A multi-band reconfigurable power amplifier for UMTS handset applications

A new practical reconfigurable structure for a multi-band power amplifier (PA) is proposed for UMTS handset applications. The proposed reconfigurable output matching network can reconfigure the output power as well as the frequency. It consists of a path-selection network, a power-reconfigurable network, and a frequency-reconfigurable network. To demonstrate the performance of the proposed structure, a 5 mm × 5 mm prototype reconfigurable PA module is developed for UMTS high-frequency band application. The fabricated PA module can cover any two bands out of three popular high-frequency UMTS bands. The fabricated amplifier module showed adjacent channel leakage ratios (ACLRs) better than -38 dBc up to the rated linear power and power-added efficiencies (PAEs) of higher than 38% at 28 dBm over all high-frequency UMTS bands. Efficiency degradation was limited to 2-3% compared to the single-band PA. Measured RF performance of the reconfigurable PA validates the usefulness of the proposed reconfigurable structure for multi-band UMTS applications.