Abstract: A wireless device includes an energy harvester to convert harvested energy into a harvested voltage, a first port selectively connected to an external USB power source, a second port selectively connected to a battery, a load including a plurality of circuits, and a power management circuit coupled to the energy harvester, the first and second ports, and the load. The power management circuit includes a controller configured to select one of the energy harvester, the USB power source, or the battery as a power source at system startup based on one or more of an amount of the harvested voltage, a presence of a connection with the USB power source, a presence of a connection with the battery, or an amount of charge or voltage stored by the battery. The power management circuit also includes a switcher matrix to power the load at system startup using the selected power source.

Abstract: This disclosure provides methods, devices, and systems for operational amplifier frequency compensation. The present implementations more specifically relate to techniques for dynamically calibrating the capacitance of a compensation capacitor based on the frequency at which an operational amplifier oscillates. In some aspects, an operational amplifier may include a differential input stage, a high gain stage, and a frequency compensation controller configured to operate the operational amplifier in a normal mode or a calibration mode. Compensation capacitors are switchably coupled between the outputs of the differential input stage and the outputs of the high gain stage based on the operating mode of the operational amplifier. More specifically, in the calibration mode, the coupling of the capacitors causes an output voltage of the op amp to oscillate relative to an input voltage. By contrast, in the normal mode, the coupling of the capacitors causes the output voltage to track the input voltage.

Abstract: A method for powering a wireless device includes determining a presence or absence of a USB power source connected to the wireless device, determining a presence or absence of a battery connected to the wireless device, obtaining a level of energy harvested from a surrounding environment of the wireless device, and powering a load of the wireless device using one of the USB power source, the battery, or the harvested energy based on the presence or absence of the USB power source, the presence or absence of the battery, and the harvested energy level.

Abstract: Implementations are disclosed for controlling a discontinuous mode power switching regulator to avoid specific switching frequencies by the regulator that may cause interference. A controller may be configured to operate in different modes to cause the switching regulator to energize and dump the inductor at different rates based on a frequency of requests to energize the inductor. The controller is to receive a plurality of requests to energize the inductor and generate a control signal based on the plurality of requests (with the control signal causing a first number of switching events at the switching regulator over a defined time period). The controller is to also determine whether a switching frequency of the switching regulator is an undesired switching frequency and switch from the first mode to a second mode (with the control signal generated while in the second mode causing the switching frequency of the switching regulator to change).

Abstract: A wireless device includes an energy harvester configured to convert energy harvested from radio-frequency (RF) signals into a harvested voltage, a storage capacitor to store a voltage, a first port selectively connected to an external USB power source, a second port connected to a battery, a load including a non-volatile memory storing configuration data indicating a plurality of charging configurations, and a power management circuit including a controller and a switcher matrix. The controller is configured to select one of the plurality of charging configurations based on one or more of a presence of a connection with the external USB power source, a type of the battery, an amount of the harvested voltage, or a level of the voltage stored on the storage capacitor. The switcher matrix is configured to charge the battery based on the selected charging configuration.

Abstract: A wireless device includes an energy harvester to convert harvested energy into a harvested voltage, a first port selectively connected to an external USB power source, a second port selectively connected to a battery, a load including a plurality of circuits, and a power management circuit coupled to the energy harvester, the first and second ports, and the load. The power management circuit includes a controller configured to select one of the energy harvester, the USB power source, or the battery as a power source at system startup based on one or more of an amount of the harvested voltage, a presence of a connection with the USB power source, a presence of a connection with the battery, or an amount of charge or voltage stored by the battery. The power management circuit also includes a switcher matrix to power the load at system startup using the selected power source.

Abstract: Methods and apparatus for baseband receiver circuits are disclosed. An example receiver circuit includes a first amplifier stage to receive input signals and generate intermediate signals responsive to the one or more input signals and based at least in part on one or more amplifiers, one or more capacitors, and one or more resistors of the first amplifier stage, a second amplifier stage to receive the intermediate signals and generate output signals responsive to the one or more intermediate signals based at least in part on one or more amplifiers, one or more capacitors, and one or more resistors of the second amplifier stage, and calibration logic configured to disconnect the first amplifier stage from the second amplifier stage, inject one or more first signals into at least the first amplifier stage and calibrate at least the first amplifier stage based at least in part on a frequency response of the first amplifier stage to the injected one or more first signals.

Abstract: Systems and methods for energy harvesting are disclosed. An example method is performed by a computing device coupled to an energy harvesting circuit and includes identifying a first time period required for the energy harvesting circuit to complete a first number of energy extraction events, the first time associated with an initial harvest voltage, determining a first value of an estimated extracted power based on the initial harvest voltage and the first number of energy extraction events, and iteratively adjusting the harvest voltage and determining the optimal harvest voltage based at least in part on values of the estimated extracted power value corresponding to the adjusted harvest voltage.

Abstract: Implementations are disclosed for a power switching regulator defined to be used for power harvesting but is instead configured to include an additional power rail. A switching regulator includes a first contact defined as a first power input to the switching regulator (with the first contact coupled to a first power source), a second contact defined as a second power input to the switching regulator (with the second contact defined to be coupled to a harvester), and a third contact whose output is defined as a storage voltage for harvesting. Instead of the third contact being used for outputting a storage voltage for harvesting, the third contact is coupled to a voltage (VSTORE) power rail for providing power (that may be configurable) to one or more electronic components of the electronic device (such as a CPU to perform dynamic voltage scaling or by a power amplifier sensitive to power efficiency).

Abstract: Method and apparatus for wirelessly transmitting and receiving power between devices are provided. A first device may convert power into RF energy and transmit the RF energy to a second device. In some implementations, the first device may steer the RF energy using beamforming techniques to the second device. The second device may receive and convert the RF energy into power for the second device. In some implementations, the second device may be powered solely or in part by power transmitted by the first device. In some implementations, the first device may include two or more RF energy harvesters and a power combiner. The power combiner may combine power from the two or more RF energy harvesters to power the second device and/or charge a battery.

Abstract: This disclosure provides an apparatus for receiving and demodulating a radio frequency signal with a sliding intermediate frequency (IF) receiver. The sliding IF receiver may include a local oscillator (LO) and a clock divider, and a logic block. The clock divider may be configured to generate a first divided LO signal and a second divided LO signal based on an LO signal. The logic block may be configured to generate a first composite LO signal and a second composite LO signal. The first composite LO signal may be based on the first divided LO signal and the LO signal. The second composite LO signal may be based on the second divided LO signal and the LO signal. The first and the second composite LO signals may be used to demodulate a received RF signal and generate baseband signals.

Abstract: Method and apparatus for controlling the power consumption of a wireless device are provided. A wireless device may include a configurable radio frequency (RF) front-end that may be configured to use fewer hardware stages and/or processing steps to reduce power consumption based at least in part on a signal quality, detected interference, or system information associated with a received RF signal. In some implementations, the configurable RF front-end may be configured to consume less power while receiving strong RF signals and configured to consume more power while receiving weak RF signals.

Abstract: Method and apparatus for controlling the power consumption of a wireless device are provided. A wireless device may include a configurable radio frequency (RF) front-end that may be configured to use fewer hardware stages and/or processing steps to reduce power consumption based at least in part on a signal quality, detected interference, or system information associated with a received RF signal. In some implementations, the configurable RF front-end may be configured to consume less power while receiving strong RF signals and configured to consume more power while receiving weak RF signals.

Abstract: Method and apparatus for wirelessly transmitting and receiving power between devices are provided. A first device may convert power into RF energy and transmit the RF energy to a second device. In some implementations, the first device may steer the RF energy using beamforming techniques to the second device. The second device may receive and convert the RF energy into power for the second device. In some implementations, the second device may be powered solely or in part by power transmitted by the first device. In some implementations, the first device may include two or more RF energy harvesters and a power combiner. The power combiner may combine power from the two or more RF energy harvesters to power the second device and/or charge a battery.

Abstract: Method and apparatus for wirelessly transmitting and receiving power between devices are provided. A first device may convert power into RF energy and transmit the RF energy to a second device. In some implementations, the first device may steer the RF energy using beamforming techniques to the second device. The second device may receive and convert the RF energy into power for the second device. In some implementations, the second device may be powered solely or in part by power transmitted by the first device. In some implementations, the first device may include two or more RF energy harvesters and a power combiner. The power combiner may combine power from the two or more RF energy harvesters to power the second device and/or charge a battery.

Abstract: Method and apparatus for wirelessly transmitting and receiving power between devices are provided. A first device may convert power into RF energy and transmit the RF energy to a second device. In some implementations, the first device may steer the RF energy using beamforming techniques to the second device. The second device may receive and convert the RF energy into power for the second device. In some implementations, the second device may be powered solely or in part by power transmitted by the first device. In some implementations, the first device may include two or more RF energy harvesters and a power combiner. The power combiner may combine power from the two or more RF energy harvesters to power the second device and/or charge a battery.

Abstract: Method and apparatus for generating and receiving a paging signal are provided. The paging signal may be received by a wireless device in a low-power state. The paging signal may include a target identification (ID) that may be associated with the wireless device. If the target ID is associated with the wireless device, the wireless device may leave the low-power state, enter an active power state and communicate with other wireless devices. The wireless device may include power harvesting circuitry to convert RF energy from the paging signal into power to operate a portion of the wireless device.

Abstract: Method and apparatus for generating and receiving a paging signal are provided. The paging signal may be received by a wireless device in a low-power state. The paging signal may include a target identification (ID) that may be associated with the wireless device. If the target ID is associated with the wireless device, the wireless device may leave the low-power state, enter an active power state and communicate with other wireless devices. The wireless device may include power harvesting circuitry to convert RF energy from the paging signal into power to operate a portion of the wireless device.

Abstract: Magnetic coupling of noise sources can have a negative impact on the net performance of sensitive circuits. A magnetic shielding loop can advantageously minimize magnetic coupling associated with a circuit on an integrated circuit (IC) by including on-chip components, off-chip components, and interface components connecting the on-chip and off-chip components. The components can include conductive paths and contact pads on a die, package, and printed circuit board. The magnetic shielding loop magnetically isolates at least one of input terminals and noise-generating elements of the circuit.

Abstract: Redundancies of power amplifiers (PAs) or low noise amplifiers (LNAs) at the front end of an RF device are used to reduce losses that typically occur at a diversity switch. A signal designator can advantageously be used to select designated signals, which are provided to the PAs for transmitting or provided by the LNAs during receiving.