Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include wireless transceiver circuitry that transmits signals towards an antenna. A signal path may carry the transmitted signals to the antenna. Reflected signals from the antenna may be carried along the signal path towards the transceiver circuitry. Coupler circuitry may include a forward coupler that taps the transmitted signals, a first reverse coupler that taps the reflected signals from the antenna, and a second reverse coupler that taps the reflected signals that have passed through the first reverse coupler. Analog processing circuitry and digital processing circuitry may be used to produce an impedance measurement from the tapped signals from the coupler circuitry. The analog processing circuitry may include analog signal mixers, low pass filters, and analog-to-digital converter circuitry.

Abstract: An electronic device may be provided with wireless circuitry. An application processor may generate wireless data that is to be transmitted using the wireless circuitry and may process wireless data that has been received using the wireless circuitry. The wireless circuitry may include multiple baseband processors, multiple associated radios, and front-end module and antenna circuitry. Sensors may be used to provide the application processor with sensor data. During operation, the application processor and the baseband processors may be used to transmit and receive wireless communications traffic. A multiradio controller integrated circuit that does not transmit or receive the wireless communications traffic may be used in controlling the wireless circuitry based on impedance measurements, sensor data, and other information.

Abstract: An electronic device may have control circuitry that uses a reflectometer to measure antenna impedance during operation. The reflectometer may have a directional coupler that is coupled between radio-frequency transceiver circuitry and an antenna. A calibration circuit may be coupled between the directional coupler and the antenna. The calibration circuit may have a first port coupled to the antenna, a second port coupled to the directional coupler, and a third port that is coupled to a calibration resistance. The reflectometer may have terminations of identical impedance that are coupled to ground. Switching circuitry in the reflectometer may be used to route signals from the directional coupler to a feedback receiver for measurement by the control circuitry or to ground through the terminations. Calibrated antenna reflection coefficient measurements may be used in dynamically adjusting the antenna.

Abstract: An electronic device may be provided with wireless circuitry. Control circuitry may be used to adjust the wireless circuitry. The wireless circuitry may include antennas that are tuned, adjustable impedance matching circuitry, antenna port selection circuitry, and adjustable transceiver circuitry. Wireless circuit adjustments may be made by ascertaining a current usage scenario for the electronic device based on sensor data, information from cellular base station equipment or other external equipment, signal-to-noise ratio information or other signal information, antenna impedance measurements, and other information about the operation of the electronic device.

Abstract: An electronic device may be provided with wireless circuitry. Control circuitry may be used to adjust the wireless circuitry. The wireless circuitry may include an antenna that is tuned using tunable components. The control circuitry may gather information on the current operating mode of the. electronic device, sensor data from a proximity sensor, accelerometer, microphone, and other sensors, antenna impedance information for the antenna, and information on the use of connectors in the electronic device. Based on this gathered data, the control circuitry can adjust the tunable components to compensate for antenna detuning due to loading from nearby external objects, may adjust transmit power levels, and may make other wireless circuit adjustments.

Abstract: Test systems for characterizing devices under test (DUTs) are provided. A test system for testing a DUT in a shunt configuration may include a signal generator and a matching network that is coupled between the signal generator and the DUT and that is optimized to apply desired voltage/current stress to the DUT with reduced source power. The matching network may be configured to provide matching and desired stress levels at two or more frequency bands. In another suitable embodiment, a test system for testing a DUT in a series configuration may include a signal generator, an input matching network coupled between the DUT and a first terminal of the DUT, and an output matching network coupled between the DUT and a second terminal of the DUT. The input and output matching network may be optimized to apply desired voltage/current stress to the DUT with reduced source power.

Abstract: Test systems for characterizing devices under test (DUTs) are provided. A test system for testing a DUT in a shunt configuration may include a signal generator and a matching network that is coupled between the signal generator and the DUT and that is optimized to apply desired voltage/current stress to the DUT with reduced source power. The matching network may be configured to provide matching and desired stress levels at two or more frequency bands. In another suitable embodiment, a test system for testing a DUT in a series configuration may include a signal generator, an input matching network coupled between the DUT and a first terminal of the DUT, and an output matching network coupled between the DUT and a second terminal of the DUT. The input and output matching network may be optimized to apply desired voltage/current stress to the DUT with reduced source power.

Abstract: In an embodiment, an antenna for a medical device, e.g., an implantable medical device (IMD), comprises an electrically conductive wire that spirals to form a three-dimensional shape of a rectangular cuboid. In another embodiment, the antenna comprises an electrically conductive wire that spirals to form a three-dimensional shape of an elliptical cylinder, an oval cylinder, an elongated pentagonal prism, an elongated hexagonal prism, or some other shape where the longitudinal diameter of the antenna is greater than the lateral diameter of the antenna. The antennas are sized to fit within a portion of a header of the medical device. Such antennas are designed to provide increased antenna gain and antenna bandwidth.

Abstract: In an embodiment, an antenna for a medical device, e.g., an implantable medical device (IMD), comprises an electrically conductive wire that spirals to form a three-dimensional shape of a rectangular cuboid. In another embodiment, the antenna comprises an electrically conductive wire that spirals to form a three-dimensional shape of an elliptical cylinder, an oval cylinder, an elongated pentagonal prism, an elongated hexagonal prism, or some other shape where the longitudinal diameter of the antenna is greater than the lateral diameter of the antenna. The antennas are sized to fit within a portion of a header of the medical device. Such antennas are designed to provide increased antenna gain and antenna bandwidth.

Abstract: To provide for an improvement in the communication between an external handheld programmer and an implantable pulse generator (IPG) implanted within a patient or an external pulse generator attached to the patient, an antenna of the programmer is positioned relative to the ground plane of the programmer such that when a person handholds the programmer in its predetermined intended orientation a radiation pattern produced by the antenna has substantially maximum RF radiation generally directed toward the patient, regardless whether the person that handholds the programmer is the patient or another person located near the patient.

Abstract: According to the invention, back-gating in a power FET caused by drain voltage changing rapidly from a higher voltage level to a lower voltage level is mitigated by use of a sensing FET that measures current flow whose level corresponds to the degree of back-gating. A compensation signal is generated using a voltage associated with the measure of current flow. A gate voltage is connected with a gate of the sensing FET and a gate of the power FET, wherein the gate voltage is adjusted or generated via a feedback path using the compensation signal such that the adjusted or generated gate voltage compensates against effects of back-gating. The sensing FET is located on a common substrate as the power FET.

Abstract: An amplifier circuit formed on a single semiconductor substrate includes a first amplifier having at least one stage for amplifying signals within a first frequency band; a first amplifier having at least one stage for amplifying signals within a second frequency band; and a tapped coil having one end thereof coupled to a stage of the first amplifier and a tap thereof coupled to a stage of the second amplifier. The amplifier circuit may be an RF amplifier circuit, a first portion of the tapped coil serving as an RF choke for said stage of the first amplifier, and a second portion of the tapped coil serving as an RF choke for said stage of the second amplifier. Sharing the tapped coil between multiple band amplifiers increases integration density.