Abstract: A battery management circuit and method for managing a power supply and one or more battery strings includes a current sensing circuit and a battery measurement circuit. The current sensing circuit is configured to: receive a current signal from at least one of the battery strings at a first terminal of the current sensing circuit; measure a magnitude of the current signal; and provide a current sensing signal indicative of the magnitude of the current signal at a third terminal of the current sensing circuit. The battery measurement circuit is configured to: receive a current sensing signal at a third terminal of the battery management circuit; measure one or more characteristics of the at least one of the battery strings; and provide a power supply control signal at a first terminal of the battery measurement circuit.

Abstract: A battery management circuit and method for managing a power supply and one or more battery strings includes a current sensing circuit and a battery measurement circuit. The current sensing circuit is configured to: receive a current signal from at least one of the battery strings at a first terminal of the current sensing circuit; measure a magnitude of the current signal; and provide a current sensing signal indicative of the magnitude of the current signal at a third terminal of the current sensing circuit. The battery measurement circuit is configured to: receive a current sensing signal at a third terminal of the battery management circuit; measure one or more characteristics of the at least one of the battery strings; and provide a power supply control signal at a first terminal of the battery measurement circuit.

Abstract: A circuit includes a power supply configured to generate a supply voltage, an electrical load coupled to receive the supply voltage from the power supply, and a switching circuit. The switching circuit has a first terminal coupled to a first terminal of the electrical load, a second terminal, and a control terminal. The first terminal and the second terminal of the switching circuit correspond to current conducting terminals of the switching circuit. The circuit also includes a current sensing circuit and at least one battery having a first terminal coupled to a corresponding terminal of the current sensing circuit. The circuit additionally includes a battery measurement circuit having a first terminal coupled to the control terminal of the switching circuit and at least a second terminal coupled to the first terminal and a second terminal opposing the first terminal of the at least one battery.

Abstract: A circuit includes a power supply configured to generate a supply voltage, an electrical load coupled to receive the supply voltage from the power supply, and a switching circuit. The switching circuit has a first terminal coupled to a first terminal of the electrical load, a second terminal, and a third, control terminal. The first and second terminals of the switching circuit correspond to current conducting terminals of the switching circuit. The circuit also includes a current sensing circuit and at least one battery having a first terminal coupled to a corresponding terminal of the current sensing circuit. The circuit additionally includes a battery measurement circuit having a first terminal coupled to the control terminal of the switching circuit and at least a second terminal coupled to first and second opposing terminals of the at least one battery.

Abstract: An envelope tracking power amplifier uses signal cancellation techniques to provide isolation between RF signals and envelope signals, without the use of filters. In this manner, the envelope tracking power amplifiers are capable of operating with envelope signals that are at or near the frequency of the corresponding RF signals. In at least one embodiment, a double balanced power amplifier is provided that includes a balanced RF input port, a balanced RF output port, and a balanced envelope input port. The balanced nature of the amplifier results in ports of the amplifier forming virtual grounds with respect to signals at other ports. In some other embodiments, a single balanced amplifier is provided that provides isolation between ports thereof.

Abstract: A drain modulator circuit for operation with a radio frequency (RF) amplifier, includes a pair of AC signal sources each of the AC signal sources having an output at which an AC signal is provided. The drain modulator circuit further includes a pair of tapped delay elements, each of which is configured to receive an AC signal from a respective one of the AC signal sources and a control element coupled to provide one or more control signals to the pair of tapped delay elements such that the tapped delay elements provide a selected instantaneous differential voltage to the RF amplifier.

Abstract: A radio frequency (RF) switch circuit includes switching devices coupled at a common node and a floating control signal circuit (CSS) coupled to the control electrodes of the switching devices and the common node and configured to isolate RF signals from the CSS and configured to provide differential voltage signals to the common node and each of the control electrodes.

Abstract: A drain modulator circuit for operation with a radio frequency (RF) amplifier, includes a pair of AC signal sources each of the AC signal sources having an output at which an AC signal is provided. The drain modulator circuit further includes a pair of tapped delay elements, each of which is configured to receive an AC signal from a respective one of the AC signal sources and a control element coupled to provide one or more control signals to the pair of tapped delay elements such that the tapped delay elements provide a selected instantaneous differential voltage to the RF amplifier.

Abstract: A radio frequency (RF) switch circuit includes switching devices coupled at a common node and a floating control signal circuit (CSS) coupled to the control electrodes of the switching devices and the common node and configured to isolate RF signals from the CSS and configured to provide differential voltage signals to the common node and each of the control electrodes.

Abstract: An RF shielded enclosure that is configurable for a variety of testing requirements, yet still maintain proper RF isolation. User-installable modules that are specialized for the desired interface, ventilation or monitoring use can be installed on the enclosure to allow interfacing between a device under test installed inside the chamber and testing and controlling equipment outside the enclosure. The enclosure is easy to manufacture as a one or multi-chamber enclosure, allowing further flexibility for testing.

Abstract: A system and method for testing wireless devices in a simulated a wireless environment is provided. RF modules for creating and receiving RF signals in a test environment are also provided. Features include RF isolation of a wireless device, including filtering signals on electrical paths to and from the device, and circuits to reduce undesired RF signals on such electrical paths, for example PCI bus paths. The system and method also include a test enclosure with isolation chambers with filtered electrical signal paths to allow testing of wireless devices inserted into the isolation chambers. This system and method also allows controlled testing of antennae diversity features of the wireless device.