| Author(s): |
Daniel G. Kuester; David R. Novotny; Jeffrey R. Guerrieri; Randy Direen; Zoya Popovic; |
| Title: |
Reference Modulation for Calibrated Measurements of Tag Backscatter |
| Published: |
April 14, 2011 |
| Abstract: |
We present a model and reference backscatter device for calibrating measurements of 860-960 MHz Ultra-High Fre- quency (UHF) tag backscattering. The model relates transmission to and backscattering from the device with a modulation depth calculable from circuit parameters. Unlike the free-space far field approximations, the model is valid in arbitrary stationary linear environments, including the near field of a transmit or measurement antenna, via S-parameters. We use the model to demonstrate an inexpensive reference backscatter device with a common lab switch and loads. Validation measurements on a network analyzer with two expressions for modulation depth agree to within 0.1 dB at 915 MHz. Finally, we present some initial calibrated measurements of backscattered power from a tag at 915 MHz, with estimated uncertainty -0.7 dB to +0.6 dB. |
| Proceedings: |
2011 IEEE International Conference on RFID |
| Pages: |
8 pp. |
| Location: |
Orlando, FL |
| Dates: |
April 12-14, 2011 |
| Keywords: |
RFID, UHF, backscatter, modulation |
| Research Areas: |
Wireless |
