Abstract: A system and method for amplifier gain measurement and compensation. A method for compensating a signal gain of an amplifier circuit includes determining a desired gain for the amplifier circuit, determining an operating temperature of the amplifier circuit, adjusting a set of signal gains based on the operating temperature to produce a set of adjusted signal gains, determining a desired gain setting based on the desired gain and the set of signal gains, and providing the desired gain setting to the amplifier circuit.

Abstract: A mixer 1100 with a plurality of signal paths typically requires separate clock generating hardware for each signal path. However, the redundancy of having multiple clock generating hardware significantly increases power consumption and integrated circuit area when the mixer 1100 is integrated into silicon. A method and apparatus 1125 containing a circuit for generating a set of clock signals that can be shared by the different signal paths is presented. Advantage is taken of the significant capacitance difference between different sampling capacitors in the mixer and the superposition property.

Abstract: A transceiver and a method of controlling aberrant transceiver operation. In one embodiment, the transceiver includes: (1) a processor, (2) an interrupt system coupled to the processor and having a flag register associated therewith, (3) detection circuits associated with corresponding functional units of the transceiver and configured to detect conditions regarding the corresponding functional units and set corresponding flags in the flag register, the interrupt system configured to assert interrupts in response thereto and (4) an interrupt-handing routine executable in the processor and configured to respond to the interrupts by carrying out at least one of loading parameters and generating warnings based on identities of the flags.

Abstract: A system and method for frequency pushing/pulling compensation in phase-locked loops including a method for cancelling frequency push/pull in an oscillator of a transmitter. The method includes computing an error signal from a signal of a phase locked loop, wherein the error signal includes an aggressor signal. Transfer characteristics are computed for the aggressor signal. A transmitted signal is filtered using the transfer characteristics to produce a correction term. The correction term is applied to a frequency control word being provided to the oscillator.

Abstract: Methods, apparatus, and articles of manufacture are described for improving distortion performance and for direct current offset cancellation in receivers. In one example, a method of improving distortion in a receiver includes determining a direct current (DC) amplitude of an offset signal, generating the offset signal, and providing the offset signal to an output of a mixer to improve the distortion performance of the mixer.

Abstract: A method for changing an effective capacitance of an amplifier circuit having a match transistor and a coupled cascode transistor includes changing an on-state of at least one of a plurality of sub-transistors of the match transistor. The method further includes changing a transconductance of the match transistor as a function of the change of the on-state. The method further includes changing an equivalent resistance, as measured between a source and a drain of the cascode transistor, as a function of the change of the transconductance of the match transistor.

Abstract: A radio receiver 2000 with a sampling mixer 1100 for creating a discrete-time sample stream by directly sampling an RF current with history and rotating capacitors 1111 and 1112, wherein the accumulated charge on the rotating capacitors is read-out to produce a sample. The mixer provides immunity to noise glitches by predicting the occurrence of the glitch (or detecting a significant difference between observed and predicted samples) and creating corrected samples for the corrupted samples. These corrected samples can be created with special circuitry 1933 (digital) or in the mixer 1100 (analog).

Abstract: A full duplex transceiver has cancellation circuitry that includes an auxiliary receiver and an auxiliary transmitter. More specifically, an analog received signal that includes transmission signal leakage is provided to a low noise amplifier (LNA), which then provides its output to a main receiver and the auxiliary receiver. The auxiliary receiver includes a portion operable to convert the received signal from the analog domain to the digital domain. The auxiliary receiver additionally includes a cancellation processor that determines the transmission signal leakage and generates a signal based on the determined leakage. This signal generated by the auxiliary receiver is provided to the auxiliary transmitter, which converts the digital signal back to the analog domain and generates a cancellation signal. The analog cancellation signal is fed back and added to the received signal at the input of the LNA.

Abstract: The present invention pertains to a method of calibrating reception properties of a radio frequency (RF) processor. The application describes two embodiments of the invention representing calibration of the properties using an auxiliary transmitter to generate a calibration signal internal to the RF processor.

Abstract: A system and method for adaptive equalization of in-package signals. A method for operating a wireless communications device having a transmitter and a receiver includes receiving a transmitted signal at the receiver, wherein the receiving of the transmitted signal occurs by mutual inductance, converting the received transmitted signal into a baseband signal, equalizing the baseband signal, computing a correction signal from the equalized baseband signal, and providing the correction signal to the transmitter. The equalizing of the baseband signal helps to eliminate or reduce multipath arising from mutual inductance between the transmitter and the receiver. The elimination of the multipath helps to improve the quality of the correction signal, thereby helping to increase the performance of the wireless communications device.

Abstract: A system and method for tuning baseband filters in wireless transceivers. A method comprises coupling a radio frequency (RF) signal generated by the wireless transmitter at an input of a wireless receiver, the RF signal having a desired frequency, measuring a magnitude of the coupled RF signal at an output of an analog-to-digital converter at an output of an analog baseband filter, wherein the magnitude is measured at the desired frequency, and adjusting a corner frequency of the analog baseband filter in response to the determining that the measured magnitude differs from a specified value.

Abstract: The present invention provides an offset balancer for use with a differential mixer employing a wireless reception and an offset quantifier configured to indicate an existing DC offset of the mixer corresponding to an existing second-order intercept point applicable to the wireless reception. In one embodiment, the offset balancer includes an offset adjuster coupled to the offset quantifier and configured to provide an offset adjustment to the existing DC offset based on increasing the existing second-order intercept point.

Abstract: A radio receiver 2000 with a sampling mixer 1100 for creating a discrete-time sample stream by directly sampling an RF current with history and rotating capacitors 1111 and 1112, wherein the accumulated charge on the rotating capacitors is read-out to produce a sample. The mixer provides immunity to noise glitches by predicting the occurrence of the glitch (or detecting a significant difference between observed and predicted samples) and creating corrected samples for the corrupted samples. These corrected samples can be created with special circuitry 1933 (digital) or in the mixer 1100 (analog).

Abstract: Methods and apparatus to implement receiver linearity enhancement are described. One example method includes controlling receiver gain by determining a level of a received signal that is to be provided to a radio frequency component; determining if the level of the received signal would cause the radio frequency components internally generated noise to increase; and when the level of the received signal would cause the radio frequency components internally generated noise to increase, reducing the level of the received signal prior to providing the received signal to the radio frequency component.

Abstract: A system and method for amplifier gain measurement and compensation. A method for compensating a signal gain of an amplifier circuit includes determining a desired gain for the amplifier circuit, determining an operating temperature of the amplifier circuit, adjusting a set of signal gains based on the operating temperature to produce a set of adjusted signal gains, determining a desired gain setting based on the desired gain and the set of signal gains, and providing the desired gain setting to the amplifier circuit.

Abstract: A multi-tap direct sub-sampling mixing system for wireless receivers is provided with a dynamically configurable passive switched capacitor filter. A front end amplifier is connected to receive a signal. The passive switched capacitor filter is connected to receive the amplified signal and has an output for providing a filtered signal. The switched capacitor filter has at least two sections that are each operable as a pole, wherein a first section of the at least two sections has sets of at least two stacked capacitors interconnected with a set of switches operable to amplify in input voltage provided to an input of the first section in response to operation of the set of switches; and a back end section connected to the output of the switched capacitor filter to receive the filtered signal.

Abstract: When a sample stream is decimated, frequency components from outside of a desired frequency band are aliased into the desired band, causing interference and loss of information. Different decimating ratios result in different frequencies aliasing into the desired frequency band. A current-mode sampling mixer 800 with capacitor banks 811 and 812 that are controlled by a digital control unit 820 with a capability to integrate and decimate an RF current at different decimating ratios is able to measure the frequency spectrum with different decimating ratios. The measured frequency spectrum is then analyzed to detect the presence of interferers aliased into the desired frequency band. The interferers can then be eliminated or avoided.

Abstract: System and method for providing type-II (and higher order) phase-locked loops (PLLs) with a fast signal acquisition mode. A preferred embodiment comprises a wireless communication device having a loop filter with a proportional loop gain path (proportional loop gain circuit 1115 ) and an integral loop gain block (integral loop gain block 1120 ). The proportional loop gain path is used during signal acquisition to provide large loop bandwidth, hence fast signal acquisition of a desired signal. Then, during the PLL's signal tracking phase, the intergral loop gain block is enabled and its output is combined with output from the proportional loop gain path to provide higher order filtering of the desired signal. An offset that may be present due to the use of the proportional loop gain path can be measured and subtracted to help improve signal tracking settling times.

Abstract: A signal processor includes a sigma-delta modulator. The input signal to the signal-delta modulator may contain a dc component that generates spurious tones in the modulator output. An input signal to the signal processor is multiplied by an output of a waveform generator to produce an up-converted signal prior to processing by the sigma-delta modulator. Preferably, the waveform generator produces a random signal, which may be a pseudorandom signal. However, other waveforms such as a bipolar binary waveform can also be used. The output of the waveform generator is delayed and multiplied by the output of the sigma-delta modulator to produce a down-converted signal with reduced spurious tones. The delay matches the delay of the sigma-delta modulator. The down-converted signal is filtered with a low-pass filter.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.