Abstract: A power distributing duplexer system is provided. In some aspects, the system includes a duplexer configured to couple an antenna to a transmitter and a receiver. The system also includes a balancing network coupled to the duplexer. The balancing network includes a network impedance. The balancing network is configured to adjust the network impedance to match an antenna impedance of the antenna. The balancing network includes a plurality of balancing network modules coupled to the duplexer. Each of the plurality of balancing network modules is configured to receive a portion of an output voltage from the duplexer.

Abstract: A circuit for a receiver with reconfigurable low-power or wideband operation may comprise one or more main signal paths each coupled to a first port and including a low-noise amplifier (LNA) configured to provide a radio frequency (RF) signal to a main mixer circuit. An auxiliary signal path may be coupled to a second port. The auxiliary signal path may include an auxiliary mixer configured to provide an on-chip matching input impedance that may match an impedance of the antenna. The first port may be coupled to an RF antenna through an off-chip matching circuit, when a low-power operation is desired. The first port may be coupled to the second port and to the RF antenna, when a wideband operation is desired.

Abstract: An adaptive cancellation circuit and method are provided. The circuit includes a main path and an auxiliary path. The main path includes a first amplifier configured to output a first amplified signal to a first mixer. The main path is configured to output a first signal comprising a wanted signal component and a distortion component. The auxiliary path includes a second amplifier configured to output a second amplified signal to a second mixer. The second mixer is connected to a filter configured to remove the wanted signal component. The auxiliary path is configured to output a second signal including the distortion component.

Abstract: According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Abstract: A circuit for a low-power and blocker-tolerant mixer-amplifier stage may include a complementary mixer formed by transmission gates having complementary structures. The complementary mixer may be configured to receive one or more radio-frequency (RF) signals and to convert the one or more RF signals to intermediate frequency (IF) current signals. A complementary TIA may be coupled to the complementary mixer and may be configured to receive the IF current signals and provide IF voltage signals. The complementary TIA may be formed by coupling an NMOS-TIA and a PMOS-TIA to a common load. A first portion of the complementary mixer may be coupled to the NMOS-TIA and a second portion of the complementary mixer may be coupled to the PMOS-TIA.

Abstract: A circuit for a common electrical balance duplexer (EBD) of a multi-path transceiver may include an EBD circuit. The EBD circuit may be coupled to output nodes of two or more transmit (TX) paths, one or more antennas, and input nodes of two or more receive (RX) paths. The EBD circuit may be configured to isolate the TX paths from the RX paths, and to provide low-loss signal paths between the output nodes of the transmit (TX) paths and one or more antennas. One or more balancing networks may be coupled to the EBD circuit to provide one or more impedances, each matching a corresponding impedance associated with one of the antennas. The output nodes of the transmit (TX) paths may include output nodes of a first and a second power amplifier (PA). The first and the second PA may share a matching transformer that is merged with the EBD circuit.

Abstract: A circuit for a low-noise interface between an amplifier and an analog-to-digital converter (ADC) may comprise a capacitor element having a capacitance of C coupled between a first and second output node of the amplifier. A resistor circuit coupled between the capacitor element and input nodes of the ADC. A desired value RL for a load resistance of the amplifier is provided by selecting suitable initial values for resistances of the resistor circuit. A desired bandwidth for the at least one amplifier is achieved by selecting a value of the capacitance C based on the desired value RL for the load resistance.

Abstract: A circuit for a large-signal electrical balance duplexer (EBD) may include a circulator that can be configured to couple an output node of a transmit (TX) path to an antenna. An EBD circuit may be coupled to the circulator, at a first port of the EBD circuit. The EBD circuit may be configured to isolate the circulator from one or more input nodes of a receive (RX) path. An attenuator may be coupled between the output node of the TX path and a second port of the EBD circuit. The attenuator may be configured to provide an attenuated signal to the EBD circuit.

Abstract: A circuit for a receiver with reconfigurable low-power or wideband operation may comprise one or more main signal paths each coupled to a first port and including a low-noise amplifier (LNA) configured to provide a radio frequency (RF) signal to a main mixer circuit. An auxiliary signal path may be coupled to a second port. The auxiliary signal path may include an auxiliary mixer configured to provide an on-chip matching input impedance that may match an impedance of the antenna. The first port may be coupled to an RF antenna through an off-chip matching circuit, when a low-power operation is desired. The first port may be coupled to the second port and to the RF antenna, when a wideband operation is desired.

Abstract: According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Abstract: A radio front end includes a power amplifier, a tone injection module, a duplexer, a balancing network, and a processor. The tone injection module is operable, in a first mode, to produce a tone having a carrier frequency that is substantially similar to a carrier frequency of an inbound wireless signal. The duplexer is operable, in the first mode, to provide electrical isolation between the outbound wireless signal and a combination signal of the tone and inbound wireless signal and is operable, in a second mode, to provide electrical isolation between the outbound wireless signal and the inbound wireless signal. The processor is operable to determine an amplitude of a tone component of the combination signal; correlate the amplitude of the tone component to an inbound frequency band isolation; and adjust baseband processing of a down converted representation of the combination signal based on the inbound frequency band isolation.

Abstract: A circuit for a low-loss duplexer with noise cancellation in a receive (RX) path of a transceiver includes a duplexer, a balancing network, and a noise cancellation circuit. The duplexer circuit is coupled to an antenna of the transceiver. The balancing network is coupled to the duplexer and provides an impedance matching an impedance associated with the antenna. The noise cancellation circuit senses a noise signal generated by the balancing network and uses the sensed noise signal to improve a signal-to-noise ratio (SNR) of the RX path.

Abstract: A circuit for a low-noise interface between an amplifier and an analog-to-digital converter (ADC) may comprise a capacitor element having a capacitance of C coupled between a first and second output node of the amplifier. A resistor circuit coupled between the capacitor element and input nodes of the ADC. A desired value RL for a load resistance of the amplifier is provided by selecting suitable initial values for resistances of the resistor circuit. A desired bandwidth for the at least one amplifier is achieved by selecting a value of the capacitance C based on the desired value RL for the load resistance.

Abstract: According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Abstract: Aspects of a method and system for a low-noise, highly-linear receiver front-end are provided. In this regard, a received signal may be processed via one or more transconductances, one or more transimpedance amplifiers (TIAs), and one or more mixers to generate a first baseband signal corresponding to a voltage at a node of the receiver, and a second baseband signal corresponding to a current at the node of the receiver. The first signal and the second signal may be processed to recover information from the received signal. The first signal may be generated via a first one or more signal paths of the receiver and the second signal may be generated via a second one or more signal paths of the receiver.

Abstract: A transceiver includes a local oscillation module, a transmitter section, and a receiver section. The local oscillation module is operable to generate a transmit local oscillation and a receive oscillation. The transmitter section includes a transmit mixing module and a transmit weaved connection that is operable to high frequency filter the transmit location oscillation. The transmit mixing module mixes the filtered transmit location oscillation with a transmit signal to produce an up-converted signal. The receiver section includes a receive mixing module and a receive weaved connection that is operable to high frequency filter the receive location oscillation. The receive mixing module mixes the filtered receive location oscillation with an RF received signal to produce a down-converted signal.

Abstract: A circuit for a low-loss electrical balance duplexer (EBD) with noise cancellation may include an EBD circuit. The EBD circuit may be coupled to one or more output nodes of a transmit (TX) path, an antenna, and a one or more input nodes of a receive (RX) path. The EBD circuit may be configured to isolate the TX path from the RX path, and to provide low-loss signal paths between the one or more output nodes of the TX path and the antenna. A balancing network may be coupled to the EBD circuit and configured to provide an impedance that matches an impedance associated with the antenna. A noise cancellation circuit may be configured to sense a noise signal generated by the balancing network, and to use the sensed noise signal to improve a signal-to-noise ratio (SNR) of the RX path.

Abstract: A circuit for a low-noise interface between an amplifier and an analog-to-digital converter (ADC) may comprise a capacitor element having a capacitance of C coupled between a first and second output node of the amplifier. A first resistor R1 may be coupled in parallel with the capacitor. A second resistor R2 may be coupled between the first output node of the amplifier and a first input node of the ADC. A third resistor R3 may be coupled between the second output node of the amplifier and a second input node of the ADC. Initial values of the resistances R1, R2, and R3 may be selected to provide a desired value RL for a load resistance of the amplifier. A value of the capacitance C may be selected so that, in combination with the desired value RL, a desired bandwidth for the amplifier is achieved.

Abstract: Embodiments of a four-port isolation module are presented herein. In an embodiment, the isolation module includes a step-up autotransformer comprising a first and second winding that are electrically coupled in series at a center node. The first port of the isolation module is configured to couple an antenna to a first end node of the series coupled windings. The second port of the isolation module is configured to couple a balancing network to a second end node of the series coupled windings. The third port is configured to couple a transmit path to the center node. The fourth port is configured to couple a differential receive path across the first end node and the second end node. The isolation module effectively isolates the third port from the fourth port to prevent strong outbound signals received at the third port from saturating an LNA coupled to the fourth port.

Abstract: A circuit for measurement of a phase noise of an oscillator may include the oscillator to generate a first signal having the same oscillation frequency as an instantaneous oscillation frequency of the oscillator. The circuit may include a first circuit that is configured to generate a second signal from the first signal. An instantaneous amplitude of the second signal may be related to the oscillation frequency of the first signal. A second circuit may be configured to integrate the second signal to generate a third signal. The third signal can be a measure of the phase noise of the oscillator. The third signal can be used to cancel some or all of the phase noise of the oscillator.