A capless impedance tuner can include first node and second nodes, a first series path, a second series path, and an inductance path, each between the first node and the second node and including a switch to allow the path to couple or uncouple the first and second nodes. Each series path can be configured to allow a substantially continuous flow of a direct current between the first node and the second node when coupled. The tuner can further include a shunt path with a switch to allow coupling or uncoupling of the second node and ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

Disclosed is an authentication reader intended to be installed on a motor vehicle opening element, the reader including a microcontroller, at least one transmitter, at least one matching circuit and a single antenna, called primary antenna, characterized by a working frequency. The matching circuit includes switching element able to switch the matching circuit between a first mode, in which the matching circuit makes it possible to match the primary antenna to a secondary antenna of an authentication device whose resonant frequency is lower than the working frequency, and a second mode, in which the matching circuit makes it possible to match the primary antenna to a secondary antenna of an authentication device whose resonant frequency is higher than the working frequency.

Disclosed is an authentication reader intended to be installed on a motor vehicle opening element, the reader including a microcontroller, at least one transmitter, at least one matching circuit and a single antenna, called primary antenna, characterized by a working frequency. The matching circuit includes switching element able to switch the matching circuit between a first mode, in which the matching circuit makes it possible to match the primary antenna to a secondary antenna of an authentication device whose resonant frequency is lower than the working frequency, and a second mode, in which the matching circuit makes it possible to match the primary antenna to a secondary antenna of an authentication device whose resonant frequency is higher than the working frequency.

An antenna impedance tuner can include first and second nodes, a bypass path, first and second series capacitance paths, and an inductance path, with each path being implemented between the first and second nodes and including a switch configured to allow the path to couple or uncouple the first and second nodes. The tuner can further include first and second shunt paths, with each shunt path being implemented between the second node and ground and including a switch configured to allow the shunt path to couple or uncouple the second node and the ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

A local oscillator frequency-based proximity sensor is disclosed. The proximity sensor includes: an integrated circuit having at least a capacitive element; and an antenna designed with an inductive element; wherein the capacitive element and the inductive element form a proximity sensor oscillating at a local oscillator (LO) frequency, wherein the integrated circuit is configured to measure a frequency offset from the LO frequency, wherein the frequency offset is indicative of a detection of a nearby object.

An antenna's resonance frequency is detuned when a part of a human body approaches or contacts the antenna and consequently results in efficiency loss. The antenna may be tuned by changing its total load capacitance such that the antenna's total load capacitance falls within a reference capacitance range of a reference capacitance, where the antenna can operate at or near its pre-determined operating resonance frequency. A tunable capacitor may be coupled to the antenna for tuning the total load capacitance of the antenna.

A system, method and computer readable medium are provided. One system includes a transmit antenna, at least one receive antenna, and a controller configured to operate the transmit antenna and the at least one receive antenna to acquire coupled signal information from a device under test. The system also includes a processor configured to approximate a shape of a structure within the device under test using changes in resonance determined from the coupled reflected signal information and caused by different materials forming the structure.

In one embodiment, a phase detection circuit includes a current signal input to receive a current signal indicative of a current amplitude of an RF signal and a voltage signal input to receive a voltage signal indicative of a voltage amplitude of the RF signal. A high-pass filter and a low-pass filter are each configured to filter one of (i) the current signal from the current signal input or (ii) the voltage signal from the voltage signal input, wherein the high-pass filter and the low-pass filter collectively cause a substantially 90 degree offset between a phase angle of the current signal and a phase angle of the voltage signal. A phase difference circuit receives the filtered current signal and the filtered voltage signal to determine a phase angle difference between the current signal and the voltage signal.

A multiport RF switch assembly with integrated impedance tuning capability is described that provides a single RFIC solution to switch between transmit and receive paths in a communication system. Dynamic tuning is integrated into each switch sub-assembly to provide the capability to impedance match antennas or other components connected to the multiport switch. The tuning function at the switch can be used to shape the antenna response to provide better filtering at the switch/RF front-end (RFFE) interface to allow for reduced filtering requirements in the RFFE. Memory is designed into the multiport switch assembly, allowing for a look-up table or other data to reside with the switch and tuning circuit. The resident memory will result in easier integration of the tunable switch assembly into communication systems.

A galvanically isolated switch system and method comprising a plurality of switches having at least one terminal in series electrical connection, at least one control input electrically connected to at least one of the plurality of switches, wherein the at least one control input is isolated from direct current voltages and at least one passive component connected across the plurality of switches.