Back to results
US 2006/0220794 A1Published application
Phase modulation for backscatter transponders
OwnerJeffrey Zhuinventor
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
OwnerJeffrey Zhuinventor
Estimating the term…
A radio frequency identification system having a passive backscatter transponder employing phase modulation. The transponder selectively couples its antenna to one of two or more impedances, wherein the impedances each produce a reflected signal when coupled to the antenna in the presence of a continuous RF wave from the reader. The reflected signals produced by the impedances are out-of-phase with each other. The transponder switches between impedances to encode transponder information into a reflected signal through phase shifts in the reflected signal. The reader detects the phase shifts in the reflected signal received at the reader to obtain the transponder information. The impedances are selected so as to produce reflected signals having a desired phase relationship or difference and having sufficient amplitude.
A radio frequency (RF) identification system, comprising:
A radio frequency (RF) identification system, comprising:
A reader for use in a radio frequency (RF) identification system employing phase modulation, the system having a transponder, wherein the transponder produces a reflected signal in response to a continuous wave RF signal, and wherein the reflected signal includes transponder information encoded using phase shifts within the reflected signal, the reader comprising:
Dependencies are inferred from the claim text.