Bandwidth Extension of a Doherty Power Amplifier Through Reduction of Packaging-Related Parasitic Effects

This paper investigates the bandwidth extension achievable for a Doherty power amplifier topology, by using a packaging approach which minimizes packaging-related parasitic effects, such as the effective inductance of bonding wires. A Doherty power amplifier module is designed using a novel packaging approach by embedding of the higher power RF transistors inside the module laminate. This embedded approach is compared against a more conventional previously developed demonstrator using wire-bonded transistor dies. Initial simulations show that the embedded Doherty amplifier can extend the bandwidth from the initial 500 MHz to 800 MHz, while maintaining similar levels of output power, drain efficiency and transducer gain. Finally, the measured performance of the embedded and wire-bonded demonstrators is also analyzed and compared.