Design of Novel Rat-Race Coupler Based Analog Pre-Distortion Circuit for 5G Applications

In this paper, Analog Pre-distortion techniques are designed at 3.5 GHz to produce linearity for PA. Firstly, the individual blocks like Wilkinson Power Divider (WPD), Hybrid Coupler (HC), Rat-race Coupler (RRC), and Phase Shifter (PS) of 90-degree Phase shift, are individually designed and simulated. After getting the simulated results, the layout of WPD, HC, and RRC are designed in Keysight ADS software and the layout of PS is designed in Dip Traces software. After designing the layout of WPD, HC, and PS is done on the Backlight PCB which is of dielectric 5. After performing the simulation of each block of APD, all the blocks are combined and APD1 & APD2 circuits are designed. Harmonic Balance (HB) Simulation is performed for both APDs to find the AM-AM, AM-PM plots, and Intermodulation distortion (IMD) points. Based on IMD points, the APD1 will provide good linearity as compared to APD2.