Abstract: A receiver uses a local oscillator to receive data transmitted via a combination of radio frequency signals using carrier aggregation. Each radio frequency signal occupies a respective radio frequency band and the radio frequency bands are arranged in two groups, a first group and a second group, separated in frequency by a first frequency region, each of the groups including one or more radio frequency bands and the first group occupying a wider frequency region than the second group. The radio frequency signals are processed using the local oscillator by setting the local oscillator, during the processing, to a frequency that is offset from the center of a band defined by outer edges of the frequency regions occupied by the two groups.

Abstract: Disclosed here is an audio system and a method of operating the same. The audio system comprises a receiver module for receiving radio frequency (RF) input signal associated with a plurality of radio stations, an Analog to Digital Converter (ADC) coupled to the receiver for digitizing the received RF input signal and a stored set of computer-executable instructions. The instructions include those for selecting a particular radio station from the plurality of radio stations, shifting the frequency of the particular radio station to an intermediate frequency (IF), demodulating the frequency shifted portion of the RF input signal to retrieve an output signal and generating a time division multiplexed signal based on the output signal.

Abstract: A circuit includes an input, two or more sampling capacitors each in a different channel, means for connecting each sampling capacitor to the input, means for discharging the sampling capacitors to a given voltage in a reset phase, and means to use the voltage across the sampling capacitor for further processing in a hold phase. The two sampling capacitors operate in anti-phase such that the reset phase and sampling phase of one channel are performed in the time period the other channel is in the hold phase.

Abstract: A method and apparatus configured to detect electromagnetic field events are disclosed. One apparatus includes an antenna and a circuit electrically connected to the antenna. The circuit includes electronics communicatively connected to the antenna via a direct current isolation circuit and an equalizer compensating for the differentiating frequency response of the antenna. The circuit also includes a logarithmic amplifier electrically connected to the equalizer and configured to generate a range of signals based on signals received at the antenna. The circuit further includes a peak detector receiving signals from the equalizer and configured to capture a peak value of the signals. The electromagnetic field event is detected at least in part based on the peak signal value.

Abstract: In one embodiment, a receiver front end circuit can receive and process multiple radio frequency (RF) signals and output downconverted signals corresponding to these signals. In turn, multiple signal processors can be coupled to this front end. Specifically, a first signal processor can receive and process the downconverted signals to output a first signal obtained from content of a first RF signal, and a second signal processor can receive and process the downconverted signals to output a second signal obtained from content of a second RF signal. In addition, the apparatus may include a detection circuit coupled to the receiver front end circuit to detect presence of at least the second signal and enable the second signal processor responsive to the detected presence.

Abstract: The present invention relates to a mixer for signals at different frequencies comprising a network of diodes formed by a pair of diodes mounted in an anti-parallel manner, the first linking point of the diodes being connected to the ground, the second linking point being connected to the ports of transmission/reception signal paths and to the port of a local oscillator path at different frequencies. An impedance matching network for dual-mode use is connected in series in the diode network between the first linking point connected to the ground and the anode of one of the diodes of the diode network. A filtering network is connected between the second linking point and each of the ports of the transmission/reception paths and of the local oscillator path.

Abstract: Apparatus for generating a plurality of radio-frequency RF subcarrier signals for transmission between two adjacent ultra-high frequency UHF broadcast channels comprises a signal generator for generating a plurality of local oscillator LO signals, and a plurality of mixers each arranged to mix one of the LO signals with one of a plurality of input signals to generate one of the RF subcarrier signals, said input signal including information to be transmitted by said RF subcarrier signal. Variable gain amplifiers can be provided to independently amplify the RF subcarrier signals before they are combined. The LO signals can have the same frequency and the input signals can have different frequencies, or the LO signals can have different frequencies and the input signals can have the same frequency. A second LO signal with a different frequency to a first LO signal can be obtained by dividing a reference frequency by a predetermined value and mixing with the first LO signal.

Abstract: One embodiment of the present invention provides a synthesizer. The synthesizer includes one or more tunable oscillators, a frequency-dividing circuit coupled to the tunable oscillators, and a multiplexer coupled to the frequency-dividing circuit. The frequency-dividing circuit includes a number of frequency dividers, and is configured to generate a number of frequency-dividing outputs. At least one frequency-dividing output has a different frequency division factor. The multiplexer is configured to select a frequency-dividing output.

Abstract: An embodiment of a variable-gain mixer for down-converting a modulated input signal into a modulated output signal in a wireless receiver is proposed. The mixer includes means for selecting a mixer gain according to a power level of the input signal, amplifying means for amplifying the input signal into a modulated intermediate current (IRF+,IRF?) in response to a control signal indicative of the selected mixer gain, the intermediate current having an intermediate component, consisting of a direct current, varying according to the selected mixer gain, means for generating the output signal from the intermediate current, the output signal having an output component, consisting of a direct current or voltage, depending on the intermediate component; in an embodiment, the mixer further includes means for setting a compensation current in response to the control signal for compensating the variation of the intermediate component, and means for adding the compensation current to the intermediate current.

Abstract: A direct conversion receiver including a mixer, a measuring module and a calibration module is provided. When the calibration module adjusts the switch duty cycle of the mixer to being shorter than a standard duty cycle, a first second-order inter-modulation distortion is measured. When the calibration module adjusts the switch duty cycle to being longer than the standard duty cycle, a second second-order inter-modulation distortion is measured. According to the measured distortions, the calibration module determines a calibration signal and provides the calibration signal to the mixer, so as to allow the mixer to have a calibrated duty cycle.

Abstract: A receiver including a mixer configured to generate (i) a first output and (ii) a second output, a first capacitance coupled to the first output, and a second capacitance coupled to the second output, A controller is configured to program (i) the first capacitance and (ii) the second capacitance to a first capacitance value in response to operating the receiver in a first mode, and program (i) the first capacitance and (ii) the second capacitance to a second capacitance value in response to operating the receiver in a second mode. The first capacitance value determines one or more of (i) linearity, (ii) gain, and (iii) noise figure of the receiver in the first mode. The second capacitance value determines one or more of (i) linearity, (ii) gain, and (iii) noise figure of the receiver in the second mode.

Abstract: Method and system for direct conversion receiver (100), transmitter (200), or transceiver (300) device. The device includes a single frequency synthesizer (102) generating a frequency synthesizer output signal. At least one frequency divider (110n) is provided for generating a reduced frequency signal by selectively dividing the single frequency synthesizer output signal by an integer divisor value. Significantly, the device is configured to vary the reduced frequency signal so as to include every frequency the direct conversion communication device is designed to receive within a plurality of frequency bands by adjusting a frequency of the single synthesizer output signal and the divisor value.

Abstract: A down-frequency conversion circuit and up-frequency conversion circuit, and a receiver and transmitter applying the same are provided. The down-frequency conversion circuit includes a harmonic mixer and general mixer, and thus becomes able to convert frequency using one LO (Local Oscillator) frequency, thereby reducing burden on generating LO frequency.

Abstract: Systems and methods for providing single-ended to differential signal conversion are described. A single-ended voltage signal may be received from an input of a low noise amplifier. The single-ended voltage signal may be coupled to a first input stage to match a source impedance of the single-ended voltage signal to a predetermined output impedance. The single-ended voltage signal with the predetermined output impedance may be output as a first voltage signal to a first converting stage. An input bias voltage may be provided to the first converting stage to bias the first voltage signal. The biased first voltage signal may be output as a first differential-ended current signal to an output of the low noise amplifier.

Abstract: A demultiplexing device that includes frequency-conversion and reception low-pass-filter units that perform a frequency converting process and a low-pass filtering process for causing a signal to pass through a desired band, perform downsampling to reduce a sampling rate to half of a data rate of an input signal, and output the signal, reception channel-filter units that waveform-shape a signal with a desired frequency characteristic and output the waveform-shaped signal. The demultiplexing device also includes a filter-bank control unit that generates a clock control signal for supplying a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on channel information, and a reception-clock supply unit that supplies a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on the clock control signal.

Abstract: A frequency conversion device for transforming a frequency of an input signal, the device comprising: a signal generator for providing a plurality N of first signals at a first frequency, where N?1, from an input signal having an in-phase component I and a quadrature signal component Q; an oscillator for generating N parallel oscillation signals, wherein the N oscillation signals are stepped in phase with respect to one another; a mixer comprising N mixing components, each mixing component being coupled to receive a respective one of the plurality of first signals and coupled to receive a respective oscillation signal for mixing the respective first signal with the corresponding oscillation signal to provide an output signal; and a common amplifier for receiving the N output signals from the N mixing components in N sequential phases for transmission.

Abstract: A receiver/transmitter and related receiving/method capable of simultaneously receiving/transmitting discontinuous frequency band signal components of an input/output signal are provided. Phase swapping on in-phase/quadrature-phase local oscillation differential signals is applied to frequency down-conversion of the input signal or frequency up-conversion of a baseband signal to be outputted to radio domain, and thereby achieve simultaneously receiving discontinuous frequency bands of the input signal and simultaneously sending different baseband signal components on discontinuous frequency bands of the output signal.

Abstract: A downconverter mixes a first comb spectrum with a local oscillator signal to generate a second comb spectrum in a lower frequency range. The first comb spectrum comprises frequency components separated from each other according to a frequency spacing interval, and the LO signal has a frequency offset relative to the first comb spectrum, where the frequency offset is a rational fraction of the frequency spacing interval. The second comb spectrum comprises lower and upper sideband responses corresponding to respective lower and upper sideband signals of the first comb spectrum. The lower and upper sideband responses in the second comb spectrum can be distinguished from each other based on the frequency offset.

Abstract: A dual conversion receiver architecture that converts a radio frequency signal to produce a programmable intermediate frequency whose channel bandwidth and frequency can be changed using variable low-pass filtering to accommodate multiple standards for television and other wireless standards. The dual conversion receiver uses a two stage frequency translation and continual DC offset removal. The dual conversion receiver can be completely implemented on an integrated circuit with no external adjustments.

Abstract: A multichannel splitter formed from 1 to 2 splitters, wherein: an input terminal of a first 1 to 2 splitter defines an input of the multichannel splitter; the 1 to 2 splitters are electrically series-connected; and first respective outputs of the 1 to 2 splitters define output terminals of the multichannel splitter.

Abstract: A method and system is disclosed for designing a radio for down-converting RF signals to IF signals by sampling the signals in a round-robin sampling circuit and multiplying the samples by coefficients that are changed at a fixed rate equal to the rate of operation of each of the sampling circuits. The circuit is able to down-convert multiple channels simultaneously to adjacent positions in the IF band, while rejecting unwanted image signals. The method and system avoids the difficulty and cost of directly digitizing the RF signal, allowing each component to operate at a greatly reduced speed. The coefficients are selected to provide the desired transfer function while keeping the output signal centered at a desired frequency.

Abstract: A coplanar waveguide (CPW) based subharmonic mixer working at 670 GHz using GaAs Schottky diodes. One example of the mixer has a LO input, an RF input and an IF output. Another possible mixer has a LO input, and IF input and an RF output. Each input or output is connected to a coplanar waveguide with a matching network. A pair of antiparallel diodes provides a signal at twice the LO frequency, which is then mixed with a second signal to provide signals having sum and difference frequencies. The output signal of interest is received after passing through a bandpass filter tuned to the frequency range of interest.

Abstract: A balanced mixer circuit (300, 400, 500, 600, 700 and 800) in a baseband receiver (202) includes an oscillator circuit (212), a mixer (214 and 215), a digital-to-analog converter (258 and 259) and a digital signal processor (250). The mixer includes CMOS devices (301, 302, 303 and 304). In response to differential outputs from the mixer, the digital signal processor controls the digital-to-analog converter to output bias voltages for the gate of at least one of the CMOS devices of the mixer to compensate for imbalance in the differential output of the mixer that may be caused by mismatch among two or more CMOS devices of the mixer or caused by other reasons, in order to increase second order intercept point of the mixer.

Abstract: A demultiplexing apparatus includes, in each of n stages, 2n FC+RXHBFs that down-sample a signal, from which a high-frequency component is removed after frequency conversion is carried out, and output the signal. The demultiplexing apparatus extracts, from an input signal including a plurality of band signals, the band signals to thereby demultiplex the input signal. The demultiplexing apparatus includes a reception-filter-bank control unit that calculates, based on channel information including bands and frequency arrangement of the band signals, a dividing position on a frequency axis and a frequency offset value indicating a frequency conversion value and instructs the FC+RXHBF, which is set as a target of output of divided signals of the input signal, about the calculated values. The FC+RXHBF carries out frequency conversion based on the frequency offset value.

Abstract: A method and system is disclosed for simultaneously down-converting multiple selected signals, such as RF signals, into adjacent ranges in an intermediate frequency band so that the total resulting bandwidth, and thus the sampling rate required to digitize the signal, is minimized. A first signal is down-converted into a range starting at a lowest selected frequency in the IF band. The next signal is down-converted, into a range higher than, but near or adjacent to, the down-converted range of the first signal, and so on. A guard band may be left between the signals if desired. In this way, the selected signals occupy the minimum bandwidth required. When the selection of signals to be down-converted is changed, the frequency ranges are dynamically adjusted so that the signals being down-converted always occupy the lowest ranges of the IF band.

Abstract: Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc) of the 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 form a down-converted signal. 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 hasehand 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: A method and device for receiving a wireless signal is provided. The device includes a passive mixer having a first input node, a second input node, and at least one output node. An oscillator is coupled to the first input node of the mixer. The output of a buffer is coupled to the second input node of the mixer. An antenna is operatively coupled to the input node of the buffer. The buffer is configured to provide isolation from the mixer.

Abstract: A mixer-amplifier of an RF signal including at least an amplifier circuit and a mixing circuit controlled at a local oscillator frequency, for amplifying a signal applied on at least one input terminal and converting a first frequency of this signal into a second, lower, frequency, and including a reverse feedback loop switched at the local oscillator frequency.

Abstract: Presented herein are systems, methods, and apparatus for ultra-low power, low noise switched capacitor radio frequency mixer. In one embodiment, there is described a method for mixing a signal. The method comprises mixing with a mixer, a received signal with a mixing signal to generate a mixed signal. The mixing signal comprises an in-phase component and an out-of-phase component and a desired frequency. The mixed signal comprises a mixed in-phase component and a mixed out-of-phase component. The method also comprises mixing one of the mixed in-phase component and the mixed out-of-phase component based on the mixing signal.

Abstract: Techniques for designing a communications unit including a signal separation module for energy harvesting. In an exemplary aspect, the signal separation module includes first and second quadrature hybrids coupled by band-pass filters (BPF's). Incoming signals within the pass-band of the BPF's are directed through the quadrature hybrids and through the BPF's, and emerge as a desired pass-band signal to be processed by an RX processing module. Incoming signals lying outside the pass-band of the BPF's are reflected from the BPF's back to the first quadrature hybrid, and output as a non-pass-band signal to be processed by an energy harvesting module. In a further exemplary aspect, the signal separation module resides in a detachable module coupleable to a wireless communications device, and a signal transmitted by the wireless communications device is coupled to the signal separation module for energy harvesting.

Abstract: There is provided a filter circuit including a passive mixer circuit, and a passive switched capacitor circuit that is connected to a rear stage of the passive mixer and includes a flying capacitor. The passive mixer circuit generates a baseband signal by multiplying an input signal supplied from a predetermined signal source impedance by each local oscillation signal and outputs the baseband signal to the passive switched capacitor circuit, the passive switched capacitor circuit performs predetermined filtering on the baseband signal supplied from the passive mixer circuit and outputs the processed baseband signal, and a capacitance of the flying capacitor of the passive switched capacitor circuit is a capacitance by which input impedance of the passive mixer circuit is matched to the signal source impedance.

Abstract: Embodiments of systems and methods for the efficient implementation of tuners are generally described herein. Other embodiments may be described and claimed.

Abstract: A frequency mixing apparatus includes a local oscillator, a signal distributor, a first frequency mixer and a second frequency mixer and a combiner. The signal distributor divides a signal generated from the local oscillator into two signals having a phase difference and outputs the two signals. The first frequency mixer has a first input port through which one of the two signals outputted through the signal distributor is inputted and a second input port connected to an RF signal. The a second frequency mixer has a first input port through which one of the two signals outputted through the signal distributor and a second input port is connected to a termination signal. The combiner combines signals respectively outputted from the first and second frequency mixers.

Abstract: Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. 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 emodulated 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: 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 form 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 receiver circuit includes a quadrature passive mixer, a first charge load, and a second charge load. The quadrature passive mixer has a differential input for receiving a differential input signal, and arranged for mixing the differential input signal with a quadrature local oscillator (LO) signal. The quadrature passive mixer has an in-phase mixer with a differential in-phase output, and a quadrature-phase mixer with a differential quadrature-phase output. The first and second charge loads are coupled to differential in-phase output and differential quadrature-phase output, respectively. In every quarter cycle of the quadrature LO signal, the differential in-phase output and the differential quadrature-phase output are arranged to be not shorted so as to avoid charging sharing between the first charge load and the second charge load, or are arranged to be shorted to cause charging sharing between the first charge load and the second charge load that generates a leakage path.

Abstract: A single-ended-to-differential mixer includes a differential pair amplifier, a passive current source, a cancellation sub-circuit, and a mixer. The differential pair amplifier is configured to receive a single-ended input signal. The differential pair amplifier includes a first input, a second input, a first output, and a second output. The passive current source is connected between (i) the differential pair amplifier and (ii) a reference potential. The cancellation sub-circuit is connected to each of the first input, the second input, the first output, and the second output of the differential pair amplifier. The cancellation sub-circuit is configured to at least partially cancel a non-linearity of the differential pair amplifier. The mixer is connected to each of the first output and the second output of the differential pair amplifier.

Abstract: A receiver includes a low noise amplifier (LNA) and multiple pairs of mixers. The LNA receives and amplifies an LNA input signal and provides at least one LNA output signal. Each pair of mixers downconverts one of the at least one LNA output signal when enabled. Each pair of mixers may be selectively enabled or disabled, e.g., based on a mode selected from among multiple modes. In one design, the LNA includes multiple load sections coupled in parallel. Each load section may be selectively enabled or disabled, e.g., based on the selected mode. In one design, first and second pairs of mixers and first and second load sections may be enabled for a high linearity mode. The first pair of mixers and the first load section may be enabled and the second pair of mixers and the second load section may be disabled for a low linearity mode.

Abstract: A sampling circuit and a receiver, with relatively simple configurations, and clocks, exhibiting excellent frequency characteristics, are provided. In discrete time circuits, a charging switch is controlled on and off using one of four-phase control signals. A rotate capacitor shares electrical charge accumulated in an IQ generating circuit via the charging switch. A dump switch is controlled on and off using a different signal from the control signal used to control the charging switch on and off, among the four-phase control signals. A buffer capacitor shares electrical charge with the rotate capacitor via the dump switch to form an output value.

Abstract: Systems and methods for using non-crystal-based reference oscillators in the transmission and reception of frequency-modulated signals are disclosed. To protect against intrusion on neighboring designated frequency bands, guard bands, having a collective width greater than the total expected error based on the contribution of the frequency error from the non-crystal-based oscillators in the transmitter and/or receiver, can be designated. To protect against inter-channel interference within a designated frequency band, transmitters and receivers can include static sub-bandwidths wider than any possible total frequency error, such that it would be impossible for a transmitter or receiver to attempt to communicate on an unintended sub-band.

Abstract: Systems and methods for combining signals from multiple active wireless receivers are discussed herein. An exemplary system comprises a first downconverter, a phase comparator, a phase adjuster, and a second downconverter. The first downconverter may be configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal. The phase comparator may be configured to mix the received signal and a downconverted signal to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison, the downconverted signal being associated with the received signal from the first antenna. The phase adjuster may be configured to alter the phase of the intermediate frequency signal based on the phase control signal. The second downconverter may be configured to downconvert the phase-shifted intermediate frequency signal to create an output 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: A two-terminal semiconductor device is formed on a semiconductor substrate. Two wiring patterns are respectively connected to terminals of the semiconductor device, and two electrode pads are respectively connected to the wiring patterns for connecting a signal input/output circuit formed on a separate substrate. Two parallel wiring patterns are respectively connected to the wiring patterns, and two reactance-circuit connection electrode pads are respectively connected to the parallel wiring patterns for electrically connecting a reactance circuit formed on the separate substrate separately from the signal input/output circuit.

Abstract: A circuit includes: a first line to which input and output signal terminals are connected; a first transistor having a first terminal connected to the first line, a second terminal connected to a ground potential, and a control terminal supplied with a first oscillation signal, the first transistor outputting the first signal and its harmonic component; a second transistor having a first terminal connected to the first line, a second terminal connected to the ground potential, and a control terminal supplied with a second oscillation signal, the second transistor outputting the second signal and its harmonic component; a first harmonic generator connected to the control terminal of the first transistor and generates a harmonic component including the harmonic component by the first transistor; and a second harmonic generator connected to the control terminal of the second transistor and generates a harmonic component including the harmonic component by the second transistor.

Abstract: Method of communicating by radio frequencies in a home-automation installation comprising at least one command transmitter and at least one command receiver, comprising the following steps: receiving by virtue of a radiofrequency receiver of a command receiver a signal transmitted by a command transmitter, —measuring the power level of the signal received, comparing the power level measured with a power level recorded in a memory of powers that are blocked at the level of the command receiver, in the case where the measured power level corresponds to the power level recorded in memory, not processing the signal received.

Abstract: A radio-frequency (RF) apparatus, which may reside in a receiver or transceiver, includes receive-path circuitry. The receive-path circuitry includes a poly-phase filter and a harmonic filter. The poly-phase filter accepts an input signal and generates two output signals. One output signal of the poly-phase filter constitutes an in-phase (I) signal. The other output signal of the poly-phase filter constitutes a quadrature (Q) signal. The a harmonic filter couples to the poly-phase filter. The harmonic filter accepts as input signals the in-phase and quadrature output signals of the poly-phase filter.

Abstract: Receiver circuitry for processing a received Very Low Intermediate Frequency signal wherein the receiver circuitry comprises a main processing path. The main processing path comprises mixing circuitry arranged to mix a received VLIF signal with a frequency down conversion signal to produce a main path signal. The receiver circuitry further comprises a direct current cancellation path comprising mixing circuitry arranged to mix a DC element of the received VLIF signal with the frequency down conversion signal to produce a DC cancellation signal. The receiver circuitry still further comprises signal summing circuitry arranged to add the DC cancellation signal in anti-phase with the main path signal.

Abstract: An RF switch for an RF splitter is disclosed, in which the bias voltage for the RF switching elements can be supplied, by using an RF to DC translator, from the RF signal on the input side to the switch. By using a native NMOS switch, routing of the RF signal is thus enabled without the necessity for an external power supply.

Abstract: A downconverter mixes a first comb spectrum with a local oscillator signal to generate a second comb spectrum in a lower frequency range. The first comb spectrum comprises frequency components separated from each other according to a frequency spacing interval, and the LO signal has a frequency offset relative to the first comb spectrum, where the frequency offset is a rational fraction of the frequency spacing interval. The second comb spectrum comprises lower and upper sideband responses corresponding to respective lower and upper sideband signals of the first comb spectrum. The lower and upper sideband responses in the second comb spectrum can be distinguished from each other based on the frequency offset.

Abstract: This invention provides an quadrature mixer which does not require a long time to adjust the amplitude value at the time of demodulation of the IQ signal. The quadrature mixer, comprising a first frequency-conversion unit that outputs a sixth signal derived by multiplying a first signal by a second and a fourth signals, a second frequency-conversion unit that outputs a seventh signal derived by multiplying the first signal by a third and a fifth signals, a first amplitude adjustment unit that outputs a eighth signal derived by multiplying the sixth signal by the third and fifth signals and a second amplitude adjustment unit that outputs a ninth signal derived by multiplying the seventh signal by the second and fifth signals.