A Novel Analog Linearizer for Solid-State Power Amplifier in Satellite Communication System

In this paper, a new, compact and low loss analog predistortion linearizer using two parallel Schottky barrier diodes (SBDs) is developed. This linearizer will be used to compensate the nonlinearity of the solid-state power amplifier (SSPA) in satellite communication system. The fundamental principle is analyzed and its corresponding equivalent circuit model is given. Then, the desired non-linear characteristics of the linearizer versus different circuit parameters have been discussed. Finally, the intermodulation distortion of a satellite SSPA with and without the designed analog linearizer when it delivers maximum output power have been measured and compared. The results show that the nonlinear characteristics of the amplifier has been corrected and its inter-modulation distortion has been significantly improved.