System and method for detecting and correcting phase error between differential signals

A quadrature generator system with phase error detection feedback, comprising:

• a quadrature generator that develops positive and negative square-wave in-phase (I) carrier signals and positive and negative square-wave quadrature phase (Q) carrier signals and that receives a differential phase error signal for correcting phase error between the I and Q carrier signals;
• and
• a phase error detector, comprising:
• a summing circuit that develops a first sum signal by summing the positive I and Q carrier signals, a second sum signal by summing the negative I and Q carrier signals, a third sum signal by summing the positive I carrier signal and the negative Q carrier signal, and a fourth sum signal by summing the negative I carrier signal and the positive Q carrier signal;
• a first mixer circuit, coupled to the summing network, that combines the first and second sum signals and develops a first polarity signal of the differential phase error signal;
• and
• a second mixer circuit, coupled to the summing network, that combines the third and fourth sum signals and develops a second polarity signal of the differential phase error signal.

A radio transceiver, comprising:

• an antenna;
• a radio frequency (RF) receive circuit that detects a received RF signal via the antenna;
• a first receive mixer, coupled to the RF receive circuit, that mixes the received RF signal with positive and negative in-phase (I) carrier signals and that develops an I receive signal;
• a second receive mixer, coupled to the RF receive circuit, that mixes the received RF signal with positive and negative quadrature phase (Q) carrier signals and that develops a Q receive signal;
• and
• a quadrature oscillator with phase error detection feedback that provides the positive and negative I and Q carrier signals, comprising:
• a quadrature local oscillator that develops the positive and negative I carrier signals and the positive and negative Q carrier signals and that receives a differential phase error signal for maintaining the I and Q carrier signals at a one-quarter period phase differential with respect to each other;
• and
• a phase error detector, comprising:
• a summing circuit that develops a first sum signal by summing the positive I and Q carrier signals, that develops a second sum signal by summing the negative I and Q carrier signals, that develops a third sum signal by summing the positive I carrier signal and the negative Q carrier signal, and that develops a fourth sum signal by summing the negative I carrier signal and the positive Q carrier signal;
• a first mixer circuit, coupled to the summing network, that combines the first and second sum signals to develop a first polarity signal of the differential phase error signal;
• and
• a second mixer circuit, coupled to the summing network, that combines the third and fourth sum signals to develop a second polarity signal of the differential phase error signal.

A method of providing a phase error signal indicative of any phase error phase error between positive and negative polarities of a first and second differential signals, comprising:

• combining positive polarity signals of the first and second differential signals and providing a first sum;
• combining negative polarity signals of the first and second differential signals and providing a second sum;
• combining a first positive polarity signal and a first negative polarity signal of the first and second differential signals and providing a third sum;
• combining a second positive polarity signal and a second negative polarity signal of the first and second differential signals and providing a fourth sum;
• mixing the first and third sums to generate a first polarity phase error signal;
• mixing the second and fourth sums to generate a second polarity phase error signal;
• and
• providing the phase error signal as the difference between the first and second polarity phase error signals.