Bidirectional differential amplifier

A bidirectional differential amplifier, comprising:

• a first differential node configured as a differential transmit input node for a transmit mode and a differential receive output node for a receive mode;
• a second differential node configured as a differential transmit output node for the transmit mode and a differential receive input node for the receive mode;
• a transmit amplifier comprising a first transistor and a second transistor coupled between the first differential node and the second differential node and configured to produce a differential output transmit signal at the second differential node, the first transistor and the second transistor together including:
• a transmit pseudo-differential input coupled with a first bias voltage source and capacitively coupled with the first differential node;
• and
• a transmit differential output coupled with the second differential node;
• and
• a receive amplifier comprising a third transistor and a fourth transistor coupled between the first differential node and the second differential node and configured to produce a differential output receive signal at the first differential node, the third transistor and the fourth transistor including:
• a receive differential input coupled with a second bias voltage source and capacitively coupled with the second differential node;
• a receive differential output cross-coupled with the first differential node;
• and
• common terminals configured to be selectively coupled with ground when in the receive mode, and with a voltage supply when in the transmit mode;
• wherein, when in the transmit mode, the third transistor and the fourth transistor are configured to supply a neutralizing transmit feedback to the first differential node that is opposite in phase relative to the differential output transmit signal;
• and
• wherein, when in the receive mode, the first transistor and the second transistor are configured to supply a neutralizing receive feedback to the second differential node that is opposite in phase relative to the differential output receive signal.