Abstract: In a shared radio frequency (RF) band, regulations or standards can stipulate that a device using an RF channel must vacate the RF channel if another device having priority to the channel is detected. It takes time, however, to move channels and this added time reduces the effective speed of the communication. In some cases, a received signal from the other device may be received on the channel when the other device is not, in fact, operating on the channel. These received signals can lead the device to move channels, thereby slowing communications unnecessarily. Accordingly, disclosed herein are a system and method for checking the characteristics of a received signal's spectrum to determine if the source of the received signal is on-channel or off-channel. This determination may be used to minimize the device from taking unnecessary interference avoidance measures, such as dynamic frequency selection.

Abstract: To provide a method for suppressing corrosion of glass to be in contact with a liquid material containing fluoride ions or a condensate of gas vaporized therefrom, without adding an alkaline substance, and further without imposing restrictions on e.g. the temperature, the pH, the fluoride ion concentration and the water content. A method for suppressing corrosion of glass to be in contact with either one or both of a liquid material containing fluoride ions and a condensate of gas vaporized from the liquid material, wherein the liquid material contains a powder containing silicon dioxide, and the silicon dioxide is contained in a molar ratio of one or more times to the fluoride ions.

Abstract: An electrically powered vehicle has a drive apparatus which includes an electric machine and an electrical energy storage device connected to the electric machine. A charging device is connected to the electrical energy storage device for the wireless transfer of energy by way of an alternating magnetic field. For that purpose, the charging device has an electronic coil which interacts with the alternating magnetic field. The electronic coil is connected to an adjustable compensating circuit.

Abstract: A signal processing device and signal processing method. A plurality of tuner circuits includes at least one that selectively provides a signal from among a plurality of signal bands potentially in an input signal in response to a control signal having a transition between a first state and a second state. A correction circuit corresponds to at least one of the plurality of tuner circuits, and is configured to receive the control signal and provide a corrected control signal for the tuner circuit. The corrected control signal has a gradual transition between the first state and the second state as compared to the transition between the first state and the second state in the control signal.

Abstract: An enhanced power cable arrangement apparatus (150) comprises a tuner housing (160), a power adaptor housing (162), and a power cable (164) extending between the tuner housing (160) and the power adaptor housing (162). A reception antenna (166) is provided that extends between the tuner housing (160) and the power adaptor housing (162), the reception antenna (166) comprising a pole portion that extends substantially in parallel with and in spaced relation to the power cable (164). A first end of the reception antenna (166) for coupling to a tuner apparatus (178) is coupled to an amplifier apparatus (194) and a common-mode filter (188).

Abstract: A method and apparatus for use in a digitally tuning a capacitor in an integrated circuit device is described. A Digitally Tuned Capacitor DTC is described which facilitates digitally controlling capacitance applied between a first and second terminal. In some embodiments, the first terminal comprises an RF+ terminal and the second terminal comprises an RF? terminal. In accordance with some embodiments, the DTCs comprise a plurality of sub-circuits ordered in significance from least significant bit (LSB) to most significant bit (MSB) sub-circuits, wherein the plurality of significant bit sub-circuits are coupled together in parallel, and wherein each sub-circuit has a first node coupled to the first RF terminal, and a second node coupled to the second RF terminal. The DTCs further include an input means for receiving a digital control word, wherein the digital control word comprises bits that are similarly ordered in significance from an LSB to an MSB.

Abstract: Methods and means related to an electronic circuit having an inductor and a memcapacitor are provided. Circuitry is formed upon a substrate such that an inductor and non-volatile memory capacitor are formed. Additional circuitry can be optionally formed on the substrate as well. The capacitive value of the memcapacitor is adjustable within a range by way of an applied programming voltage. The capacitive value of the memcapacitor is maintained until reprogrammed at some later time. Oscillators, phase-locked loops and other circuits can be configured using embodiments of the present teachings.

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 resonator of a VCO includes a fine tuning main varactor circuit, an auxiliary varactor circuit, and a coarse tuning capacitor bank circuit coupled in parallel with an inductance. The main varactor circuit includes a plurality of circuit portions that can be separately disabled. Within each circuit portion is a multiplexing circuit that supplies a selectable one of either a fine tuning control signal (FTAVCS) or a temperature compensation control signal (TCAVCS) onto a varactor control node within the circuit portion. If the circuit portion is enabled then the FTAVCS is supplied onto the control node so that the circuit portion is used for fine tuning. If the circuit portion is disabled then the TCAVCS is supplied onto the control node so that the circuit portion is used to combat VCO frequency drift as a function of temperature. How the voltage of the TCAVCS varies with temperature is digitally programmable.

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: 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 tunable narrow band radio frequency (RF) filter (200) includes an RF input (225), an RF output (227), a capacitive network (201-209) for coupling the RF input (225) with the RF output (227) and an inductive network (219-223) for resonating the filter at a predetermined center frequency. A number of semiconductor devices such as varactor diodes (215, 217, 229, 233) are used for tuning respective capacitors in the capacitive network (201-209). A single voltage source (Vc) is used for tuning each one of the respective varactor diodes for moving the resonant frequency of the filter over a substantially wide frequency range.

Abstract: Example biased varactor networks and methods to use the same are disclosed. A disclosed example apparatus includes a bias voltage generator to generate a first bias voltage and a second bias voltage, the second bias voltage selected to be different from the first bias voltage, and a varactor network comprising first and second varactors connected to receive a control voltage, the control voltage configurable to control a capacitance of the varactor network, the capacitance of the varactor network comprising a first capacitance of the first varactor determined by a first difference between the control voltage and the first bias voltage and a second capacitance of the second varactor determined by a second difference between the control voltage and the second bias voltage.

Abstract: The invention provides a variable tuning circuit capable of extending a variable range in a high frequency band, ensuring the value of L of an inductor to increase the value of Q of a circuit in a low frequency band, and preventing a reduction in gain, an increase in noise, and unstable oscillation. A variable tuning circuit includes: a first parallel resonance circuit that includes a varactor diode, a capacitor connected in series to the varactor diode, and a first inductor connected in parallel to the varactor diode and the capacitor; and a second parallel resonance circuit that includes a second inductor connected in parallel to the varactor diode with a direct current cut-off capacitor interposed therebetween. When the varactor diode has a maximum capacitance, a resonant frequency of the second parallel resonance circuit is set about a lowest frequency in a variable frequency range.

Abstract: A multi-band VOC includes a plurality of oscillators, each oscillators having an oscillatory range respectively; a plurality of capacitor tanks is provided in each oscillators, and each capacitors is composed of a plurality of capacitors in series connection; a voltage detecting device is provided to detect a voltage signal, and to select an oscillator; one end of a logic controller is provided to electrically connect to the voltage detecting device, and another end is provided to electrically connect to the capacitor tank, which is provided a control signal to drive capacitance of the capacitor tank; and a multiple device is provided to output an oscillation frequency.

Abstract: Provided is a tunable magnetic field amplifying device capable of easily adjusting resonance frequencies and tuning usable bands by using discrete elements to vary electric properties of elements that are used for amplifying a magnetic field of a specific microwave band. The tunable magnetic field amplifying device includes a Swiss roll formed by winding a metal sheet coated with a dielectric in a spiral cylinder shape once or several times; and a tunable capacitor connected between an inner sheet of and an outer sheet of the metal sheet for tuning a resonance frequency.

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 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: The present invention relates to a tunable circuit, or admittance, arrangement comprising at least one capacitive branch with at least a tunable first capacitor, and tuning application means. It further comprises at least one resonant branch comprising at least a second capacitor and an inductor, said second capacitor and said inductor being connected in series. Said at least one capacitive branch and said at least one resonant branch are connected in parallel, and said tuning application means are adapted for application of a DC tuning voltage. The capacitance of said first and/or second capacitor and/or the inductance of said inductor are selected such that the frequency dependency of the tunability of a varactor arrangement forming the equivalent varactor arrangement of the admittance arrangement can be controlled at least in a selected frequency range.

Abstract: A tuning arrangement for a resonant circuit, the tuning arrangement having an output reactance dependent upon a plurality of input applied signals one of which is an input tuning signal, and comprising: an array of tuning circuits connected in a network whose output reactance is used to control the resonance frequency of the resonant circuit, each tuning circuit having a control input and having a reactance which varies in dependence upon the value of a control signal applied to the control input; means for generating a plurality of different control signals for application to the control inputs of the tuning circuits; and each such control signal varying substantially linearly with the input tuning signal throughout a predetermined range specific to that control signal, so that the frequency response of the resonant circuit to the input tuning signal is substantially linear throughout a desired range of the input tuning signal.

Abstract: An untethered device, configured to inductively couple to a source device, includes a tunable resonant circuit having a resonance frequency and configured to generate a supply voltage for the untethered device in response to a varying magnetic field produced by the source device. The tunable resonant circuit includes an inductive coil comprising a center tap and a capacitive circuit coupled to the inductive coil. The capacitive circuit includes an anti-series arrangement of varactor diodes that behave as a capacitance when placed in reverse bias. A frequency control circuit is coupled to the tunable resonant circuit and includes a control voltage source coupled to the center tap of the inductive coil. The control voltage source produces a control signal to place the varactor diodes in reverse bias and to change the capacitance of the capacitive circuit, thereby effecting a change in the resonance frequency of the tunable resonant circuit.

Abstract: The invention provides a variable tuning circuit capable of extending a variable range in a high frequency band, ensuring the value of L of an inductor to increase the value of Q of a circuit in a low frequency band, and preventing a reduction in gain, an increase in noise, and unstable oscillation. A variable tuning circuit includes: a first parallel resonance circuit that includes a varactor diode, a capacitor connected in series to the varactor diode, and a first inductor connected in parallel to the varactor diode and the capacitor; and a second parallel resonance circuit that includes a second inductor connected in parallel to the varactor diode with a direct current cut-off capacitor interposed therebetween. When the varactor diode has a maximum capacitance, a resonant frequency of the second parallel resonance circuit is set about a lowest frequency in a variable frequency range.

Abstract: An embodiment of the present invention provides a method, comprising minimizing non-linear distortion effects in a circuit by applying tuning voltages within a predetermined voltage range to a plurality of oppositely oriented tunable capacitors within the circuit, thereby reducing the non-linear distortion effects. An embodiment of the present invention may further comprise applying an RF voltage within specified limits and wherein the predetermined voltage range may be determined so the combined capacitance of the plurality of tunable capacitors within the circuit remains essentially constant. Further, the predetermined voltage range may be derived by a CV curve that results in a constant total capacitance with no non-linear distortion.

Abstract: Receiver comprising an RF input filter including a digitally controlled capacitor bank with n capacitors being controlled by a tuning control signal for varying the tuning frequency of the RF input filter within a tuning range. For an improvement of the receiver in price/performance ratio the n capacitors of the digitally controlled capacitor bank are monolythically integrated, whereas the bandwidth of the tunable RF input filter is being adjusted to the maximum relative spread of said capacitors. A continuous tuning control signal is being supplied through an analogue to digital (AD) converter to said capacitor bank and to a first input of a differential stage, an output of the AD converter being coupled through a digital to analogue (DA) converter to a second input of a differential stage, an output of the differential stage being coupled to a control terminal of a variable capacitance diode being arranged in parallel to the digitally controlled capacitor bank.

Abstract: The invention relates to a tuner for converting a radio frequency signal into an intermediate frequency signal, said tuner comprising a voltage converter supplying a control signal, a mixer associated with an oscillator which is voltage-controlled by said control signal. The invention is characterized in that said voltage converter comprises: an auto-oscillating circuit generating an alternating voltage signal of a variable level, rectifying means for supplying a direct voltage signal of a variable level based on said alternating voltage signal of a variable level, an additional circuit for reducing the variations of the attenuation coefficient of said auto-oscillating circuit, said additional circuit receiving said direct voltage signal of a variable level and supplying said control signal. The invention provides an inexpensive solution having an improved performance in terms of spectral purity, ease of implementation and stability of control of said intermediate frequency signal.

Abstract: A linear tuning varactor circuit has the first single-end varactor circuit, the second single-end varactor circuit and a voltage divider. The first single-end varactor circuit has tuning terminal receiving the tuning voltage to change the capacitance thereof The second single-end varactor circuit has a reference voltage terminal receiving the reference with constant voltage. The first single-end varactor circuit and the second single-end varactor circuit are coupled to each other in series and have a node. The voltage divider is coupled to the tuning terminal, the reference voltage terminal and the node. The node has a divided voltage, which results from dividing a voltage difference between the tuning voltage and the reference voltage by the voltage divider with a pre-set voltage dividing ratio.

Abstract: An integrated component for radiofrequency applications has a resonant circuit with tuning diodes and trimming diodes that are connected in parallel. A programmable conductor network generates a trimming voltage at a trimming input that enables the production of a specific relationship between a voltage present at a tuning input and the resonant frequency of the resonant circuit.

Abstract: A linear voltage controlled capacitance circuit is provided that includes a plurality of MOS varactor pairs. Each MOS varactor pair is operable to receive a first tuning voltage, a second tuning voltage, and a bias voltage unique to the MOS varactor pair. The capacitance circuit is operable to generate a positive tank node signal and a negative tank node signal based on the first and second tuning voltages and the bias voltages. A means to control voltage-to-capacitance gain is also provided to compensate for coarse tuning capacitance change.

Abstract: An electronic component has at least a first diode and a second diode that are capacitance diodes. The characteristic curve of the second diode has a fixed, known relationship to that of the first diode. For example, the first diode and the second diode can have an identical variation ratio, being the quotient of the maximum and minimum adjustable capacitances. These components are suitable for use in television tuners, for example in three-band tuners, where diodes having the same characteristic curve and coming from different components are arranged and connected in each sub-receiving unit. The integration of a plurality of diodes reduces the number of components required, and also the time and cost involved in grouping together diodes with good synchronization properties.

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: In a secondary tuning circuit, a capacitor is provided between a connection point between a direct-current blocking capacitor and a tuning coil and a connection point between a varactor diode and another direct-current blocking capacitor. The capacitor, another tuning coil and the varactor diode form a trap circuit. As a result, it is possible to prevent a frequency selection characteristic of the multiple-tuning circuit from deteriorating due to an undesired new tuning circuit formed by a static capacitance generated in a non-conductive state of the switch diode.

Abstract: A high-frequency amplifier circuit for a UHF television tuner includes an FET having a first gate for inputting a UHF band television signal and a second gate for applying an AGC voltage which varies the gain. The second gate is grounded via a series circuit including a resistor and a DC-cutting capacitor. The impedance of the DC-cutting capacitor is sufficiently lower than the resistance of the resistor in the UHF band.

Abstract: An integrated component for radiofrequency applications has a resonant circuit with tuning diodes and trimming diodes that are connected in parallel. A programmable conductor network generates a trimming voltage at a trimming input that enables the production of a specific relationship between a voltage present at a tuning input and the resonant frequency of the resonant circuit.

Abstract: An electrically tunable radio frequency (RF) amplifier includes a resonant circuit having a voltage variable capacitance as one of its elements. In one approach, a drain diffusion capacitance of one of the transistors within the amplifier is used as the voltage variable capacitance. A voltage adjustment unit is provided to adjust a bias voltage on the voltage variable capacitance to change the capacitance value thereof and thus modify the operating frequency range of the amplifier. In one embodiment, the voltage adjustment unit also provides a power supply noise blocking function.

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: A variable frequency oscillator (VFO) circuit having an increased frequency tuning range to selectively obtain operating frequencies above and below a set frequency. The circuit includes a tank inductor connected in parallel with a tank capacitor for primarily defining the set oscillating frequency of the VFO circuit. A switchable capacitor is included for selectively providing a predetermined step-wise decrease of the oscillating frequency to a frequency value below the set frequency of the circuit, and a varactor is included for accommodating selective tuning of the oscillating frequency within a range of frequency values below the set frequency. The inventive circuit selectively includes a switchable inductance element which is selectively electromagnetically coupled to the tank inductor to decrease the overall inductance value of the VFO circuit and, thereby, selectively increase the oscillating frequency above the set frequency value.

Abstract: A double-tuned circuit of a tuner that can be switched for tuning to a plurality of frequency bands by turning a switching diode ON or OFF restrains degradation of a selectivity caused by an undesirable additional tuning circuit or parasitic tuning circuit formed by a capacitance generated when the switching diode is OFF and inter-terminal capacitance of a resistor. A double-tuned circuit of a tuner is also provided that exhibits good selectivity with reduced damping to a tuning circuit in a low-band receiving mode, and also exhibits a wider tuning range. A feed resistor for high-band receiving is directly connected to a switching diode in a primary tuning circuit, and the feed resistor for high-band receiving is connected to a switching diode via a coil in a secondary tuning circuit.

Abstract: A receiver for receiving both first-type reception signals, for example TV signals, and second-type reception signals, for example, FM-radio signals. The receiver may be used in multimedia applications. In the receiver, a reception signal is fed via an input section RFI-L, RFA-L, BPF-L to a mixer MIX-L. To obtain a relatively good performance, a band-pass filter BPF-L in the input section can be tuned through a frequency band, in which reception signals of both the first and the second type are present. The filter characteristics of the band-pass filter BPF-L are switched in accordance with the type of reception signal desired. For example, switching provides a passband which is substantially narrower for FM reception than for TV reception.

Abstract: A variable time delay network (210) includes segments (270, 260) which are connected in parallel to form variable time delay network (210). Segment (270) includes a varactor diode (222) and an inductive element (223) connected in series at an anode electrode (290) of varactor (222). A cathode electrode (291) of varactor diode (222) connected to a node (220). Segment (260) includes a varactor (221) and a bypass capacitor (224) connected in series at a cathode electrode (292) of varactor (221). Cathode electrode (292) is connected at a node (225). An anode electrode (293) of varactor (221) connected to node (220). The impedance at node (220) presented to a signal that is to be time delayed remains constant at the center frequency of the signal via a bias voltage applied at node (225) while controlling and changing the time delay of the signal via a bias voltage applied at node (220).

Abstract: A filter comprises an inductor, a first variable capacitance diode, a second variable capacitance diode having nearly identical characteristic as the first variable capacitance diode, a control terminal for applying voltage to the first and the second variable capacitance diodes, an input terminal, an output terminal and a signal line between the input terminal and the output terminal. A cutoff frequency is controllable with the voltage applied to the control terminal. The variable frequency filter which can receive a large signal has reduced size due to a structure in which the first and the second variable capacitance diodes having nearly identical characteristics are connected either in series or in parallel with their polarities reversed against each other.

Abstract: A selective RF circuit for a double conversion tuner includes three double tuned bandpass circuits, each of which is tunable over approximately one-third of the tuning range. Switching diodes are used at the input and the output of each of the bandpass sections for selectively activating one of the bandpass sections and deactivating the remaining ones in response to a bandswitching signal. Operational amplifiers or other devices supply the input and output switching diodes by providing a current sink for the active bandpass and current sources for the inactive bandpasses.

Abstract: A satellite broadcasting receiving tuner having a band-pass filter capable of adequately attenuating and removing disturbing wave components having frequencies in the vicinity of 480 MHz and capable of being easily tuned to the high-end frequency. The tuner has at least the band-pass filter for transmitting a down-converted received satellite broadcasting signal and a frequency converter section for converting the received satellite broadcasting signal transmitted through the band-pass filter into a signal having an intermediate frequency.

Abstract: A tuning circuit is formed of inductors connected in series, voltage-controlled variable capacitance means connected in parallel to the inductors, switch means connected in parallel to one of the inductors and capacitance means connected in parallel to another of the inductors, and the resonance frequency of a resonant circuit of the inductor and the capacitance means is set higher than the resonance frequency of the tuning circuit. When the switch means is turned off to change the frequency of the -tuning circuit to the lower frequency band, the frequency variable ratio of the tuning circuit becomes large and when the switch means is turned on to change the frequency to the higher frequency band, such frequency variable ratio becomes small, and the frequency variable width of the lower frequency band can be set almost equal to the frequency variable width of the higher frequency band by adequately selecting the capacitance of the capacitance means.

Abstract: A selective RF circuit for a double conversion tuner includes three sections: low and mid band double tuned bandpass sections and a high band double tuned bandpass section. Each section includes tuning varactors and one or more coupling varactors. The varactors are operated in a first tuning mode for exhibiting a variable capacitance and in a second mode for presenting a substantial low impedance across their terminals. A microprocessor controlled circuit arrangement applies DC potentials to the tuning and coupling varactors and to two pairs of switching diodes simultaneously for selecting and tuning the desired bandpass section. The varactors in each bandpass section are complemented with fixed capacitors selected so that the product of the loaded Q and the coupling factor of any active double tuned bandpass filter is maintained substantially equal to unity over the entire tuning range.

Abstract: A variable-frequency oscillator configuration, in particular for tuners, includes a feedback network for an oscillator amplifier. The feedback network contains a series circuit formed by two resonant circuit inductors and a resonant circuit capacitor, connected in parallel with a series circuit formed by a further resonant circuit capacitor and a variable capacitor. A switching device is connected to a coupling node between the two inductors, for short circuiting the first resonant circuit capacitor and the resonant circuit inductor connected thereto under the control of a switching signal. The feedback network can consequently be switched over between two frequency bands and is symmetrical with regard to the high-frequency effect.

Abstract: A band switchable resonant circuit for a voltage controlled oscillator has an inductive component in parallel with a plurality of varactor diodes. Some of the varactor diodes are selectively switchable to control the frequency range of circuit operation.

Abstract: A band switchable double tuned circuit having a balanced secondary is presented. A primary tunable tank circuit with a plurality of first inductances is tuned to a first frequency by a first capacitor coupled in parallel with the first inductances. A secondary tank circuit with a plurality of second inductances inductively coupled to ones of the first inductances has a second capacitor coupled in parallel with the second inductances for tuning the secondary to the first frequency. The DC reference potential for the secondary circuit, is coupled to a nodal junction of the plurality of second inductances with the secondary tank circuit providing a balanced signal output. At least one of the plurality of first inductances and the second inductances are switchable for bandswitching the tuning of the primary and secondary tank circuits to a second frequency.

Abstract: An oscillator comprising an amplifier device, a capacitive divider bridge whose terminals are connected between a control electrode of the device and a reference voltage, the intermediate junction point of this bridge being connected to a principal electrode of the device, and also comprising, in parallel between the control electrode and the reference voltage, a tuning circuit having parallel branches: a first branch with an inductance in series with a variable capacitance, and, a second branch equivalent to a variable capacitance. The tuning circuit has a third branch constituted by a capacitance in parallel with the first branch, while a series inductance whose value is smaller than that of the tuning inductance is arranged between the junction point connecting the two latter branches and the junction point connecting the control electrode of the device to the second branch and to the divider bridge.

Abstract: A tuner circuit is basically composed of: a series of a low-band coil and a high-band coil disposed on the signal side; a series of a low-band coil and a high-band coil disposed on the earth side; and a switching diode disposed between a junction of the low-band coil and high-band coil on the signal side and another junction of the low-band coil and high-band coil on the earth side. Further, the junction of the low-band coil and high-band coil on the signal side is connected to a band switching terminal via a first bias resistor while an input side terminal of the low-band coil on the signal side is connected with a second bias resistor.

Abstract: An electronic circuit (300) includes first (302) and second (304) variable impedance devices coupled together. The first (302) and second (304) variable impedance devices are designed such that each exhibits a transfer function which is substantially inverse with respect to the other about the operating point of the electronic circuit. This provides for an electronic circuit which exhibits very low distortion characteristics. Circuits such as tunable filters, voltage-controlled oscillators (VCOs), receivers, etc. will benefit from using an electronic circuit (300) which exhibits such low distortion characteristics.