In this paper. a CMOS Class-J Doherty power amplifier (PA) integrating a Class-G driver and an Impedance-Modulated-Quadrature-Transformer (IMQT) to enhance back-off efficiency for multimode operations is presented. The Class-J Doherty PA utilizes a second harmonic termination to improve its efficiency. To further augment efficiency at deep back-off output power. https://www.roneverhart.com/Turbosound-TS-18SW700-8A-18-Low-Frequency-Loudspeaker-p31480/