Prof. Patrick RoblinRUWAYBIH RABIH RUWAYBIH ALSULAMI2022-06-012022-06-01https://drepo.sdl.edu.sa/handle/20.500.14154/58024This dissertation presents a novel 2-input 3-Way architecture and design methodology for dual-band Doherty power amplifiers to be referred as 3-Way DB-DPA. It also presents a new digitally controlled 4-input 3-Way DB-DPA that is based on the 2-input 3-Way DB-DPA. The 3-Way DB-DPA consists of two main amplifiers, one for each band, and an auxiliary amplifier handling both bands. This new 3-Way DB-DPA enables the average drain efficiency in concurrent dual-band operation to be improved compared to the traditional 2-Way DB-DPA by avoiding early clipping in the main amplifiers while benefiting from load-pulling from the auxiliary PA. The improvement of the 3-Way DB-DPA has been verified in theory and simulation at the current- source reference plane (CSRP) as well as in measurement, with a fabricated PA. A statistical analysis using 2D CW signals with LTE probability distribution functions (PDF) is performed for the new PA’s architecture at the CSRP, which demonstrates an improvement in the concurrent average efficiency by 15 points, compared to the conventional 2-Way DB-DPA. In 2-input 3-Way DB-DPA non-concurrent operation, the measured CW drain efficiency in the lower-band (1.5 GHz) is 82.8% at peak and 66.6% at 9.6 dB backoff; for the upper-band (2.0 GHz), 70.0% at peak and 48.4% at 9.4 dB backoff. In 4-input 3-Way DB-DPA non-concurrent operation, the measured CW drain efficiency in the lower-band (1.5 GHz) is 81.5% at peak with optimal out- phasing angle ∆φ=172◦, and 67.4% at 8.7 dB backoff with ∆φ=166◦, and for the upper-band (2.0 GHz), 66.7% at peak with ∆φ=−57◦, and 59.8% at 8.5 dB backoff with ∆φ=−67◦. The CW concurrent-balanced drain efficiency reaches 66.2/52.0% in the 2-input 3-Way DB-DPA at 3/6 dB backoff. The 2-input 3-Way DB-DPA is also tested with modulated signals. In single-band operation, at 1.5 and 2.0 GHz the aver- age power and average drain efficiency after DPD are 31.2/33.4 dBm and 50.4/41.2%, for an OFDM/LTE signal with 10 MHz bandwidth and 9.5 dB PAPR and 35.1/37.4 dBm and 65.0/53.7%, respectively, for an LTE signal with 10-MHz bandwidth and 6.1 dB PAPR. In concurrent operation, the 2-input 3-Way-DPA is driven by two 10- MHz LTE uncorrelated signals, one at 1.5 GHz with 6.86 dB PAPR, and one at 2.0 GHz with 6.26 dB PAPR, and the average total power and average concurrent drain efficiency after DPD are 37.5 dBm and 54.24%, respectively.en