A linearization circuit reduces intermodulation distortion in a differential amplifier that includes a first stage and a second stage. The linearization circuit receives a first signal that includes a first frequency and a second frequency and generates a difference signal having a frequency approximately equal to the difference of the first frequency and the second frequency, generates an envelope signal based at least in part on a power level of the first signal, and adjusts a magnitude of the difference signal based on the envelope signal. When the differential amplifier receives the first signal at an input terminal, the first stage receives the adjusted signal, and the second stage does not receive the adjusted signal, intermodulation between the adjusted signal and the first signal cancels at least a portion of the intermodulation between the first frequency and the second frequency from the output of the differential amplifier.

A system and methods for cancelling transmission leakage signals in a wide bandwidth Distributed Antenna System (DAS) having remote units is disclosed. An internal cancellation circuit within the remote unit is employed to reduce the transmitted leakage signals by generating a cancellation signal. This cancellation signal is added to the received signal to cancel the transmission leakage signal in the receiving signal path. A pilot signal generation circuit is employed to optimize the cancellation circuit operating parameters. The frequency of the pilot signal is swept over a range to determine the pilot frequency having the highest electromagnetic coupling. The amplitude and phase of the cancellation signal is then optimized to minimize the level of transmission leakage in the receiving transmission path.

A method for operating a transceiver includes generating, by the transceiver, a first signal that includes an estimate of an interference signal leaked from a transmit path to a receive path of the transceiver. Generating the first signal includes obtaining a baseband transmit signal that includes a baseband of a transmit signal transmitted via the transmit path. Generating the first signal also includes calculating a harmonic phase that includes a phase of a harmonic of the baseband transmit signal. Generating the first signal also includes estimating a phase shift in accordance with an envelope of the baseband transmit signal. Generating the first signal also includes determining a phase of the first signal in accordance with the estimated phase shift and the calculated harmonic phase such that interference of a receive signal received via the receive path is reduced according to the first signal.

An electronic device is provided. The electronic device includes a housing including a first surface, a second surface disposed facing an opposite side of the first surface, and a side surface configured to surround at least a portion of a space between the first surface and the second surface, a first elongated metal member configured to form a first portion of the side surface and including a first end and a second end, at least one communication circuit electrically connected to a first point of the first elongated metal member through a capacitive element, at least one ground member disposed in an interior of the housing, and a first conductive member configured to electrically connect a second point of the first elongated metal member to the ground member. The second point of the first elongated metal member is disposed closer to the second end than to the first point.

A system for phase noise mitigated communication including a primary transmitter that converts a digital transmit signal to an analog transmit signal, a primary receiver that receives an analog receive signal and converts the analog receive signal to a digital receive signal, an analog self-interference canceller that samples the analog transmit signal, generates an analog self-interference cancellation signal based on the analog transmit signal, and combines the analog self-interference cancellation signal with the analog receive signal and a digital self-interference canceller that samples the digital transmit signal, generates a digital self-interference cancellation signal based on the digital transmit signal, and combines the digital self-interference cancellation signal with the digital receive signal.

An apparatus for interference cancellation in wireless communication systems configured for reception, comprises a receive signal path configured to convey an overall receive (Rx) signal comprising an Rx signal and a residual transmit (Tx) signal, from an antenna port to an Rx input port of a transceiver, and at least one cancellation path configured to receive a leakage Tx signal from the antenna port. Further, the apparatus comprises a cancellation unit configured to apply a cancellation signal to the overall Rx signal in the receive signal path and a compensation unit configured to generate the cancellation signal by modifying the leakage Tx signal in the cancellation path, based on a compensation control signal. In addition, the apparatus comprises a feedback receiver unit configured to generate the compensation control signal based on the residual Tx signal in the overall Rx signal and the cancellation signal.

A FET-based RF switch architecture and method that provides for independent control of FETs within component branches of a switching circuit. With independent control of branch FETs, every RF FET in an inactive branch that is in an open (capacitive) state can be shunted to RF ground and thus mitigate impedance mismatch effects. Providing a sufficiently low impedance to RF ground diminishes such negative effects and reduces the sensitivity of the switch circuit to non-matched impedances.

An amplifier includes a gain transistor including a control terminal to receive an input signal. A degeneration inductor is coupled between the first terminal of the gain transistor and ground. A shunt inductor and a capacitor are coupled in series between the control terminal of the gain transistor and ground, and form a filter to attenuate frequencies of the input signal within a frequency range. The degeneration inductor and the shunt inductor form a transformer to provide impedance matching.

A duplex communication system includes a duplexer for transmitting and receiving signals, a transmitter part connected to the duplexer, and a receiver part connected to the duplexer, the receiver part comprising an amplifier for amplifying a received signal to provide an amplified received signal and a demodulator for downconverting the amplified received signal, and a second-order intermodulation distortion (IMD2) compensation module for compensating for second-order intermodulation distortion. The system also includes an adaptive filtering module that obtains a transmitter reference signal, generates filter coefficients for the IMD2 compensation module and also adjusts a direct current (DC) bias of the demodulator based on the reference signal.

A transceiver for In-Band Full-Duplex communication is provided. The transceiver includes a duplexer and a bidirectional frequency transposition module, the frequency transposition module being suitable for transposing a signal to be transmitted, with a predetermined frequency shift, F, in order to obtain a transmit signal, and for transposing the receive signal, with the same frequency shift, in order to obtain the received signal, with the frequency band of the signal to be transmitted and the frequency band of the received signal thus being separated by a frequency shift which is double the predetermined frequency shift.