Abstract: Embodiments include semiconductor devices related to compound varactor circuits. Specifically, a semiconductor device may be constructed of a modified anti-series string of varactor pairs, wherein one varactor in a varactor pair has an effective area larger than the other varactor. Varactor pairs in the anti-series string are arranged such that adjacent varactors coupling varactor pairs have equal effective areas. In some embodiments, the anti-series string may have four varactors (two varactor pairs.) In other embodiments, the anti-series string may have eight varactors (four varactor pairs) or twelve varactors (six varactor pairs). The compound varactor using the modified anti-series string of varactor pairs may be advantageous in reducing second harmonics related to parasitic capacitances in anti-series varactor applications.

Abstract: A receiver for radio communication comprises: four antennas; an antenna tuning apparatus for simultaneously tuning the four antennas, the antenna tuning apparatus comprising adjustable impedance devices, each of the adjustable impedance devices having a reactance at a frequency, the reactance of any one of the adjustable impedance devices being adjustable by electrical means; four single-input and single-output low-noise amplifiers; four analog processing and conversion circuits; a multiple-input signal processing device delivering a signal to a destination, the multiple-input signal processing device delivering a tuning instruction; a tuning control unit, the tuning control unit receiving the tuning instruction from the multiple-input signal processing device, the tuning control unit delivering tuning control signals to the antenna tuning apparatus as a function of the tuning instruction.

Abstract: Control for a portable communication device (300) includes a control knob (304) which has an outer shell (610, 610a) at least partially formed of a dielectric material. The control knob is sized and shaped to facilitate fingertip control of the portable communication device, and has an integrated antenna (608, 608a) disposed within the outer shell. An axial member (612, 708) is provided on which the outer dielectric shell and the antenna are mounted to facilitate rotation of the control knob. A control device (606, 606a) is provided which is configured to control at least one electronic circuit (806) of a portable communication device responsive to a user rotation of the outer dielectric shell. The integrated antenna (608, 608a) is arranged to interface to at least one radio frequency communication circuit of a portable communication device.

Abstract: An improved grounding technique for mechanically adjustable rotary capacitors uses a directly grounded bronze sliding contact to effectively and continuously ground the rotating comb-like blades of the capacitor. RF measurements of the continuity and repeatability of the capacitance settings prove the suitability of the modified capacitors for using in pre-calibrated multi-capacitor MHz range impedance tuners.

Abstract: A tunable diplexer includes a high band port, a low band port, an antenna port, a high pass filter, and a low pass filter. The high pass filter is coupled between the high band port and the antenna port, and is configured to pass signals within a high pass band between the high band port and the antenna port. The high pass filter includes a high band path stop band zero, which is configured to selectively attenuate signals within a high band path stop band. The low pass filter is coupled between the low band port and the antenna port, and is configured to pass signals within a low pass band between the low band port and the antenna port. The low pass filter includes a low band path stop band zero, which is configured to selectively attenuate signals within a low band path stop band.

Abstract: An antenna tuning apparatus for a multiport antenna array used for sending and/or receiving electromagnetic waves for radio communication comprises: 4 antenna ports, 4 user ports, 10 adjustable impedance devices each presenting a negative reactance and having a terminal coupled to one of the antenna ports, 4 windings each having a first terminal coupled to one of the antenna ports and a second terminal coupled to one of the user ports, and 10 adjustable impedance devices each presenting a negative reactance and having a terminal coupled to one of the user ports. All adjustable impedance devices are adjustable by electrical means. Any small variation in the impedance matrix of the antenna array, caused by a change in operating frequency or a change in the medium surrounding the antennas, can be compensated with a new adjustment of the adjustable impedance devices.

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 method includes receiving a desired channel indication in a radio tuner, determining a band of operation in which the channel is located, and if the channel is within a first band coupling multiple inductors into a resonant tank, and if the desired channel is within a second band coupling a single inductor into the resonant tank.

Abstract: A method applied in a tuning circuit comprising a plurality of turning cells is disclosed. the method comprises: laying out a array of tuning cells in a matrix configuration, the matrix comprising a first dimension and a second dimension; assigning a first index associated with the first dimension and a second index associated with the second dimension to each tuning cell; controlling each tuning cell using a word line and a bit line; and summing up outputs from all tuning cells to form a combined output. The tuning cell provides a first circuit value or a second circuit value according to the logical value of the bit line, and the difference between the first circuit value and the second circuit value is determined such that a turning resolution of the tuning circuit is determined.

Abstract: A method and apparatus for detecting RF field strength. A field strength reference generator develops a field strength reference current as a function of a field strength of a received RF signal; and a field strength quantizer develops a digital field-strength value indicative of the field strength reference current. In one embodiment, detected field strength is used to dynamically vary the impedance of a tank circuit whereby, over time, induced current is maximized.

Abstract: A circuit includes a first filter comprising a first inductor coupled to a first variable capacitor, wherein the first filter is associated with a first resonant frequency. The circuit further comprises an amplifier coupled to the first filter and a second filter coupled to the amplifier. The second filter comprises a second inductor coupled to a second variable capacitor, wherein the second filter is associated with a second resonant frequency that is substantially the same as the first resonant frequency. At least a portion of the first filter and at least a portion of the second filter are formed on an integrated circuit.

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 embodiment of the present invention provides an apparatus, comprising at least one anti-parallel pair VVC network comprised of two parallel VVCs with one biased in the opposite polarity of the other and at least one anti-series VVC network comprised of two VVCs configured in series, one biased in the opposite polarity of the other such that the resulting AC capacitive variations produce a desired capacitance variation.

Abstract: A broadband tuner includes a tracking filter with calibration to compensate for component errors and drift. The filters use off-die inductors that are preferably within a system-in-package (SIP) with other critical tuner components, which produces a highly integrated tuner front end with high Q filters within a single package. High voltage varactors with a large tuning range can be used for variable capacitors. The integration of the tuner into a SIP allows the tuner design to be optimized for cost and performance while keeping the critical RF layout requirements within the tuner. A configurable tuner front end enables modes for low noise, high linearity, good input return loss (S11) across the entire RF band, and applying a test tone in the calibration mode. The switchable mode enables the tuner to be effective during weak terrestrial reception, strong terrestrial reception, and connection to a cable plant.

Abstract: The tuner circuit comprises a HF input and a HF output with a loop through function, wherein a variable capacitance diode is coupled with a first terminal to the HF input and with a second terminal to the HF output for providing a passive loop through function. The variable capacitance diode is in particular in a passing mode, when no DC reverse voltage is applied, for providing a passive loop through function. In a preferred embodiment, the tuner circuit is designed for reception of television channels, and for the variable capacitance diode one or two tuning variable capacitance diode is used being designed for satellite tuners with a frequency range of 1-2 GHz, or a specially designed variable capacitance diode with a capacitance ratio C1/C25>18 at a frequency of 1 MHz for DC reverse voltages of 1 and 25 Volts is used.

Abstract: A plurality of varactors are coupled via a first electrode to a shared terminal that in turn can operably couple to a source of control voltage. A second electrode for each varactor couples to a corresponding switch, where each switch couples to at least two different voltage levels. So configured, the second electrode of each varactor can be individually connected to either of two voltage levels. This can be leveraged to control, in coarse steps, the overall aggregate effective capacitance presented by these components. At least some of these varactors can have differing corresponding capacitances, the specific values of which can be selected in order to facilitate relatively equal spacing and substantially equal rates of reactance change versus the control voltage value between aggregate-capacitive reactance ranges as correspond to differing settings for the switches at various levels for the control voltage source.

Abstract: A method applied in a tuning circuit comprising a plurality of turning cells is disclosed. the method comprises: laying out a array of tuning cells in a matrix configuration, the matrix comprising a first dimension and a second dimension; assigning a first index associated with the first dimension and a second index associated with the second dimension to each tuning cell; controlling each tuning cell using a word line and a bit line; and summing up outputs from all tuning cells to form a combined output. The tuning cell provides a first circuit value or a second circuit value according to the logical value of the bit line, and the difference between the first circuit value and the second circuit value is determined such that a turning resolution of the tuning circuit is determined.

Abstract: In a double-tuning circuit including a primary tuning circuit having a first inductor and a first variable capacitive element connected in parallel and a secondary tuning circuit having a second inductor and a second variable capacitive element connected in parallel, a fixed part of a copper-foil pattern is connected to a connection point at which the double-tuning circuit is connected to an input terminal of a frequency mixing circuit, and a tip part of the copper-foil pattern extends to near the first inductor, whereby a trap circuit for attenuating an image frequency component is formed. A pattern is formed between a ground-side terminal of the first inductor and the ground, and a capacitor is connected between a connection point at which the first inductor is connected to one terminal of the pattern and a ground-side terminal of the second variable capacitive element.

Abstract: An integrated variable voltage diode capacitor topology applied to a circuit providing a variable voltage load for controlling variable capacitance. The topology includes a first pair of anti-series varactor diodes, wherein the diode power-law exponent n for the first pair of anti-series varactor diodes in the circuit is equal or greater than 0.5, and the first pair of anti-series varactor diodes have an unequal size ratio that is set to control third-order distortion. The topology also includes a center tap between the first pair anti-series varactor diodes for application of the variable voltage load. In preferred embodiments, a second pair of anti-series varactor diodes is arranged anti-parallel to the first pair of anti-series varactor diodes so the combination of the first pair of anti-series varactor diodes and the second pair of anti-series varactor diodes control second-order distortion as well.

Abstract: A line structure is provided which includes a ferroelectric film which is formed on at least one surface of both sides of a substrate and a permittivity of which changes according to a magnitude of an applied voltage, an inductor which is formed on a first side of the substrate, and a capacitor which has a capacitance corresponding to the permittivity of the ferroelectric film and the substrate.

Abstract: An integrated tuner circuit has an arbitrary IF (intermediate frequency) output. The tuner includes an integrated circuit with a fixed-frequency control loop and a matched external variable capacitance Ct, to achieve tracking of a tuned LC band-pass filter with an arbitrary oscillator.

Abstract: A fully integrated, programmable mixed-signal radio transceiver comprising a radio frequency integrated circuit (RFIC) which is frequency and protocol agnostic with digital inputs and outputs, the radio transceiver being programmable and configurable for multiple radio frequency bands and standards and being capable of connecting to many networks and service providers. The RFIC includes a tunable resonant circuit that includes a transmission line having an inductance, a plurality of switchable capacitors configured to be switched into and out of the tunable resonant circuit in response to a first control signal, and at least one variable capacitor that can be varied in response to a second control signal, wherein a center resonant frequency of the resonant circuit is electronically tunable responsive to the first and second control signals that control a first capacitance value of the plurality of switchable capacitors and a second capacitance value of the at least one variable capacitor.

Abstract: A resistance having a high impedance is connected between anode terminals of two variable capacitance diodes sharing a cathode, and the components described above are sealed in one package. The resistance can be formed of a diffusion region between p-regions of the variable capacitance diodes or can be formed of polysilicon and disposed on a chip. Thus, the resistance can be mounted while a chip size of the variable capacitance diode is maintained. Accordingly, it is not required that a bias resistance having a high impedance is additionally provided, whereby achieving reduction in the substrate mounting area and reduction in costs of the set.

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 tuning circuit comprises, at least, a first circuit K1 which serially connects a first variable capacitor element 21a and a second variable capacitor element 31a, an inductance element 23a which is parallely connected to the first circuit K1 and constitutes a resonance circuit with the first circuit K1; a second circuit K2 which includes a switch element 26a and a third resistor 27a serially connected to each other and is parallely connected to the first circuit K1; and a first resistor 24a and a second resistor and 25a which are connected to both ends of the first variable capacitor element 21a, respectively and apply a predetermined tuning voltage.

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 a T network tuner, a variable shunt capacitor is provided between the signal input and ground that is ganged to the variable input matching capacitor. The operation is mechanically arranged such that, as one decreases the capacitance of the variable input matching capacitor, one increases the capacitance of the shunt capacitor to assist in high frequency matching, both to increase the maximum matchable load resistance and to decrease the minimum matchable load resistance. The variable shunt capacitor therefore assists at the high frequency ranges to bring the antenna impedances down to the transmitter output impedance, thus to establish an extended matching range tuner capable working between 160 and 10 meters.

Abstract: A resonator circuit (10) has a pair of varactor diodes (13, 14), a capacitor (15), and a transformer (20) coupled in parallel with the capacitor and varactor diodes. Further, in order to provide a high frequency output an impedance inverter network (35, 36) is coupled to the transformer.

Abstract: A semiconductor torsional micro-electromechanical (MEM) switch is described having a conductive movable control electrode; an insulated semiconductor torsion beam attached to the movable control electrode, the insulated torsion beam and the movable control electrode being parallel to each other; and a movable contact attached to the insulated torsion beam, wherein the combination of the insulated torsion beam and the control electrode is perpendicular to the movable contact. The torsional MEM switch is characterized by having its control electrodes substantially perpendicular to the switching electrodes. The MEM switch may also include multiple controls to activate the device to form a single-pole, single-throw switch or a multiple-pole, multiple-throw switch. The method of fabricating the torsional MEM switch is fully compatible with the CMOS manufacturing process.

Abstract: The invention relates to a resonator (200,300) with variable resonance frequency, intended for connection to an amplifier, thus forming an oscillator, said resonator comprising a resonator circuit (205,305) for deciding the resonance frequency of the resonator and the oscillator, said resonator circuit comprising an inductance (L), a variable capacitance (Cj), and means (Vtune) for varying the capacitance. The resonator also comprises connection means (C1, Ck; C1, Ck, C2) for connecting the resonator to an amplifier. The resonator is provided with means (Vtune) for varying the capacitance of the connection means in proportion to the variation of the capacitance (Cj) of the resonator circuit. Preferably, the means (Vtune) for varying the capacitance (Ck) of the connection means are arranged such that an essentially constant relationship (Ck/Cj) is maintained between the capacitance (Ck) of the connection means and the first capacitance (Cj) of the resonator across all resonance frequencies.

Abstract: The invention provides a unique apparatus and method which varies the capacitance coupled to a circuit. In one embodiment, the variable capacitance comprises a unique variable capacitance array with multiple capacitance modules which can be selectively enabled. Each capacitance module has a capacitive value and a corresponding parasitic capacitance. The invention provides high linearity, low spread, improves the response to power fluctuations by maintaining a consistent relationship between the capacitive value and the parasitic capacitance in each capacitance module. For example, the invention can be used with devices to provide a linear variation of capacitance. In addition, the invention can be used to calibrate a wide range of devices.

Abstract: A voltage controlled tunable resonant circuit (100) has at least two resonant frequency ranges and reduced self modulation, and includes a resonant element (120), a variable reactance element (130), and a first voltage variable capacitor (VVC) (150). The variable reactance element (130) is coupled to the resonant element (120). The VVC (150) has two fixed capacitance values corresponding to two fixed capacitance bias voltage ranges, and is coupled to the resonant element (120) and the variable reactance element (130). The first VVC (150) is controlled by a first DC bias voltage (190) selected to be within one of the two fixed capacitance bias voltage ranges to establish one of the two resonant frequency ranges over which the voltage controlled tunable resonant circuit (100) is tuned by variation of the variable reactance element (130).

Abstract: A unitary tuning structure of a UHF tuner includes an inductance loop, an inductance adjustment element attached to a top portion of the inductance loop so as to be foldable with respect to the inductance loop about an axis parallel to the printed circuit board to which the inductance loop is attached and a capacitance adjustment tab attached to a side portion of the inductance loop so as to be foldable with respect to the inductance loop about an axis perpendicular to the printed circuit board. In another form of the unitary tuning structure, a second inductance loop can be attached within the first loop.

Abstract: A radio frequency transmitter, amplitude modulated, having a single tuner that tunes the frequency oscillator, the isolating filter and the antenna impedance, all at the same time. The transmitter includes a tunable carrier generator for generating a carrier signal of a desired frequency, and a carrier isolator for filtering the carrier signal so as to ensure a clean, isolated carrier signal. A power amplifier is included for amplifying the signal from the carrier isolator. The power amplifier has a certain output impedance. An antenna is connected for transmitting the amplified signal from the power amplifier. The antenna also has a certain impedance. The transmitter further includes an impedance matching device connected between the antenna and the power amplifier for matching the antenna impedance and the power amplifier impedance. Finally, a single control knob is provided for simultaneously controlling the tunable carrier generator, the carrier isolator and the impedance matching device.

Abstract: A high frequency coil arrangement, comprising an input side coil and an output side coil electromagnetically coupled with each other, the input side coil being divided into two coil elements having substantially equal inductances by provision of a tap, characterized in that two parallel tuner capacitors are provided for the two coil elements for providing two tuner circuits of equal frequencies, and that a further separate capacitor is provided and connected with both ends of the input side coil for adjustment of its tuning frequency.

Abstract: Tuning varactor circuitry is disclosed for a dielectric resonator stabilized oscillator (2). A varactor diode (22) is electrically connected in a loop (24) with an RF bypass capacitor (26), and the voltage across the diode is varied. In a first embodiment, first and second dielectric substrates (36, 38) face each other along the plane of the loop (24), with the loop (24) therebetween. In another embodiment, the loop (24) is around a peripheral side wall (52) of the dielectric resonator substrate (46). In another embodiment, the loop (24) is formed on the same surface (54) of a microstrip circuit substrate (56) with a transmission line (10).

Abstract: An oscillator circuit suitable for use in a local oscillator of a tuner of a television receiver set. A feedback circuit comprised of a feedback capacitor (17) is connected between a junction of a tuning diode (10) and a correcting capacitor (11) connected in series therewith and the emitter of an oscillation transistor (1). Oscillation voltage developing across the correcting capacitor is fedback to the emitter of the oscillation transistor through the feedback capacitor. When the tuning diode is conditioned to have a large capacitance value, a large oscillation voltage is fedback to the transistor through the feedback capacitor whereas when the tuning diode is conditioned to have a small capacitance value, a small oscillation voltage is fedback to the transistor through the feedback capacitor. The oscillator circuit continues to oscillate stably over a wide frequency range whenever the tuning diode changes from the small capacitance value to the large capacitance value or vice versa.

Abstract: A UHF tuner employing resonant cavities with tuned lines has a discrete air trimmer capacitor which includes a fixed electrode connected to the tunable line with one or more insulated turns of silver wire and a movable electrode guided into the fixed electrode to provide characteristics of lower minimum capacity, higher maximum to minimum capacity ratio, smaller physical size, higher Q and lower cost than conventional capacitor trimmers.