A Passive Diode Detector with Harmonic Suppression

This paper presents an efficient design of a passive detector using a single Schottky barrier diode. A compact bandstop unit with multiple stopbands is designed using the step impedance section and open-stub which is then integrated in the detector circuit. It improves the sensitivity of the detector and rejects up to fourth harmonic including the fundamental RF signal. A prototype detector is fabricated at 2.26 GHz. The measured results shows that the fundamental component is suppressed by at least 18.5 dB with rejection up to fourth harmonic.