Method and system for a RFID transponder with configurable feed point for RFID communications
View Patent ↗A Method and system for a RFID transponder with configurable feed point for RFID communications is provided. In this regard, an RFID transponder may receive RF signals via a leaky wave antenna and modulate an amplitude of a backscattered signal associated with the received RF signals by switching between a plurality of feed points of the leaky wave antenna to vary an input impedance of said RFID transponder. Each of the plurality of feed points may be located in a different position in the resonant cavity of the leaky wave antenna. The input impedance may be controlled by switching a load in and out of a receive path of the RFID transponder. The leaky wave antenna may be integrated within and/or on an integrated circuit, an integrated circuit package, or a combination thereof.
1. A leaky wave antenna, comprising:
a reflective surface configured to reflect electromagnetic energy corresponding to a signal;
a partially reflective surface configured to reflect less than all of the electromagnetic energy corresponding to the signal, the partially reflective surface being spaced apart from the reflective surface to form a cavity therebetween;
a plurality of feed points configured to inject signals into the cavity, the signal being injected into the cavity by one of the plurality of feed points based upon an input impedance of the leaky wave antenna,
wherein the input impedance of the leaky wave antenna is set by a position of the one of the plurality feed points that injects the signal relative to the reflective surface, and
the partially reflective surface includes a plurality of slots to allow a portion of the electromagnetic energy to radiate from the leaky wave antenna, a spacing between the plurality of slots being adjustable via micro-electromechanical systems (MEMS) to set a Q factor for the leaky wave antenna.
2. The leaky wave antenna of claim 1 , wherein each of the plurality of feed points is disposed at a different location relative to the reflective surface to provide different input impedances for the leaky wave antenna.
3. The leaky wave antenna of claim 1 , further comprising a micro-electromechanical system (MEMS) configured to vary a distance between the reflective surface and the partially reflective surface.
4. The leaky wave antenna according to claim 3 , wherein the MEMS moves at least one of the reflective surface and the partially reflective surface.
5. The leaky wave antenna according to claim 4 , wherein the MEMS varies the distance between the reflective surface and the partially reflective surface based on a bias voltage provided to the MEMS to set a resonant frequency of the leaky wave antenna.
6. The leaky wave antenna according to claim 5 , wherein the MEMS causes at least one of the reflective surface and the partially reflective surface to move through deflection.
7. The leaky wave antenna according to claim 1 , wherein the partially reflective surface is a metal surface in which the plurality of slots are formed.
8. The leaky wave antenna according to claim 7 , wherein a bandwidth of the leaky wave antenna is determined by a spacing, dimension, shape and orientation of the plurality of slots.
9. The leaky wave antenna according to claim 8 , wherein the spacing between the slots corresponds to a signal to be transmitted or received.
10. The leaky wave antenna according to claim 1 , wherein the reflective surface and the partially reflective surface are coplanar microstip waveguides.
11. The leaky wave antenna according to claim 1 , wherein the cavity is filled with a dielectric.