Abstract: According to one embodiment, a compact broadband radio frequency (RF) receiver circuit includes a low noise amplifier which includes a first amplifier stage, a second amplifier stage, an inter-stage network including a higher order filter network, where the inter-stage network is coupled between the first amplifier stage and the second amplifier stage, and a double resonance transformer network coupled to an output of the second amplifier stage. The RF receiver circuit includes a low pass filter and a mixer circuit coupled between the low noise amplifier and the low pass filter.

Abstract: An active antenna system comprises a coupling block adapted to sample a portion of a first telecommunication signal and a compensation block. The compensation block is coupled to the coupling block and is adapted to apply at least a phase compensation to the portion of the first telecommunication signal, thereby obtaining a first compensation signal. The coupling block is further adapted to combine the first telecommunication signal and the first compensation signal into a compensated first telecommunications signal to be fed into an antenna arrangement.

Abstract: A circuit arrangement includes a coreless transformer. A trimming device is connected to the transformer and includes a variable capacitance and/or inductance.

Abstract: An impedance circuit includes an input terminal, a first and a second capacitive arrangement and an output terminal coupled to the input terminal by a network. The network includes the first and the second capacitive arrangement. The first capacitive arrangement includes a varactor circuit having a varactor and at least one series circuit. The at least one series circuit includes a capacitor and a switch in series connection and is coupled parallel to the varactor circuit. The second capacitive arrangement comprises an additional capacitor.

Abstract: Real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a radio frequency receiver system. The radio frequency receiver system includes two non-linear equations that may be solved to determine the reflection coefficient of the antenna. The tunable matching network is repeatedly perturbed and the power received by the antenna is measured after each perturbation at the same node in the matching network. The measured power values are used by an optimizer in converging to a solution that provides the reflection coefficient of the antenna. The reflection coefficient of the antenna may be used to determine the input impedance of the antenna. The elements of the matching circuit are then adjusted to match the input impedance of the antenna.

Abstract: A receiver includes a low noise amplifier having an input for receiving a radio frequency signal, and an output. The receiver further includes a tracking filter having an input coupled to the output of the low noise amplifier. The tracking filter including a bandpass filter configured to pass the radio frequency signals. The bandpass filter includes a variable capacitor having a first electrode coupled to the input of the tracking filter for receiving the radio frequency signals, and a second electrode coupled to a power supply terminal. The bandpass filter further includes a transformer having a primary winding including a first terminal coupled to the first electrode of the variable capacitor and a second terminal coupled to a second power supply terminal. The transformer further includes a secondary winding.

Abstract: A test system (200) for testing for missing or shorted parts within a tuner circuit includes a signal generator (202) for applying a harmonic-containing baseband time varying RF test signal to the tuner circuit. The tuner circuit is tuned to a harmonic of test signal. A detector 208 coupled to the baseband IF output of the tuner circuit detects the voltage generated in response to the applied RF test signal. A voltage measurement device (210) measures voltage detected by detector to provide an indication of the gain. Significant changes in the gain indicate missing part(s) or short circuits.

Abstract: A mobile wireless communications device may include a portable housing, and a supply modulator carried by the portable housing. The supply modulator may include an output node, a linear amplifier coupled to the output node, and a switching amplifier also coupled to the output node. The switching amplifier may include at least one sensing transistor configured to sense current output from the linear amplifier and generate a drive voltage, and a hysteretic comparator coupled to the at least one sensing transistor and configured to be driven by the drive voltage. The mobile wireless communications device may also include a radio frequency (RF) power amplifier coupled to the output node of the supply modulator, and a wireless transceiver carried by the portable housing and coupled to the RF power amplifier.

Abstract: Embodiments of circuits, apparatuses, and systems for a voltage regulator with a bandwidth variation reduction network are disclosed. Other embodiments may be described and claimed.

Abstract: Provided are apparatuses, systems and methods for performing communication using wireless power. According to one general aspect, a communication device using wireless power may include: a controller configured to determine whether a mutual resonance occurs between a target resonator and a source resonator; and a modulator configured to modulate data based on whether the mutual resonance occurs.

Abstract: A system that incorporates teachings of the present disclosure may include, for example, a method involving a step to tune a plurality of tunable reactive elements by measuring a drift in reactance of at least one of the plurality of tunable reactive elements away from a desired reactance. Additional embodiments are disclosed.

Abstract: A superheterodyne receiver apparatus includes a tuning circuit for selecting and receiving a high frequency signal, the circuit being composed of a voltage-variable capacitance element and an inductance element; and a frequency converting unit for frequency converting the high frequency signal to an intermediate frequency signal. The superheterodyne receiver apparatus further includes an electrically rewritable read only memory; a calculation unit for calculating tuning voltage setting data, which are used to set the tuning circuit to a tuning voltage corresponding to a desired reception frequency, in accordance with a mathematical expression that uses the data stored in the memory as coefficients; and a D/A conversion unit for D/A converting the tuning voltage setting data to the tuning voltage.

Abstract: The present invention is intended to be able to ensure detecting whether an open-circuit occurs to a feeder within short time with simple configuration. A receiving apparatus 2 according to the present invention receives image information transmitted from a capsule endoscope 3 through a coaxial cable and a receiving antenna selected and switched to from among coaxial cables 9a to 9d connected to receiving antennas 8a to 8d, respectively by a changeover switch 20. The receiving apparatus 2 includes a changeover switch 22, an open-circuit detecting circuit 23, and a control unit 26. The changeover switch 22 branches the coaxial cables 9a to 9d near the changeover switch 20, and selects and switches to one of the branched coaxial cables.

Abstract: Method and system for tuning a tunable antenna uses a comparison between a signal response at two different tuning frequencies to determine how or if the tuning needs to be further adjusted. With the approach, the method and system arrive at a frequency shift that is centered about the desired antenna frequency, which point there is no net change in the signal response. In a further aspect, a frequency to which a tuned antenna is tuned is shifted to verify whether the antenna is still in tune. Modifications to minimize disturbance of the output received signal that would otherwise be caused by the frequency shifting are contemplated.

Abstract: A wireless terminal includes an RF transceiver, an auto tuner, and an antenna. When a remote signal is received at the wireless terminal, the auto tuner is adjusted in accordance with the received signal to optimize OTA performance of the wireless terminal. As further remote signals are received by the wireless terminal, the tuner is readjusted. As a user inputs information to be transmitted, the tuner is also readjusted in accordance with the transmission signals to optimize OTA performance of the wireless terminal, and a best compromise between the TX OTA performance and the RX OTA performance is calculated. Current/temperature information may also be obtained for readjusting the tuner.

Abstract: A mobile terminal including a terminal housing having a first ground, a printed circuit board disposed in the terminal housing and having a second ground, and a leakage current preventing member installed between the first and second grounds and configured to block a direct current (DC) and passing an alternating current (AC) so as to prevent a leakage current from flowing to the terminal housing during a recharging of the mobile terminal.

Abstract: A heterodyne receiver has a mixer with at least one transistor whose operating point can be varied dynamically. The quality of the output signal from the mixer is assessed in order to control the operating point. The operating point is set such that the collector current is increased when the intermodulation interference is high, thus improving the intermodulation resistance. The collector current is reduced when the intermodulation interference is low, thus reducing the transistor noise. Furthermore, the current drawn is reduced in this situation. The circuit and the method are particularly suitable for RF receivers without tunable input filters, and for receivers in which the power consumption must be low.

Abstract: An antenna damping circuit in which the frequency characteristics of damping amount can be made substantially flat by providing a resistor (Ra) between PIN diodes (D1, D2) having a resistance varying upon application of a control voltage (Vc) and a capacitive dummy antenna circuit (10), and setting its resistance high enough to neglect the capacity of the dummy antenna circuit (10) sufficiently when the dummy antenna circuit (10) is viewed from the side of the PIN diodes (D1, D2) thereby substantially eliminating the influence of capacity of the dummy antenna circuit (10).

Abstract: In a signal communication device, a frequency-selective filter has at least one component that is biased by a control signal to establish a center frequency of the frequency-selective filter. A closed-loop bias generator is provided to generate the control signal and to adjust the control signal based, at least in part, on a comparison of the control signal and a reference signal.

Abstract: In one embodiment, a frequency agile receiver is provided that includes an antenna: a first diode having its anode coupled to ground through a first conductor; a second diode having its anode coupled to the cathode of the first diode through a second conductor, the antenna coupling to the second conductor, the second diode having its cathode coupled to an output node through a third conductor, wherein at least one of the first, second, and third conductors comprises a shape memory alloy conductor; and a tuning circuit adapted to drive a bias current into the shape memory alloy conductor.

Abstract: In one embodiment, a receiver includes a voltage margin controller, a set of first components coupled to the voltage margin control, and a set of offset compensation controllers coupled to the set of first components.

Abstract: A frequency mixer includes a semiconductor substrate. An input current feedback amplifier is formed on the semiconductor substrate and receives a radio frequency (RF) signal and a local oscillator (LO) signal. An inverting current feedback amplifier is formed on the semiconductor substrate and connected to the input current feedback amplifier for inverting the LO signal and producing a half-wave signal. An output current feedback amplifier is formed on the semiconductor substrate and connected to an output of the input and inverting current feedback amplifiers and operative as an inverting summer for the RF and LO signals such that the output polarity of the RF signal is reversed.

Abstract: A system for generating a tuning voltage including a processor, a tank circuit, and a feedback loop. The processor creates a tuning voltage that is provided to the tank circuit. A feedback loop optimizes tuning performance by adjusting the tuning voltage based on radio signal strength.

Abstract: A tuning circuit of a filter is disclosed to correct a cut-off frequency of the filter. The tuning circuit comprises a current generation unit which includes a first transistor and a resistor, and a capacitor compensation unit which includes a second transistor and a capacitor unit.

Abstract: Various embodiments of the present invention relate to circuits for and methods of generating a bias current for a plurality of data transceivers on an integrated circuit. According to one embodiment, an integrated circuit having a plurality of data transceivers comprises a first data transceiver receiving a reference voltage. A plurality of data transceivers are preferably coupled to the first data transceiver, where each the data transceiver of the plurality of data transceivers receives a reference current based upon the reference voltage from the first data transceiver. According to alternate embodiment of the invention, an external resistor is coupled to a data transceiver to generate a fixed bias current in addition to a variable bias current. A method of generating a bias current for a plurality of data transceivers is also disclosed.

Abstract: In a signal communication device, a frequency-selective filter has at least one component that is biased by a control signal to establish a center frequency of the frequency-selective filter. A closed-loop bias generator is provided to generate the control signal and to adjust the control signal based, at least in part, on a comparison of the control signal and a reference signal.

Abstract: A disclosed method tunes a signal from a channelized spectrum having a predetermined channel spacing. A signal of interest having a predetermined maximum bandwidth is mixed with a local oscillator signal, which has a frequency that is an integer multiple of the channel spacing or one-half of a channel spacing displaced from an integer multiple of the channel spacing. The local oscillator signal is selected to frequency translate the signal of interest to within a near-baseband passband whose lower edge is spaced from DC by at least about the maximum bandwidth of the signal of interest. Problems associated with 1/f noise, DC offsets, and self-mixing products are avoided or substantially diminished. Other methods and systems are also disclosed.

Abstract: In a signal communication device, a frequency-selective filter has at least one component that is biased by a control signal to establish a center frequency of the frequency-selective filter. A closed-loop bias generator is provided to generate the control signal and to adjust the control signal based, at least in part, on a comparison of the control signal and a reference signal.

Abstract: An integrated circuit is provided with a power supply terminal and an external circuit connecting terminal which is DC insulated from an internal high-frequency circuit and is connected to an external circuit. An interface is provided with an address identifying circuit having applied with an address identifying voltage corresponding to address data and for setting the interface to receive only channel selection data by the address identifying voltage. The address identifying circuit is connected to the external circuit connecting terminals, and a first resistor is connected between the power supply terminal and the external circuit connecting terminal. The external circuit connecting terminal is DC shorted to the ground, a second resistor is connected between the external circuit connecting terminal and the ground, or the external circuit connecting terminal is DC insulated from the ground.

Abstract: A radio wave receiver for receiving radio waves having a predetermined frequency, the receiver comprises an antenna, an variable capacitor connected to the antenna, a memory, and a controller which determines an optimum capacitance of the variable capacitor with which the radio wave receiver is in a predetermined reception state and writes optimum capacitance data into the memory and, controls the variable capacitor based on the optimum capacitance data.

Abstract: When a signal of GSM 900 frequency band is transmitted, a bias voltage setting circuit sets an optimum bias voltage for the GSM 900 frequency band to a first stage amplifier and a second stage amplifier. The transmission signal is amplified by the two amplifiers. A signal that is output from the second stage amplifier is supplied to a low-pass filter. The low-pass filter attenuates unnecessary radiation waves from the transmission signal. A GSM 900 frequency band amplifier amplifies the output signal of the low-pass filter and outputs the amplified signal. When a signal of DCS 1800 frequency band is transmitted, the bias voltage setting circuit sets an optimum bias voltage for the DCS 1800 frequency band to the first stage amplifier and the second stage amplifier. A DCS 1800 frequency band amplifier amplifies an output signal of the second stage amplifier and outputs the amplified signal.

Abstract: A tuning circuit having an amplitude-varying function is disclosed that comprises a coil, a capacitor, and a resistance-adjusting element connected in parallel to the coil and the capacitor for varying resistance at time of resonance of the tuning circuit, wherein the amplitude of an output signal of the tuning circuit is varied by varying the resistance with the resistance-adjusting element.

Abstract: A cordless digital audio headphone is disclosed. The headphone includes a pair of earphones connected to a headband. The earphones provide audible signals. The headphone also includes a memory unit positioned on the headband for containing digitally stored audio information. A processor is disposed on the headband, and is coupled to the memory unit for retrieving the digitally stored information from the memory unit. An analog to digital converter receives the digitally stored audio information, and provides the audible signal to the earphones.

Abstract: Systems and methods for reducing interference in an enhanced radio receiver from a transmitter when both are located in the same aircraft are provided. The enhanced radio receiver detects and attenuates a signal from the transmitter, without attenuation or interference with other desired signals. An enhanced radio transmitter may inform the enhanced radio receiver of the frequency of transmission via a data communication path such that the enhanced radio receiver attenuates the transmitted frequency for the duration of transmission.

Abstract: A calibration circuitry includes an adjustable capacitor, a voltage generator, a reference voltage generator, and a controller. The reference voltage generator provides a reference voltage. The voltage generator provides a measurement voltage that depends on the capacitance of the adjustable capacitor. The capacitance of the adjustable capacitor varies in response to a control signal. The controller provides the control signal based on the relative values of the reference voltage and the measurement voltage.

Abstract: An integrated tuner circuit includes a first terminal to which a UHF TV signal is input via a UHF amplifier. The amplifier is switched to an operating state when a UHF TV signal is received. A switching-voltage generation circuit includes a first switching circuit for generating a switching voltage used to switch the operating state of a UHF high-frequency amplifying circuit.

Abstract: A regulation circuit, incorporated in a single integrated circuit with a first circuit load, which as an input coupled to a power supply which produces a source voltage, and a first output coupled to the first circuit load. The regulation circuit comprises an input capacitor for reducing the magnitude of a voltage change at the first output, and at least a first voltage regulator for producing a predetermined voltage at the first load.

Abstract: A direct conversion receiver comprises a low noise amplifier, a bandpass filter, a mixer circuit and a baseband processing assembly. The low noise amplifier is capable of receiving communication signals from an antenna and, in turn, the bandpass filter is capable of filtering the received signals to a bandpass including a reception frequency band. The mixer circuit is electrically connected to an output of the bandpass filter, and can demodulate the received signals into differential signals in two channels. The baseband processing assembly is electrically connected to the mixer circuit opposite said bandpass filter. In this regard, the baseband processing assembly can process the demodulated differential signals in at least one of the channels. And to compensate DC offset from the demodulated differential signals, for each channel the baseband processing assembly includes a pair of dynamic offset compensation elements and a static offset compensation element.

Abstract: A semiconductor integrated circuit device for communication is provided with a PLL circuit or the like formed therein, the PLL circuit which is capable of realizing the compensation of fluctuation due to temperature change, the inhibition of increase in the chip area and the ensurement of the performance margin, and which controls a VCO having multiple oscillation frequency bands. In the case where automatic calibration is performed by switching a switch to a side of a DC voltage source in the PLL circuit using a VCO having multiple oscillation bands, a tuning voltage (Vtune) of an RFVCO is fixed to a voltage value of a DC voltage source. However, since a temperature characteristic of canceling a VCO oscillation frequency is given to the DC voltage source, it is possible to minimize the influence on the band selection when a calibration table comes to no optimum one.

Abstract: In a non-contact IC card, a driving portion 5 sequentially switches a resonance frequency of a resonance circuit 1. A reference voltage generating portion 6 receives an output voltage of resonance circuit 1 for outputting a prescribed reference voltage. An output value measuring portion 7 measures a magnitude of the output voltage of resonance circuit 1 at each resonance frequency using the reference voltage as a reference. An output value storing portion 8 stores a measurement value (an output value). A manner determining portion 9 selects the largest one of the output values stored in output value storing portion 8, and determines a switching manner corresponding thereto as a suitable switching manner. Thus, the suitable switching manner allowing the most efficient power supply can be achieved.

Abstract: In a heterodyne stage having a separating filter providing broadband termination for an output of a mixer, a resistance having the value of a system impedance is arranged between the separating filter and a following intermediate-frequency filter, the resistor being interconnected with a resonance element tuned to the intermediate frequency in such a way that the resistor, at the intermediate frequency, has minimal attenuation of the useful signal and, at all other frequencies, terminates the output of the mixer with the system impedance.

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 regulation circuit, incorporated in a single integrated circuit with a first circuit load, which as an input coupled to a power supply which produces a source voltage, and a first output coupled to the first circuit load. The regulation circuit comprises an input capacitor for reducing the magnitude of a voltage change at the first output, and at least a first voltage regulator for producing a predetermined voltage at the first load.

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.

Abstract: An apparatus and method for detecting the presence of a signal component in an arbitrary signal, where the signal component has a desired frequency. The apparatus includes an error signal generator and a detector. The error signal generator has an input for receiving a reference signal having a reference frequency, a second input for receiving the arbitrary signal having the signal component and an output for generating a difference signal dependent upon a difference in frequency between the reference frequency and the desired frequency. The detector has an input for receiving the difference signal and an output for producing a detector signal when the magnitude of the difference signal is greater than a threshold magnitude. The detector signal indicates the presence of the signal component in the arbitrary signal.

Abstract: An electronic tuning system includes an electronic tuner for adjusting the predetermined control voltage of a voltage controlled oscillator (VCO) to tune the local frequency signal to radio waves on an arbitrary channel in accordance with channel selection information. A booster circuit boosts a source voltage to generate a boosted voltage in order to ensure the predetermined control voltage. A non-volatile memory stores the channel selection information in response to a predetermined write voltage. The boosted voltage of the booster circuit is utilized as the predetermined write voltage.

Abstract: In a method for calibrating or aligning a multistage selective amplifier including an oscillator circuit and at least one tuning circuit, the tuning voltages respectively necessary for aligning the respective tuning circuits to the required receiving frequency are calculated directly from a mathematical relationship between the respective tuning voltage and the oscillator voltage. In order to achieve this, a characteristic multiplicative coefficient and a characteristic additive factor for each tuning circuit are stored in a memory upon manufacturing or switching on the device. In order to select a desired receiving frequency, the respective stored values as well as an oscillator voltage are provided to an amplification circuit, which correspondingly amplifies the oscillator voltage by the multiplicative coefficient and the additive factor and then provides the resulting output value as a tuning voltage to the respective tuning circuit.