差分放大器的优势

However, this influence（指RF的二次谐波和本振的二次谐波混频产生基带的二次谐波） will be negligible if a differential down-converter circuit design is employed since the common mode rejection of the differential circuits can significantly suppress the even-order distortion.

        --3.2.2.2. Second-Order Distortion 《RF System Design of Transceivers for Wireless Communications》

The LO leakage level at the input of the LNA through the substrate may reduce more than 20 dB if a differential LNA is used instead of a single end LNA, and a differential I/Q down-converter is employed in both cases.

        --3.2.3.4. Receiver RF Chain Reverse Isolation 《RF System Design of Transceivers for Wireless Communications》

To suppress the LO leakage emission in a single chip direct conversion transmitter, differential circuits may need for all the stages from the LPF, I/Q modulator, up to PA driver output.

        --3.2.3.6. Direct-ConversionTransmitter 《RF System Design of Transceivers for Wireless Communications》