A Compact linearizer for Independently Tuning the Gain Characteristic at C-Band

This paper presents a compact linearizer for independently tuning the gain characteristic at C-band. The proposed analog predistortion (APD) linearizer is designed to use a two-way synthesis technique to decouple the characteristic of gain and phase, and both ways are designed by capacitors, inductors, and microstrip lines for cutting down the layout size. This proposed APD operates at a center frequency of 3.8 GHz and only has a size of 3.2*2.8 cm
²
. The result shows that the tuning range of AM/AM and AM/PM is more than 2.3 dB and less than 4.5 degrees. Using a 100 MHz long-term evolution (LTE) signal with a 9.9 dB peak-to-average power ratio (PAPR) as the excitation of the power amplifier (PA), this APD linearizer can improve its Adjacent Channel Power Ratio (ACPR) by more than 7 dB.