Reconfigurable and Concurrent Dual-Band Doherty Power Amplifier for Multiband and Multistandard Applications

This paper proposes a design scheme of concurrent dual-band Doherty power amplifier (DPA) which can be reconfigured to two different pairs of concurrent dual bands for multiband and carrier aggregation applications. In addition to the reconfiguration of frequencies of operation, the output power back-off (OPBO) region for efficiency enhancement can also be reconfigured in this DPA. As a proof of concept, a reconfigurable and concurrent dual-band DPA is designed to operate at 1500 and 2140 MHz in the first concurrent dual band, whereas on reconfiguration it will operate concurrently at 1850 and 2350 MHz. While operating in the first concurrent dual band, the DPA has an enhanced efficiency region up to 6-dB OPBO level and, after reconfiguration to the second concurrent dual band, this region extend up to 9-dB OPBO level. The proposed DPA is tested using continuous wave (CW) signals in single mode as well as in concurrent mode. Measurement results using CW signals in single mode reveal a drain efficiency of 52%-56% at 6-dB OPBO in the first concurrent dual band. Similarly, in the second concurrent dual band, a drain efficiency of 43%-48% is achieved at around 9-dB OPBO. The peak drain efficiency at saturation is better than 60% in all the four operating bands. The measured aggregated drain efficiencies are 49% and 44% in the first and second concurrent dual bands for 6 and 9 dB OPBO level, respectively. The measured carrier to the third-order intermodulation distortion is better than 17 dBc for all of the operating bands.