Patent ID: 8385860
Filing Date: 2013-02-26
Classification: G01R

Abstract:
1. A power detector comprising: a reference voltage generator configured to receive a bias voltage and generate a reference voltage; a square signal generator configured to receive a voltage having a high frequency input voltage superimposed on the bias voltage and output a signal including the reference voltage, a voltage of a square of the high frequency input voltage, and a high-frequency signal; a detection circuit having a first lowpass filter configured to filter out the high-frequency signal from the output signal of the square signal generator and output a mean value, a first operational amplifier configured to amplify error between an output voltage of the first lowpass filter and the reference voltage and output the error as a control voltage, and a feedback transistor configured to feed a feedback current according to the control voltage back to an output terminal of the square signal generator, the detection circuit being configured to reduce the error between the output voltage of the first lowpass filter and the reference voltage to detect high frequency power based on the feedback current; and an output circuit configured to output a voltage according to the control voltage.