Cellular phone with a logarithmic detector

摘要

A transmitter for a cellular phone comprising an antenna and being operable at a first radio frequency band and a second radio frequency band is disclosed. In one embodiment, the transmitter includes a first power amplifier and a second power amplifier. The first power amplifier has a first input for a first signal at the first radio frequency band and a first output for an amplified first signal, the first output being connected to the antenna. The second power amplifier has a second input for a second signal at the second radio frequency band and a second output for an amplified second signal, the second output being connected to the antenna. The transmitter further comprises a single control module which is associated with the first and second outputs of the power amplifiers and comprises a logarithmic detector. The control module generates a control signal which is a function of an amplified signal and a reference signal in order to control the two power amplifiers.