Nowadays, there are three prominent multilevel topologies, diode-clamped multilevel inverter, capacitor-clamped multilevel inverter and cascaded multilevel inverter.

The paper analyses the electric circuit and the working principle of the avalanche of the bipolar transistor of the pulser with a cascade connected bipolar transistor structure.

Last we present two new pre-distortion, a pre-distortion using twice mixing operation and linearizer using anti-parallel Schottky diodes which are directly connected with pa.