Battery-assisted backscatter RFID transponder

• US 20060007049A1
• Filed: 06/30/2005
• Published: 01/12/2006
• Est. Priority Date: 07/01/2004
• Status: Abandoned Application

• Current Assignee: PowerID Ltd.
• Original Assignee: PowerID Ltd.
• Inventors: Nitzan, Zvi, Guri, Gaby, Lavee, Doron
• Application Number:
  US11/169,704
• Publication Number:
  US 20060007049A1
• Time in Patent Office: Days
• US Class Current: 343/904
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A radio frequency transponder includes at least one battery, which is coupled to provide electrical power for operating the transponder and at least one antenna, which is configured to receive and backscatter RF interrogation radiation from an interrogation device. An integrated circuit is arranged to store a code including information and, powered only with energy provided by the battery, to vary a radiation characteristic of the antenna responsively to the code so as to modulate the information onto the backscattered radiation.

Claims

1. An antenna for transmitting information from a radio frequency (RF) transponder, wherein the antenna is configured to receive RF interrogation radiation at a first power level from an interrogation device, to backscatter the interrogation radiation at a second power level that is greater than 75% of the first power level, and wherein the antenna has a variable radiation characteristic, which is controllable by the transponder so as to modulate the information onto the backscattered radiation.

2. The antenna according to claim 1, wherein the second power level is greater than 95% of the first power level.

3. The antenna according to claim 1, wherein the antenna is selected from the group consisting of at least one of a monopole, a bent monopole, a dipole, a bent dipole, a patch, an array antenna and a combination thereof.

4. The antenna according to claim 1, wherein the antenna is configured to receive and backscatter the interrogation radiation in one of an ultra-high frequency (UHF) range and a microwave frequency range.

5. The antenna according to claim 1, wherein the antenna is configured to receive and backscatter transverse electromagnetic (TEM) radiation.

6. The antenna according to claim 1, wherein the antenna comprises a feed-point, and wherein the radiation characteristic comprises a radar cross-section (RCS) of the antenna, and wherein the antenna is controllable to modulate the information responsively to variations of a load impedance at the feed-point of the antenna so as to vary the RCS between two or more different RCS values.

7. The antenna according to claim 6, wherein the antenna is configured to maximize at least one of the two or more RCS values responsively to a low resistive load condition applied to the feed-point of the antenna, thereby maximizing a communication range of the transponder.

8. The antenna according to claim 6, wherein the antenna is arranged to maximize a modulation depth defined as a ratio between two of the two or more RCS values.

9. The antenna according to claim 8, wherein the antenna is configured to jointly maximize the modulation depth and a communication range of the transponder.