The present disclosure provides a method for compensating an imbalance between an I path and a Q path of a receiver. The method includes: sending a cosine signal and a sine signal through a signal generator, transmitting the cosine signal and the sine signal in the I path and Q path respectively; calculating autocorrelation values of the I path and the Q path in the signal receiving direction; determining a comparison result of amplitudes of the cosine signal received by the I path and the sine signal received by the Q path according to the autocorrelation values; calculating an adjustment compensation value of an analog domain gain amplifier, and an amplitude value and a phase value in a digital domain according to the comparison result of amplitudes; and compensating and adjusting the signal according to the adjustment compensation value, the amplitude value and the phase value.

The radio communication device according to the present invention comprises: a baseband/intermediate frequency band unit that quadrature-modulates an in-phase component and a quadrature component of a digital baseband signal, converts the digital baseband signal into an analog intermediate frequency signal, and outputs the analog intermediate frequency signal; and a radio frequency band unit that generates a radio frequency signal by frequency-converting the analog intermediate frequency signal from the baseband/intermediate frequency band unit, amplifies the generated radio frequency signal, and transmits the amplified radio frequency signal. The baseband/intermediate frequency band unit further includes an analog correction filter that corrects the in-phase component and the quadrature component of the digital baseband signal, based on phase information on an analog filter in the baseband/intermediate frequency band unit and phase information on an analog filter in the radio frequency band unit.

The radio communication device according to the present invention comprises: a baseband/intermediate frequency band unit that quadrature-modulates an in-phase component and a quadrature component of a digital baseband signal, converts the digital baseband signal into an analog intermediate frequency signal, and outputs the analog intermediate frequency signal; and a radio frequency band unit that generates a radio frequency signal by frequency-converting the analog intermediate frequency signal from the baseband/intermediate frequency band unit, amplifies the generated radio frequency signal, and transmits the amplified radio frequency signal. The baseband/intermediate frequency band unit further includes an analog correction filter that corrects the in-phase component and the quadrature component of the digital baseband signal, based on phase information on an analog filter in the baseband/intermediate frequency band unit and phase information on an analog filter in the radio frequency band unit.

Apparatus and methods for power amplifier bias modulation for multi-level supply envelope tracking are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier that amplifies a radio frequency signal, a multi-level supply envelope tracker that generates a power amplifier supply voltage of the power amplifier based on an envelope signal indicating an envelope of the radio frequency signal, and a bias modulation circuit that modulates a bias of the power amplifier based on a voltage level of the power amplifier supply voltage.

Apparatus and methods for power amplifier bias modulation for low bandwidth envelope tracking are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier that amplifies an RF signal and a low bandwidth envelope tracker that generates a power amplifier supply voltage for the power amplifier based on an envelope of the RF signal. The envelope tracking system further includes a bias modulation circuit that modulates a bias signal of the power amplifier based on a voltage level of the power amplifier supply voltage.

Multi-level envelope tracking systems with adjusted voltage steps are provided. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, an MLS modulator that controls selection of the regulated voltages over time based on an envelope signal corresponding to an envelope of a radio frequency (RF) signal amplified by the power amplifier, and a modulator output filter coupled between an output of the MLS modulator and the power amplifier supply voltage. The envelope tracking system further includes a switching point adaptation circuit configured to control the voltage level of the regulated voltages outputted by the MLS DC-to-DC converter based on a power level of the RF signal.

Multi-level envelope trackers with an analog interface are provided herein. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, an MLS modulator that controls selection of the regulated voltages over time based on an analog envelope signal corresponding to an envelope of the RF signal amplified by the power amplifier, and a modulator output filter coupled between an output of the MLS modulator and the power amplifier supply voltage.

Multi-level envelope tracking systems with separate DC and AC paths are provided. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, an MLS modulator that controls selection of the regulated voltages over time based on an envelope signal corresponding to an envelope of a radio frequency (RF) signal amplified by the power amplifier, an AC path filter coupled between an output of the MLS modulator and the power amplifier supply voltage, and a DC path filter coupled between a DC voltage and the power amplifier supply voltage.

A low-power double-quadrature receiver is disclosed. The double-quadrature receiver includes a quadrature signal generator configured to generate a first quadrature signal and a second quadrature signal based on each component of a differential input signal, and a switching stage configured to perform down-conversion on the first quadrature signal and the second quadrature signal.

An electronic circuit including: a differential multiplier circuit with a first differential input and a second differential input and a differential output; and a phase locked loop (PLL) circuit including: (1) a balanced differential mixer circuit with a first differential input electrically connected to the differential output of the differential multiplier circuit, a second differential input, and an output; (2) a loop filter having an output and an input electrically connected to the output of the balanced differential mixer circuit; and (3) a voltage controlled oscillator (VCO) circuit having an input electrically connected to the output of the loop filter and with an output electrically feeding back to the second differential input of the balanced differential mixer circuit.