Abstract: In one form, an integrated receiver includes a tracking bandpass filter, a tunable lowpass filter, and a mixer formed on a single integrated circuit chip. The tracking bandpass filter has an input for receiving a radio frequency (RF) input signal, and an output, and comprises a variable capacitor having a capacitance that varies in response to a bandpass frequency control signal, in parallel with an integrated inductor. The integrated inductor comprises a plurality of windings formed in a plurality of metal layers. The tunable lowpass filter has an input coupled to the output of the tracking bandpass filter, and an output and having a tuning input for receiving a cutoff frequency signal. The mixer has a signal input coupled to the output of the tunable lowpass filter, a local oscillator input for receiving a local oscillator signal, and a signal output for providing a converted RF signal.

Abstract: A radio-frequency (RF) device for a wireless communication device includes a grounding element, an antenna, a first DC blocking element for cutting off a direct-current (dc) signal route between a grounding terminal of the antenna and the grounding element, a capacitive sensing unit capable of using a radiating element of the antenna to sense an environment capacitance within a specific range, a second DC blocking element electrically connected between the radiating element and the feed-in element for blocking a dc signal path from the radiating element to the feed-in element, and a high-frequency blocking element electrically connected between the radiating element and the capacitive sensing unit for blocking a high-frequency signal path from the radiating element to the capacitive sensing unit.

Abstract: A down-conversion circuit for a receiver circuit is disclosed, the down-conversion circuit comprises a first passive switching mixer arranged to down-convert a received radio frequency, RF, signal with a first local oscillator, LO, signal (LO1) having a first duty cycle for generating a first down-converted signal at an output port of the first passive switching mixer. The down-conversion circuit further comprises a second passive switching mixer arranged to down-convert the received RF signal with a second LO signal (LO2) having the same LO frequency as the first LO signal (LO1) and a second duty cycle, different from the first duty cycle, for generating a second down-converted signal at an output port of the second passive switching mixer.

Abstract: A RFID transponder includes a resonant circuit for providing a clock signal at a predetermined clock frequency, a self-calibration stage for calibrating the resonant circuit's current clock frequency towards the predetermined clock frequency. The self-calibration stage is adapted to compare a first clock frequency of the resonant circuit determined during an interrogation period, during which the resonant circuit is excited by an external RF signal, with a second clock frequency determined during a frequency maintenance period, during which the resonant circuit is excited internally through an oscillation maintenance circuit of the RFID transponder and to calibrate the resonant circuit towards the predetermined clock frequency based on the comparison result.

Abstract: A novel digitally controlled antenna tuning circuit that enables the implementation of low cost, wideband tuning circuits for antennas in receive applications. The invention is operative to switch a plurality of tuning elements into and out of a main receive signal path. Each individual tuning element is switched into or out of the receive signal path using a single PIN diode. For series connected tuning elements, the diode is connected in parallel to the tuning element. For tuning elements connected in parallel, the diode is connected in series with the tuning element. The diodes are switched in accordance with control voltages which forward bias the diodes to effectively create a low resistance path thus either inserting or removing a tuning element from the receive signal path depending on its configuration in the circuit.

Abstract: An oscillator circuit having a source of an oscillating signal, a tank circuit including an inductor and a capacitor, and a discretely switchable capacitance module configured to control an amount of capacitance in the oscillator circuit. The discretely switchable capacitance module includes, in one embodiment, a capacitor coupled between a first node and a second node, a switch, having a control node, coupled between the second node and a third node; and a DC feed circuit, having a first end coupled to the second node and a second end configured to receive a first or second control signal. The control node of the switch is tied to a predetermined bias voltage. When the first control signal is applied, the capacitor is coupled between the first node and the third node via the switch such that the capacitor is coupled in parallel with the capacitor of the tank circuit, and when the second control signal is applied the capacitor is decoupled from the tank circuit.

Abstract: Disclosed herein is a signal receiving apparatus including: a resonance section configured to receive an input signal at a variable resonance frequency; a signal supplying section configured to supply an electrical signal having a desired reception frequency to the resonance section; a mixture section configured to mix a resonance signal, which is output by the resonance section when the resonance section receives the electrical signal from the signal supplying section, with a switching signal having the desired reception frequency; and a control section configured to change a resonance characteristic of the resonance section and measure the phases of mixed signals output by the mixture section before and after the resonance characteristic changing operation to control the resonance frequency of the resonance section in order to change the resonance frequency in a direction to reduce a difference between the phases of the mixed signals before and after the resonance characteristic changing operation.

Abstract: Systems, devices and methods are provided to switch between transmit and receive modes in wireless hearing aids. One aspect relates to an apparatus for use within a communication system that has an inductive coil connected to a tuning capacitor at a node. An amplifier is connected to the node through a DC blocking capacitor to receive an induced signal in the inductive coil in a receive mode. A driver energizes the inductive coil with a driven signal in a transmit mode. According to various embodiments, the apparatus transforms the inductive coil, the tuning capacitor and the DC blocking capacitor into an equivalent series resonant circuit to reduce an inductive load in the transmit mode, and transforms the inductive coil, the tuning capacitor and the DC blocking capacitor into an equivalent parallel resonant circuit to increase an inductive load in the receive mode.

Abstract: In a transmitting arrangement a power amplifier is coupled to a radio-frequency antenna arrangement via a controllable matching apparatus. This allows direct impedance transformation of the output of the power amplifier to the input of the radio-frequency antenna arrangement. There is no need for transformation to the 50 ohm standard. The power amplifier, matching apparatus and a control circuit for controlling the impedance of the matching apparatus form a functional unit, which is advantageously in the form of a monolithically integrated structure in a semiconductor body. A receiving arrangement is produced in the same way, comprising an antenna, a filter device and a matching apparatus connected between them.

Abstract: A resonator system and method are provided which includes/uses a tunable reference resonator, parts for tuning the reference resonator to a reference value via a controlled variable for the reference resonator, a tunable circuit resonator, and parts for tuning the circuit resonator which are designed such that the controlled variable for the reference resonator is used as a measure of the tuning of the circuit resonator, and wherein the reference resonator and/or the circuit resonator is/are designed as a surface acoustic wave component, a bulk acoustic wave component and/or a diaphragm oscillator.

Abstract: When changeover switch (26) selects the output of L band filter (23), changeover switch (28) is turned off and mixer (29) is operated as an amplifier such that the oscillation frequency of local oscillator (31) is controlled based on data fed to data terminal (37) and a channel selection can be performed in mixer (32). When changeover switch (26) selects the output of V band filter (25), changeover switch (28) is turned on and a channel selection is performed based on data fed to data terminal (37) in mixer (29). With this arrangement, the need for a tuning filter is eliminated and a broadband tuner not requiring manpower for adjustments can be provided.

Abstract: Herein disclosed is a broadcast wave receiving apparatus, comprising: first and second tuning circuits each having a resonance frequency; first controlling means for controlling one of the first and second tuning circuits to ensure that the resonance frequency of one of the first and second tuning circuits is tuned to a specific frequency before allowing one of the first and second tuning circuits to detect a broadcast wave at the specific frequency; judging means for judging whether or not to receive the broadcast wave detected by one of the first and second tuning circuits on the basis of predetermined threshold information on the broadcast waves; and second controlling means for controlling the other of the first and second tuning circuits to ensure that the resonance frequency of the other of the first and second tuning circuits is tuned to the specific frequency before allowing the other of the first and second tuning circuits to produce a broadcast signal indicative of the broadcast wave detected by one

Abstract: An apparatus in accordance with one embodiment of the present invention may include a local oscillator having an electroacoustic resonator; and zero intermediate frequency signal processing circuitry coupled to the local oscillator. In certain embodiments, the electroacoustic oscillator may be a thin film bulk acoustic resonator.

Abstract: An unconditionally stable on-chip filter includes a filtering section and at least one negative resistance module. The filtering section is operably coupled to filter a signal and includes realizable integrated circuit passive components. The at least one negative resistance module is operably coupled to compensate for integrated circuit losses of the filtering section. The realizable integrated circuit passive components have values that are robust, in comparison to parasitic values, have minimal integrated circuit real estate, and provide realizable values for various integrated circuit manufacturing processes including CMOS technology.

Abstract: A tuner includes a tunable filter for selecting a desired RF signal in response to a tuning control signal and a tunable image trap for rejecting the undesired image signal corresponding to the desired RF signal responsive to the tuning control signal coupled in cascade between an RF amplifier and a mixer. The tunable trap also serves as an impedance transformation element between the tunable filter and said mixer. The arrangement is particularly useful in a tuner in which the frequency range of the local oscillator signal is below the frequency range of the received RF signals.

Abstract: A setting apparatus for setting the tuning voltage of a tunable resonant circuit has an amplification device which amplifies an oscillator tuning voltage, output by a phase locked loop, nonlinearly to produce the tuning voltage. The gain of the amplification device can be set by a digital gain control signal. The signal resolution of the setting apparatus can be controlled in different ways as a function of the gain by using two differently driven digital/analog converters.