2.45 GHz detector design for biomedical transponder application

This paper discusses the design of a minimum-power 2.45 GHz pulse receiver for use in a semi-active, duplex RF transponder. A 50 /spl Omega/ microstrip stub-matched zero-bias diode detector forms the heart of the unit, achieving a tangential sensitivity of -56 dBm. Three-pole bandpass filtering provides rejection of out-of-band signals, typically 28 dB in the 900 MHz cellular band. The prototype receiver consumes 20 /spl mu/A from a 3 V Lithium coincell and occupies 6 cm/sup 2/ of surface mount board space.