Abstract: A frequency plan is provided for particular use in a transceiver. Advantageously, a single oscillator may be used to generate desired frequency signals. One or more power splitters receive the signal and equally divide the signal into first and second signals having a frequency substantially equal to the original. Multipliers on each arm of the transceiver receive a signal and increase the frequency of the signal. In one exemplary embodiment, multiple signals having different frequencies may be transmitted over the same cable due in part to the generated frequency separation between the signals. In another exemplary embodiment, multiple signals may be transmitted over multiple cables. Additionally, multiple signals over one or more cables may be transmitted at or below 3 GHz.

Abstract: A frequency plan is provided for particular use in a transceiver. Advantageously, a single oscillator may be used to generate desired frequency signals. One or more power splitters receive the signal and equally divide the signal into first and second signals having a frequency substantially equal to the original. Multipliers on each arm of the transceiver receive a signal and increase the frequency of the signal. In one exemplary embodiment, multiple signals having different frequencies may be transmitted over the same cable due in part to the generated frequency separation between the signals. In another exemplary embodiment, multiple signals may be transmitted over multiple cables. In another exemplary embodiment, the frequency plan may self correct a transmit signal based on a reference signal, such as the receive signal. Additionally, multiple signals over one or more cables may be transmitted at or below 3 GHz.

Abstract: A radio frequency (RF) receiver includes an oscillator for outputting an oscillation signal from an output port thereof, a limiter for dividing the oscillation signal output from the oscillator into a branch signal at a predetermined dividing ratio outputting the branch signal, an amplifier for amplifying the branch signal output from the limiter, a frequency multiplier for outputting a local oscillation signal having a frequency obtained by multiplying a frequency of the amplified signal by a predetermined multiplicand, a mixer for mixing the local oscillation signal and a signal supplied from an antenna, a band-pass filter for receiving a signal output from the mixer and outputting an intermediate frequency (IF) signal, a detector for producing a detected signal by detecting the IF signal, and a controller connected directly with the output port of the oscillator for performing an operation according to the detected signal based on the oscillation signal as a clock signal.

Abstract: An integrated transmit circuit includes a voltage controlled oscillator (702) for generating an input frequency signal (e.g., VCO) that is provided to a divide by two quadrature generator circuit (706) which generates therefrom in-phase and quadrature clocking signals (I, IB, Q, QB) that are applied to control a plurality of transmission gates (711-718) configured in a matched switching topology (710) so as to selectively pass pulses from the input frequency signal, thereby generating interleaved LO pulses (Ø1, Ø1B, . . . Ø4, Ø4B). By applying the interleaved LO pulses to control the transmission gates (26, 28, 30, 32, 34, 36, 38, and 40) in the upmixer (720), the +I, ?I, +Q, ?Q input signals are interleaved over a plurality of phases of a carrier period to produce differential outputs (42, 44).

Abstract: A split delay-line oscillator for secure data transmission is disclosed. In one embodiment, an apparatus for a split delay-line oscillator for secure data transmission includes a first modulator/demodulator block in a first device, the first modulator/demodulator block operable to insert a first variable delay to modulate a frequency of a shared carrier signal passing through the first modulator/demodulator block, and a second modulator/demodulator block in a second device, the second modulator/demodulator block operable to insert a second variable delay to modulate the frequency of the shared carrier signal passing through the second modulator/demodulator block, wherein the first and second devices create a shared secret by contributing data on the frequency-modulated shared carrier signal.

Abstract: A method of calculating uplink output power in a wireless communication system is disclosed. More specifically, the method includes receiving a message which includes a command to a mobile station (MS) to perform handover from a current serving cell to a target cell, which is one of neighbor cells, performing handover to the target cell according to the message, measuring power of a downlink transmission channel in the target cell, and calculating the uplink output power by using only the measured power and without considering previous measured powers from the current serving cell if the measured power is used for a first calculation to obtain the uplink output power after the MS moves to the target cell.

Abstract: The present invention discloses a mixer comprising with an input stage (100) for receiving and amplifying input signals (VINP, VINN) and an output stage (300) for outputting output signals (Voutp, Voutn). A switching stage (200) is coupled between the input stage (100) and the output stage (300), the switching stage (200) mixing the amplified input signals with a local oscillator signal (vlop, vlon) to produce the output signals (Voutp, Voutn) at the output stage (300). An RC circuit (cop, rop; con, ron) is connected to the output stage (300) and adapted to move the pole of the output signals.

Abstract: A dual-band input transceiver block is formed to operably receive one of a 2.4 GHz radio frequency signal or a 5.0 GHz radio frequency transceiver signal in a manner that minimizes duplication of circuitry and creates a combined circuit path for RF front end input stages for much of the input stage. More specifically, the embodiments of the present invention include separate amplification and mixing stages whose outputs are combined by a stabilized load with circuitry for removing a common mode feedback signal. As such, downstream components, such as amplifiers, filters, analog-to-digital converters, and other input path circuit elements, are not duplicated and may be used regardless of whether the dual-band transceiver is operating in a first or second frequency band. Operation is, in the described embodiment, only one frequency input at a time though the invention is not limited to such operation.

Abstract: A radio frequency receiver on an integrated circuit (RFIC) includes an oscillator circuit, which generates a radio frequency (RF) oscillatory signal having a predetermined frequency that is outside of an intermediate frequency passband of the RFIC. An amplitude modulator modulates the RF oscillatory signal to produce an amplitude modulated signal which is applied to a mixer that downconverts the amplitude modulated signal. A calibration circuit receives the downconverted signal, including second order modulation (IM2) products, and, responsive to the IM2 products, generates a bias signal that is applied to the mixer to reduce the IM2 products.

Abstract: A system and method for receiving a signal, comprising an input adapted to receive a radio frequency signal having a strong interferer; a signal generator, adapted to produce a representation of the interferer as an analog signal generated based on an oversampled digital representation thereof; and a component adapted to cancel the strong interferer from radio frequency signal based on the generated analog signal to produce a modified radio frequency signal substantially absent the interferer. The system typically has a nonlinear component that either saturates or produces distortion from the strong interferer, which is thereby reduced. The system preferably employs high speed circuits which digitize and process radio frequency signals without analog mixers.

Abstract: A mixing circuit is provided that includes a charge circuit, an oscillating circuit inlet step which is connected to a circuit which feeds an oscillating signal, and a signal inlet step. The oscillating circuit inlet step comprises at least two bipolar-transistors and the emitters thereof are connected to a constant potential which is independent from the oscillating signal. The mixing circuit is used, preferably, in a base station or a mobile radio device of a cellular radio network.

Abstract: A dual-LO mixer is disclosed. The dual-LO mixer receives an input signal, a first reference signal of a first reference frequency, and a second reference signal of a second reference frequency, and performs a frequency translation to convert the input signal into an output signal, wherein the frequency difference between the input signal and the output signal is a sum or a difference of the first reference frequency and the second reference frequency.

Abstract: A high performance radio frequency receiver includes a low noise amplifier with large binary and stepped gain control range, controlled impedance, and enhanced blocker immunity, for amplifying and converting a radio frequency signal to a current; a pulse generator for generating in-phase and quadrature pulses; a crossover correction circuit and pulse shaper for controlling a crossover threshold of the pulses and interaction between in-phase and quadrature mixers; and a double balanced mixer for combining the RF signal with the pulses to generate an intermediate frequency or baseband zero intermediate frequency current-mode signal. The in-phase and quadrature pulses have a duty cycle of 20-35%. The intermediate frequency signal and second order harmonics may be filtered with a high frequency low pass filter and a current injected complex direct-coupled filter.

Abstract: A receiver apparatus for tracking and rejecting a Transmit (Tx) signal in a wireless communication system and an operation method thereof are provided. The receiver apparatus includes a controller for receiving channel frequency information of the Tx signal and for controlling an operation for tracking and rejecting a frequency of the Tx signal; a phase locked loop for generating an oscillation frequency by generating a control voltage according to the channel frequency information of the Tx signal under the control of the controller and for filtering a signal corresponding to the oscillation frequency among signals input to a low noise amplifier; and the low noise amplifier for amplifying power while minimizing noise of a signal filtered by the phase locked loop.

Abstract: Selectable sizes for a local oscillator (LO) buffer and mixer are disclosed. In an embodiment, LO buffer and/or mixer size may be increased when a receiver operates in a high gain mode, while LO buffer and/or mixer size may be decreased when the receiver operates in a low gain mode. In an embodiment, LO buffer and mixer sizes are increased and decreased in lock step. Circuit topologies and control schemes for specific embodiments of LO buffers and mixers having adjustable size are disclosed.

Abstract: A high-order harmonics generator includes a plurality of high-pass filters to block out DC signals. In one embodiment, high-pass filters are coupled to the output signals from an envelope detector and a power detector. A high-pass filter can also be coupled to the output of a multiplier that multiplies the filtered envelope signal and the filtered power signal. Additional multipliers may also be used at outputs of multipliers in a cascaded chain of multipliers for higher harmonics generation.

Abstract: An apparatus including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first circuit may be configured to generate a demodulated signal in response to a modulated signal and a seed value selected in response to a first control signal. The second circuit may be configured to generate a second control signal in response to the demodulated signal. The third circuit may be configured to generate the first control signal in response to the second control signal, a compensation signal, and the first control signal, where generation of the first control signal includes adding the second control signal, the compensation signal, and a latched version of the first control signal. Generation of the latched version of the first control signal may include sampling the first control signal in response to a clock signal. The compensation signal may compensate for variation in the clock signal.

Abstract: Certain embodiments for an analog zero-IF interface for GSM receivers, where a receiver may receive RF signals and downconvert the RF signal to a VLIF signal in the analog domain. The VLIF signal may be further downconverted to a baseband signal in the analog domain. The baseband signal may be an analog signal. Aspects of the invention may comprise amplifying the received RF signal, mixing the amplified RF signal down to a VLIF signal, filtering the VLIF signal, amplifying the VLIF signal, mixing the filtered VLIF signal to a baseband signal, and filtering the baseband signal. The local oscillator signal to the mixer that may downconvert the RF signal to a VLIF signal may be an output of a programmable local oscillator, and may be one of a plurality of frequencies. The mixer that generates the baseband signal may be a harmonic-reject mixer.

Abstract: A system for tuning a radio-frequency signal includes a first input path, a second input path, a common reference generator, a selector, a mixer, and a filter. The first input path and the second input path propagate a first single-ended input signal and a second single-ended input signal, respectively, to the selector. The selector converts the first single-ended input signal and the second single-ended input signal into a first differential input signal and a second differential input signal, respectively, using a reference signal generated by the common reference generator. The selector selectively couples one of the first and the second input path to an input of the mixer. The mixer downconverts a selected on of the differential input signals received from the selector. The filter attenuates a portion of the downconverted input signal outside a passband associated with the filter.

Abstract: A method and frequency converter for a radio rapid frequency signal scanning and including a local oscillator signal synthesis source (112) producing a local oscillator signal (502) with local oscillator bursts (210). The local oscillator bursts (210) contain pulse width modulated RF frequency pulses (602). Each local oscillator burst having, for a pre-determined duration, RF frequency pulses within an effective amplitude above a pre-determined threshold (260). Each local oscillator burst (210) having also has effective amplitude pulse shaping envelope (504) that reduces at least one frequency domain component magnitude (310) of the local oscillator signal (300). A radio frequency mixer (110) receives an RF signal input (104) and the local oscillator signal to produce an output signal (160) at a frequency related to a combination of a frequency of the RF signal input and a frequency of the local oscillator signal.

Abstract: The present invention provides a local oscillator (LO) leakage controller for use with a receiver. In one embodiment, the LO leakage controller includes a comparison unit configured to process an LO leakage error signal from the receiver to provide a leakage cancellation signal. Additionally, the LO leakage controller also includes a leakage counterbalance unit coupled to the comparison unit and configured to adapt the leakage cancellation signal to the receiver to counterbalance LO leakage in the receiver.

Abstract: Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. Briefly stated, such methods, systems, and apparatuses operate by receiving an EM signal and an aliasing signal having an aliasing rate. The EM signal is aliased according to the aliasing signal to down-convert the EM signal. The term aliasing, as used herein, refers to both down-converting an EM signal by under-sampling the EM signal at an aliasing rate, and down-converting an EM signal by transferring energy from the EM signal at the aliasing rate. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a demodulated baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

Abstract: An LR polyphase filter implemented with inductors and resistors and capable of operating at high frequencies is described. In one design, the LR polyphase filter includes first and second paths, with each path including an inductor coupled to a resistor. The first and second paths receive a first input signal and provide first and second output signals, respectively, which may be in quadrature. For a differential design, the polyphase filter further includes third and fourth paths, which receive a second input signal and provide third and fourth output signals, respectively. The four output signals may be 90° out of phase. The first and second input signals are for a differential input signal. The first and third output signals are for a first differential output signal, and the second and fourth output signals are for a second differential output signal. Each inductor may be implemented with a transmission line.

Abstract: Second-order intermodulation distortion can be suppressed in a direct conversion radio receiver having a downconversion mixer by calibrating resistors and a current source in the mixer. A test signal is applied to the signal inputs of the mixer transconductor. The resistances of first and second variable resistor circuits connected to the switching quad are then varied while also varying a variable current source. Each time the resistances and current are set to new values, the resulting mixer output signal is measured. When the measured output signal is determined to be at a minimum, the variable resistors and current source are left at the corresponding values to which they have been set. Adjusted in this manner, the current source counteracts the DC offset voltage at the mixer output.

Abstract: A shielded differential inductor forms a high quality factor (high-Q) inductor that is configured to attenuate frequency spurs and/or noise from magnetic coupling generated by electrical structures on or off of a substrate as well as interference received by other components from magnetic coupling generated by the inductor. The shielded differential inductor includes a differential inductor and a shield that substantially isolates the electrical field between the inductor and the substrate to reduce substrate current loss. The shield includes sets of finger structures that extend beyond the width of the inductor and a hub and spoke configuration of ground conductors that connect the sets of finger structures to ground.

Abstract: Methods, systems, and apparatuses for down-converting and up-converting an electromagnetic signal. In embodiments, the invention operates by receiving an electromagnetic signal and recursively operating on approximate half cycles of a carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to forme a down-converted signal. In embodiments, up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency. When the invention is being used in the frequency modulation or phase modulation implementations, the oscillating signal is modulated by an information signal before it causes the switch to gate a bias signal. The output of the switch is filtered, and the desired harmonic is output.

Abstract: A direct conversion multi-band TV tuner includes: a plurality of RF (radio frequency) paths for processing the RF signal and for generating a plurality of processed RF signals, respectively; and a TSC (tri-state chopper) based quadrature frequency converter for receiving one of said processed RF signals and converting the received processed RF signal into a in-phase baseband signal and a quadrature baseband signals; wherein the TSC based quadrature frequency converter operates in accordance with a first set of periodic three-state control signals and a second set of periodic three-state control signals that are approximately 90 degrees offset from the first set of periodic three-state control signals.

Abstract: A phase detector includes a plurality of phase detectors located in a phase correction loop, each phase detector configured to receive as input a radio frequency (RF) input signal and an RF reference signal, each of the plurality of phase detectors also configured to provide a signal representing a different phase offset based on the phase difference between the RE input signal and the RF reference signal; and a switch configured to receive an output of each of the plurality of phase detectors and configured to select the output representing the phase offset, that is closest to a phase of an output of an amplifier.

Abstract: A receiver circuit comprising a quadrature passive mixer having an input and an output, and an input impedance of the quadrature passive mixer provides a band-pass response. One or more output impedances coupled to the output of the quadrature passive mixer. A low noise amplifier (LNA) having an input and an output coupled to the quadrature passive mixer, the LNA configured to provide substantially linear transconductance over a predetermined input range.

Abstract: Aspects of a method and system for enabling simultaneous FM transmitter and FM receiver functions using an integrated Bluetooth Local Oscillator Generator (LOGEN). A Bluetooth® LOGEN may be utilized to generate Bluetooth® signal that comprise (I) and (Q) components for use in Bluetooth® communication. The Bluetooth® LOGEN may then be utilized by a DDFS to generate FM radio (I) and (Q) signals for FM radio reception. The Bluetooth® LOGEN may also be utilized by a second DDFS to generate FM radio (I) and (Q) signals for FM radio reception. The Bluetooth® signals may be kept at the same frequency, or reduced in frequency, for use in clocking the DDFS. A frequency word may also be utilized to clock the two DDFS. The outputs of each DDFS may be a constant frequency while the inputs to each DDFS may vary in frequency.

Abstract: A method and apparatus is disclosed to effectively frequency translate a filter characterized as a low quality factor (Q) filter corresponding to a baseband frequency of approximately zero Hertz or to an intermediate frequency (IF) to a filter characterized as a high Q filter at frequencies greater than the baseband frequency or the IF. A downconversion mixer is used to frequency translate a communication signal to the baseband frequency or the IF using a first local oscillator signal to provide a downconverted communication signal. A filter characterized as the low Q filter corresponding to the baseband frequency or the IF filters the downconverted communication signal to provide a filtered communication signal. An upconversion mixer is used to frequency translate a communication signal using a second local oscillator signal, the second local oscillator signal being substantially similar in frequency of the first local oscillator signal.

Abstract: A single-ended-to-differential mixer includes a differential input circuit having a single-ended input. The differential input circuit is responsive to a single-ended input signal to generate first and second signals. The single-ended-to-differential mixer includes a passive tank circuit in communication between a reference voltage and the differential input circuit. The single-ended-to-differential mixer includes a mixer circuit in communication with the differential input circuit and responsive to the first and second signals and a second input signal to generate a differential mixer output signal.

Abstract: A synthesizer includes a synthesizer unit for generating a local oscillation signal based on a reference oscillation signal output from a reference oscillation unit including a MEMS resonator, a frequency fluctuation detector for detecting a frequency fluctuation of the MEMS resonator, and a frequency adjuster for adjusting a frequency of the local oscillation signal based on the frequency fluctuation detected by the frequency fluctuation detector. This synthesizer can output a signal with a stable frequency, even when an MEMS resonator demonstrating a large fluctuation in an oscillation frequency to temperatures is used.

Abstract: Mixer topologies that have sufficiently high IIP2 and sufficiently low quadrature error to make zero IF receivers possible without special calibration techniques. This simplifies the receiver, avoids circuit startup delay and provides more stable performance over time and temperature. The methodology to achieve this performance in preferred embodiments consists of as many as three elements: (a) a high power local oscillator buffer circuit capable of driving low impedance loads coupled to the bases of the bipolar mixer transistors, (b) an optimized bias block for the mixer core and (c) incorporating two or more electronically programmable quad sections and selecting the best quad for use. Other types of transistors may also be used.

Abstract: A frequency plan is provided for particular use in a transceiver. Advantageously, a single oscillator may be used to generate desired frequency signals. One or more power splitters receive the signal and equally divide the signal into first and second signals having a frequency substantially equal to the original. Multipliers on each arm of the transceiver receive a signal and increase the frequency of the signal. In one exemplary embodiment, multiple signals having different frequencies may be transmitted over the same cable due in part to the generated frequency separation between the signals. In another exemplary embodiment, multiple signals may be transmitted over multiple cables. Additionally, multiple signals over one or more cables may be transmitted at or below 3 GHz.

Abstract: In a satellite radio navigation receiver receiving a transmitted radio navigation signal, a method of removing I/Q-mismatches in the received signal, comprising: resolving the received signal into I and Q signal component, and providing them as inputs to a demixing stage which removes unwanted signals, the demixing stage including first and second cross-coupled adaptive filters, whose coefficients are updated by the outputs of the demixing stage, the outputs of the demixing stage representing an IQ mismatch corrected signal. The coefficients are updated only by the polarity values of the outputs, resulting in great simplification. The receiver may be a zero-IF or low-IF receiver, and may operate on time domain or frequency domain signals.

Abstract: Methods and apparatuses are provided for dynamic frequency scaling of an intermediate frequency (IF) signal within a radio device.

Abstract: A modulation circuit is provided that generates an output signal obtained by modulating an input signal with a local signal and includes a local input section that receives the local signal and generates the local signal and an inverted local signal obtained by inverting the local signal, a signal input section that receives the input signal and generates the input signal and an inverted input signal obtained by inverting the input signal, a first multiplying section that outputs from a terminal that receives the input signal a first multiplied signal obtained by multiplying the local signal with the input signal, a second multiplying section that outputs from a terminal that receives the inverted input signal a second multiplied signal obtained by multiplying the inverted local signal with the inverted input signal, an output section that adds the first multiplied signal to the second multiplied signal and generates the output signal, and a transmission line that sends to the output section the first multipl

Abstract: A RF receiver includes a low noise amplifier and blocking module, a down conversion module, and a local oscillation module. The low noise amplifier and blocking module is coupled to receive an inbound RF signal, wherein the amplified inbound RF signal includes a desired RF signal component and a blocking RF signal component; attenuate the blocking RF signal component of the amplified inbound RF signal; and pass, substantially unattenuated and amplified, the desired RF signal component of the inbound RF signal to produce a desired inbound RF signal. The down conversion module is coupled to convert desired inbound RF signal into an inbound signal based on a receive local oscillation. The local oscillation module is coupled to produce the receive local oscillation, wherein the local oscillation module includes a notch filter module coupled to attenuate signal components of the receive local oscillation at frequencies corresponding to harmonics of the blocking RF signal component.

Abstract: When a power supply switch is turned on and an RF signal and an LO signal are input to a bipolar transistor, a mixed signal of both signals is output as an IF signal. When the power supply switch is turned off, the bipolar transistor operates as two diodes connected between a base terminal and an emitter terminal and between the base terminal and a collector terminal. When the IF signal and the LO signal are input, the input signals are mixed with each other by the diodes and the RF signal is output. Accordingly, one frequency conversion has a plus conversion gain and when bidirectional frequency conversion is performed by the use of one frequency converter, an external circuit such as a signal path switching switch is not necessary.

Abstract: A receiver has a first voltage control oscillator configured to generate a first oscillation signal, a second voltage control oscillator configured to generate a second oscillation signal having a first phase, a first phase comparator configured to detect a phase difference between the first and second oscillation signals, a demodulator configured to perform demodulation processing of the received signal and to generate timing information of a second phase included in the first oscillation signal, a second phase comparator configured to detect the phase difference between the first and second oscillation signals, and a first control voltage generator configured to generate a first control voltage for controlling a phase and a frequency of the second voltage control oscillator based on the phase difference detected by the second phase comparator.

Abstract: Heretofore, a plurality of packages were used in a high frequency module in which a plurality of waveguide terminals were positioned resulting in problems, such as degradation of characteristics in the connection lines between packages, lower ease of assembly when mounting and connecting the connection lines, increased cost, and so forth. To solve these problems, a plurality of cavities having a part or the entire side metallized is formed in a multi-layer dielectric substrate. The multi-layer dielectric substrate is provided with a plurality of waveguide terminals, microstrip line-waveguide converters, RF lines, bias and control signal wiring, and bias and control signal pads. A high frequency circuit is mounted within the cavity and sealed with a seal and cover. This is intended to reduce the number of package, improve performance, improve fabrication, and lower the cost.

Abstract: To realize a software radio processing with a reduced circuit area by hardware and software which can process transmission and reception, or synchronization and demodulation in time division. There are provided a circuit DRC that can dynamically change a configuration with a structure that can change the configuration at a high speed, a general processor, and an interface for connection with an external device such as an AD converter or a DA converter. Software radio is realized by using a software radio chip that conducts plural different processing such as transmission and reception, or synchronization and demodulation in time division. The different processing during the radio signal processing can be conducted in time division. As a result, the software radio can be realized with a circuit of a reduced area in a software radio system that allocates regions of an FPGA to the respective processing.

Abstract: A communication device includes: a first oscillator to generate a local signal based on a control signal for regulating at least one of phase oise and jitter in the local signal; a frequency converter to convert a first signal having first frequency to a second signal having second frequency by using the local signal; a filter to remove undesired signal component from the second signal and output a third signal; and a controller to generate the control signal based on the second signal and the third signal.

Abstract: A radio communication device includes: a local oscillator; an amplifier amplifying an output signal of the local oscillator and outputting a local oscillation frequency and a harmonic wave component thereof; and a harmonic mixer receiving an output signal of the amplifier and an information signal, and generating an up-converted signal of the information signal with the harmonic wave component based on the local oscillation frequency, while allowing the harmonic wave component to pass through.

Abstract: The apparatus (20) for determining a frequency offset error comprises an input (24.1) for receiving a digitally coded frequency demodulated signal (demod Ip2). The frequency demodulated signal (demod Ip2) is processed by digital means (35) for performing a correlation, and by digital means (36) for performing a minimum-maximum evaluation. In order to determine whether a conflation criterion and a minimum-maximum criterion are fulfilled, the apparatus (20) comprises digital processing means (38) to calculate the current offset of the frequency demodulated signal (demod Ip2) and to cancel the current offset if both criteria are fulfilled.

Abstract: In the radio-wave receiving apparatus according to the invention, a signal received by a receiving antenna is amplified and the amplified received signal is input into a multi-stage frequency conversion circuit including a plurality of basic circuits connected in series. The multi-stage frequency conversion circuit converts the frequency of the received signal from the antenna into frequencies based on signals input from the frequency divider circuit sequentially, thereby to output a signal “a” which is obtained by conversions into gradually lower frequencies. Detection is performed by a detection circuit on the basis of the signal. Thereby, a radio-wave receiving apparatus which requires no local oscillating circuit nor a PLL circuit and is also stable in operation and high in accuracy is realized.

Abstract: There is disclosed a frequency synthesizer having an HF synthesizer for generating a first reference frequency signal having a variable frequency in a high-frequency band as a unit synthesizer, an LF synthesizer for generating a second reference frequency signal in a low-frequency band as another unit synthesizer, and an arithmetic circuit including a mixer for receiving the first and second reference frequency signals, a divider for receiving the second reference frequency signal, a mixer for receiving the first reference frequency signal and an output signal from the divider, a divider for receiving an output signal from the mixer, a divider for receiving an output signal from the mixer and capable of switching a division ratio, and a switch for switching and outputting output signals from the dividers, wherein an output signal of the switch is outputted as a first local signal, and an output signal from the divider is outputted as a second local signal.

Abstract: A method and system for dynamically shifting spurious tones away from the desired frequency in a virtual local oscillator receiver, such that any undesired signal residing at such spurious tones are effectively delineated from the desired signal and removed from the RF input signal. The system detects the presence of potential undesired blocker signals in the RF input signal, and initiates an iterative power comparison and mixer signal adjustment loop. As the virtual local oscillator uses two mixer signals, the frequency of one of the mixer signals is adjusted during the loop until the power of the down-converted signal is minimized to a predetermined level. Minimized power in the down-converted signal is indicative of the absence of the blocker signal, since the presence of a relatively high power signal is indicative of a blocker signal overlapping with a desired signal.

Abstract: A feed-forward device is provided for a mixer including a diplexer having a radio frequency port, an intermediate frequency port, and a common port; and a mixing circuit receiving an in-phase local oscillator signal and an out-of-phase local oscillator signal and having an output coupled to the common port of the diplexer. The feed-forward device includes: a first signal sampler having an input adapted to sample the in-phase local oscillator signal and to output a sampled in-phase local oscillator signal; a second signal sampler having an input adapted to sample the out-of-phase local oscillator signal and to output a sampled out-of-phase local oscillator signal; and an arrangement for coupling the sampled in-phase local oscillator signal and the sampled out-of-phase local oscillator signal to the common port of the diplexer.