Patent ID: 6169885
Filing Date: 2001-01-02
Classification: H03F,H04B

Abstract:
A radio device comprising: a transmitter that transmits radio communications wherein said transmitter comprises a power amplifier that generates an amplified radiofrequency output signal wherein said power amplifier uses both a positive supply voltage and a negative bias voltage for operation wherein said negative bias voltage is less than a supply ground voltage and wherein said power amplifier receives the negative bias voltage at a negative bias voltage input; and a control circuit that enables said power amplifier during transmission, said control circuit comprising a switch coupled in series between the positive supply voltage and said power amplifier, said switch being activated in response to a transmit activation signal when the negative bias voltage is applied to said power amplifier, and wherein activation of said switch in response to the transmit activation signal is prevented when the negative bias voltage is not applied to said power amplifier wherein activation of said switch is prevented responsive to a feedback signal from said negative bias voltage input.