Abstract: An apparatus for adjusting a component in a receiver system to eliminate distortion. The apparatus may include a receiver system and a tuning circuit. The receiver system may process a tracking signal to generate an output signal. The tracking signal may include a radio frequency (RF) signal and a test signal. The processing of the first tracking signal may introduce a distortion into the output signal. The tuning circuit may be operatively coupled to the receiver system. The tuning circuit may determine an adjustment value and send the adjustment value to the receiver system. The receiver system may adjust a component of the receiver system using the adjustment value to eliminate the distortion in a second RF signal that is caused by the component.

Abstract: The present invention relates to adjustment of interconnect power levels in high-speed differential serial links. In an example embodiment, a digital signal received at a digital input port is converted in a driver into a corresponding differential signal and provided to output ports connected to a differential transmission line for provision to a receiver. For adjusting the interconnect power levels between the driver and the receiver a voltage regulator is interposed between a voltage source and the driver. The voltage regulator provides regulated supply voltage to the driver. In operation, the voltage regulator receives from control circuitry a control signal indicative of a predetermined regulated voltage for provision to the driver for a pre-selected type of data transmission. In dependence upon the received control signal the voltage regulator selects the corresponding reference voltage and provides it to the driver.

Abstract: An apparatus and method for antenna matching according to a position and an angle of a portable terminal is provided. Operations of the portable terminal include, when at least one of a position and an angle of the portable terminal is changed, determining an optimal Tunable Matching Network (TMN) set value corresponding to the position and the angle, and performing antenna matching according to the optimal TMN set value.

Abstract: A wideband RF tracking filter having a set of parallel tuned resonator amplifier stages with a de-Q resistor for each subband is disclosed. The resonant amplifier contains programmable tuned LC tank impedance and an array of parallel voltage to current converters (V2I) for each subband. The de-Q resistor together with the array of V2I converters provides a flat gain over each subband and each of the other subbands covering different frequencies.

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: There is provided a method of configuring a radio receiver, the radio receiver comprising signal receiving means, and at least one adjustable component coupled to the signal receiving means; the method comprising setting the at least one component to a first value selected from a plurality of values; measuring the quality of a signal received via the signal receiving means and the at least one adjustable component; repeating the steps of setting and measuring for at least a second value selected from the plurality of values; and determining the value of the at least one adjustable component that provides the highest measured signal quality.

Abstract: Systems and methods are disclosed that use multiple DC-DC (direct-current-to-direct-current) regulators and configurable DC-DC regulators with respect to multi-band audio receivers in order to allow for the use of different DC-DC regulator switching clock signals for different audio broadcast bands. The systems and methods disclosed thereby help to alleviate interference problems typically caused by switching devices used in the DC-DC conversion process. The embodiments described are also applicable to switching power supplies run from alternating current (AC) power sources and to Class D amplifiers working with broadcast radios.

Abstract: An handheld wireless communication device that is cradleable in one hand during text entry. A display, key field and trackball navigation tool are located on a front face of the device. At least some keys of the key field are arranged in key-columns and each of the key-columns is vertically offset from adjacent key-columns. Alphanumeric input keys include several alphabetic keys with letters arranged in a traditional (QWERTY), but non-ITU Standard E.161 telephone letter layout. A microprocessor is provided that receives operator commands from the keys and the trackball navigation tool and which affects corresponding changes to the display based on user input. A menu key is positioned adjacent to the trackball navigation tool that upon actuation displays an available action menu on the display in dependence of the currently running application on the device.

Abstract: A rectifier circuit includes a bias circuit that outputs a first direct-current voltage and a second direct-current voltage; a first MOS transistor that has a gate and a source; and a second MOS transistor that has a gate, a source, and a drain connected to the source of the first MOS transistor. Only the first direct-current voltage is applied between the gate and the source of the first MOS transistor, and only the second direct-current voltage is applied between the gate and the source of the second MOS transistor. The rectifier circuit also includes a coupling capacitor that has a first end which is connected to the source of the first MOS transistor, and a second end to which an alternating-current signal is input.

Abstract: A first bias circuit outputs a first direct-current voltage to charge a first capacitor based on a clock signal. A second bias that outputs a second direct-current voltage to charge a second capacitor based on a clock signal. A first MOS transistor has a gate and a source. The first direct-current voltage is applied between the gate and the source of the first MOS transistor to bias the gate of the first MOS transistor. A second MOS transistor has a gate and a source, and a drain connected to the source of the first MOS transistor. The second direct-current voltage is applied between the gate and the source of the second MOS transistor to bias the gate of the second MOS transistor. A coupling capacitor has a first end connected to the source of the first MOS transistor, and a second end to which an alternating-current signal is input.

Abstract: A Radio Frequency (RF) transceiver includes a baseband processor, a receiver section, and a transmitter section. The receiver section communicatively couples to the baseband processor and includes a plurality of tuned RF circuits. The transmitter section communicatively couples to the baseband processor and includes a plurality of tuned RF circuits. In a calibration operation, the transmitter section applies a RF test signal to its plurality of tuned RF circuits. The baseband processor applies a plurality of tuning control settings to each the tuned RF circuit. The baseband processor, for each of the plurality of tuning control settings, measures an output of the tuned RF circuit. The baseband processor selects a tuning control setting for the tuned RF circuit based upon at least one measured output of the tuned RF circuit. Finally, the baseband processor is operable to apply a selected tuning control setting to the tuned RF circuit.

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 radio frequency circuit is generated as an integrated circuit that is arranged to provide transmission, receipt, and storage of data. The data is transmitted and received across a radio frequency band. An antenna is included within the integrated circuit, wherein the antenna is manufactured at the time the integrated circuit is manufactured. A power source is mounted adjacent to the integrated circuit. The integrated circuit and the power source are encapsulated within the same integrated circuit package.

Abstract: In some embodiments, a method is provided for identifying a communication interface of an electronic unit attached to a connector of an electronic device. A voltage pulse is generated in the device on a pin of the connector. The voltage on the pin is measured, as it is affected by a load in the unit. The measured voltage is compared with predetermined voltage criteria. Communication interface identification is performed on the unit dependent on the comparison.

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: A rectifier circuit includes a bias circuit that outputs a direct-current voltage; a first MOS transistor that has a gate and a source; and a second MOS transistor that has a gate, a source, and a drain connected to the source of the first MOS transistor. Only the direct-current voltage is applied between the gate and the source of the first MOS transistor, and only the direct-current voltage being applied between the gate and the source of the second MOS transistor. The rectifier circuit also includes a coupling capacitor that has a first end which is connected to the source of the first MOS transistor, and a second end to which an alternating-current signal is input.

Abstract: An object of the present invention is to provide a receiver, a digital-analog converter and a tuning circuit in which temperature compensating components can be formed on a semiconductor substrate while reducing component costs. An FM receiver 100 is constituted by including an antenna 1, a high frequency receiving circuit 2, a local oscillator 3, two digital-analog converters (DACs) 4, 6, a control section 8, a mixing circuit 9, an intermediate frequency amplification circuit 10, a detection circuit 11, a low frequency amplification circuit 12 and the speaker 13. The DACs 4, 6 have a predetermined temperature coefficient, of which output voltage is changed in accordance with ambient temperature. When a characteristic of VCO 31 is changed with variations of ambient temperature so as to cause a control voltage applied to the VCO 31 to be changed, output voltages of the DACs 4, 6 are also changed similarly.

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: 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: Electronic circuitry supports utilization of a series of pulses of varying width to tune a transducer (e.g., a coil that produces or receives a magnetic field) for transmitting or receiving. For example, a control voltage generator generates a sequence of digital pulses of varying pulse widths to produce respective control voltages. The control voltage generator applies a produced control voltage to a varactor element whose capacitance changes depending on a magnitude of the produced control voltage. The varactor element forms part of a tank circuit. Consequently, the series of pulse widths controls an operating frequency of the tank circuit at different times. The tank circuit includes an inductive coil that is tuned to produce or receive a magnetic or inductive field.

Abstract: An electronic circuit having reverse scan tuning comprises an IC radio having the forward scan function, in which a VCO capacitor is connected in parallel to a series connected resistor and switch, and a second switch is connects an input to an IF limiter amplifier to either circuit ground or a voltage supply. The invention makes it convenient for a user to search for a radio station by not having to start a search for a lower band station at the lowest end of the frequency band. The user does not need to push reset button to return to the lowest frequency when the user wants to receive a station whose frequency is lower than the current station.

Abstract: A receiver such that the period required for tracking adjustment, temperature compensation is not needed, and tracking errors due to fluctuation of the power supply voltage are prevented from increasing, and a tracking adjusting method for the receiver. A DAC 4 generates a voltage according to the value of data (Do) inputted from an MPU 81 by using a control voltage outputted from a low-pass filter 35 in a local oscillator 3 as a reference voltage used during digital-analog conversion. A multiplier circuit 5 analog-multiplies the output voltage of the DAC 4 by a predetermined multiplier. The output voltage of the multiplier circuit 5 is applied as a tuning voltage to a high-frequency tuning circuit 20.

Abstract: A constant current source for generating a constant reference current that is relatively temperature insensitive. The constant current source comprises: i) first circuitry for generating a first output current that increases with increases in temperature; ii) second circuitry for generating a second output current that decreases with increases in temperature; and iii) a current combiner circuit that combines the first and second output currents to thereby generate the constant reference current. A change in the first output current caused by a temperature change is at least partially offset by a change in the second output current caused by the temperature change.

Abstract: An integrated center frequency selectable resonant coupling network suited for use in an integrated circuit is disclosed. The network includes an integrated coupling transformer having a secondary winding for coupling to a load and a primary winding for coupling to a source; a first integrated capacitive circuit controllably coupled across one of the primary and secondary windings and when so coupled operable to resonate with the integrated coupling transformer at a frequency in a first frequency band; and a second integrated capacitive circuit coupled across a second one of the primary and the secondary windings that is operable to resonate with the integrated coupling transformer at a frequency in a second frequency band.

Abstract: A system and method of improving the rejection of intermodulation (IM) distortion in receivers (100) employing varactor tuning preselecters by exploiting the attenuating properties of a tunable preselecter at specific voltages. The invention takes advantage of a first preselecter (101) and a second preselecter (105) already present in existing receiver circuits enabling them to provide attenuation to incoming radio frequency (RF) signals. This enables the receiver to better operate without the burden of interference and without the need to retrofit the receiver with added attenuator circuitry.

Abstract: A shortwave radio-receiver shows an improved reception sensitivity that can be used in a highly convenient way. The receiver is adapted for the superheterodyne system and the PLL synthesizer system and includes a front end circuit 33A for converting the received shortwave signal into an intermediate frequency signal. It also includes a formation circuit 50 for forming a tuning voltage VMB to be applied to the variable capacity diode of the antenna module and a jack J32. When the antenna module is in use, the formation circuit 50 is controlled in response to the reception frequency of the front end circuit 33A so as to modify the tuning voltage VMB and make the latter correspond to the reception band of the received shortwave broadcast to be received. The tuning voltage VMB is applied from the jack J32 to the variable capacity diode and, at the same time, the received signal is fed to the front end circuit 33A.