摘要:
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.
摘要:
According to one embodiment, a compact low-power receiver comprises a front-end producing a front-end gain and a back-end producing a back-end gain. The front-end includes a transconductance amplifier providing digital gain control and outputting an amplified receive signal, a mixer for generating a down-converted signal from the amplified receive signal, and a transimpedance amplifier (TIA) including a current mode buffer. The TIA provides gain control for amplifying the down-converted signal to produce a front-end output signal. In one embodiment, the back end includes a second-order low-pass filter to produce a filtered signal from the front-end output signal and an analog-to-digital converter (ADC), wherein the filtered signal is fed directly to the ADC without direct-current (DC) offset cancellation being performed. In various embodiments, the front-end gain is substantially greater than the back-end gain.
摘要:
A receiver includes a frequency translation bandpass filter (FTBPF) and an RF receiver section. The RF receiver section includes an amplifier section, a phase information detection module, an amplitude information detection module, and analog to digital conversion (ADC) modules. The FTBPF is operable to filter an inbound radio frequency (RF) signal to produce a filtered inbound RF signal. The amplifier section is operable to amplify the filtered inbound RF signal to produce an amplified inbound RF signal. The phase information detection module, when enabled, is operable to determine phase information from the amplified inbound RF signal. The amplitude information detection module, when enabled, is operable to determine amplitude information from the amplified inbound RF signal. A first one of the ADCs is operable to convert the phase information into digital phase information and a second one of the ADCs is operable to convert the amplitude information into digital amplitude information.
摘要:
Embodiments of an RF front-end are presented herein. In an embodiment, the RF front end comprises a power amplifier (PA), a noise-matched low-noise amplifier (LNA), a balance network, and a four-port isolation module. A first port of the isolation module is coupled to an antenna. The second port of the isolation module is coupled to the balancing network. The third port is coupled an output of the PA. The fourth port is coupled to a differential input of the noise-matched LNA. The isolation module effectively isolates the third port from the fourth port to prevent strong outbound signals received at the third port from saturating the LNA coupled to the fourth port. Isolation is achieved via electrical balance. In an embodiment, the signal path coupling the antenna at the first port to the differential input of the LNA at the fourth port is shorter than a wavelength of the inbound signal received by the antenna.
摘要:
According to one embodiment, an input control unit to provide isolation and electrostatic discharge (ESD) protection for a circuit in an RF transceiver comprises a switching device coupled between an input of the circuit and ground. The switching device is configured to provide ESD protection while the circuit is activated. The switching device is further configured to ground the input while the circuit is non-activated, thereby concurrently isolating the input and providing ESD protection. A method for providing isolation and ESD protection for a circuit in an RF transceiver comprises activating the circuit, providing ESD protection while the circuit is activated, deactivating the circuit, and coupling an input of the circuit to ground, thereby concurrently isolating the input and providing ESD protection while the circuit is non-activated. The method and switching device can be used to provide isolation and ESD protection to receive bands in the RF transceiver.
摘要:
A front end module includes a duplexer and a balancing network. The duplexer includes a compensation circuit and a transformer three windings having five nodes. The first node for operably coupling an antenna to the first winding; the second node operable to receive an outbound wireless signal and operably couples the first winding to the second winding; the third node operably couples the second winding to a balancing network; the fourth node operably coupled to output a first signal component corresponding to an inbound wireless signal from the third winding; and the fifth node operably coupled to output a second signal component corresponding to an inbound wireless signal from the third winding. The duplexer provides electrical isolation between the first and second signal components and the outbound wireless signal. The compensation module is operable to compensate the electrical isolation between the first and second signals and the outbound wireless signal.
摘要:
A method and apparatus is disclosed to effectively frequency translate a filter characterized as a low quality factor (Q) filter corresponding to a baseband frequency of approximately zero Hertz or to an intermediate frequency (IF) to a filter characterized as a high Q filter at frequencies greater than the baseband frequency or the IF. A downconversion mixer is used to frequency translate a communication signal to the baseband frequency or the IF using a first local oscillator signal to provide a downconverted communication signal. A filter characterized as the low Q filter corresponding to the baseband frequency or the IF filters the downconverted communication signal to provide a filtered communication signal. An upconversion mixer is used to frequency translate a communication signal using a second local oscillator signal, the second local oscillator signal being substantially similar in frequency of the first local oscillator signal. The frequency translation by the upconversion mixer, in effect, translates the filter characterization from the low Q filter to the high Q filter at frequencies greater than the baseband frequency or the IF.
摘要:
A radio frequency (RF) transceiver front-end includes an antenna, an RF receiver section, an RF transmitter section, a balancing circuit, and a multiple node isolation and coupling circuit. The multiple node isolation and coupling circuit is coupled to the antenna, the RF receiver section, the RF transmitter section, and the balancing circuit. The multiple node isolation and coupling circuit provides an inbound RF signal from the antenna to the RF receiver section and provides an outbound RF signal from the RF transmitter section to the antenna, wherein, by providing an isolating signal to the balancing circuit, the multiple node isolation and coupling circuit substantially isolates the outbound RF signal from the inbound RF signal.
摘要:
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.
摘要:
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.