Abstract: An entire radio transceiver can be easily integrated into one IC chip. In order to integrate the IF filters on the chip, a heterodyne architecture with a low IF is used. A single, directly modulated VCO is used for both up-conversion during transmission, and down-conversion during reception. Bond-wires are used as resonators in the oscillator tank for the VCO. A TDD scheme is used in the air interface to eliminate cross-talk or leakage. A Gaussian-shaped binary FSK modulation scheme is used to provide a number of other implementation advantages.

Abstract: A combination of a phase shifter, a measurement receiver, and an offset estimator enable the d.c. offset in the transmit path of a quadrature transmitter to be distinguished from the d.c. offset in the measurement receiver. The measurement receiver performs a first measurement on the transmit path output with a “normal” phase shift of 0 degrees and 90 degrees for in-phase (I) and quadrature (Q) components, and a second measurement with a “special” phase shift for the I and Q components. In one embodiment, the “special” phase shift for the I and Q components is 180 degrees and 270 degrees, respectively.

Abstract: An entire radio transceiver can be completely integrated into one IC chip. In order to integrate the IF filters on the chip, a heterodyne architecture with a low IF is used. A single, directly modulated VCO is used for both up-conversion during transmission, and down-conversion during reception. Bond-wires are used as resonators in the oscillator tank for the VCO. A TDD scheme is used in the air interface to eliminate cross-talk or leakage. A Gaussian-shaped binary FSK modulation scheme is used to provide a number of other implementation advantages.

Abstract: A noise-canceling LNA circuit for amplifying signals at an operating frequency f in a receiver circuit is disclosed. The LNA circuit comprises a first and a second amplifier branch, each having an input terminal connected to an input terminal of the LNA circuit. The first amplifier branch comprises an output terminal for supplying an output current of the first amplifier branch and a common source or common emitter main amplifier. The main amplifier has an input transistor having a first terminal, which is a gate or base terminal, operatively connected to the input terminal of the first amplifier branch, a shunt-feedback capacitor operatively connected between the first terminal of the input transistor and a second terminal, which is a drain or collector terminal, of the input transistor, and an output capacitor operatively connected between the second terminal of the input transistor and the output terminal of the first amplifier branch.

Abstract: A common source or common emitter LNA circuit for amplifying signals at an operating frequency f in a receiver circuit is disclosed. The LNA circuit comprises an input transistor arranged to, in operation, be biased to have a transconductance gm at the operating frequency f, and having a first terminal, which is a gate or base terminal, operatively connected to an input terminal of the LNA circuit. The LNA circuit further comprises a shunt-feedback capacitor operatively connected between the first terminal of the input transistor and a second terminal, which is a drain or collector terminal, of the input transistor. Furthermore, the LNA circuit comprises an output capacitor operatively connected between the second terminal of the input transistor and an output terminal of the LNA circuit. The output capacitor has a capacitance value CL<gm/f.

Abstract: A method and system for achieving increased efficiency in a quadrature modulated power amplifier (11) are disclosed. In some embodiments, a supply path (36, 40) and a gain path (38, 42) are provided in each of an I-channel and a Q-channel. The supply path (36, 40) produces a variable voltage and the gain path (38, 42) produces a gain control signal. The variable voltage and gain control signal are used by a variable gain power amplifier (44, 46) to modulate a local oscillator signal to produce a modulated radio signal.

Abstract: Circuits and methods are disclosed for reducing interference from transmitter leakage in a radio transceiver. An exemplary method for reducing interference from transmitter leakage in a radio transceiver comprises downconverting, filtering, and sampling a radio frequency signal comprising a desired signal and a transmitter leakage signal to obtain a sampled signal of interest. The method further comprises generating a sampled distortion signal estimate that estimates one or more distortion products of the transmitter leakage signal, such as a squared amplitude obtained from a square-law device or corresponding digital function. Finally, the method comprises combining the sampled distortion signal estimate with the sampled signal of interest to obtain interference-reduced signal samples.

Abstract: A communication device has a controller operatively connected to at least a first transceiver and a second transceiver, wherein the first transceiver receives signals on one or more channels within a first frequency band and the second transceiver transmits signals on one or more channels within a second frequency band, wherein the first and second frequency bands are adjacent one another so that each of the first and second frequency bands has an adjacent border and a nonadjacent border. Coexistence between the first and second transceivers is achieved by adjusting receive and/or transmit filters associated with the transceivers to create a guard band that is located more in the first frequency band if the second transceiver is using frequencies close to its adjacent border, and a guard band that is more in the second frequency band if the second transceiver is not using frequencies close to its adjacent border.

Abstract: The present invention takes advantage of a phase correlation process at a receiver, for example the plurality of different clock phases that are provided for ascertaining the most favourable phase for burst reception in a digital signalling link, and uses this phase correlation information for a different purpose. For example, the plurality of different clock phases are used to provide an indication of the quality of the received signal. The quality of the received signal can then be used to adapt one or more parameters in the digital plurality of different clock phases signalling link, to save power when desired.

Abstract: An entire radio transceiver can be compeltely integrated into one IC chip. In order to integrate the IF filters on the chip, directly modulated VCO is used for both up-conversion during transmission, and down-conversion during reception. Bond-wise are used as resonators in the oscillator tank for the VCO. A TDD scheme is used in the air interface to eliminate cross-talk or leakage. A Gaussian-shaped binary FSK modulation scheme is used to provide a number of other implementation advantages.

Abstract: A digital affine transformation modulator and power amplifier drives a transmitter antenna. The modulator performs an affine transformation on a signal, wherein the I, Q space is mapped to a plurality of sectors. A signal in a sector is expressed as the sum of two vectors, the angles of which define the sector boundaries. A digital power amplifier comprises a plurality of amplifier cells, each cell comprising at least two amplifier units. For a given signal, each amplifier unit selectively amplifies a clock signal having a phase corresponding to one of the boundary angles of the signal's affine transformed sector. A subset of the plurality of amplifier cells receiving each phase clock signal are enabled, based on the magnitude of the associated vector describing the signal in affine transform space. The modulation scheme exhibits higher efficiency than quadrature modulation, without the bandwidth expansion and group delay mismatch of polar modulation.

Abstract: A frequency translation filter 500 is configured to receive a radio frequency (RF) signal 501 comprising first and second non-contiguous carriers or non-contiguous frequency ranges. The frequency translation filter comprises a mixer 503 configured to mix the RF signal 501 received on a first input with a local oscillator (LO) signal 505 received on a second input. A filter 507 comprises a frequency dependent load impedance, the filter having band-pass characteristics which, when frequency translated using the mixer 503, contain first and second pass-bands corresponding to the first and second non-contiguous carriers or non-contiguous frequency ranges. The first and second pass-bands are centered about the local oscillator frequency.

Abstract: An entire radio transceiver can be completely integrated into one IC chip. In order to integrate the IF filters on the chip, a heterodyne architecture with a low IF is used. A single, directly modulated VCO is used for both up-conversion during transmission, and down-conversion during reception. Bond-wires are used as resonators in the oscillator tank for the VCO. A TDD scheme is used in the air interface to eliminate cross-talk or leakage. A Gaussian-shaped binary FSK modulation scheme is used to provide a number of other implementation advantages.

Abstract: A modulation circuit for use in a radiofrequency transmitter includes a local oscillator circuit configured to generate one or more local oscillator signals at a desired frequency and with a duty cycle at or about twenty-five percent, and a modulator configured to generate one or more modulated signals responsive to the one or more local oscillator signals and one or more baseband information signals. In at least one embodiment, the modulation circuit includes a modulator comprising a combined mixing and transconductance circuit that includes a transistor circuit for each baseband information signal serving as a modulation input to the modulator. Each transistor circuit comprises a first transistor driven by the baseband information signal and coupling a modulator output node to a corresponding transconductance element, and a second transistor driven by one of the one or more local oscillator signals and coupling the corresponding transconductance element to a signal ground node.

Abstract: A processing device (40) for processing an analog complex input signal generated by downconversion of an aggregated-spectrum radio-frequency signal in a radio-receiver (10), wherein the complex input signal comprises a plurality of sub bands (S1-S4) scattered across a total frequency band (4) of the complex input signal. The processing device (40) comprises a plurality of processing paths (P1-PN). wherein each processing path (P1-PN) is adapted to process an associated sub band (S1-S4). Each processing path comprises a complex mixer (CM1-CMN) adapted to frequency translate the complex input signal, and an analog channel-selection filter (CSF1-CSFN) arranged to filter an output signal of the complex mixer (CM1-CMN) and pass the frequency translated associated sub band (S1-S4). A control unit (60) is adapted to receive control data indicating frequency locations of the sub bands (S1-S4) and, for each processing path (P1-PN).

Abstract: Decoding a received Orthogonal Frequency Division Multiplex (OFDM) signal that occupies a first set of subcarriers in a radio frequency spectrum includes ascertaining an interference model that represents interference occurring in the first set of subcarriers caused by a transmitted OFDM signal that occupies a second set of subcarriers in the radio frequency spectrum. A set of scaled soft values is produced that represents information conveyed by the received OFDM signal over the first set of subcarriers, wherein each scaled soft value in the set of scaled soft values corresponds to a respective one of the subcarriers in the first set of subcarriers, and wherein a scaling amount applied to each of the scaled soft values is based on a corresponding level of interference in said respective one of the subcarriers as indicated by the interference model. A decoding process is performed that generates detected data from the scaled soft values.

Abstract: Methods and apparatus are disclosed for automatically adjusting antenna impedance match in a wireless transceiver employing phase-amplitude modulation. According to some embodiments of the invention, a wireless transceiver comprises a transmitter circuit and a receiver circuit connected to the antenna by a transmit/receive duplexer. An electronically adjustable matching network is located between the transmitter output and the antenna. To control the adjustable matching network, a directional coupler is located between the transmitter output and the matching network to separate transmit signals reflected from the antenna system, including the antenna, the matching network and the T/R duplexer. The reflected transmit signals are routed to the receiver circuit, which digitizes the reflected signal and determines an antenna reflection coefficient based on the digitized reflected signal and the modulation signal used to create the transmit signal.

Abstract: A combination of a phase shifter, a measurement receiver, and an offset estimator enable the d.c. offset in the transmit path of a quadrature transmitter to be distinguished from the d.c. offset in the measurement receiver. The measurement receiver performs a first measurement on the transmit path output with a “normal” phase shift of 0 degrees and 90 degrees for in-phase (I) and quadrature (Q) components, and a second measurement with a “special” phase shift for the I and Q components. In one embodiment, the “special” phase shift for the I and Q components is 180 degrees and 270 degrees, respectively.

Abstract: The present disclosure generally relates to the field of receiver structures in radio communication systems and more specifically to passive mixers in the receiver structure and to a technique for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency.

Abstract: A delta-sigma analog-to-digital converter (ADC) is disclosed.