Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: Filter coefficients are generated by testing a wireless communication system using single-tone signals. While using the filter coefficients in a filter module, signal imbalance caused by a local oscillator or analog elements in a wireless communication system can be eliminated, so as to prevent the wireless communication system from being affected by the noises.

Abstract: A receiver circuit, e.g., a low-IF receiver, including two mixing paths. The two mixing paths scale an input signal respectively by two mixing gains and shift phase of the input signal respectively by two mixing phase offsets to provide two mixed signals. The two mixing gains and the two mixing phase offsets are arranged to produce an amplitude adjustment between amplitudes of the two mixed signals and a phase difference of 90 degrees plus a phase adjustment between phases of the two mixed signals. With the amplitude adjustment and/or the phase adjustment properly tuned to nonzero value(s) in association with band-pass response of the receiver circuit, image rejection can be achieved and optimized. Associated method is also disclosed.

Abstract: A radio may define a channel plan to include one or more channels, and each channel may include a plurality of overlapping filters. Each filter may overlap at least one other filter, such as by an expected bandwidth of an incoming signal. The overlapping filters may extend over a frequency range based in part on an expected frequency error of the incoming signal. Due in part to the overlapping nature of the filters, the incoming signal will be within at least one of the filters. Since only one of the filters must receive the incoming signal, the filters may be narrower than might otherwise be the case, particularly in an application that includes frequency error. Accordingly, the filters may be narrower than their respective channels, and therefore receive less noise and interference. This improves signal-to-noise and improves the quality of the link and range.

Abstract: A wireless receiver for UWB or other format receives a useful signal in a particular band of frequencies in spite of interference components. The wireless receiver has two or more different types of tunable band reject filter, involves detecting interference in the received signal, and selecting which of the different types of filter to use according to thresholds of parameters of the detected interference. The filter is then tuned according to the detected interference and the useful signal is then received with the interference suppressed using the selected BRF. As the different types of filters have different drawbacks and benefits, by having multiple types, and selecting which to use according to the detected interference, the filtering can be better matched to the detected interference, or the drawbacks can be reduced for example.

Abstract: An integrated calibrator provides for magnitude and phase response calibration of RF receivers to produce amplitude flatness and phase linearity across the frequency range of the RF receiver by using a simple square law diode detector and a frequency-stepped two-tone source. A two-tone source generator provides two sinusoidal signals separated by a specified frequency delta about a center frequency. The center frequency is stepped across the bandwidth of the RF receiver. At each center frequency the two sinusoidal signals are input to the RF receiver and to the diode detector. The two sinusoidal signals are processed by both the receiver path and the calibrator path, and the results are used by the calibrator to generate coefficients for a correction filter in the receiver path at each of the stepped center frequencies.

Abstract: A receiver, such as a television tuner, includes a radio frequency (RF) filter circuit. The RF filter circuit includes a filter, a first node, and a second node coupled to the filter, and a conversion signal path having an input coupled to the first node and an output coupled to the second node, the conversion signal path having an active mixer coupled between the first node and the second node. The active mixer can include, for example, a first transconductor and a first mixer coupled in series between the first node and the second node. The RF filter circuit further includes a feedback signal path having an input coupled to the second node and an output coupled to the first node, the feedback signal path including a second transconductor and a second mixer coupled in series between the second node and the first node.

Abstract: A repeater using a digital filter is disclosed. The repeater comprises a MUX filter for filtering an RF signal received through an antenna or a signal to be transmitted through the antenna; a low noise amplifier for lowering noise of the signal filtered by the MUX filter; a down converter for converting the signal outputted from the low noise amplifier into an IF band signal to digitalize the signal; a digital filter for filtering the digital signal outputted form the down converter based on parameters inputted by a user; a filtering controller for controlling the digital filter by using a filtering coefficient calculated based on the parameters; an up converter for converting the signal filtered by the digital filter into an RF band signal; and a high power amplifier for amplifying the signal outputted from the up converter to a high power signal.

Abstract: The invention relates to a device comprising a direct path block with an input and an output, and a feedback block with an input and an output, the input of the direct path block being adapted to receive a multi-channel input signal with a given frequency range and the output of the direct path block being adapted to output an output signal with a base band frequency range, the output of the direct path block being coupled to the input of the feedback block and the input of the direct path block being coupled to the output of the feedback block. The direct path block comprises a first transposing unit (4) adapted to transpose the input signal to the base band frequency range and the feedback block comprises a filtering unit (3) adapted to filter the transposed signal at the output of the direct path block, a second transposing unit (5) adapted to transpose the filtered signal to the given frequency range and to feed back the transposed signal at the input of the direct path block.

Abstract: Analog interference filter devices and methods for isolation of desirable portions of a radio frequency signal. Signal compensation is used to provide desirable center frequency, passband width, ripple, rolloff, stopband and distortion performance. The filter is implemented with passive and/or active components.

Abstract: A transceiver with an adaptable filter and a method of controlling the settings of the filter to adapt to local channel assignments and usage are provided. The adaptable filter is connected in at least one of the transmitter path and the receiver path of the transceiver to separate signals from adjacent spectrum blocks to permit use of all of the channels in the adjacent spectrum blocks and to separate signals in adjacent or nearby channels in a shared-channel block. A method and system for forward link control signalling are provided. The forward link control signalling includes a frame for transmission that includes at least one control channel that includes control information for receivers sharing a common characteristic, and a guide channel that includes information pertaining to the at least one control channel, including control information for receivers sharing a common characteristic.

Abstract: Exemplary embodiments of the invention disclose receiver baseband filtering. In an exemplary embodiment, the filter device may comprise a continuous-time filter and a discrete-time filter operably coupled to the continuous time-filter. The discrete-time filter may include a passive infinite impulse response filter operably coupled between the continuous-time filter and an amplifier. The discrete-time filter may also include an active infinite impulse response filter operably coupled between an output of the amplifier and an input of the amplifier. The discrete-time filter may be configured to combine an output of the active infinite impulse response filter and an output of the passive infinite impulse response filter to form a composite signal. Furthermore, the amplifier may be configured to receive and amplify the composite signal.

Abstract: According to one embodiment, an array antenna apparatus includes a distributor, transmission phase shifters, transmission amplifiers, transmission filters, transmission/reception switches, limiters, reception filters, low-noise amplifiers, reception phase shifters, a combiner, a vacuum vessel, a refrigerating unit, and a cooling plate.

Abstract: A receiver includes an antenna configured to receive a set of RF signals, and a low-noise amplifier (LNA) coupled to the antenna and amplify the set of RF signals to generate a set of amplified signals. The receiver further includes a down-conversion mixer configured to down convert the set of amplified signals to baseband frequencies. The receiver further includes a low-pass filter configured to filter from the set of amplified signals to baseband frequencies an out-of-band signal. The receiver further includes a high-pass filter configured to reverse the filtering of the low-pass filter. The receiver further includes a peak detector configured to determine whether the LNA is operating at saturation; and an automatic-gain controller configured to decrease a gain of the LNA based on the determination of the peak detector.

Abstract: A filter includes a base and a sidewall extending from the base. The base and the sidewall cooperatively define a cavity. The filter further includes a signal input unit, and a signal output unit having a signal output port. The signal output port is located on the sidewall and extends outside of the cavity. The signal output port is connected to a conductive post received within the cavity. The conductive post collects radio signals and outputs the collected radio signals via the signal output port. The signal output unit further includes a signal detection module. The signal detection module includes a coupling plate, a coupling signal output terminal, and a probe. The coupling plate is electrically connected to the probe. The probe is located adjacent to the conductive post to receive radio signals surrounding the conductive post and output the received radio signals via the coupling output terminal.

Abstract: In one embodiment, a Radio Frequency Identification (RFID) reader circuit includes a Radio Frequency (RF) source, a RF power amplifier coupled to an output of the RF source in a transmitting path, a first RF bandpass filter coupled between the output of the RF source and a mixer module, and a low noise amplifier in a receiving path being coupled to an input of a second RF bandpass filter. The mixer module receives a signal from the first RF bandpass filter and a signal from the second RF bandpass filter, the mixer module multiplies the signal from the first RF bandpass filter with the signal from the second RF bandpass filter to recover the backscatter sidebands in the signal from the second RF bandpass filter, and the first and second RF bandpass filters provide identical or nearly identical delay of signals. Other systems, methods and circuits are also described.

Abstract: A signal processing apparatus is disclosed which includes: a detection section configured such that based on a result of the error correction of a signal generated by a single carrier system, the detection section detects the presence or absence of spectrum inversion in the signal; and a selection section configured such that if the detection section detects the spectrum inversion, the selection section selects the spectrally inverted signal as the signal subject to the error correction, and that if the detection section does not detect the spectrum inversion, then the selection selects the spectrally uninverted signal as the signal subject to the error correction.

Abstract: A receiver 650 operates in close proximity to at least one other component 610, 611, 612 causing interferences in signals received by the receiver 650. It is determined (steps 2002; 2003) whether and at which frequency a higher harmonic of and/or an inter-modulation product with signals generated by the other component 610 causes interference in signals received by the receiver 650, based on information about signals generated by the other component 610, 611, 612. At least one characteristic of the receiver 650 is adjusted to diminish an influence by a determined interference.

Abstract: A broad band packet radio communication system is characterized by the carrier sense multiplexing connection method operated on a harsh frequency arrangement where an occupied band width of a modulation transmission/reception wave and a modulation side lobe are wide and the frequency channel interval is narrow. It is possible to improve the reception adjacent channel interference characteristic among a plurality of terminals belonging to the respective cells existing in the vicinity of adjacent frequency cell boundary area. The RSSI system is subjected to a narrow-band channel filtering (a narrow-band filter (BPF or LPF) having a band narrower than one-channel occupied band width) while the reception/demodulation system is subjected to a wide-band channel filtering (a wide-band filter (BPF or LPF) having a pass band equal to or wider than the one-channel occupied band width).

Abstract: A circuit for baseband harmonic rejection includes multiple transconductance cells coupled to one another at outputs of the transconductance cells and configured to receive down-converted signals that vary from one another to produce a weighted current signal proportional to a voltage corresponding to a respective down-converted signal. The circuit also includes a feedback impedance coupled between an input of one of the transconductance cells and the outputs of the transconductance cells. Each of the transconductance cells has an effective transconductance of a first magnitude for frequency components of the down-converted signal arising from a first harmonic and an effective transconductance of a second magnitude less than the first magnitude for frequency components of the down-converted signal arising from harmonics at integer multiples of the first harmonic.

Abstract: A method and apparatus for receiving data in high-speed applications wherein an analog-to-digital converter (ADC) samples a received signal and a data decoder implemented with a tree search algorithm detects the bits of the sampled data for timing recovery. In some embodiments, a Viterbi detector is implemented to provide accurate bit detection for data output while tree search detected data is used to determine the optimal sampling phase for the ADC. In some embodiments, after the phase acquisition stage of timing recovery has completed, the tree search decoder may decrease the rate of data detection to maintain phase tracking.

Abstract: An anti-jamming system includes a tunable negative jamming signal feedback loop for feedback suppression of a received jamming signal. The system includes a zero IF phase locked loop (PLL) jamming signal receiver having a synchronous demodulator and a phase detector. A VCO is included in the PLL, as well as a phase detector and a loop filter. A replica jamming signal generator includes a tracking modulator with a baseband signal input coupled to an output of a synchronous demodulator in the receiver and a carrier input provided by the VCO. An output of the tracking modulator is negatively fed back to the input of the receiver to suppress the jamming signal in the received input.

Abstract: Provided is a high-frequency module that can prevent a transmission signal from reaching a reception circuit and that can achieve high mounting density. A first duplexer for a first frequency band is mounted on a circuit substrate, and a second transmission filter and a second reception filter that constitute a second duplexer for a second frequency band are embedded in the circuit substrate. The second transmission filter and the second reception filter are embedded in the circuit substrate in locations that overlap at least a part of a projection region that is formed by projecting the first duplexer in a thickness direction of the circuit substrate. The first frequency band and the second frequency band are separated from each other by at least a prescribed frequency range.

Abstract: A method of filtering and a RF filtering circuit comprising a LO adapted to generate in-phase and quadrature LO signals; a quadrature passive mixer operatively connected to the LO; a filtering impedance operatively connected to the quadrature passive mixer, wherein the voltage at an input node of the quadrature passive mixer comprises the voltage across the filtering impedance up-converted to a frequency of a LO signal received by the quadrature passive mixer. Preferably, the voltage across the filtering impedance comprises a frequency of an input signal of the quadrature passive mixer down-converted by a frequency of the in-phase and quadrature LO signals and filtered by the filtering impedance.

Abstract: Certain aspects of the present disclosure relate to a method for equalizing a pulse signal corrupted by a noise and by various channel effects for obtaining a signal based on the periodic-sinc pulse, which is suitable for Finite Rate of Innovation (FRI) processing applied at a receiver of a pulse-based communication system (e.g., an Ultra-Wideband receiver).

Abstract: Provided is a high-frequency module that can prevent a transmission signal from reaching a reception circuit and that can achieve high mounting density. A first duplexer for a first frequency band is mounted on a circuit substrate, and a second transmission filter and a second reception filter that constitute a second duplexer for a second frequency band are embedded in the circuit substrate. The second transmission filter and the second reception filter are embedded in the circuit substrate in locations that overlap at least a part of a projection region that is formed by projecting the first duplexer in a thickness direction of the circuit substrate. The first frequency band and the second frequency band are separated from each other by at least a prescribed frequency range.

Abstract: A speech processing engine is provided that in some embodiments, employs Kalman filtering with a particular speaker's glottal information to clean up an audio speech signal for more efficient automatic speech recognition.

Abstract: Provided is a high-frequency module that can prevent a transmission signal from reaching a reception circuit and that can achieve high mounting density. A first duplexer for a first frequency band is mounted on a circuit substrate, and a second transmission filter and a second reception filter that constitute a second duplexer for a second frequency band are embedded in the circuit substrate. The second transmission filter and the second reception filter are embedded in the circuit substrate in locations that overlap at least a part of a projection region that is formed by projecting the first duplexer in a thickness direction of the circuit substrate. The first frequency band and the second frequency band are separated from each other by at least a prescribed frequency range.

Abstract: A receiver includes a low noise amplifier having an input for receiving a radio frequency signal, and an output. The receiver further includes a tracking filter having an input coupled to the output of the low noise amplifier. The tracking filter including a bandpass filter configured to pass the radio frequency signals. The bandpass filter includes a variable capacitor having a first electrode coupled to the input of the tracking filter for receiving the radio frequency signals, and a second electrode coupled to a power supply terminal. The bandpass filter further includes a transformer having a primary winding including a first terminal coupled to the first electrode of the variable capacitor and a second terminal coupled to a second power supply terminal. The transformer further includes a secondary winding.

Abstract: Embodiments of the present invention provide a filter, a receiver, a transmitter, and a transceiver. The filter includes a resonant cavity component, a microstrip filtering component, and two connecting pieces, where the resonant cavity component includes at least two resonant cavities connected in parallel, each resonant cavity is provided with a resonator and a tuning screw, the microstrip filtering component includes a dielectric substrate and a microstrip positioned on the dielectric substrate, one of the connecting pieces matches and connects one end of the microstrip to the resonator on one resonant cavity, the other connecting piece matches and connects the other end of the microstrip to the resonator on another resonant cavity, and impedance of the resonant cavity component is less than impedance of the microstrip filtering component.

Abstract: An improved quadrature bandpass-sampling delta-sigma analog-to-digital demodulator is provided, which includes a loop filter, an A/D responsive to the loop filter, and a first feedback D/A responsive to the A/D up-converted in frequency by a first multiplier and a clock. A first summing circuit is responsive to the first D/A and an RF input for providing an input to the loop filter. A plurality of feedback D/As is responsive to the A/D up-converted in different frequencies by a plurality of multipliers and a plurality of clocks for providing feedback inputs to the loop filter. The loop filter comprises a plurality of resonators arranged in cascade configuration, a plurality of analog mixers to provide frequency shifting of the error signals propagating through the resonators, and a plurality of summing circuits responsive to the feedback D/As.

Abstract: An integrated calibrator provides for magnitude and phase response calibration of RF receivers to produce amplitude flatness and phase linearity across the frequency range of the RF receiver by using a simple square law diode detector and a frequency-stepped two-tone source. A two-tone source generator provides two sinusoidal signals separated by a specified frequency delta about a center frequency. The center frequency is stepped across the bandwidth of the RF receiver. At each center frequency the two sinusoidal signals are input to the RF receiver and to the diode detector. The two sinusoidal signals are processed by both the receiver path and the calibrator path, and the results are used by the calibrator to generate coefficients for a correction filter in the receiver path at each of the stepped center frequencies.

Abstract: An object of the present invention is to provide a CRC circuit with more simple structure and low power consumption. The CRC circuit includes a first shift register to a p-th shift register, a first EXOR to a (p?1)th EXOR, and a switching circuit. A data signal, a select signal, and an output of a last stage of the p-th shift register are inputted to the switching circuit, and the switching circuit switches a first signal or a second signal in response to the select signal to be outputted.

Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band comprising an aviation VHF communication band, an aviation VHF navigation band, an aviation L-band, or combinations thereof. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: In a splitter, a first band pass filter is connected between an antenna terminal and a first terminal, a high pass filter and a second band pass filter are connected between the antenna terminal and a second terminal, a pass band of the second band pass filter is higher than a pass band of the first band pass filter, a cut off frequency of the high pass filter is located closer to the high-frequency side than the pass band of the first band pass filter, the pass band of the second band pass filter is located closer to the high-frequency side than the cut off frequency, and the high pass filter also functions as a notch filter having an anti-resonant frequency in a transition region such that the steepness of the transition region between the pass band of the second band pass filter and the attenuated band is high.

Abstract: Provided is a high-frequency module that can prevent a transmission signal from reaching a reception circuit and that can achieve high mounting density. A first duplexer for a first frequency band is mounted on a circuit substrate, and a second transmission filter and a second reception filter that constitute a second duplexer for a second frequency band are embedded in the circuit substrate. The second transmission filter and the second reception filter are embedded in the circuit substrate in locations that overlap at least a part of a projection region that is formed by projecting the first duplexer in a thickness direction of the circuit substrate. The first frequency band and the second frequency band are separated from each other by at least a prescribed frequency range.

Abstract: An interference wave signal removing device that can surely remove an interference wave signal is provided. An interference wave signal remover includes a controller, a notch filter, an entire-range frequency scanner, and a local frequency scanner. The controller detects the interference wave signal based on a frequency scanning result by the entire-range frequency scanner, and sets the notch filter to attenuate the interference wave signal frequency. Based on input signals to the notch filter, the local frequency scanner frequency-scans in a local frequency band including an attenuation band of the notch filter. The controller detects a frequency drift of the interference wave signal frequency based on the frequency scanning result by the local frequency scanner, and updates the setting of the notch filter to attenuate the interference wave signal frequency after the frequency drift.

Abstract: A variable filter device has: a first series arm which is serially connected to a signal line, includes a variable capacitance and an inductance, and constitutes a series resonator; first and second parallel arms, which are connected between the signal line and the ground on both sides of the first series arm, each of which includes a variable capacitance and an inductance, and constitutes a grounded series resonator. The first series arm defines the center frequency of the pass band, and the first and second parallel arms define attenuation poles sandwiching the pass band.

Abstract: Method for optimizing the delay spread performance of a radio receiver (200) includes evaluating (306) a delay spread environment to determine if a desired RF signal is being received under conditions of low delay spread or high delay spread. If a low delay spread condition, the baseband digital data signal is filtered using a narrow filter (310). Otherwise, the signal is filtered using a wide bandwidth filter (312) having a bandwidth wider than the narrow filter. The center frequency of the wide bandwidth filter is selectively shifted (316, 320) in accordance with a predetermined frequency offset if a second received power level of an interfering signal in an adjacent channel exceeds the first received power level by a predetermined threshold amount. This frequency shift of the filter allows for improved delay spread performance while minimizing any performance degradation when an interfering signal is present on an adjacent channel.

Abstract: What is described is a circuit arrangement and a method for synchronizing the communication signals between a repeater station (S) of a single-frequency simulcast radio communication network (N) and user terminals (T) with respect to a universal reference signal sent by a central station (M) of the network (N) communicating with the repeater station (S). A frequency offset is determined between a universal frequency reference signal received from the central station (M) and a local frequency reference signal of the repeater station (S), and in the repeater station (S) there are provided a first feedback control loop for supplying a signal for controlling a local oscillator of the repeater station (S) on the basis of the said determined frequency offset, and a second direct control loop for supplying a signal for compensating the residual synchronization difference of the local oscillator (16) to which the transmitter device of the station (S) is tuned.

Abstract: A wireless communication device includes a demodulation unit which demodulates a predetermined reception frequency, an S/N improvement processing unit which performs an S/N improvement process on a demodulated signal output from the demodulation unit, a first filter which performs an adaptive operation with respect to a frequency having a largest amplitude in a signal output from the S/N improvement processing unit, and outputs a filter coefficient updated by the adaptive operation, a controller which calculates the frequency of the largest amplitude defined by the filter coefficient output from the first filter, and controls the demodulation unit to update the reception frequency so as to reduce a difference between the frequency having the largest amplitude and a predetermined frequency, and a second filter which limits a range of a frequency bandwidth of the demodulated signal based on the frequency having the largest amplitude.

Abstract: A signal processing apparatus includes a signal processing unit configured to carry out signal processing on a single-carrier signal and a multi-carrier signal by making use of a plurality of common filters shared by the single-carrier signal and the multi-carrier signal.

Abstract: A novel and useful reconfigurable superheterodyne receiver that employs a 3rd order complex IQ charge-sharing band-pass filter (BPF) for image rejection and 1st order feedback based RF BPF for channel selection filtering. The operating RF input frequency of the receiver is 500 MHz to 1.2 GHz with varying high IF range of 33 to 80 MHz. The gain stages are inverter based gm stages and the total gain of the receiver is 35 dB and in-band IIP3 at mid gain is +10 dBm. The NF of the receiver is 6.7 dB which is acceptable for the receiver without an LNA. The architecture is highly reconfigurable and follows the technology scaling.

Abstract: An electronic device includes an adjustable filter with a first filter element, and a second filter element coupled to the first filter element. The second filter element includes a field effect transistor (FET) including a source terminal, a drain terminal, and a gate terminal. The source terminal and the gate terminal are coupled to a reference voltage. A control circuit is coupled to the drain terminal and is configured to apply a control voltage thereto to vary a capacitance between the source and drain terminals to adjust the adjustable filter.

Abstract: Interference in an unlicensed frequency band is spatially filtered out from received signals at a wireless device operating in the unlicensed frequency band. Energy received at a plurality of antennas of the wireless is device is analyzed to detect interference in the unlicensed frequency band. The detected interference is classified by type. Parameters for a nulling filter are generated or selected based on the type of interference detected in the received energy. During a time interval when it is expected to receive desired signals, the nulling filter is applied using the parameters to signals obtained from energy received at the plurality of antennas during the time interval.

Abstract: A method of detecting the position of a wavefront in a time-varying signal corresponding to an event is disclosed. According to one aspect, the method includes digitizing a signal received by a detector to produce a working signal, filtering the working signal N4 times with a band-pass filter to obtain N4 filtered working signals with different pass-bands, detecting a peak of the N4 filtered working signals to detect the position of a first wavefront as a function of time of occurrence. The N4 points are plotted such that an ordinate is one of the times of occurrence and an abscissa is the width of the associated band. An exponential asymptote that fits a maximum number of the N4 points is applied, and the position of the wavefront is determined as the ordinate of the point that has the maximum abscissa and substantially fits the exponential asymptote.

Abstract: An interference wave signal frequency is highly accurate and the interference wave signal is surely removed. A controller of an interference wave signal remover detects the interference wave signal based on a frequency scanning result by an entire-range frequency scanner, and sets a notch filter to attenuate the interference wave signal frequency. A local scan frequency band BWfL of a local frequency scanner is set by having the interference wave signal frequency as its central frequency, and local scan frequencies BINL are set so that frequency bands overlap with each other between adjacent frequency BINA. The local frequency scanner frequency-scans input signals to the notch filter. The controller calculates a frequency error ?f of the interference wave signal frequency from the local frequency scanner, corrects the interference wave signal frequency which is from the entire-range frequency scanner by the frequency error ?f, and updates the setting of the notch filter.

Abstract: A system for cancellation of a reciprocal-mixing noise may comprise a down-converter mixer that may be configured to down convert a radio-frequency (RF) signal and to generate a baseband signal. The RF signal may include a desired signal and a blocker signal. A first signal path may be configured to receive the baseband signal and to generate a first signal. A second signal path may be configured to receive the baseband signal and to generate a second signal. A subtraction module may be configured to subtract the second signal from the first signal and to generate an output signal. The second signal may comprise the reciprocal-mixing noise, and the output signal may comprise the desired signal substantially free from the reciprocal-mixing noise.

Abstract: A preselect circuit maintains the dynamic range of a received RF input signal during bandpass filtering of the received RF input signal. The preselect circuit includes a Q-deficient passive bandpass filter for coupling to an antenna to receive a received RF input signal. The preselect circuit further includes a Q-enhancement circuit coupled to the Q-deficient passive bandpass filter, wherein the Q-enhancement circuit increases a Q-value of the Q-deficient passive bandpass filter by compensating for resistive inductive losses in the bandpass filter.

Abstract: A high quality factor frequency translated bandpass filter (FTBPF) with harmonic rejection includes multiple transconductance cells configured to convert a received radio frequency (RF) voltage signal into respective RF current signals. Each of the transconductance cells are weighted such that the FTBPF has an effective transconductance of a first magnitude for frequency components of the received RF voltage signal arising from a first harmonic and an effective transconductance of a second magnitude less than the first magnitude for frequency components of the received RF voltage signal arising from harmonics at integer multiples of the first harmonic. The FTBPF also includes multiple frequency conversion cells coupled to the transconductance cells and configured to mix respective ones of the RF current signals with multiple non-overlapping local oscillator signals.