Abstract: A transmission module is provided that includes a transmitter, a loopback receiver, and a QEC controller. In a first state, the QEC controller calibrates the loopback receiver to remove quadrature imbalance in the loopback receiver. In a second state, a communication pathway is provided between the transmitter and the loopback receiver, and the QEC controller identifies quadrature imbalance in the transmitter based at least one a comparison of the data signals at the output of the loopback receiver with data signals at the input of the transmitter. Based on the comparison, the QEC controller can adjust one or more characteristics of the transmitter to correct quadrature errors in the transmitter.

Abstract: Embodiments of the present invention may provide a receiver. The receiver may include an RF section and a quadrature mixture, coupled to the RF section, to downconvert a first group of wireless signals directly to baseband frequency quadrature signals and to downconvert a second group of wireless signals to intermediate frequency quadrature signals. The receiver may also include a pair of analog-to-digital converters (ADCs) to convert the downconverted quadrature signals to corresponding digital quadrature signals. Further, the receiver may include a digital section having two paths to perform signal processing on the digital baseband frequency quadrature signals and to downconvert the digital intermediate frequency signals to baseband cancelling a third order harmonic distortion therein. The receiver may be provided on a monolithically integrated circuit.

Abstract: Apparatus and methods are disclosed related to low-voltage radio transmitters with high spectral purity. One such apparatus includes a baseband path with a predistortion stage, a programmable filter, and an upconverter core. In an embodiment, the programmable filter is placed between the predistortion stage and the upconverter core. In an embodiment, the programmable filter is configured by a controller to reject out-of-band noise introduced at the predistortion stage or earlier.

Abstract: Apparatus and methods for analog-to-digital conversion of quadrature receive signals are provided herein. In certain implementations, a transceiver system includes at least a first pair of analog-to-digital converters (ADCs) associated with a first quadrature receiver channel and a second pair of ADCs associated with a second quadrature receiver channel. The first and second pairs of ADCs can provide analog-to-digital conversion of the same receive signal, but can have different noise profiles relative to one another, such as a low pass noise profile and a band pass noise profile. The transceiver system can further include a reconstruction filter for combining the outputs of at least the first and second pairs of ADCs to generate output signals associated with a lower overall noise profile relative to that of either pair of ADCs alone.

Abstract: The invention may provide a receiver including a front-end block to provide a front-end gain on a radio-frequency input signal. The front-end block may include a mixer to convert the radio-frequency input signal to a baseband signal. The receiver also may include a wide-band peak detector coupled to the front-end block and a baseband block to provide a baseband gain on the baseband signal. An analog-to-digital converter may convert the baseband signal to a digital signal. The receiver may further include narrow-band peak detector coupled to an output of the analog-to-digital converter. An automatic gain control circuit may independently control the front-end gain and the baseband gain based on outputs from the wide-band peak detector and narrowband peak detector.

Abstract: Embodiments of the present invention may provide a receiver. The receiver may include an RF section and a quadrature mixture, coupled to the RF section, to downconvert a first group of wireless signals directly to baseband frequency quadrature signals and to downconvert a second group of wireless signals to intermediate frequency quadrature signals. The receiver may also include a pair of analog-to-digital converters (ADCs) to convert the downconverted quadrature signals to corresponding digital quadrature signals. Further, the receiver may include a digital section having two paths to perform signal processing on the digital baseband frequency quadrature signals and to downconvert the digital intermediate frequency signals to baseband cancelling a third order harmonic distortion therein. The receiver may be provided on a monolithically integrated circuit.

Abstract: A transmission module is provided that includes a transmitter, a loopback receiver, and a QEC controller. The QEC controller identifies quadrature imbalance in the transmitter based at least one a comparison of the data signals at the output of the loopback receiver with data signals at the input of the transmitter. Based on the comparison, the QEC controller can adjust one or more characteristics of the transmitter to correct quadrature errors in the transmitter.

Abstract: A transmission module is provided that includes a transmitter, a loopback receiver, and a QEC controller. In a first state, the QEC controller calibrates the loopback receiver to remove quadrature imbalance in the loopback receiver. In a second state, a communication pathway is provided between the transmitter and the loopback receiver, and the QEC controller identifies quadrature imbalance in the transmitter based at least one a comparison of the data signals at the output of the loopback receiver with data signals at the input of the transmitter. Based on the comparison, the QEC controller can adjust one or more characteristics of the transmitter to correct quadrature errors in the transmitter.

Abstract: Apparatus and methods are disclosed related to low-voltage radio transmitters with high spectral purity. One such apparatus includes a baseband path with a predistortion stage, a programmable filter, and an upconverter core. In an embodiment, the programmable filter is placed between the predistortion stage and the upconverter core. In an embodiment, the programmable filter is configured by a controller to reject out-of-band noise introduced at the predistortion stage or earlier.

Abstract: Apparatus and methods are disclosed related to phase synchronization in transmitters. One such apparatus includes a wireless transmitter with two or more separate and unrelated local oscillators. The apparatus can provide RF signals to multiple antenna elements, which can be implemented in systems such as beamforming systems or multiple input multiple output (MIMO) systems. A phase difference between local oscillators is determined using outputs of receivers. The phase difference can be used to adjust a phase of signals associated with one or more of the local oscillators, such that the phase of each signal provided to the multiple antenna elements can be aligned.

Abstract: Apparatus and methods are disclosed, such as those involving an RF receiver. One such apparatus includes a front end having an input and an output. The front end forms part of an RF signal receive path. The front end includes a front-end resistor configured to receive an input signal; and a passive mixer downstream of the front-end resistor on the receive path. The passive mixer mixes the input signal with a local oscillation signal. The front-end includes a transimpedance amplifier located downstream of the passive mixer on the receive path. The transimpedance amplifier includes an input and an output. The front end further includes a feedback resistor coupled between the input and output of the transimpedance amplifier. The gain of the front end is a ratio of the feedback resistance to the front-end resistance, and is temperature- and frequency-insensitive. The apparatus also provides relatively constant input impedance and high linearity.

Abstract: The invention may provide a receiver including a front-end block to provide a front-end gain on a radio-frequency input signal. The front-end block may include a mixer to convert the radio-frequency input signal to a baseband signal. The receiver also may include a wide-band peak detector coupled to the front-end block and a baseband block to provide a baseband gain on the baseband signal. An analog-to-digital converter may convert the baseband signal to a digital signal. The receiver may further include narrow-band peak detector coupled to an output of the analog-to-digital converter. An automatic gain control circuit may independently control the front-end gain and the baseband gain based on outputs from the wide-band peak detector and narrowband peak detector.

Abstract: Apparatus and methods are disclosed, such as those involving an RF receiver. One such apparatus includes a front end having an input and an output. The front end forms part of an RF signal receive path. The front end includes a front-end resistor configured to receive an input signal; and a passive mixer downstream of the front-end resistor on the receive path. The passive mixer mixes the input signal with a local oscillation signal. The front-end includes a transimpedance amplifier located downstream of the passive mixer on the receive path. The transimpedance amplifier includes an input and an output. The front end further includes a feedback resistor coupled between the input and output of the transimpedance amplifier. The gain of the front end is a ratio of the feedback resistance to the front-end resistance, and is temperature- and frequency-insensitive. The apparatus also provides relatively constant input impedance and high linearity.

Abstract: Apparatus and methods are disclosed, such as those involving a low noise amplifier. One such apparatus includes a low noise amplifier circuit configured to receive a signal at an input node and to output an amplified signal at an output node. The low noise amplifier circuit includes a first transistor of a first polarity; and a second transistor of a second polarity complementary to the first polarity. The first and second transistors are connected in series between first and second supply voltage nodes via the output node. The circuit further includes a third transistor cascoded with one of the first transistor or the second transistor, but does not include a transistor cascoded with the other transistor. This configuration allows the low noise amplifier circuit to provide an increased high-frequency gain and linearity while having improved high-frequency system noise figure in, for example, deep submicron CMOS technology.

Abstract: Apparatus and methods are disclosed related to low-voltage radio transmitters with high spectral purity. One such apparatus includes a baseband path with a predistortion stage, a programmable filter, and an upconverter core. In an embodiment, the programmable filter is placed between the predistortion stage and the upconverter core. In an embodiment, the programmable filter is configured by a controller to reject out-of-band noise introduced at the predistortion stage or earlier.

Abstract: The present disclosure describes a variable gain transconductor having gain and/or linearity performance that are selectively controllable in operation. In one embodiment the gain and/or linearity performance are selectively controllable in response to the strength of an input signal, such as an incoming radio frequency (RF) signal to a radio receiver. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a number of operating bias cells. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a number of operating transconductance (gm) cells. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a combination of operating bias cells and gm cells.

Abstract: Apparatus and methods are disclosed, such as those involving a low noise amplifier. One such apparatus includes a low noise amplifier circuit configured to receive a signal at an input node and to output an amplified signal at an output node. The low noise amplifier circuit includes a first transistor of a first polarity; and a second transistor of a second polarity complementary to the first polarity. The first and second transistors are connected in series between first and second supply voltage nodes via the output node. The circuit further includes a third transistor cascoded with one of the first transistor or the second transistor, but does not include a transistor cascoded with the other transistor. This configuration allows the low noise amplifier circuit to provide an increased high-frequency gain and linearity while having improved high-frequency system noise figure in, for example, deep submicron CMOS technology.

Abstract: Apparatus and methods are disclosed related to phase synchronization in transmitters. One such apparatus includes a wireless transmitter with two or more separate and unrelated local oscillators. The apparatus can provide RF signals to multiple antenna elements, which can be implemented in systems such as beamforming systems or multiple input multiple output (MIMO) systems. A phase difference between local oscillators is determined using outputs of receivers. The phase difference can be used to adjust a phase of signals associated with one or more of the local oscillators, such that the phase of each signal provided to the multiple antenna elements can be aligned.

Abstract: The present disclosure describes a variable gain transconductor having gain and/or linearity performance that are selectively controllable in operation. In one embodiment the gain and/or linearity performance are selectively controllable in response to the strength of an input signal, such as an incoming radio frequency (RF) signal to a radio receiver. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a number of operating bias cells. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a number of operating transconductance (gm) cells. In one embodiment, gain and/or linearity performance of the variable gain transconductor are selectively controllable by selecting or deselecting a combination of operating bias cells and gm cells.

Abstract: This invention describes the obtainment of impact-resistant materials from a block copolymer that comprises as monomers an alkadiene (conjugated diene) and a vinyl aromatic compound, which is used as impact modifier to obtain such materials and in which, at least, one of the blocks of the vinyl aromatic compound is polydisperse. The invention allows obtaining morphologies such as rods, points or capsules by incorporating such copolymer into a polymeric matrix derived from vinyl aromatic monomers independently from other agents such as chain transfer agents, and achieving increases, in the impact values up to 50% through the use of the copolymer of this invention.