Power amplifier arrangement with enhanced bandwidth

A power amplifier arrangement, wherein the power amplifier arrangement is a Doherty power amplifier based on two coupled transmission lines, the power amplifier arrangement comprising:

• a first power amplifier having an input and an output, which is a main amplifier, and a second a power amplifier having an input and an output, which is an auxiliary amplifier;
• an input power splitter having an input and a first output and a second output;
• and
• a quadrature coupler having an input port, a through port, a coupled port and an isolated port, wherein the quadrature coupler comprises two coupled transmission lines, a first terminal of the first transmission line is the input port, a second terminal of the first transmission line is the through port, a first terminal of the second transmission line is the coupled port and a second terminal of the second transmission line is the isolated port;
• wherein:
• the input of the first power amplifier is coupled to the first output of the input power splitter;
• the output of the first power amplifier is coupled to the through port of the quadrature coupler;
• the input of the second power amplifier is coupled to the second output of the input power splitter;
• the output of the second power amplifier is coupled to the coupled port of the quadrature coupler;
• the input port of the quadrature coupler is coupled to a load;
• and
• the isolated port of the quadrature coupler is not connected to any component;
• and
• a coupling coefficient of the two coupled transmission lines is determined based on an output power backoff level at which the power amplifier arrangement is desired to operate.