Modified Gan Based Sequential Load-Modulated-Balanced-Amplifier Avoiding Schottky-Gate Effects & Increase Linearisability

This article highlights a fundamental issue in the GaN based amplifiers, specially in the S-LMBA and tries to solve the issue using additional hardware. The Control-PA or CPA is heavily saturated for efficiency and high input voltages are needed at the input, this causes the intrinsic gate-diode conduction and gate current is leaked into the PA. In return the peak voltage of the CPA may vary which causes a clipping effect and thus leads to degradation in the linearization. To solve this, here, an analog clipper based approach is explained with a custom setup which is able to linearize the DUT at varying average powers and with varying signal PAPR. For evaluation, the works shows two signal BW of 20- and 80- at a center frequency of 3.7 GHz.