Abstract: Radio-frequency (RF) apparatus includes receiver analog circuitry that receives an RF signal and provides at least one digital signal to receiver digital circuitry that functions in cooperation with the receiver analog circuitry. The receiver analog circuitry and the receiver digital circuitry are partitioned so that interference effects between the receiver analog circuitry and the receiver digital circuitry tend to be reduced.

Abstract: A transmitter 1 transmits from a transmission antenna 7 a mixture signal containing a radio-frequency (RF)-band modulated signal, and a portion of power of a local oscillation signal used for frequency conversion. Meanwhile, a receiver 8 detects the transmitted signal by means of a reception antenna-detection section 9. In the reception antenna-detection section 9, a plurality of base unit reception circuits 11 are disposed. Each base unit reception circuit 11 includes a planar printed antenna 12 such as a patch antenna, an amplifier circuit 13 formed on a very small planar circuit by means of an MMIC technique, and a mixer circuit 14 serving as a square-law detector. Respective outputs of the base unit reception circuits 11 are power-mixed and fed to the IF signal demodulation section. The IF signal demodulation section 10 demodulate reception data.

Abstract: A diversity receiver includes first and second reception circuits using a superheterodyne principle. At stationary reception, reception of the audio signals and the data employing a phase diversity reception system is performed such that the signals received by the first reception antenna are supplied to the first reception circuit, the signals received by the second reception antenna are supplied to the second reception circuit, and phases of first and second intermediate-frequency signals are controlled and the first and second intermediate-frequency signals are added. At reception-frequency search, reception of the audio signals employing an antenna-switching diversity reception system is performed such that the signals received by at least one of the first and second antennas are supplied to the first reception circuit and reception of the data and the reception-frequency search are performed, and the signals received by the first and second antennas are supplied to the second reception circuit.

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: A radio reception apparatus is a radio reception apparatus for demodulating a multicarrier signal modulated according to multicarrier modulation. It includes a plurality of antenna sections, each for receiving a multicarrier signal, a plurality of carrier selection sections, each of the carrier selection sections selecting at least one subcarrier signal for each of the antenna sections out of the multicarrier signal received by each of the antenna sections, an antenna selection section for selecting a reception antenna section from among the antenna sections based on the signal strengths of the subcarrier signals selected by the carrier selection sections, and a demodulation section for demodulating the multicarrier signal received by the antenna section selected by the antenna selection section.

Abstract: A multi-channel tuner apparatus is provided which is capable of simultaneously and independently selecting a plurality of channels for reception. The apparatus comprises a plurality of tuners, each of which converts a selected channel to a near-zero intermediate frequency. The output signals from the tuners are supplied to respective sample/hold circuits, whose outputs are supplied to a single analogue/digital converter for multiplexing the tuner signals and converting them to the digital domain. A common demodulator arrangement processes the digital domain signal to extract the information from all of the selected channels.

Abstract: A filter wherein the poles and zeroes are programmable in a high speed control loop to form a particular desired filter profile. The control loop retrains the filter's poles and zeroes during the “off” time between the reception or transmission time slots. Desired pole and zero frequencies are injected and peak values are stored in sample and hold circuits. This eliminates variations from voltage supplies, component tolerance, temperature, aging, etc.

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 tunable receiver is disclosed including a plurality of select filters to perform an initial band selection, a variable-gain low noise amplifier (LNA) whose gain is controlled to prevent its output power level to exceed a pre-determined power threshold, a plurality of digitally-tunable tracking filters to pass signals within a selected channel and to reject signals in a corresponding image band, a second LNA to further amplify the received RF signal and to generate differential signal outputs, a down converting stage which converts the received RF signal to an IF signal while rejecting signals in the image band, an IF trap to further reject undesired signals present at the output of the down converting stage, an IF amplifier to amplify the IF signal to compensate for losses, an IF filter to provide channel select and reject undesirable signals, and a variable-gain IF amplifier to amplify the IF signal and maintain its power level within specification.

Abstract: While a spectrum waveform of an output signal from a subtracter (207) is visibly monitored, an operator controls a variable phases shifter (208) based upon a second control signal (CL2) so that a shape of a spectrum waveform of an output signal from a subtracter (207) is approximated to a spectrum waveform of a desirable wave to change a phase of a local oscillation frequency signal from a local oscillator (206). As a result, a phase of a duplicated loop signal is changed. Also, the operator controls a variable attenuator (209) based upon a first control signal (CL1) so that a shape of this spectrum waveform is approximated to a spectrum waveform of a desirable wave (20) to change a signal level of the duplicated loop signal.

Abstract: A dual digital television tuner includes first and second direct conversion circuits, each having a pair of mixers and a local oscillator, in which a digital television signal is input to the pair of mixers, which directly output baseband signals. The first direct conversion circuit may have a frequency divider or a multiplier. Each of the pair of mixers, the local oscillator, the frequency divider, and the multiplier is constituted by a balanced circuit. An oscillation signal of the local oscillator in the first direct conversion circuit is input to the pair of mixers of the first direct conversion circuit through the frequency divider or the multiplier.

Abstract: A channel scanning method in a multi-channel digital broadcast is provided for enabling a user to identify the broadcast contents of a channel being currently received with accuracy during the channel scan, even though the broadcast contents may change within a channel scanning time period. In one embodiment of the channel scanning method, a receive channel is switched at predetermined intervals (the scanning time period), it is checked whether the broadcast contents of the channel being received currently, after the channel switching, will change within the scanning time period, and a time period for receiving the channel is prolonged, if the broadcast contents will change.

Abstract: An electronic alignment system for a television signal tuner utilizes first and second controllers for generating respective first and second control signals for respective first and second signal processing circuits of a signal processing arrangement, with the first and second signal processing circuits having respective first and second tunable elements responsive to the respective first and second control signals. A deviation range of the first control signal is higher than a deviation range of the second control signal.

Abstract: Needless signal that causes interference is prevented from entering to eliminate the generation of interfering signal. A television tuner is provided with a band switching circuit to which television signals of a plurality of channels arranged in a predetermined frequency band are supplied, the band switching circuit has a plurality of filters having the cutoff frequency of every one octave frequency in the predetermined frequency band, the cutoff frequency of the plurality of filters is made continuous every one octave in the predetermined frequency band, and the television signal of the channel to be received is sent out through a specified filter having the cutoff frequency within one octave from the frequency of the television signal of the channel to be received.

Abstract: An input circuit for an AM/FM radio receiver having an FM intermediate frequency rejection circuit and an AM image frequency rejection circuit, an FM input circuit for receiving frequency-modulated input signals and an AM input circuit for receiving amplitude-modulated input signals, and PIN diodes are provided for switching from AM operation to FM operation between the FM intermediate frequency rejection circuit and the AM image frequency rejection circuit. The PIN diodes connect the FM intermediate frequency rejection circuit for high-frequency signals to ground when FM operation is selected, and a control voltage is applied to the switching device for providing automatic gain control between the FM intermediate frequency rejection circuit and the AM image frequency rejection circuit when AM operation is selected.

Abstract: A monitoring receiver accepts program preferences from an operator. When active, the receiver automatically monitors alternate frequencies for programming that matches the program preferences, alerts the operator when a match is found, and may switch to a preferred program.

Abstract: A TV tuner unit uses a frequency-selective element before or after the resonance stage of either a UHF or VHF tuner for separation of UHF signals from VHF signals. Thus, performance is preserved while eliminating the need for circuitry including high and low pass filters and related switches.

Abstract: A low-priced digital broadcast receiving tuner suitable for miniaturization will be provided. According to the present invention, it is possible to provide a low-priced digital broadcast receiving tuner having higher productivity as well as a less number of components than a conventional tuner because, on one surface of an insulating board, there is formed a first tuner while, on the other surface thereof, there is formed a second tuner, and therefore a single insulating board can be shared.

Abstract: An electronic alignment system for a television signal tuner utilizes first and second controllers for generating respective first and second control signals for respective first and second signal processing circuits of a signal processing arrangement, with the first and second signal processing circuits having respective first and second tunable elements responsive to the respective first and second control signals. A deviation range of the first control signal is higher than a deviation range of the second control signal.

Abstract: A broadband television receiver front end for receiving a broadband RF input signal and outputting an IF output signal is disclosed. A high pass input filter on the front end attenuates carrier signal frequencies that lie below a cut off frequency of said high pass filter. Thereby advantageously allowing for a number of carrier signals to propagate below the cutoff frequency in such a manner that these signals have a decreased effect on television signals propagating within a television signal band. By high pass filtering on the input a low noise amplifier disposed for receiving a filtered signal from the high pass filter does not amplify noise caused by lower frequency carriers. As a result an amplified signal provided to up-conversion and a down-conversion mixers results in an increased immunity to noise in the output IF signal from the front end.

Abstract: A phase-locked loop (PLL) tuning controller monitors a voltage value of an automatic frequency control (AFC) signal, and detects a first frequency at which a first threshold voltage value accords with the AFC voltage value while varying an oscillation frequency of a local oscillator in either direction of frequency-increasing or frequency-decreasing in accordance with an AFC value when a synchronous signal of a broadcasting to be received is first detected. After then, a second frequency at which a second threshold voltage value having a value different from the first threshold value accords with the AFC voltage value while varying the oscillation frequency in a reversed direction for which the first frequency has been detected. Then the second frequency is locked as a center frequency of the broadcasting to be received. Accordingly, even if the AFC voltage level irregularly varies, the tuning frequency is fixed to the original center frequency of the broadcast to be received.

Abstract: The present invention encompasses a mobile station comprising a transmitter for transmitting outgoing signals from the mobile station and a receiver for receiving incoming signals, the receiver coupled to the transmitter and having N subreceivers, where N is an integer greater than one and each of the N subreceivers may independently be tuned to a desired frequency.

Abstract: A method for tuning a cavity filter is provided. The cavity filter includes a plurality of tuning members. The method includes selecting a stored set of positional values for the tuning members, driving the tuning members of the cavity filter to the stored set of positional values, and further adjusting the position of the tuning members as necessary to achieve a desired frequency response for the cavity filter.

Abstract: A tuner block in which a modulator and an IF/demodulator circuit are integrally formed. The tuner block has a casing for accommodating a tuner, the IF/demodulator circuit and the modulator, and sixteen pins consecutively disposed at an outside of the casing. A number of the pins is reduced as compared with a conventional tuner block by supplying an electrical power to the modulator and the tuner through a common pin, dispensing with pins carrying unnecessary signals and pins which carry no signal and rearranging other pins. Potential for noise and interference between signals is reduced by maximizing displacements of connector pins which carry signals which are likely to interact. A switching arrangement provides for utilizing either a conventional tuner block or a tuner block according to the present invention on a circuit board.

Abstract: A tuning circuit, as for a television receiver or video recorder, employs switchable tuning circuits including micro-electronic electro-mechanical switches for selecting the ones of an array of capacitors and/or inductors as is useful in tunable circuits. The array of capacitors and/or inductors and micro-electro-mechanical switches of the switched tuning matrix is formed on an integrated circuit or an electronic circuit substrate along with amplifiers and other electronic elements of the tuning circuit for which the switched tuning matrix is employed. The switchable capacitance and inductance matrices are well suited for use in the resonators employed in the pre-selector filters, post-selector filters and oscillators of electronic tuners, such as those employed in television receivers and video recorders.

Abstract: Frequency matching method and apparatus to automatically adjust the frequency of a communication signal received by a mobile system are provided. The apparatus comprises: a baseband unit for changing frequency of a signal received through an antenna and providing an output signal; a control unit for recognizing one or more frequency characteristics of the output signal and applying a control voltage in accordance with the respective frequency characteristics; a matching unit connected to the antenna for changing the signal frequency according to the control voltage; and a memory in which control voltage values for the respective frequency characteristics are stored. Accordingly, signal gain is optimized in correspondence with the respective frequency characteristics and thereby signal reception and transmission are improved.

Abstract: An antenna circuit which is improved the deterioration of amplitude characteristic in a strong electric field, an antenna circuit for AM broadcasting which can surely inhibit and damp FM-band signals in the strong electric field and amplifies to output AM-band signals, and an antenna circuit for AM/FM broadcasting in which AM-band signals are not damped by means of an FM-band filter. In the first antenna circuit, the output signal of an antenna (10) is supplied to the base of a transistor Tr2 forming a current amplification type amplifier having a high-input and low-output impedance and the emitter of the transistor Tr2 is grounded through a coil L6 and connected to an FM receiver (16) through a band-pass filter (38). In the second antenna circuit for receiving AM broadcasting, an input terminal is connected to an AM amplifier circuit (36) through coils (L7) and L8 in series and to the gate G of a field effect transistor FET.

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: A signal convertor for modulating or demodulating an input signal x(t), comprising: a synthesizer for generating wideband mixing signals &phgr;1 and &phgr;2, which vary irregularly over time, where &phgr;1*&phgr;2 has significant power at the frequency of a local oscillator signal being emulated; a first mixer coupled to said synthesizer for mixing said input signal x(t) with said mixing signal &phgr;1 to generate an output signal x(t) &phgr;1; and a second mixer coupled to said synthesizer and to the output of said first mixer for mixing said signal x(t) &phgr;1 with said mixing signal &phgr;2 to generate an output signal x(t) &phgr;1 &phgr;2.

Abstract: In a television tuner system, a printed board is disposed within a frame having a side plate. A tuner and an intermediate frequency circuit are disposed adjacent to each other on the printed board. The tuner has a mixer and a local oscillator. The intermediate frequency circuit includes at least a SAW filter having a plurality of terminals. A first ground conductor is formed between the tuner and the intermediate frequency circuit. A second ground conductor is formed at a peripheral edge of the printed board. The SAW filter is placed along the second ground conductor in such a manner that the terminals of the SAW filter are arranged substantially parallel to the side plate. The local oscillator is disposed substantially on a line extending from the arrangement of the terminals of the SAW filter. With this arrangement, the distance between the output terminals and the local oscillator is greater than that between the input terminal and the local oscillator.

Abstract: A reception control system for automobiles according to the present invention includes tuners for a plurality of receivers for receiving various types of waves including at least an AM/FM broadcast wave, a TV broadcast wave and a GPS wave. The tuners are separated from receiver bodies and integrally incorporated into an antenna section (a plurality of antenna elements+an AM/FM reception circuit+a TV reception circuit) including at least a plurality of antenna elements. The tuners are supplied with a digital control signal through a LAN provided in an automobile thereby to control reception of waves.

Abstract: Disclosed is a digital TV receiver performing a channel selection using stored channel information and a method for selecting a channel. With respect to a broadcasting signal which is not being currently viewed, the receiver activated at a predetermined period of time to receive that broadcasting signal. The receiver receives and stores channel information for that signal. A channel selection is performed by displaying the stored channel information or an effective channel according to the stored channel information, at the time of switching of a reception mode. Since the channel selection is performed using the stored channel information, the invention can save a time for selecting a channel and provide convenience of use.

Abstract: The short range radio receiver for motor vehicle data comprises antenna circuits (1-4) connected to a unit (10-15) for processing a carrier in a plurality of specific frequency bands which is modulated by a data signal, the unit (10-15) comprising frequency-transposing circuits (11, 23-28) connected to demodulation circuits (13) supplying the demodulated data, and frequency discrimination circuits (21, 22) are provided, connected to the antenna circuits (1-4), to determine respective reception levels within the bands in order to compare them with each other and to control the frequency transposing circuits (11, 23-28) depending on the result of the comparison.

Abstract: The high frequency tuning amplifier for buffer has a tuning circuit consisting of a serial circuit of the first and second inductors connected between the output of transistor amplifying stage and the power source, a first capacitor connected in parallel to the serial circuit of first and second inductors, a serial circuit of the second and third capacitors connected in parallel to the second inductor and a switching element to which a band switch voltage is supplied, connected between the connecting point of the second and third capacitors and the reference voltage point. The tuning circuit is tuned to the high band frequency when the switching element is turned ON and to the low band frequency when the switching element is turned OFF.

Abstract: Between one end of a high-band tuning coil in a primary tuning circuit and one end of a high-band tuning coil in a secondary tuning circuit, a first switch diode and a second switch diode connected in series are provided. A second coupling coil is provided between the ground and the connection point of the first switch diode and the second switch diode. Both first switch diode and second switch diode are set to a continuity state or a non-continuity state to switch between a high-band state and a low-band state.

Abstract: A method and apparatus for wide range automatic frequency control. A control signal indicating a frequency within one of a plurality of frequency bands is received by an oscillator. In response, the oscillator generates a tuning signal having the indicated frequency. Based on the tuning signal, receive logic receives an input signal to obtain a sequence of values. Compare logic compares the sequence of values to a predetermined pattern. If the sequence of values does not match the predetermined pattern, frequency control logic outputs a different control signal to the oscillator to adjust the frequency of the tuning signal to another one of the plurality of frequency bands. Another input signal is received to obtain a new set of values and the new set of values is compared the predetermined pattern.