Abstract: The gain of an amplifier in a receiver operating in a cellular communication system is controlled by determining one or more gain variability metrics, which are then used to produce first and second threshold values. A frequency difference between a current carrier frequency and a target carrier frequency is ascertained and then compared to the threshold values. Target gain setting production is based on comparison results: If the frequency difference is larger than the first threshold, a first automatic gain control algorithm is performed; if the frequency difference is smaller than the first threshold and larger than the second threshold, a second automatic gain control algorithm is performed, wherein the second automatic gain control algorithm uses a current gain setting as a starting point; and if the frequency difference is smaller than both the first and second thresholds, the current gain setting is used as the target gain setting.

Abstract: A digital circuit in a baseband receiver to compensate for the IQ mismatch by aligning the amplitude of ? with {tilde over (Q)} and by aligning the phase of {tilde over (Q)} to be 90 degrees away from ?.

Abstract: A Bias Unit Element (UE) has a digital input, a sign input, and a chop clock. The sign input is exclusive ORed with the chop clock to generate a signed chop clock. Each Bias UE comprises a positive Bias UE and a negative Bias UE, each comprising groups of NAND gates generating an output and a complementary output, each of which are coupled to differential charge transfer lines through binary weighted charge transfer capacitors to a differential charge transfer bus comprising a positive charge transfer line and a negative charge transfer line. The chopped sign input enables the positive Bias UE when the sign bit is positive and enables the negative Bias UE when the sign bit is negative.

Abstract: An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancelation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.

Abstract: An apparatus is comprised of a processor, first and second first Phase-Locked Loop Waveform Generators (PLLWGs), first and second Voltage Controlled Oscillators (VCOs), and a Radio Frequency (RF) switch. The processor generates first and second data program signals to program the first PLLWG and the second PLLWG, respectively, and generates a first and second trigger command signals instructing the first and second PLLWGs to generate first and second analog tuning signals, respectively. The first PLLWG, coupled to the processor, generates the first analog tuning signal. The second PLLWG, coupled to the processor, generates the second analog tuning signal. The first VCO, coupled to the first PLLWG, generates a first channel frequency signal. The second VCO, coupled to the second PLLWG, generates a second channel frequency signal. The RF switch selectively outputs one of a first pre-switch frequency signal and a second pre-switch frequency signal.

Abstract: Techniques for generating a local oscillator (LO) signal are disclosed. In one design, an apparatus includes an oscillator, a divider, and a phase locked loop (PLL). The oscillator receives a control signal and provides an oscillator signal having a frequency determined by the control signal. The divider receives the oscillator signal and generates multiple divided signals of different phases. The PLL receives a reference signal and a selected divided signal and generates the control signal for the oscillator. The divider is powered on and off periodically and wakes up in one of multiple possible states, with each state being associated with a different phase of the selected divided signal. Phase continuity of the selected divided signal is ensured by using the divider in a feedback loop with the PLL. The PLL locks the selected divided signal to the reference signal, and the selected divided signal has continuous phase due to the reference signal having continuous phase.

Abstract: A filtering system includes a first filtering module, which includes a first frequency translating device and a first filter. The first frequency translating device includes a center frequency control end that receives a first control signal and an input end that receives an input signal, and performs a first frequency translation on the input signal by utilizing a first control frequency of the first control signal as a center frequency. The first filter performs a first filter on the input signal according to equivalent impedance of a circuit coupled to the input end, and generates in collaboration with the first frequency translating device a first filtered input signal at an output end of the filtering system. The equivalent impedance determines a bandwidth of the first filtered input signal.

Abstract: A mixer includes an input stage to convert an RF input signal to an output signal, and a mixer core to mix the output signal from the input stage with a local oscillator signal. The input stage may include an input cell having a first differential pair of cross-connected transistors, and a linearizer coupled to the input cell. The linearizer may include a second differential pair of transistors having first and second inputs coupled to the input terminals and first and second outputs coupled to the output terminals.

Abstract: Example embodiments comprise a diversity receiver, and corresponding method, for measuring a differential phase between a first local oscillator of a first antenna and a second local oscillator of a second antenna in the presence of a primary interference signal and at least one secondary interference signal. The method may comprise receiving a primary communication signal, a primary reference signal and additional reference signals, and processing these signals such that a summation signal does not substantially comprise the at least one secondary interference signal. The estimation of differential phase is achieved by a phase shift calculation between processed signal components, using that a summation of all signal components equals, or is approximately equal to, a predetermined signal.

Abstract: A receiver using a harmonic mixer includes a signal receiver for receiving a first signal, a frequency generator for synchronizing a phase of the received first signal, down-converting a frequency size of the synchronized first signal as much as a first size, and outputting the down-converted signal as a second signal; a first harmonic mixer unit for receiving the first signal and the second signal, generating a third signal having a frequency size down-converted as much as a second size, and outputting the third signal. The receiver further includes a second harmonic mixer unit for receiving the third signal and outputting an In-phase signal having a frequency size down-converted as much as a third size, and a third harmonic mixer unit for receiving the third signal and outputting a Quadrature-phase signal having a frequency size down-converted as much as a third size.

Abstract: A conversion circuit (20) for converting a complex analog input signal having an in-phase, I, component and a quadrature-phase, Q, component resulting from frequency down conversion of a radio-frequency, RF, signal (XRF) to a frequency band covering 0 Hz into a digital representation is disclosed. It comprises a channel-selection filter unit (40) arranged to filter the complex analog input signal, thereby generating a channel-filtered I and Q components, and one or more processing units (53, 53a-b). Each processing unit comprises four mixers (60-75) for generating a first and a second frequency-translated I component and a first and a second channel-filtered Q component based on two LO signals with equal LO frequency and a 90° mutual phase shift. Furthermore, each processing unit comprises a combiner unit (85, 120) for generating a first, a second, a third, and a fourth combined signal proportional to sums and differences between said frequency translated I and Q components.

Abstract: A communications radio or transceiver having an extended upper operating frequency limit of at least 6 GHz. The radio includes a first IF conversion stage for receiving and downconverting a RF input signal to a first IF signal, and a second IF conversion stage for downconverting the first IF signal to a second IF signal. The first and the second conversion stages each have adjustable first and second attenuators, a serial peripheral interface (SPI) for controlling the attenuators in response to command words, a mixer coupled to an output of the second attenuator, and a buffer for applying a local oscillator (LO) signal to an input of the mixer. Each conversion stage is in the form of an integrated circuit chip. Component devices of each chip and electrical connections between the components, are dimensioned so that the chip has a 6 GHz upper frequency limit.

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

Abstract: A signal processing circuit includes a first multiplying unit which multiplies a first signal including a first frequency by a second signal including a second frequency and outputs a third signal, a second multiplying unit which multiplies the first signal by a fourth signal of a second frequency with phase lagging of a first phase difference relative to the second signal and outputs a fifth signal, a third multiplying unit which multiplies the first signal by the sixth signal of the second frequency with phase lagging of a second phase difference relative to the second signal and outputs a seventh signal, a first adding unit which adds the third signal, the fifth signal and the seventh signal respectively weighted and a signal generating unit which controls the first and the second phase difference based on a control signal and outputs the second, the fourth and the sixth signal.

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: An apparatus and method are disclosed for providing test mode contact pad reconfigurations that expose individual internal functional modules or block groups in an integrated circuit for testing and for monitoring. A plurality of switches between each functional module switches between passing internal signals among the blocks and passing in/out signals external to the block when one or more contact pads are strapped to input a pre-determined value. Another set of switches between the functional modules and input/output contact pads switch between functional inputs to and from the functional modules and monitored signals or input/output test signals according to the selected mode of operation.

Abstract: A tuner system for receiving a plurality of frequency bands includes a low noise amplifier coupled with a band selection filter to select a desired band. The tuner system further includes a complex RF filter to produce a complex RF signal from the selected band. The tuner system includes two double-quadrature converters, the first double-quadrature converter frequency down-converts the complex RF signal to a complex baseband signal. The complex baseband signal passes through a baseband filter that contains two identical lowpass filters for obtaining a baseband in-phase (I) signal and a quadrature (Q) signal. The second double-quadrature converter up-converts the baseband I and Q signals to respective IF I and Q signals that are significantly free of the positive third IF harmonic. The third IF-harmonic free I and Q signals are further processed by a complex bandpass filter. The bandpass filter has a programmable frequency center and a programmable bandwidth.

Abstract: The present invention discloses a multi-carrier receiving device and method. The multi-carrier receiving device includes an antenna, a splitter, a plurality of analog extraction modules, a combiner, an analog-to-digital converter, and a plurality of digital extraction modules, where input ends of the plurality of analog extraction modules are connected to an output end of the splitter; an input end of the combiner is connected to output ends of the plurality of analog extraction modules, and an output end of the combiner is connected to an input end of the analog-to-digital converter; an output end of the analog-to-digital converter is connected to each of the plurality of digital extraction modules; and the plurality of digital extraction modules extracts a single-carrier digital signal from a digital signal obtained after analog-to-digital conversion.

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: Content transfer involving a gesture is described. In an implementation, a method is implemented by a mobile communications device that includes recognizing a gesture input via a touchscreen of the mobile communications device that is indicative of a direction, the touchscreen including a display of content. One or more other mobile communications devices are located that are positioned, approximately, along the indicated direction of the gesture. A communication is formed to transfer the content to the located one or more other mobile communications devices.

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

Abstract: An integrated RF device includes at least one RF amplifier configured to be electrically coupled alternatively to a selected one of a RF signal input and a RF test source. A first mixer stage includes a first local oscillator and is electrically coupled to the at least one RF amplifier. At least one second mixer stage includes a second local oscillator and is electrically is coupled to the first mixer. The at least one baseband amplifier is electrically coupled to the second mixer. At least a selected one of the RF amplifier and the baseband amplifier has at least one actuator and at least one actuator terminal configured to provide an actuator setting. A method to self-heal an integrated RF receiver device is also described.

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: Embodiments related to analog front-ends for wireless and wired are described and depicted.

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: 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: A tuner system for receiving a plurality of frequency bands includes a low noise amplifier coupled with a band selection filter to select a desired band. The tuner system further includes a complex RF filter to produce a complex RF signal from the selected band. The tuner system includes two double-quadrature converters, the first double-quadrature converter frequency down-converts the complex RF signal to a complex baseband signal. The complex baseband signal passes through a baseband filter that contains two identical lowpass filters for obtaining a baseband in-phase (I) signal and a quadrature (Q) signal. The second double-quadrature converter up-converts the baseband I and Q signals to respective IF I and Q signals that are significantly free of the positive third IF harmonic. The third IF-harmonic free I and Q signals are further processed by a complex bandpass filter. The bandpass filter has a programmable frequency center and a programmable bandwidth.

Abstract: A wideband receiver for a wireless communication system and a method for controlling the same are provided. In the wideband receiver for a wireless communication system, a receive path includes a mixer for receiving a Radio Frequency (RF) signal having a frequency fSG and for converting the RF signal into an Intermediate Frequency (IF) signal having a frequency fIF by mixing the RF signal with a first local oscillation signal having a first local oscillation frequency fLO1, and at least one Phase Locked Loop (PLL) for providing the local oscillation signal to the mixer. A control block determines whether a half-IF signal having a center frequency of fSG?fIF/2 exists in the IF signal, and when the half-IF signal exists, controls the at least one PLL to generate a second local oscillation signal having a second local oscillation frequency fLO2 greater than the first local oscillation frequency fLO1.

Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers.

Abstract: A double frequency-conversion receiving circuit used for a radio-frequency SIM card, including a low-noise amplifier (01), a high-medium-frequency mixer (02), a low-medium-frequency mixer (03), a local oscillator (04), a quadrature I/Q circuit (05), and a low-medium-frequency processing circuit (07), characterized in that it also includes a frequency divider (06) that performs N frequency dividing to a high-local-oscillation signal generated by the local oscillator (04), wherein the divided low-local-oscillation signal is inputted into the quadrature I/Q circuit (05), the outputted I/Q local-oscillation signal is inputted into the low-medium-frequency mixer (03) to obtain, after mixing, a low-medium-frequency signal, and the low-medium-frequency signal is further processed by the low-medium-frequency processing circuit (07) to output the signal needed, which has gone through the double frequency-conversion.

Abstract: A system for estimating parameters of an incoming signal is provided. At least one antenna is coupled to at least one suitable receiver. The antenna(s) are spatially translated in an arbitrary trajectory. As the antenna(s) is being spatially translated, a data processing means samples the incoming signal at set intervals based on a clock signal provided by a system clock. By sampling the incoming signal at different times at different spatial locations on the arbitrary trajectory, the system acts as a synthetic antenna array. The different samplings of the incoming signal at different times and positions provide signal diversity gain as well as different readings which can be used to estimate and/or calculate various parameters of the incoming signal. The different samplings can be used to detect the incoming signal, estimate its angle of arrival, estimate its time of arrival, as well as other parameters.

Abstract: A method and system for managing Digital to Time Conversion (DTC) is provided. The method comprises receiving a first Radio Frequency (RF) signal and a second RF signal. The second RF signal is a phase-shifted first RF signal. The method further comprises converting the first RF signal to a first Intermediate Frequency (IF) signal and the second RF signal to a second IF signal. Further, a time delay between the first IF signal and the second IF signal is estimated based on a time difference measurement technique. The second RF signal is processed based on the estimated time delay to compensate for a delay error associated with the second RF signal.

Abstract: Receiver architectures and methods of processing harmonic rich input signals employing harmonic suppression mixers are disclosed herein. The disclosed receivers, mixers, and methods enable a receiver to achieve the advantages of switching mixers while greatly reducing the mixer response to the undesired harmonics. A harmonic mixer can include a plurality of mixers coupled to an input signal. A plurality of phases of a local oscillator signal can be generated from a single local oscillator output. Each of the phases can be used to drive an input of one of the mixers. The mixer outputs can be combined to generate a frequency converted output that has harmonic rejection.

Abstract: Receiver architectures and methods of processing harmonic rich input signals employing harmonic suppression mixers are disclosed herein. The disclosed receivers, mixers, and methods enable a receiver to achieve the advantages of switching mixers while greatly reducing the mixer response to the undesired harmonics. A harmonic mixer can include a plurality of mixers coupled to an input signal. A plurality of phases of a local oscillator signal can be generated from a single local oscillator output. Each of the phases can be used to drive an input of one of the mixers. The mixer outputs can be combined to generate a frequency converted output that has harmonic rejection.

Abstract: A single side band (SSB) mixer includes an in-phase SSB mixer unit and a quadrature-phase SSB mixer unit. The in-phase SSB mixer unit generates an in-phase output current, and includes a first transformer load in which a portion of a quadrature-phase output current flows. The quadrature-phase SSB mixer unit generates the quadrature-phase output current, and includes a second transformer load in which a portion of the in-phase output current flows. The SSB mixer may be used in a wide frequency band without degrading frequency selectivity.

Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers.

Abstract: A receiver includes a radio frequency metal-oxide-semiconductor amplifier, a mixer, and an intermediate frequency amplifier. The radio frequency metal-oxide-semiconductor amplifier is used for receiving amplifying a signal of a first band and a signal of a second band of a satellite microwave band from an external antenna circuit according to a control signal. The mixer is coupled to the radio frequency metal-oxide-semiconductor amplifier for reducing the signal of the first band to a signal of a first intermediate frequency band according to a first oscillation frequency of a local oscillator, or reducing the signal of the second band to a signal of a second intermediate frequency band according to a second oscillation frequency of the local oscillator. The intermediate frequency amplifier is coupled to the mixer for amplifying and outputting the signal of the first intermediate frequency band and the signal of the second intermediate frequency band.

Abstract: A wireless communication unit (200) comprises a radio frequency (RF) receiver for receiving an RF signal and providing the received RF signal to an off-channel signal detector (218) and a quadrature down conversion mixer circuit comprising at least one dynamic matching mixer stage (226, 228, 250, 252). The off-channel signal detector (218) is arranged to detect whether an off-channel signal level of the received RF signal exceeds a threshold and, in response to determining that the received off-channel RF signal exceeds the threshold, the off-channel signal detector (218) deactivates the at least one dynamic matching mixer stage. Also described is a semiconductor that comprises a receiver, and a method of operation therefor.

Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers. The high selectivity RF circuit comprises channel select filters, a down-converter, an up-converter and a programmable local oscillator.

Abstract: A wireless receiver is provided that includes a multi-step gain-control low-noise amplifier (LNA) stage and a mixer stage. The LNA stage is operable to amplify at least one input signal to generate at least one LNA output. The mixer stage is directly coupled to the LNA stage (without an intervening external bandpass filter) and is operable to down-convert the LNA output to generate a mixer output.

Abstract: A circuit, electrical device or other apparatus for band stacking and/or band translating multiple transmissions. Such transmissions may be satellite transmissions, terrestrial transmissions, signals carried across a wired network such as a cable network, and so forth. Two sets of left-hand polarized and right-hand polarized signals may be accepted by an embodiment. One left-hand polarized signal and one right-hand polarized signal may be band stacked such that the left-hand polarized signal occupies a first frequency and the right-hand polarized signal occupies a second frequency, thereby permitting the two signals to be transmitted simultaneously across a single transmission line as a first unique signal. The second left-hand polarized signal and second right-hand polarized signal may likewise be combined into a second unique signal for transmission. The first and second unique signals may be stacked as a first stacked output and a second stacked output by a band translating circuit.

Abstract: Techniques involving the generation of signals at particular frequencies are disclosed. For instance, an apparatus may include an oscillator module, a synthesizer module, and a control module. The oscillator module produces an oscillator signal having a first frequency. From the oscillator signal, the synthesizer module produces an output signal having a second frequency. A frequency multiplier corresponds to the first and second frequencies. The control module selects the first frequency and the frequency multiplier such that a difference between the second frequency and a nearest integer multiple of the first frequency is greater than a predetermined threshold. As a result, reductions in spurious outputs may be achieved.

Abstract: Systems and methods for demodulating a plurality of contiguous channels contained within a bandlimited portion of a radio-frequency (RF) input signal are provided. In an embodiment, the bandlimited portion of the RF input signal is down-converted to baseband. After down-conversion, the bandlimited portion overlaps at baseband with a mirror image of the bandlimited portion. The plurality of contiguous channels within the down-converted signal similarly overlap at baseband and subsequently occupy a bandwidth substantially equal to half that required before down-converting. Image rejection is performed in the digital domain to recover each of the plurality of overlapping channels.

Abstract: A tracking filter for attenuating out-of-band signals and adjacent channel signals in a receiver is described. In one exemplary design, an apparatus includes a tracking filter, an LNA, and a downconverter. The tracking filter includes a summer, a filter, and an upconverter. The summer subtracts a feedback signal from an input signal and provides a first signal. The LNA amplifies the first signal and provides a second signal. The downconverter frequency downconverts the second signal and provides an output signal. The filter filters (e.g., differentiates) the output signal and provides a third signal. The filter blocks a desired signal and passes out-of-band signal components. The upconverter frequency upconverts the third signal and provides a fourth signal from which the feedback signal is derived. The tracking filter has an equivalent bandpass filter response and a variable center frequency determined based on the frequency of the desired signal.

Abstract: A radio frequency (RF) transceiver includes an RF transmitter that generates an outbound RF signal at a carrier frequency that is based on a transmitter local oscillation. An RF front-end receives an inbound RF signal that includes a desired signal component that is based on the outbound RF signal and that includes an undesired signal component. The RF front-end includes a first RF combiner module that attenuates the undesired signal component to produce a desired RF signal. A down conversion module generates a down converted signal from the desired RF signal based on a receiver local oscillation. A receiver processing module generates inbound data from the down converted signal. A frequency control module controls the carrier frequency, based on an interference rejection signal, to control the attenuation of the undesired signal component.

Abstract: Receivers (5) for simultaneously receiving different radio frequency signals according to different standards are provided with first frequency translating stages (1) for converting the radio frequency signals into first intermediate frequency signals and second frequency translating stages (2) for converting the first intermediate frequency signals into second intermediate frequency signals and processing stages (3) for retrieving first information from the first intermediate frequency signals and second information from the second intermediate signals. As a result, such receivers (5) have relatively low power consumption. The first frequency translating stages (1) comprise first oscillators (19) and first mixers (11) and further first mixers (12). The second frequency translating stages (2) comprise second oscillators (29) and second mixers (21) and further second mixers (22) and third mixers (23) and further third mixers (24).

Abstract: The signal to noise ratio performance of a RF communication system can be improved by providing resistance to transmitter self-jamming and eliminating or reducing the need for a transmit rejection filter or other measures such as limiters or blanking switches. An anti-jam low noise amplifier provides enough rejection and jamming immunity to reduce or eliminate the need for the transmit reject filter. Thus, the system noise performance is improved by eliminating the filter and the associated losses which cause signal to noise ratio performance degradation.

Abstract: An RFID transceiver (200) includes a common frequency source (250), a receiving channel (230) and a transmitting channel (240). The common frequency source (250) is configured to provide a predefined intermediate frequency signal fIF, and a predefined carrier frequency signal fc. The RFID receiving channel (230) includes an upconverting mixer (232) having a first input coupled to receive the predefined intermediate frequency signal fIF, a second input coupled to receive the predefined carrier frequency signal fc, and an output, the upconverting mixer (232) operable to produce an upconverted signal at a frequency defined by fc±fIF.

Abstract: A mixer mixes respective signals of L1, L2C, and L5-E5a with a local oscillation signal where the frequency of the L1 signal has an image relationship with the frequencies of the L2C and L5-E5a signals to conduct frequency conversion. An image removal mixer mixes the respective position signals of 1stIF with a local oscillation signal where the frequency of the L1 signal of the 1stIF has an image relationship with the frequencies of the L2C signal and the L5-E5a signal of 1stIF to conduct frequency conversion. The image removal mixer then outputs the L1 signal of 2ndIF and the L2C and L5-E5a signals of 2ndIF, independently. A branching filter separates the L2C and L5-E5a signals of 2ndIF from each other, and outputs the separated signals.