Abstract: A receiver, in particular for mobile radio, includes a receiver branch with a mixer, downstream of an analog/digital converter. A reference generator generates a reference clock, which is fed to the converters or PLL synthesizers of the mixer by integral multiplication or division. As a result, a particularly energy-saving and space-saving circuit configuration is realized, which has a low level of mutual interference between the signals and is suitable (in particular for Universal Mobile Telecommunication System, UMTS). In a preferred embodiment, the receiver is developed into a transceiver by providing a transmission path.

Abstract: An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator.

Abstract: A zero intermediate frequency (ZIF) radio frequency (RF) digital mixer (200) includes a low noise amplifier (LNA) (203), a first RF mixer stage (205) for mixing an RF signal from the at least one LNA with a first local oscillator signal operating a first predetermined frequency. A second RF mixer stage (207) is then utilized for mixing in-phase (I) and quadrature (Q) digital signals from the first RF mixer stage (205) with a plurality of second local oscillator signals (LO) operating at a second predetermined frequency. The invention significantly improves current drain by eliminating the need for a linear transconductance stage while still maintaining high degrees of isolation and linearity.

Abstract: The present invention relates to a self-adaptive band-pass filtering device in a microwave signal transmitter and/or receiver, the receiver being connected to a microwave signal receiving antenna connected to the input of a low-noise amplifier, a mixer that receives, on the one hand, the output signal of the low-noise amplifier and, on the other hand, the signal from a frequency synthesizer, characterized in that the self-adaptive filtering device comprises, upstream of the amplifier, on the one hand, at least one filtering means having at least two different frequency bands and, on the other hand, means for selecting either a filtering means or one of the frequency bands depending on the frequency of the signal to be received.

Abstract: A receiver apparatus is provided with a receiver section including an amplifying stage for amplifying a high frequency signal received by an antenna, a frequency converting stage for converting a frequency of the output signal of the amplifying stage, a local oscillator for supplying a local oscillating signal to the frequency converting stage, and a signal processing section for supplying a control signal to the receiver section depending on signal intensity inputted to the receiver section, or to the signal processing section from the receiver section. The frequency converting section includes a plurality of parallel frequency converters, and an adder for adding output signals of the frequency converters. The signal processing section controls the number of the frequency converters to be operated.

Abstract: A multiple purpose antenna system for installation on a highway truck to receive and transmit signals. The system includes an antenna for communication of electromagnetic frequency signals having multiple band widths, a multiplex unit coupled to the antenna having circuitry for simultaneously passing multiple signals of band widths, and a filter unit. The filter is coupled to the multiplex unit for filtering signals received from the multiplex unit into multiple sets of band width ranges. The sets include a first frequency range for use by a first receiver apparatus, a second frequency range for use by a second receiver apparatus, and a third frequency range for use by a third receiver apparatus. The filter unit may be included within a satellite electronic communications unit. The first receiver apparatus may be a weather band radio apparatus. The third receiver apparatus may be an AM/FM commercial radio.

Abstract: A dual channel downconverter that includes a two-channel heterodyne receiver architecture for downconverting two frequency-agile, pulsed RF signals to identical fixed IF signals without the use of a tunable local oscillator. This accomplishes downconversion while preserving, in the IF output signals, any amplitude modulations present in the RF signals. The device also preserves phase difference changes present in the RF signals while rejecting the phase modulations common to those input signals. The present device facilitates complex response measurements of pulsed two-port RF devices while operating in a target system such as a radar transmitter, including insertion gain, insertion phase, residual phase noise, error vector magnitude, AM noise, and group delay, all with increased accuracy, good repeatability, good dynamic range, and decreased measurement time.

Abstract: The present invention is directed to a system and method of reducing frequency interference in a circuit when the harmonics of at least two frequencies could cause interference when such harmonics interact with each other. In one embodiment, a determination is made as to which harmonic could possibly support such interference, and based upon the determined harmonic, determining which combination within said determined harmonic is likely to cause the interference.

Abstract: The mixer circuit is a singled ended input to a double balanced high dynamic range mixer with only two base-emitter junctions across the supply. It provides for the use of bondwires to off chip ground as DC block and DC feed elements. The single ended input and differential output balanced mixer is well suited for the input stage of an integrated radio receiver—off chip circuitry is usually single ended, but on chip circuits are usually differential. No off chip differential RF circuits or baluns are required which reduces off chip component count and improves radio performance. The mixer circuit has lower LO drive requirements because of the DC coupled LO port. This results in better radio performance and a smaller die area because of the DC coupled IF port.

Abstract: This patent describes a method and system which overcomes the LO-leakage problem of direct conversion and similar RF transmitters. To solve this problem a virtual LO™ signal is generated within the baseband which is tuned to the incoming RF signal. The virtual local oscillator (VLO) signal is constructed using signals that do not contain a significant amount of power (or no power at all) at the wanted output RF frequency. Any errors is generating the virtual LO signal are minimized using a closed loop correction scheme.

Abstract: A radio for use in microwave datalink applications in which a common local oscillator is used for both a final radio frequency (RF) up-converter stage and an initial RF down converter stage. The frequency of the common local oscillator corresponds to an integer multiple of a local oscillator needed for an earlier up-converter or later down converter stage. The circuit can be used to provide a radio frequency carrier in a 30 GHz band using Coaxial Resonator Oscillators (CRO's) that lend themselves to a planar microstrip circuit implementation.

Abstract: A receiver is operable even if including a local oscillator generating a signal at high frequencies but not in a wide frequency range. The receiver includes: a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into respective signals of plural first intermediate frequencies corresponding to a frequency of the received signal; and a second frequency converter for converting the signals of the first intermediate frequencies into a signal of a second intermediate frequency.

Abstract: A radio frequency (RF) integrated circuit (IC) includes a local oscillation module, analog radio receiver, analog radio transmitter, digital receiver module, digital transmitter module, and digital optimization module. The local oscillation module is operably coupled to produce at least one local oscillation. The analog radio receiver is operably coupled to directly convert inbound RF signals into inbound low intermediate frequency signals based on the local oscillation. The digital receiver module is operably coupled to process the inbound low IF signals in accordance with one of a plurality of radio transceiving standards to produce inbound data. The digital transmitter is operably coupled to produce an outbound low intermediate frequency signal by processing outbound data in accordance with the one of the plurality of radio transceiving standards. The analog radio transmitter is operably coupled to directly convert the outbound low IF signals into outbound RF signals based on the local oscillation.

Abstract: Adaptive receiver system that adjusts to the level of interfering signals. An adaptive system is provided for use with a radio receiver to adapt to interfering signals associated with a received RF signal. The radio receiver includes a LNA to receive the RF signal and produce an amplified signal that is coupled to a down-converting mixer that produces a mixer output. A peak detector is coupled to receive the mixer output to produce a peak signal. An integrator is coupled to the peak detector to receive the peak signal and produce an integrated signal and a mixer is coupled to receive the integrated signal and a transmit power indicator to produce a current control signal that is coupled to the LNA. The current control signal is used to control a bias current of the LNA, so that cross modulation associated with the received RF signal is reduced.

Abstract: A millimeter wave band communication apparatus includes a millimeter wave band transmitter receiving a plurality of input modulation signal waves to transmit a millimeter wave band multiplex signal wave, and a millimeter wave band receiver receiving the transmitted millimeter wave band multiplex signal wave to restore the plurality of input modulation signal waves. The millimeter wave band transmitter includes a frequency arranging circuit generating a multiplex signal wave having respective frequency bands of the plurality of input modulation signal waves arranged on the frequency axis independent of each other, a frequency up-converter up-converting the generated multiplex signal wave to the millimeter wave band, and a transmission circuit transmitting the millimeter wave band multiplex signal wave.

Abstract: The invention provides a mixer comprising a multiplier circuit having a first and a second mixer, a generator for generating two first and two second control signals for controlling the first and second mixers, wherein the first and second control signals are in each case balanced signals and the first control signals have a frequency f1 and the second control signals have a different frequency f2.

Abstract: A phase interpolation receiver for receiving angle modulated radio frequency signals. The receiver comprises mixers for down-converting the received angle modulated signal to lower frequency signals, limiters, interpolation filters, and a demodulator. The mixers down-convert the received RF signal to a low IF intermediate frequency signal. The low IF intermediate frequency signal is limited. After further down-conversion to zero IF, using quadrature mixers, the limited signal is phase interpolated. The intermediate frequency is chosen such that the limited signal comprises an unwanted signal at twice the intermediate frequency that acts as a noise spreading signal for spectrally spreading of quantization noise generated by the limiters, and the cut-off frequency of the interpolation filters is chosen such that the unwanted signal and the spread quantization noise are suppressed.

Abstract: A circuit configuration for mixing a differential desired signal with a differential local oscillator signal includes two difference amplifiers which are controllable on the input side by the desired signal and cross-coupled on the output side. Currents flowing through the difference amplifiers are switched by the components of the local oscillator signal in alternation. The circuit makes a lower supply voltage possible, given the presence of only two transistor levels.

Abstract: A direct conversion receiver apparatus includes a local oscillator to produce a first local oscillation signal and a second oscillation signal. A first modulation circuit modulates the first local oscillation signal, and a second modulation circuit modulates the second local oscillation signal. A RF mixer mixes a received radio frequency signal with the modulated first local oscillation signal, and another RF mixer mixes the received radio frequency signal with the modulated second local oscillation signal. Demodulating circuits translate desired signals of the mixed signal from the RF mixers into band and translate undesired signals of the mixed signal out of band. Filters remove the undesired signals from the demodulated signals.

Abstract: A superhet receiver in which an input signal is frequency down-converted in a first mixer (14) to produce a first IF signal comprising a wanted channel signal and an image channel signal. The first IF signal, without image rejection filtering, is frequency down-converted in a second mixer (24) to produce a second, lower IF signal comprising at least the wanted channel signal having a bandwidth corresponding to a predetermined passband of a channel filter (32) coupled to the output of the second mixer. The local oscillator signals used in the first and second frequency down conversion processes are varied in order to produce successively different image channel signals in the first IF signal and to maintain the wanted channel signal in the second IF signal within the passband of the channel filter (32).

Abstract: There is disclosed a radio frequency (RF) demodulation circuit comprising: 1) a first RF mixer having a first input port for receiving an in-phase RF signal having a frequency of RF and a second input port for receiving an in-phase local oscillator (LO) signal having a frequency of LO, wherein LO is approximately equal to one-half of RF, and wherein the first RF mixer generates a first intermediate frequency (IF) signal having a frequency of LO; 2) a second RF mixer having a first input port for receiving an out-of-phase RF signal having a frequency of RF and a second input port for receiving an out-of-phase local oscillator (LO) signal having a frequency of LO, and wherein the second RF mixer generates a second intermediate frequency (IF) signal having a frequency of LO; and 3) a first signal combiner for combining the first and second IF signals to generate a composite IF signal, wherein the first signal combiner combines a first leakage signal from the first RF mixer and a second leakage signal from the se

Abstract: An ultra-wideband receiver system includes an intelligent-preselector stage to up-convert received signals to signals within a first IF frequency-range with stepped first oscillation signals, a first down-converting stage to down-convert the signals within the first IF frequency-range to signals within a second IF frequency-range with a fixed second oscillation signal, and a second down-converting stage to down-convert the signals within the second IF frequency-range to signals within a third IF frequency-range with stepped third oscillation signals. The center frequency of the first IF frequency-range may be at least 30% to 35% higher than a highest frequency in the receive-frequency range to provide an image frequency far from (e.g., more than twice) the highest frequency in the receive-frequency range. The receiver may also include a synthesizer to generate the first, second and third oscillation signals with half-integer frequency dividers based on a master reference signal.

Abstract: A double balanced mixer for mixing an RF input signal with a local oscillator signal to provide at an output an intermediate frequency signal with a high third order intercept point. A first and second local oscillator balun receives a local oscillator signal. A first and second RF balun receives a RF signal. A first mixer is coupled to the first local oscillator balun and the first RF balun. A second mixer is coupled in parallel with the first mixer. The second mixer is coupled to the second local oscillator balun and the second RF balun. The parallel coupled mixers provide an intermediate frequency signal. A first intermediate frequency balun is coupled to the first mixer and a second intermediate frequency balun is coupled to the second mixer. The mixer also has increased isolation.

Abstract: A multi-stage channel select filter and associated methods are disclosed that can be used, for example, with receiver architectures and associated methods that are also described herein. The multi-stage channel select filter can include a plurality of cascaded stages including at least one tunable stage. Each stage can include a digital mixer, a low pass filter and a decimator, with the decimator for each tunable stage including a tunable decimator having a decimation rate selection signal as an input. In addition, each non-tunable stage, if any are utilized, can include a decimator having a fixed decimation rate. In operation, the first cascaded stage is configured to receive a digitized channel signal spectrum, and the last cascaded change is configured to output a baseband signal representative of a desired channel within the digitized channel spectrum.

Abstract: The bandwidth of the band pass filter is to be kept narrow to prevent C/N deterioration, and yet the video carrier and the audio carrier on the final output channel are to be maintained at the same level even if its center frequency deviates from the design value. A double frequency converter is provided with a first mixer for frequency conversion of input signals with first local oscillation signals into first intermediate frequency signals; a second mixer for frequency conversion of the first intermediate frequency signals into output signals with second local oscillation signals; and a band pass filter disposed between the first mixer and the second mixer, wherein the frequency of the first local oscillation signals and that of the second local oscillation signals can be shifted by the same frequency.

Abstract: A frequency down-converter (18) for a receiver (10) in a wireless telecommunications system. The down-converter (18) is capable of simultaneously processing a plurality of signal channels without increased signal distortion over a relatively wide bandwidth. The frequency down-converter (18) employs a suitable mixer (28), bandpass filter (32), attenuator (34) and transformer (36) that are tuned to provide the desired frequency down-conversion and amplitude control over the desired wideband width. In one embodiment, the bandpass filter passes a frequency band at 25 MHz or above. The frequency down-converter (18) generates the IF signal in a single step down-conversion process, or generates the IF signal and then a baseband signal in a two step down-conversion process.

Abstract: Embodiments of a frequency modulated (FM) demodulator and associated methods are generally described. According to but one example embodiment, an apparatus is disclosed comprising a receiver front-end, to receive a signal from one or more antenna(e) and generate quadrature components of the received signal, and a frequency-shifted, cross-multiplied differentiator demodulator, coupled with the receiver front-end, to generate a demodulated representation of the received signal centered at a select intermediate frequency.

Abstract: A low pass filter for removing a high harmonic wave of an local oscillation signal LO1 is provided between the first stage local oscillation circuit and a mixer circuit, and a cut-of frequency of the low pass filter changes in response to the frequency of the local oscillation signal LO1. In the conventional structure, for the interference of high harmonic wave represented by an output spurious, simply inserting a low pass filter is not sufficient, and it is also necessary to provide a bypass filter, or the structure for more surely connecting the sealed cap or the substrate to ground, etc. In contrast, according to the foregoing structure of the present invention, even when receiving low frequency, the high harmonic wave can be attenuated to a sufficient level without a band width restriction, and such structure required in the conventional structure for the interference of high harmonic wave can be omitted, and a cost reduction or improved degree of freedom in design choice can be achieved.

Abstract: DC offset is estimated in a wireless receiver during a period when receive energy is blocked from reaching a mixer within the receiver. The estimated DC offset value may then be used to reduce DC offset within the wireless receiver when a receive signal is subsequently being processed.

Abstract: A multiple conversion tuner comprises a plurality of cascade-connected frequency changers, each of which comprises a mixer and a local oscillator. The tuner also comprises a local oscillator frequency selecting circuit which controls the frequencies of the local oscillators. The frequencies are controlled so that the final mixer converts a desired signal to the final intermediate frequency and so that the frequency band occupied by the desired signal at the output of each mixer is within the passband of the following intermediate frequency part of the tuner.

Abstract: A programmable digital divider operates under the control of a division controller to derive a second synthesized frequency based on a first synthesized frequency. The programmable divider divides the first synthesized signal to derive the second synthesized signal. The division amount is an integer, but varies between integer values if necessary to achieve a non-integer average division value. The majority of the noise generated by the frequency synthesizer is generated away from the centerline frequency and is easily filtered by narrowband filter. The frequency synthesizer may optionally be incorporated into a modified phase-locked loop to generate the second synthesized signal. By using a digital divider, instead of a traditional phase-locked loop, these embodiments allow for integration of the frequency synthesizer onto an integrated circuit, thereby lowering cost and improving resistance to noise spurs. This approach is particularly suited to telecommunications applications.

Abstract: A method is provided for selecting the frequencies of local oscillators and intermediate frequency converters of a receiver that selects the frequency for a first intermediate frequency converter, selects a frequency for a first local oscillator above the frequency of the first intermediate frequency converter to provide an overlapping harmonic first gap, and selects a frequency for a second local oscillator to provide a harmonic gap overlapping said first gap.

Abstract: A mixer oscillator stage, which can be used both with a switched 2-band concept and a 3-band concept without changing the architecture of the oscillators which exceeds the number of mixers and by coupling the mixer(s) and oscillators via a switching circuit so as to switch between the different oscillators in dependence upon the part of the band converging the signal.

Abstract: A high-frequency composite component can achieve reduction in size and weight, while providing high performance. A portable wireless device incorporates the high-frequency composite component, including a multi-layer substrate, with a low noise amplifier LNA and a band pass filter BPF constituting parts of a high-frequency circuit, with an input terminal, an output terminal, and control terminals on the substrate. The low noise amplifier LNA is constituted of transistors, an inductor, capacitors, and resistors. The band pass filter BPF is constituted of strip lines, an inductor, and capacitors. The low noise amplifier LNA and the band pass filter BPF are connected with each other within the substrate via a matching capacitor. The amplifier ground and filter ground are separated within the substrate and connected respectively to separate ground terminals on the substrate.

Abstract: A carrier reproducing apparatus and method enabling stable operation even at a low S/N, wherein, when phase signals are locked and exceed a predetermined value, a tracking circuit generates a signal and an oscillation frequency of a signal output from a numerical control oscillation circuit is controlled so that the phase signals do not exceed the predetermined value and wherein a down sampling circuit and an interpolation circuit convert signals having a frequency of more than twice the symbol rate to signals having a frequency of twice the symbol rate.

Abstract: In a multi-heterodyne stage for a receiver or spectrum analyzer, a first mixer has a symmetrical output which produces first intermediate-frequency signals of equal-value and are oppositely-phased, which, after passing through an intermediate-frequency filter, are combined in a second mixer having a symmetrical input into a second intermediate frequency.

Abstract: A system for using a translation loop upconverter and power amplifier including a secondary phase-error correction loop uses the output of the upconverter to lock a feedback loop during a time in which the output of the power amplifier is insufficient to provide feedback to the upconverter. After the power amplifier has developed sufficient power to provide feedback to the upconverter, the feedback to the upconverter is taken from the output of the power amplifier. By placing a phase detector and phase shifter in the secondary feedback path taken from the output of the power amplifier, any phase distortion present in the system can be detected and corrected.

Abstract: A MIMO radio transceiver to support processing of multiple signals for simultaneous transmission via corresponding ones of a plurality of antennas and to support receive processing of multiple signals detected by corresponding ones of the plurality of antennas. The radio transceiver provides, on a single semiconductor integrated circuit, a receiver circuit or path for each of a plurality of antennas and a transmit circuit or path for each of the plurality of antennas. Each receiver circuit downconverts the RF signal detected by its associated antenna to a baseband signal. Similarly, each transmit path upconverts a baseband signal to be transmitted by an assigned antenna.

Abstract: A radio receiver having a selectable first downconverter stage for each mode to convert radio frequencies to intermediate frequencies, a second downconverter stage to convert the intermediate frequencies to baseband frequencies, said second downconverter stage being common to both modes, and channel selection at baseband frequencies by means of re-configurable filtering. A radio receiver having a selectable first downconverter stage for each mode to convert radio frequencies to intermediate frequencies, a second downconverter stage to convert the intermediate to baseband frequencies, said second downconverter stage being common to all modes, and channel selection at baseband frequencies by means of re-configurable filtering.

Abstract: Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

Abstract: A digital portable telephone unit of the invention is equipped with: an antenna through which signal is transmitted and received; a radio section which conducts the frequency conversion of signal and outputs IF (intermediate frequency) and RSSI (receive signal strength indicator); a demodulation section which demodulates the IF to output receive data; an A/D converter which outputs digitalizing the voltage of RSSI; and a control section which receives the receive data and outputs audio signal. The demodulation section outputs a trigger to indicate a symbol point of RSSI to the A/D converter.

Abstract: It is described a method for realizing, in a radio transmission system, a carrier synchronization and for cancelling one or more co-channel interfering signals from a recived main signal, in which a synchronous down-conversion of the received main signal and of each of the interfering signal is performed to obtain respective intermediate frequency signals; and then a synchronous demodulation of the intermediate frequency signals so obtained is carried out.

Abstract: A device for reception of the signals of satellite radio navigational systems (SRNS) GPS/Glonass comprises an input unit having two filters and an amplifier, a first signal frequency converter comprising two amplifiers and a mixer two channels (GPS and (Glonass) of the second signal frequency converter, each of which includes a filter, a mixer, a controlled-gain amplifier and a threshold device consisting of a level-controlled two-bit quantizer.

Abstract: A two-port millimeter-wave demodulation device is particularly adapted for wireless 60 GHz transmission systems. The device for the downconversion and demodulation of a modulated RF signal does not comprise a mixing stage. The RF signal to be downconverted is supplied to a linear two-port device having a single power sensor connected to the output of the two-port device. The two-port device comprises a three-port junction having two inputs and one output connected to the power sensor. One input of the three-port junction is supplied to the RF signal and the other input of the three-port junction is supplied (without switching) with a further RF signal originating either from a local oscillator or with a signal derived from the RF signal to be downconverted. FIG.

Abstract: A circuit arrangement for providing impedance translation filtering comprises a first path and a second path. In a base band variant the first path is a feed forward path which comprises first and second series connected transconductance gain stages (10, 12), and the second path is a feedback which comprises third and fourth transconductance gain stages (18, 20), each having an inverting output. An output of the first gain stage is coupled to an input of the fourth gain stage. In operation, the impedance presented at its output determines the impedance presented at an input of the circuit arrangement.

Abstract: A double conversion-type electronic tuner includes a first IF signal amplifying circuit having a field-effect transistor that amplifies an intermediate frequency signal at a predetermined gain, and input the resultant signal to a down-converter via a band-pass filter. The electronic tuner further includes a temperature compensating section formed by a serial circuit composed of an NTC-thermistor provided between the first IF signal amplifying circuit and a coupling capacitor of the band-pass filter. In this structure, when the temperature is changed, the degree of coupling between the circuits is varied to compensate for a variation of the gain caused by a change in temperature. Moreover, the characteristic of a capacitor forming a parallel resonant circuit in the band-pass filter is also varied by a change in temperature, and the matching loss is reduced.

Abstract: A double conversion tuner (DCT) free of spurious signals generated by the local oscillator frequencies and the crystal reference frequency is described herein. These spurious signals are generated by the first and/or second oscillator signals as well as by their harmonic frequencies. Spurious signals are also generated when the crystal reference frequency is not properly selected. In the past, complex-mechanical designs had to be used to isolate circuit blocks to reduce these spurious signals. By using a dynamic first intermediate frequency and/or selecting the value of the crystal reference frequency, these spurious signals can be reduced or eliminated.

Abstract: An LO generation circuit generates an LO signal by doubling and quadrupling the frequency of a VCO signal. The frequency doubling and quadrupling provides high VCO-RF isolation as well as suppression of spurious noise signals in the LO output. The frequency doubler takes a quadrature signal input and utilizes mixer cores having double balanced transistor pairs to provide an output signal having doubled frequency but maintaining the phase balance of the input signal.

Abstract: A frequency conversion circuit includes a plurality of mixers coupled to a plurality of local oscillators. A plurality of phase lock loop circuits control the local oscillation frequencies of the local oscillators. Preferably, the local oscillators oscillate at intervals or step frequencies set or programmed by the PLL circuits.

Abstract: A semiconductor integrated circuit comprising a first circuit block including an oscillation circuit considered to be a noise generator and a second circuit block including circuits considered to be easily affected by a noise generated by the oscillation circuit, being most likely led to a malfunction are created on a single semiconductor substrate with the first and second circuit blocks separated from each other. To put it more concretely, the first and second circuit blocks are respectively created in a first island area and a second island area on the surface of the semiconductor substrate. The first and second island areas are each enclosed by an insulating isolation band. A low-resistance semiconductor area is created in a base area excluding locations occupied by active elements in the first and second island areas and is connected to a stable voltage terminal.