Abstract: A satellite broadcast receiver apparatus includes a plurality of signal conversion units provided corresponding to a plurality of signals transmitted from one or more satellites, each signal conversion unit frequency-converting a corresponding signal for output; a signal terminal that can input/output an electrical signal; a signal select circuit provided between the plurality of signal conversion units and the signal terminal to transmit a desired signal among the signals output from the plurality of signal conversion units to the signal terminal in accordance with a control signal applied to the signal terminal; and a power supply control unit controlling voltage supply to the plurality of signal conversion units. The power supply control unit supplies an operating voltage to at least one of the plurality of signal conversion units selected in accordance with information based on the control signal, and suppresses supply of the operating voltage to the remaining signal conversion units.

Abstract: A radio frequency receiver 30, 32, includes a first component block 12, 16, 18, 20; a second compensating component block 22, 22a–22b, 34; and control circuitry 26 operable for controlling the state (e.g., load, bias, gain) of the first component block. When the control circuitry 26 causes a change in the state of the first component block that is expected to induce a DC offset in a signal, the control circuitry 26 changes the state of the second component block to compensate for an estimate of the DC offset. Preferably, the second component block is a filter 22, 22a–22b, 34, that temporarily changes from a nominal cutoff frequency to an elevated cutoff frequency so that voltage will settle quickly and accurately at an estimated voltage, the estimated voltage being predetermined and based on the state change to the first component block. A method is also described for practicing the invention.

Abstract: A direct-down conversion receiver may include a transconductance-capacitor (GmC) filter to filter undesirable mixing products and provide a filtered baseband-differential signal. The GmC filter may include first and second transconductance-capacitor (GmC) circuits in series and a transconductance-feedback circuit in feedback with the second transconductance-capacitor circuit. The GmC circuits may comprise cross-coupled pairs of transistors to receive a baseband-differential signal and generate a differential output current. The GmC circuits may also comprise MOSCAPs coupled respectively between the differential inputs of the GmC circuit and internal-feedback nodes. In some embodiments, a substantially-constant bias voltage may be maintained across the voltage-dependent capacitors to allow the voltage-dependent capacitors to provide a substantially constant capacitance.

Abstract: An integrated semiconductor mixer includes a substrate (10), a radio-frequency balun (12) disposed on the substrate (10), a local oscillator balun (14) disposed on the substrate (10), an intermediate-frequency port (16) disposed on the substrate (10), and a mixer diode array (18), disposed on the substrate (10), that communicates with the radio-frequency balun (12), the local oscillator balun (14), and the intermediate-frequency port (16), in which the radio-frequency balun (12) is shielded from the local oscillator balun (14) by plated holes (20).

Abstract: A receiver capable of reducing a low-frequency noise generated when a component is integrally formed on a semiconductor substrate by using CMOS process or MOS process. A high-frequency amplifier circuit 11, a mixing circuit 12, a local oscillator 13, intermediate-frequency filters 14 and 16, an intermediate-frequency amplifier circuit 15, a limit circuit 17, an FM detection circuit 18, and a stereo demodulation circuit 19 constituting an FM receiver are formed as a one-chip component 10. This one-chip component 10 is formed on a semiconductor substrate by using the CMOS process or the MOS process. The amplification elements contained in the mixing circuit 12, the intermediate-frequency filters 14 and 16, the intermediate-frequency amplifier circuit 15, and the local oscillator 13 are formed by using the p-channel type FET.

Abstract: The level of the harmonics of oscillation signals for synchronous detection to be inputted to a mixer circuit for converting frequencies is suppressed low.

Abstract: A communications transceiver is implemented by modifying a GPS user equipment. In a data reception mode, a communications signal that has a carrier frequency outside the L-band, and that has been phase modulated by a PN code and by data encoded therein, is received from a conventional L-band GPS antenna. The signal is downconverted to the L-band input frequency of the GPS transceiver, and subjected to automatic gain control. The GPS transceiver software is modified so as to recognize and replicate the PN code, and to demodulate the data-bearing signal. In the data transmission mode, the data to be transmitted are modulated onto the selected PN code sequence. The data-modulated PN signal is converted to a non L-band transmission frequency. Normal operation of the GPS transceiver navigation functions is maintained in parallel with the communications functions.

Abstract: A digital radio frequency receiver capable of receiving RF signals at a plurality of signal strengths thereby extending the dynamic range of the receiver without introducing a control loop while allowing a stable gain control algorithm to be implemented in software is described. Various embodiments of a digital radio receiver process a range of signals outside normal analog to digital converter capabilities and bypass the delays resulting from gain control loops.

Abstract: A frequency converter comprises an impedance matching unit connected to a current switching stage and a transconductance amplifier stage. The impedance matching unit has an impedance for conjugate power match. For example, the impedance matching unit is a parallel resonant circuit that includes an inductor and a capacitor that are formed as an integrated circuit. Thus, the frequency converter that has high conversion gain and low noise is obtained.

Abstract: A direct-conversion receiver includes an analog stage for receiving an incident signal from a transmission channel, mixers and programmable-gain amplifiers. The receiver further includes at least one compensation module having input and output terminals respectively connected between the output of the mixers and the input of the programmable-gain amplifiers. The compensation module compensates for both a static DC voltage offset and a possible dynamic DC voltage offset of the analog stage.

Abstract: A differential mixer includes DC currents that reduce flicker noise in the mixer circuit without increasing local oscillator drive requirements. The differential mixer circuit includes an RF transconductance circuit and a local oscillator (LO) switching circuit. The RF transconductance circuit converts a differential RF input signal to a differential RF current. The LO switching circuit commutates the differential RF input signal according to a local oscillator signal to frequency translate the RF input signal. The DC currents or bleeder currents are added directly to the field effect transistors in the RF transconductance circuit, which reduces the flicker noise produced by the mixer. The DC currents do not pass through the FETs in the LO switching circuit so there is no increase in the LO drive requirements.

Abstract: The present invention includes a transceiver and a method of operating the same that includes in the transmitter a power control circuit that operates on an analog differential signal containing data packets individually. The power control circuit initially transmits a series of data symbols with known values, periodically strobes the transceiver system for correct power levels and incrementally increases the power level of the transceiver until the optimal gain is reached, without exceeding the maximum output power.

Abstract: The present invention describes active double-balanced mixers. The mixers use an isolation and matching section that provides RF section input matching and superior isolation between the LO and RF port. The mixers can be implemented using an inexpensive semiconductor processing technology, obviating the need for matching inductors and facilitating a low-cost, low-power fully integrated wireless receiver.

Abstract: A transmission power amplifier unit of a base-station apparatus for compensating for non-linear distortion of a transmission power amplifier by feed-forward control is provided with a gain varying unit for varying gain of the transmission power amplifier unit. At start-up of the transmission power amplifier unit, a controller determines whether the base-station apparatus is in a blossoming mode or breathing mode, maximizes gain of the transmission power amplifier unit by controlling the gain varying unit if the mode is the blossoming mode and increases the gain gradually in proportion to the passage of time if the mode is the breathing mode.

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

Abstract: A forward signal equalizer for a forward amplifier for two-way coaxial cable systems, of the type having a distribution center distributing forward signals, and having reception facilities for receiving return signals from said cable system, the system having forward amplifiers for receiving forward signals, and having return amplifiers, and the forward signal equalizers are settable to provide varying amplifier specifications, and having receptacles for receiving plug-in equalizer components for varying the specifications of the forward amplifier, the equalizer components having a range of varying performance characteristics so that a component can be selected and plugged in to the forward signal equalizer to produce the performance specifications desired at a predetermined location in the cable system.

Abstract: Between a mixer and an intermediate frequency amplifying circuit, there are an intermediate frequency tuning circuit which, for reception of a TV signal, is tuned between a chrominance subcarrier frequency and a video intermediate frequency in an intermediate frequency band, and for reception of an FM broadcasting signal, is tuned nearly to the chrominance subcarrier frequency, and a first trap circuit which attenuates a sound intermediate frequency of an adjacent channel. Next to the intermediate frequency amplifying circuit, there is a second trap circuit which, for reception of a TV signal, brings about attenuation between the video intermediate frequency in the intermediate frequency band and the sound intermediate frequency of the adjacent channel and, for reception of an FM broadcasting signal, brings about attenuation around the video intermediate frequency.

Abstract: In an analog baseband signal processing system and method, gain and offset are measured for each of a plurality of stages. The DC content inherent to the amplifier and filter circuitry is measured by known means. A digital number for each gain and offset level is generated and converted to digital, numerical form of correction of each stage, and converted back to analog form to make the compensation without corrupting near DC signals. In a preferred form, first and second channels of the analog baseband signal processor are provided for in-phase and quadrature channels in a direct conversion, solid-state telephone receiver.

Abstract: A variable gain amplifier includes circuit elements that may be partially powered down during transmit modes of operation and that may be powered back up whenever the radio transceiver receives a data packet within a specified settle time even for high throughput RF communications. The radio transceiver circuit may be powered down even in high throughput communications during a transmit mode to reduce power consumption. A DC offset cancellation block is operably coupled to the variable gain block to substantially remove any DC offset from the amplified output. The variable gain amplifier is further able to provide DC offset cancellation within the required settle time by holding the offset value during a dormant mode of operation.

Abstract: The local area positioning system (LAPS) slave receiver is an extremely sensitive, ultra low noise, high speed up-converting microwave receiver operating in the 900 Mhz to 1.6 Ghz frequency range and is designed for use with a positioning system. The receiver, which may include fiber optic links, allows detection and switching of high speed short duration pulses used to control an associated highly stable 1.0 Ghz start/stop event counter. The receiver, in combination with the counter, is capable of measuring RF propagation distances with an accuracy of 12 inches.

Abstract: Receiver comprising a resonance amplifier for selectively amplifying a modulated carrier signal being coupled to signal demodulator for narrow band demodulation. The resonance amplifier comprising a cascade of first and second transconductance amplifiers (TC1, TC2) being included in a loop, outputs thereof being coupled via first and second parallel RC filters (R1C1; R2C2) to inputs of the second and first transconductance amplifiers (TC1, TC2), respectively, the loop also includes a signal inverter (INV) for signal inversion.

Abstract: A gain calibration circuit for a radio frequency mixer in a wireless transceiver includes a reference signal generator that generates a reference signal. A comparator receives the reference signal and a second signal that is proportional to current flowing through the transmitter mixer and generates a difference signal. An adjustment circuit adjusts a transconductance gain of the mixer based on the difference signal. The adjustment circuit includes a plurality of binary weighted transconductance cells. The transconductance gain is calibrated during idle time between data packets or after power on, hardware reset, or software reset.

Abstract: A tuner comprises a frequency changer which converts an input signal to a predetermined fixed intermediate frequency. The frequency changer is followed by an IF filter having a filter parameter, such as center frequency, which is electronically adjustable. A controller adjusts the adjustable filter characteristic so as to achieve a predetermined desired filtering performance, such as ensuring that the filter center frequency corresponds to the desired intermediate frequency. The controller comprises a local oscillator having the same type of tuned circuit as the IF filter. A phase locked loop compares the local oscillator frequency with a reference frequency and controls the tuned circuits of the IF filter and the local oscillator.

Abstract: A bidirectional amplifier circuit includes first and second input ports, first and second output ports, a power amplifier, and first, second, third, and fourth filter circuits. The power amplifier includes at least first and second input terminals and first and second output terminals. The first filter circuit is coupled between the first input port and the power amplifier first input terminal. The second filter circuit is coupled between the second input port and the power amplifier second input terminal. The third filter circuit is coupled between the first output port and the power amplifier first output terminal. The fourth filter circuit is coupled between the second output port and the power amplifier second output terminal. Carrier waves of differing frequencies may be injected into the amplifier circuit first and second input ports, and transmitted from the first and second output ports.

Abstract: Tunable upconversion mixers that have a controllable passband response and provide substantial image rejection, making costly post-mixing filtering at least optional, if not unnecessary for many applications. A single mixer is able to support several frequency bands (and/or be accurately tuned within one frequency band) by means of varying the capacitance in a tunable load circuit for the mixer circuit. The tunable mixer comprises a mixer circuit having inputs for receiving a signal to be upconverted and an oscillator signal to be mixed with the signal to be upconverted. The mixer generates a mixer output signal at a desired sideband frequency and an image signal at an image frequency.

Abstract: A method in a radio communication device having a receiver receiving a wideband signal in the presence of narrowband blockers method in direct conversion and intermediate frequency RF receivers including determining power for signal distortion products (40), determining power for a desired signal and the distortion products (41), filtering the signal distortion products with a filter having a bandwidth of rejection, and dynamically adjusting a rejection property (43) as a function of the power for both the desired signal and the signal distortion products. In some embodiments, a determination is made whether a ratio of powers exceeds a threshold (45) as a condition for adjusting the rejection property.

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

Abstract: Wireless communications equipment that wirelessly communicates signals on a plurality of communication frequencies includes: a baseband frequency-side frequency conversion means that performs conversion between baseband signals on the baseband frequency and signals on a stipulated frequency higher than the baseband frequency and different from the intermediate frequency, an intermediate frequency-side frequency conversion means that performs conversion between the signals on said stipulated frequency and intermediate frequency signals on a plurality of intermediate frequencies corresponding to a plurality of communication frequencies, and an unwanted frequency signal component removal means that removes signal components of unwanted frequencies from the signals on said stipulated frequency.

Abstract: A method and apparatus for receiving radio frequency signals in a communication system is described. The inventive method and apparatus utilizes an inventive receiver circuit that downconverts an input signal so that interference components of the input signal can be easily removed at baseband. Specifically, the inventive receiver circuit operates by sub-sampling a first intermediate frequency signal in such a way that an unwanted signal is not aliased into a wanted signal, and can therefore be filtered therefrom after sub-sampling. Thus, the present invention allows the use of a relatively simple tuner, with a single downconversion stage, without imposing excessive requirements on the filtering in the tuner.

Abstract: A radio frequency amplifier of improved intermodulation performance is provided by connecting first and second transconductance amplifiers in antiphase so that third order intermodulation products cancel each other but the reduction in gain is relatively small. The transconductance stages comprise long tail pairs of transistors provided with tail current sources formed by transistors whose bases are connected to a bias voltage source. The first transistor has an emitter connected via a resistor to ground. The second transistor has an emitter connected via another resistor to the emitter of the first transistor.

Abstract: A triplexer and a multilayered structure thereof. The triplexer comprises a first filter circuit and a low pass filter circuit connected in parallel to an input terminal, and a second filter circuit and a third filter circuit connected in parallel to an output terminal of the low pass filter circuit. The first filter circuit passes a signal of a first frequency band, and the low pass filter circuit passes a signal of a predetermined frequency band which is lower than the first frequency band. The second filter circuit extracts a signal of a second frequency band from the predetermined frequency band signal, and the third filter circuit extracts a signal of a third frequency band from the predetermined frequency band signal, which third frequency band is lower than the second frequency band. The low pass filter circuit includes a notch circuit for extending a portion of the predetermined frequency band, neighboring the first frequency band.

Abstract: A FET mixer uses a balun having a primary and secondary, with the primary coupled to an radio frequency signal input. The mixer also includes a pair of field effect transistors (FETs), wherein the gates are coupled to one another and to a local oscillator input. One of the source and the drain of the second of the two transistors is coupled at a node to one of the source and the drain of the other of the two transistors, and the node is coupled to ground. The other of the source and the drain of the first of the two transistors is coupled to one side of the secondary of the balun and the other of the source and the drain of the second of the two transistors is coupled to the other side of the secondary of the balun. An intermediate frequency signal output is coupled to a point in the circuit path between the first and second transistors.

Abstract: A system for a wireless mobile station is disclosed. The system enables the mobile station to adaptively adjust sleep durations and wakeups during a low power idle mode between paging channel slots. The adjustment of sleep durations and wakeups are based on number of key-presses or other input/output (I/O) activities within a fixed number of paging channel slots. The adjustment increases standby time for the mobile station.

Abstract: A wireless remote unit is operable to demodulate signals received over a plurality of different bands, such as the FM broadcast band, and one or more higher frequency bands. The various bands have different channels and the selection of the band and the channel is accomplished by control signals received by the receiver. The control signal can carry menu information in one direction to the user and can carry user data, including the identity of the user, in the other direction. There can be multiple transmitters, wherein each transmitter sends information on a different channel within a band, and tunes remote units to a particular transmitter based upon proximity to that transmitter. The transmitter is capable of displaying visual data. The visual data includes a predetermined number of advertisements to be displayed during a user session, prompted either by a user logging onto the system, or by the system's detection of a user's presence.

Abstract: A differential RF input signal drives the plus and minus terminals of a center tapped primary winding, which couples the differential RF input signal to the plus and minus terminals of a center tapped secondary winding. From the secondary winding, the coupled, differential RF signal drives a double-balanced mixer core operating in response to a differential local oscillator signal. The output of the mixer core is a differential IF signal representative of the differential RF input signal down-converted at the local oscillator frequency. A step reduction in gain associated with the RF input signal may be implemented using bypass circuitry coupled across the primary of the transformer, wherein a relatively small resistance or impedance is coupled across the primary to effectively reduce the load of the differential amplifiers driving the primary.

Abstract: The invention relates to a frequency converter designed for supplying an output signal having a radio frequency FR equal to the difference between the frequency FLO of a signal OS originating from an oscillator VCO and the frequency FI of an input signal IS. The frequency converter has two quadratic modules QM1 and QM2 for separating the signal originating from the-oscillator OS and the input signal IS into two components (LO1, LO2) and (FI1, FI2) in phase quadrature, two mixers MX1, and MX2 for multiplying the components thus obtained two-by-two, and combination means COMB for recombining the output signals RS1 and RS2 of the mixers MX1 and MX2. The frequency converter operates internally a good rejection of the image frequency while providing a good performance as regards noise and gain and an improved linearity as compared with known converters. Thus, frequency shifting before transmission in a wireless telephone may be accomplished.

Abstract: An amplifier circuit for amplifying an input signal to generate an amplifier output signal incorporates a cascaded series of reflection amplifiers arranged along a signal path and operative to amplify signals propagating in a forward direction along the signal path. The circuit is operative to counteract signal propagation in a reverse direction along the signal path, thereby hindering spontaneous oscillation from arising within the circuit. Incorporation of reflection amplifiers into the circuit enables it to provide high gain, for example 50 dB, while consuming low currents, for example, tens of microamperes. The circuit is especially suitable for use at intermediate frequencies in radio receivers such as mobile telephones.

Abstract: A receiving method for dual-mode receiver. When a received communication signal is a wideband signal, the dual-mode receiver is configured as a direct-conversion receiver, and when a received communication signal is a narrowband signal, the dual-mode receiver is configured as a low-IF receiver.

Abstract: In a radio receiver, clock distribution changes, that is, enabling or disabling the clock signals to specific circuit blocks at specific times to reduce power consumption, can cause changes in the DC offset level. Knowledge about clock distribution changes can be used to improve receiver performance. Specifically, information about clock distribution changes is stored during signal reception, and used to predict the presence of DC offset step changes.

Abstract: An amplification system for reducing DC offset in an input signal uses a low pass filter to isolate a DC component of the input signal. The system then subtracts the DC component from the input signal. In one embodiment, the system includes first and second amplifiers in addition to the low pass filter. The first amplifier amplifies the input signal to generate a first amplified signal at a differential output port of the amplification system. The second amplifier amplifies a low pass filtered version of the input signal to generate a second amplified signal at the differential output port of the amplification system. The outputs of the first and second amplifiers are connected to the differential output port of the amplification system in such a way that the first and second signals combine 180 degrees out of phase at the output port.

Abstract: A high-speed receiver, adapted to receive signals over an input line in the presence of narrowband radio frequency interference (RFI). The receiver includes a RFI canceller module, which is coupled to receive samples of the interference from the input line. The module includes an adaptive bandpass filter, which is adapted to track a dominant frequency of the interference, and to generate a filtered output in a narrow frequency range centered on the dominant frequency. A corrector is coupled to receive the filtered output from the adaptive bandpass filter and to generate, responsive thereto, an estimate of the interference in the signals received by the receiver. A subtractor is adapted to subtract the estimate of the interference from the signals received by the receiver so as to generate a corrected output signal.

Abstract: A power amplifier system has a high frequency power amplifier circuit section employing source-grounded enhancement type n-channel MESFETs for receiving a drain bias voltage and a gate bias voltage of zero volts or positive low potentials supplied from a unipolar power supply, and amplifying a superposed input signal therewith to output an amplified signal indicative of a change in drain currents. An output matching circuit section applies impedance matching to the amplified signal and outputs the resultant signal. A gate bias voltage circuit section supplies a gate bias voltage to the high frequency power amplifier circuit. When a forward direct current gate voltage is applied to a gate terminal with a source terminal coupled to ground, the DC gate voltage becomes greater than or equal to 0.65 volts, the DC gate voltage causing a gate current value per gate width of 100 micrometers to exceed 100 microamperes.

Abstract: A direct conversion receiver including a filtering system for improving signal reception in the receiver is disclosed. In one embodiment, the direct conversion receiver comprises a first filter adapted to receive a plurality of receive signals comprising a receive band. The first filter is configured to attenuate a frequency range of the receive band to de-emphasize signals within of the frequency range. The direct conversion receiver also comprises a second filter coupled to a signal processing logic output and is configured to amplify the signals in the frequency range of the receive band, the signal processing logic being coupled to the output of the first filter and configured to substantially attenuate a plurality of unwanted signals in the receive band.

Abstract: A radio frequency front-end receiver includes a single stage low noise amplifier connected with a resistor array and a capacitor array, and a Gilbert-type mixer connected with a PMOS transconductance stage, an inductor and a serially connected current source. The resistor array enables the adjustment of the power gain of the low noise amplifier. The capacitor array tunes the low noise amplifier so that the maximum power gain is at the desired operating frequency. The PMOS transconductance stage reduces the power consumption of the mixer. The inductor increases the impedance and the current source improves the common-mode rejection of the mixer.

Abstract: A receiver with reduced near field noise is described. The receiver has a far range receiving section configured to sense a desired signal that includes near field noise. The receiver further includes a near range receiving section configured to sense a near field noise reference signal. An adaptive noise canceller (ANC) of the receiver is configured to detect the magnitude of an error vector from the far range receiving section. The ANC is configured to adjust the phase and gain of the near field noise reference signal in response to the magnitude of the error. Accordingly, the ANC can generate a corrected near field noise reference signal that is added to the desired signal with an adder. The near field noise is canceled by the addition of the corrected near field noise signal. The ANC uses a least mean square technique to determine the amount of correction needed.

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

Abstract: An intermediate frequency input circuit is coupled between output nodes of a frequency mixing circuit and input nodes of an intermediate frequency amplifier circuit. The intermediate frequency input circuit includes a pair of input nodes; a pair of output nodes; and resonance circuits, which are coupled between the pair of input nodes and resonate with an intermediate frequency of a selector channel. A series circuit is coupled between one of the pair of input nodes and one of the pair of output nodes. The series circuit includes a first trap circuit for trapping an intermediate frequency component of an upper adjacent channel coupled to first resistor. The intermediate frequency input circuit further includes a second series circuit, which is coupled between the other of the pair of input nodes and the other of the pair of output nodes. The second series circuit includes a second trap circuit for trapping an intermediate frequency component of a lower adjacent channel coupled to a second resistor.

Abstract: A system and method for canceling DC offset for Mobile Station Modems having direct conversion architectures. The present invention is a fast acquiring DC offset cancellation block that provides rapid and accurate DC offset estimates and cancellation techniques to support direct conversion architectures. The fast acquiring DC offset cancellation block combines four mechanisms to rapidly acquire and remove a DC offset estimate after power up, temperature changes, receiver frequency changes, and gain setting changes by increasing high pass loop bandwidth and adjusting DC offset levels at baseband. After removing the DC offset in large portions, the high pass loop bandwidth is decreased to fine tune the previous estimate and to remove any small variation in DC offset due to receiver self-mixing products.

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

Abstract: A multi-carrier receiver for a radio telecommunications network is described, comprising a downconverter for downconverting a received analog radio frequency signal to an intermediate frequency (IF) signal; a control unit for controlling the power level of the IF signal; a coupler for coupling a representative value of the IF signal to the control unit; a delay element located downstream of the coupler for delaying the propagation of the IF signal to an electronic component, the control unit controlling the power level of the IF signal by feed forward control to keep this IF power level within a dynamic range of the electronic component. The electrical component is preferably a first analog to digital converter (ADC). The control unit preferably comprises a log amplifier and a second ADC. The delay element is preferably a filter or a delay line.