Epcos Ag

Qualcomm Incorporated

Nxp B.v.

U.S. Philips Corporation

Qualcomm Technologies, Inc.

Adrianus Van Bezooijen

Maurice Adrianus De Jongh

Erwin Spits

Christophe Chanlo

Kevin Robert Boyle

Francesco Gatta

John Joseph Hug

Dmitry Pavlovich Prikhodko

Hakan Inanoglu

Evert D Van Veldhuizen

David Loweth Winslow

Jacobus Govert Sneep

Marc Victor Arends

Leon Metreaud

Ronald Koster

Dmitri Pavlovitch Prikhodko

Hermana Wilhelmina Hendrika De Groot

Robbin Damen

Maurice De Jongh

Dmitri P Prikhodko

A user equipment (UE) is provided that detunes a receive antenna while a transmit antenna transmits. To determine the detuning, the UE first transmits a signal through the transmit antenna while the receive antenna is sequentially coupled through known loads. At each load, the UE determines an input reflection coefficient for a transmit path to the transmit antenna. Based upon the known loads and the corresponding input reflection coefficients, the UE determines a load to couple to the receive antenna to perform the detuning.

Computation-based detuning of coupled antennas

A user equipment (UE) is provided that includes an antenna switch array for demultiplexing a reference signal sequentially to each antenna in a plurality of antennas. While the antenna switch array selects an antenna, the UE measures a reflection coefficient for the antenna. The UE then tunes the antenna responsive to the reflection coefficient measurement.

Antenna impedance detection and tuning

A wireless communication device is provided with an in-device capability of characterizing the coupling between a pair of antennas. The wireless communication device determines the coupling through an operating gain measurement and through calibration gain measurements obtained through test ports.

In-device characterization of antenna coupling

An apparatus includes a radio-frequency (RF) path that includes an antenna tuner. The apparatus also includes calibration circuitry coupled to the antenna tuner. The calibration circuitry is configured to selectively isolate an antenna from a component of the RF path.

Calibration and adaptive control of antenna tuners

An impedance detector includes a sensing circuit with an adjustable impedance. The sensing circuit is coupled to a signal path. Further, an evaluation circuit is coupled to the sensing circuit.

Multi-band impedance detector

A cheaper to produce, smaller and easy to drive adaptive antenna module is presented. The module comprises a signal path, an antenna, and a tuning circuit with two variable impedance elements. The tuning circuit operates over a restricted range of impedances and maintains the series resonance characteristic of the antenna.

Adaptive antenna module

An adjustable impedance matching network for providing an adjustable matching impedance (Rm) is presented. The matching network includes first and second impedance adjusting circuits. The first impedance adjusting circuit is adapted to adjust the value of an imaginary part of the matching impedance while substantially maintaining the value of a real part of the matching impedance based on frequency information frequency and a target reference value. The second impedance adjusting circuit is adapted to adjust the value of an imaginary part of the matching impedance to be substantially equal to zero based on the frequency information, so as to adjust the real part of the matching impedance to be substantially equal to the target reference value.

Adaptive impedance matching network

An impedance matching network includes an impedance matching circuit for dynamically matching an impedance between a source and a load. Matching is done by varying the real part and the imaginary part of the impedance of the impedance matching circuit independently.

Dynamic impedance matching network and method for matching an impedance between a source and a load

A device includes a matching stage coupled between a first signal terminal and a second signal terminal. A signal path extends between the first signal terminal and the second terminal. An adjustable impedance element is connected to the signal path. A detection circuit is coupled to the signal path and configured to derive matching information. A control circuit is coupled between the detection circuit and the adjustable impedance element. The control circuit is configured to control the adjustable impedance element.

Device comprising a controlled matching stage

According to the general concept disclosed herein, a circuit for adaptive matching of a load impedance to a predetermined load-line impedance of a load-line connected to a power amplifier output includes a fixed matching network between the power transistor and an adaptive matching network, whereby the fixed matching network acts as an impedance inverter which results in a relatively low insertion loss at high power. Results indicate that the impedance-inverting network can be used over more than a factor of 10 in impedance variation. Further, the usage of the fixed matching network, close to the power transistor, allows for the implementation of transmission zeros and/or for a well defined load impedance at a predetermined harmonic frequency, independent of the (variable) load impedance at the fundamental frequency.

Load-line adaptation

The invention relates to an antenna which is coupled to an RF amplifier. Environmental conditions change the impedance of the antenna, which reduces output power, efficiency and linearity. A circuit is provided which is designed to detect the impedance of the antenna. With the measured impedance, impedance matching can be accomplished. The circuit for detecting the impedance detects the signal travelling from the RF amplifier to the antenna, and measures the peak voltage and the peak current of this signal. Furthermore, the phase difference between the voltage and the current is measured. The advantage of the circuit is its compactness allowing for an easy integration on a chip. Furthermore, an impedance matching circuit is suggested which makes use of the above circuit for detecting the impedance.

Circuit for detecting a magnitude and phase of an impedance of a load

A communications circuit processes a signal in at least one predetermined communications standard such as GSM or UMTS. A switched capacitor impedance matching unit is provided, controlled by driver control unit. The driver control unit is arranged to control the driver to start switching of the capacitors of the switched capacitor array during transition periods in the signals.

MEMS capacitor circuit and method

Device () comprising controlled matching stages () for matching second stages such as antenna stages () to first stages such as power amplifier stages () get a simple construction by providing the controlled matching stages () with deriving means () for deriving first signals and second signals from output signals of the first stages, with detecting means () for detecting phases between the first signals and the second signals, and with controlling means () for controlling adjustable impedance networks () in response to said detecting for said matching. The deriving means () comprise elements () such as passive elements such as inductors and capacitors, with the first signals being the output signals and the second signals being derived via the elements (). The detecting means () comprise phase detectors (-) made of first and second limiters () for limiting the first and second signals and mixers () for mixing the limited first and second signals. The controlling means () comprise analog-to-digital converters () such as limiters and digital circuits () such as up-down counters.

A current limiting circuit, especially for an RF power amplifier (PA) having a power control loop. The circuit is adapted to sense a representation of a bias current fed to a final stage of the PA. The sensed representation of the bias current is compared to a predetermined reference current and a signal is fed back to the power control loop upon the sensed representation of the bias current exceeding the reference current so as to limit output current of the PA. This provides a limitation of a current drawn by the PA which is generally insensitive to supply voltage and temperature variations. Optionally, a second circuit may be added to limit current drawn by the PA. The second circuit comprising a high accuracy VI converter that is adapted to compare a voltage VLIM representing a feed-back voltage of the power control loop and a predetermined reference voltage VBGAP. The circuit is operatively connected to the VI converter so as to reduce the output current lout upon the voltage VLIM representing the feed-back voltage exceeding the predetermined reference voltage VBGAP. Under antenna mismatch conditions both circuits help to limit a supply current drawn by the PA compared to prior art power control loops that are unable to detect and limit a high current draw under mismatch conditions.

Current limiting circuit for RF power amplifier

The invention refers to a circuit and a method for detecting the impedance of a load, whereby the circuit and the method can be used by an impedance matching circuit. Impedance matching circuits need a complex algorithm to adjust the impedance accordingly. This algorithm renders the response time to be long. It has been found out that the complexity partially stems from the fact that the phase of the reflection coefficient is not known over the full range of 0&#xb0; to 360&#xb0;. A quadrature phase detector is used to provide the full phase information.

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Molenhoek, Netherlands

Adrianus Van Bezooijen