| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-frequency signal detection circuit efficiently detecting high-frequency signals with low power consumption. SOLUTION: The high-frequency signal IN is intermitted by a switch 3 according to a pulse signal PS, and supplied to a resonance circuit composed of a capacitor 4 and an inductor 5. The signal SA whose amplitude has been amplified with the resonance circuit is supplied to the gate of an NMOS7 along with a bias voltage VB from a bias voltage source 6. The NMOS7 is set to be operate in a weak inversion region by the bias voltage VB. The signal SA is inverted and half-wave rectified by the NMOS7, and outputted to a node NB as signal SB. The high-frequency component of the signal SB outputted to the node NB is eliminated by a capacitor 9, and the signal of the same frequency as the pulse signal PS is detected by a determination part 10. If the signal of the same frequency as the pulse signal PS is detected, a high-frequency signal IN is determined. COPYRIGHT: (C)2008,JPO&INPIT
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