To design, manufacture and test a single-chip Ka-band Doherty amplifier.

The Doherty concept has proven to be a very effective technique for designing amplifiers, which maintain a high efficiency over a wide range of operating conditions. This technique is extensively used in terrestrial applications like base stations where power efficiency is getting more and more attention. Power efficiency is also of concern for space and the Doherty concept could certainly help in designing more efficient PAs. Ka-band is now being considered for mobile services that could offer very high capacity as compared to the existing ones at L-band. The ideal solution would be based on a Ka-band active array but this implementation is hindered by the lack of efficient PAs. This activity intends to demonstrate the feasibility of efficient PAs at Ka-band. Thanks to the advent of GaN technology, the efficiency of power amplifiers (PA) has already progressed significantly. The combination of this new technology with clever design techniques like Doherty could lead to efficiencies beyond 40% in Ka-band which is twice as high as compared to more commonly used GaAs technology. The activity aims at demonstrating this level of performance with a single-chip implementation targeting an output power in the range of few watts. The activity consists of the following tasks: - Literature and patent study, - Identification of preferred topologies, - PA preliminary design (1st run), manufacturing and test, - PA detailed design (2nd run), manufacturing and test, - Conclusion and way forward.