Comparison on powering passive sensor RFID via variation of modulation indexes

In this paper we present data on how powering passive sensor radio frequency identification (RFID) transponder can be performed more efficiently. We focused on the industrial, scientific and medical (ISM) band around 5.8 GHz. We investigated how different modulation indexes for amplitude shift keying (ASK) affect the rectification process. The rectifier configuration is Greinacher one with two HSMS2862 and the other with two PCC110 diodes from Avago and Powercast, respectively. The highest achieved power gain was 6.4 dB at a modulation index m of 100% compared to a continuous wave signal at an input power of -12.7dBm for the HSMS2862 rectifier.