Biasing an amplifier using a mirror bias signal

A method of manufacturing a power amplifier bias circuit, the method comprising:

• coupling a base of an emitter follower transistor to a base of an emitter follower mirror transistor;
• coupling a collector of a reference transistor to an input port, the input port configured to receive a reference signal;
• coupling a collector of the emitter follower transistor and a collector of the emitter follower mirror transistor to a power supply port;
• coupling a base of the reference transistor to an emitter of the emitter follower mirror transistor such that, in operation, the emitter follower mirror transistor biases the reference transistor;
• and
• coupling an emitter of the emitter follow transistor to an output port to provide a biasing signal to an amplifying device such that, in operation, a voltage at a node between the base of the emitter follower transistor and the base of the emitter follower mirror transistor is approximately twice a base-emitter voltage (2Vbe) of the amplifying transistor.