摘要 |
To realize a high frequency power detection circuit constituting a detection circuit by a GaAs semiconductor and thereby capable of realizing a small sized, low cost, and broad band detection circuit and suppressing variations in the detection characteristics due to variations in a pinchoff voltage of the field effect transistors, the invention is a detection circuit for detecting an envelope of a high frequency signal, comprising a field effect transistor to the gate of which the high frequency signal is input, a gate bias circuit for providing a gate bias voltage to the gate of the field effect transistor, a capacitor connected between the drain of the field effect transistor and the ground, and a load capacitor and a load resistor connected in parallel between the source of the field effect transistor and the ground, wherein a detection signal corresponding to the envelope of the high frequency input signal is output from the source of the field effect transistor. Various gate biasing circuits are ultimately disclosed.
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