Complete analysis and design for a Q/V band (46‐52 GHz ) wideband analog predistorter

This article shows the complete analysis and design for a Q/V (46-52 GHz) band wideband analog predistorter (APD). First, the reflection coefficient for hybrid coupler's through port with complex impedance is corrected. Second, the acceptable error region is introduced to analyze the influence of different nonlinear loads. Levenberg-Marquardt algorithm is then used to solve the circuit parameters of the hybrid T matching network. Finally, a Q/V band (46-52 GHz) wideband APD is fabricated and measured. The measurement results are in good agreement with the analysis results. Furthermore, the linearized traveling-wave tube amplifiers (TWTA) gain compression is less than 0.5 dB, and the phase change of TWTA after linearization is less than 4°. The C/IM3 shows more than 10 dB improvement.