments and receive local oscillator signals from independent local oscillators. Each receiver segment can process a different bandwidth of the radio frequency signal. Two different bandwidths of the radio frequency signal can be processed concurrently by different receiver segments.

Abstract: Aspects of this disclosure relate to a segmented receiver for a wireless communication system. The segmented receiver includes a first receiver segment and a second receiver segment configured to receive respective radio frequency signals. The radio frequency signals can be orthogonally polarized. Branch circuits in each receiver segment can provide a radio frequency signal to different mixers. The different mixers can be included in different receiver segments and receive local oscillator signals from independent local oscillators. Each receiver segment can process a different bandwidth of the radio frequency signal. Two different bandwidths of the radio frequency signal can be processed concurrently by different receiver segments.

Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, an RTWO includes a differential transmission line connected in a ring and a plurality of segments distributed around the ring. The segments include metal stubs extending from the RTWO's differential transmission line. The metal stubs aid in providing access to additional layout resources for tuning capacitors and other circuitry of the RTWO's segments, while permitting the length of RTWO's ring to be relative short. Thus, the metal stubs do not inhibit the RTWO from operating with relatively high oscillation frequency, while providing connectivity to tuning capacitors that tune the RTWO's oscillation frequency over a wide tuning range and/or provide fine frequency step size.

Abstract: Aspects of this disclosure relate to a segmented receiver for a wireless communication system. The segmented receiver includes a first receiver segment and a second receiver segment configured to receive respective radio frequency signals. The radio frequency signals can be orthogonally polarized. Branch circuits in each receiver segment can provide a radio frequency signal to different mixers. The different mixers can be included in different receiver segments and receive local oscillator signals from independent local oscillators. Each receiver segment can process a different bandwidth of the radio frequency signal. Two different bandwidths of the radio frequency signal can be processed concurrently by different receiver segments.

Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, an RTWO includes a differential transmission line connected in a ring and a plurality of segments distributed around the ring. The segments include metal stubs extending from the RTWO's differential transmission line. The metal stubs aid in providing access to additional layout resources for tuning capacitors and other circuitry of the RTWO's segments, while permitting the length of RTWO's ring to be relative short. Thus, the metal stubs do not inhibit the RTWO from operating with relatively high oscillation frequency, while providing connectivity to tuning capacitors that tune the RTWO's oscillation frequency over a wide tuning range and/or provide fine frequency step size.

Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, an RTWO includes a differential transmission line connected in a ring and a plurality of segments distributed around the ring. The segments include metal stubs extending from the RTWO's differential transmission line. The metal stubs aid in providing access to additional layout resources for tuning capacitors and other circuitry of the RTWO's segments, while permitting the length of RTWO's ring to be relative short. Thus, the metal stubs do not inhibit the RTWO from operating with relatively high oscillation frequency, while providing connectivity to tuning capacitors that tune the RTWO's oscillation frequency over a wide tuning range and/or provide fine frequency step size.

Abstract: Apparatus and methods for frequency tuning of rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, distributed quantized tuning is used to tune a frequency of the RTWO. The RTWO includes a plurality of segments distributed around the RTWO's ring, and the segments include tuning capacitors and other circuitry. The distributed quantized frequency tuning is used to control the tuning capacitors in the RTWO's segments using separately controllable code values, thereby enhancing the RTWO's frequency step size or resolution. Moreover, in configurations including multiple RTWO rings that are locked to one another to reduce phase noise, the distributed quantized frequency tuning can be used to separately set the tuning capacitors across multiple RTWO rings that are coupled to one another.

Abstract: Apparatus and methods for frequency tuning of rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, distributed quantized tuning is used to tune a frequency of the RTWO. The RTWO includes a plurality of segments distributed around the RTWO's ring, and the segments include tuning capacitors and other circuitry. The distributed quantized frequency tuning is used to control the tuning capacitors in the RTWO's segments using separately controllable code values, thereby enhancing the RTWO's frequency step size or resolution. Moreover, in configurations including multiple RTWO rings that are locked to one another to reduce phase noise, the distributed quantized frequency tuning can be used to separately set the tuning capacitors across multiple RTWO rings that are coupled to one another.

Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, an RTWO includes a differential transmission line connected in a ring and a plurality of segments distributed around the ring. The segments include metal stubs extending from the RTWO's differential transmission line. The metal stubs aid in providing access to additional layout resources for tuning capacitors and other circuitry of the RTWO's segments, while permitting the length of RTWO's ring to be relative short. Thus, the metal stubs do not inhibit the RTWO from operating with relatively high oscillation frequency, while providing connectivity to tuning capacitors that tune the RTWO's oscillation frequency over a wide tuning range and/or provide fine frequency step size.

Abstract: Apparatus and methods are disclosed related to tuning a resonant frequency of an LC circuit. In some implementations, the LC circuit can be embodied in a low noise amplifier (LNA) of a receiver. The receiver can include a component configured to generate an indicator of received signal strength indication (RSSI) of a radio frequency (RF) signal received by the receiver. A control block can adjust the resonant frequency of the LC circuit based at least in part on the indicator of RSSI. As another example, the receiver can include an oscillator, such as a VCO, separate from the LC circuit that can be used to tune the resonant frequency of the LC circuit. These apparatus can compensate for variation in a zero imaginary component of an impedance across the LC circuit.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO having a tuning voltage input and a frequency tuning circuit configured to set a frequency band setting of the VCO. The frequency tuning circuit can include a voltage monitor configured to compare the voltage level of the tuning voltage input to one or more tuning voltage threshold levels, a control circuit configured to control at least a frequency band setting and a bias current setting of the VCO, and an amplitude detection circuit configured to compare an amplitude of an oscillation signal of the VCO to one or more amplitude threshold levels.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO and a calibration voltage generation circuit that can generate a calibration voltage for controlling a tuning voltage input of the VCO when the VCO is being coarsely tuned. Additionally, the calibration voltage generation circuit can sense a temperature of the PLL, and can control a voltage level of the calibration voltage to provide compensation based on the sensed temperature. The calibration voltage generation circuit can include a bandgap reference circuit configured to generate a zero-to-absolute-temperature (ZTAT) current and a proportional-to-absolute temperature (PTAT) current, and the calibration voltage can be generated based in part on a difference between the PTAT current and the ZTAT current.

Abstract: One aspect of this disclosure is an apparatus including an oscillator that includes a secondary LC circuit to increase a tuning range of the oscillator and/or to reduce a phase noise of the oscillator. Another aspect of this disclosure is an apparatus that includes oscillator with a primary LC circuit and a secondary LC circuit. This oscillator can operate in a primary oscillation mode or a secondary oscillation mode, depending on whether oscillation is set by the primary LC circuit or the secondary LC circuit.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO having a tuning voltage input and a frequency tuning circuit configured to set a frequency band setting of the VCO. The frequency tuning circuit can include a voltage monitor configured to compare the voltage level of the tuning voltage input to one or more tuning voltage threshold levels, a control circuit configured to control at least a frequency band setting and a bias current setting of the VCO, and an amplitude detection circuit configured to compare an amplitude of an oscillation signal of the VCO to one or more amplitude threshold levels.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO and a calibration voltage generation circuit that can generate a calibration voltage for controlling a tuning voltage input of the VCO when the VCO is being coarsely tuned. Additionally, the calibration voltage generation circuit can sense a temperature of the PLL, and can control a voltage level of the calibration voltage to provide compensation based on the sensed temperature. The calibration voltage generation circuit can include a bandgap reference circuit configured to generate a zero-to-absolute-temperature (ZTAT) current and a proportional-to-absolute temperature (PTAT) current, and the calibration voltage can be generated based in part on a difference between the PTAT current and the ZTAT current.