Magnetically coupling radio frequency antennas

Abstract

The present disclosure is directed to a system and method for using magnetically coupled antennas to enhance receptivity and/or reading range of radio frequency (RF) transaction devices. In some implementations, a method for boosting RF signals includes wirelessly receiving an RF signal from a transaction terminal at a passive antenna. The passive antenna is magnetically coupled to the antenna of a transaction card. The transaction card is inserted in a mobile host device and configured to execute a payment application using user credentials in response to at least a transaction request and transmits at least one transaction response to the transaction terminal based, at least in part, on the executed transaction application and using the antenna either standalone or through the coupled antenna configuration. The RF signal is transmitted to the transaction card using the inductive coupling with the terminal.

What is claimed is: 
     
         1 . A transaction system, comprising:
 a transaction card, comprising:
 a dynamic antenna; 
 a memory-card interface that connects to a mobile host device; 
 a communication module that wirelessly receives Radio Frequency (RF) signals from and transmits RF signals to a transaction terminal; 
 secure memory that stores user credentials and a payment application used to execute financial transactions with the transaction terminal, the user credentials and the transaction application associated with an institution; 
 a user-interface module that presents and receives information through the GUI of the mobile host device; 
 a processing module that executes the transaction using the user credentials in response to at least a transaction request received by the RF module and transmits at least one transaction response to the terminal based, at least in part, on the executed transaction application; and 
   a boosting element including a passive antenna configured to magnetically couple with the dynamic antenna and increase an operating range of RF signal communication between the dynamic antenna and the transaction terminal.   
     
     
         2 . The transaction system of  claim 1 , the passive antenna included in a first layer, further comprising a second layer coupled to the first layer and including an adhesive configured to affix the passive antenna to a device hosting the transaction card and at least proximate a card slot of the host device. 
     
     
         3 . The system of  claim 1 , the passive antenna included in a first layer, further comprising a second layer including substantially planar ferrite and a first surface and a second surface, the first surface affixed to the first layer and the second surface affixed to the second layer. 
     
     
         4 . The system of  claim 1 , the passive antenna substantially planar and at least twice as large as the dynamic antenna. 
     
     
         5 . The system of  claim 4 , the passive antenna comprising an antenna in a shape of a coil. 
     
     
         6 . The system of  claim 1 , the passive antenna configured to magnetically couple to the dynamic antenna inside the transaction card to substantially operate as a single antenna. 
     
     
         7 . The system of  claim 6 , the single antenna tuned to perform at an operating range greater than an operating range of the dynamic antenna inside the transaction card. 
     
     
         8 . The system of  claim 1 , the boosting element integrated in a housing of the host device for the transaction card. 
     
     
         9 . The system of  claim 1 , the mobile host device operates independent of interference from the boosting element. 
     
     
         10 . The system of  claim 1 , the boosting element affixed to an inner surface of a battery cover of the mobile host device. 
     
     
         11 . The system of  claim 1 , the boosting element affixed to the terminal, the terminal operates independent of interference from the boosting element. 
     
     
         12 . The system of  claim 1 , the transaction card configured to execute transactions with RF enabled terminals using RF signals transmitted in accordance with contactless standards ISO 14443 Type A and Type B, MiFare, RFID, Felica, NFC, ISO 15693, or Bluetooth. 
     
     
         13 . The system of  claim 1 , the user credentials associated with one of a credit card account, a checking account, a debit account, a gift account, or a prepaid account. 
     
     
         14 . The system of  claim 1 , wherein the processing module comprises:
 a security module that generates the transaction response based, at least in part, on the user credentials and the transaction application; and   an operating system with a runtime environment that executes the transaction application independent of the mobile host device.   
     
     
         15 . A method for boosting an RF-signal communication range between a transaction card and a terminal, comprising:
 magnetically coupling an antenna of a transaction terminal and a passive antenna inside a boosting element;   magnetically coupling the passive antenna inside the boosting element with a dynamic antenna of a transaction card, the transaction card inserted in a mobile host device, the boosting element coupled with the terminal antenna regenerating a terminal magnetic field with a higher flux density near the transaction card effecting an indirect magnetic coupling of the terminal antenna with the dynamic antenna; and   wirelessly communicating RF signals between the terminal and the transaction card using indirect magnetic coupling.   
     
     
         16 . The method of  claim 15 , the indirect magnetic coupling through the boosting element allowing communication between the terminal and the transaction card at a greater operating range than direct coupling between the terminal antenna and the dynamic antenna inside the transaction card. 
     
     
         17 . The method of  claim 15 , further comprising substantially reducing interference generated by material of the mobile host device. 
     
     
         18 . The method of  claim 15 , the passive antenna adjacent a surface of the mobile host device or a surface of the terminal. 
     
     
         19 . The method of  claim 15 , the passive antenna magnetically coupled to the dynamic antenna to substantially operate as an antenna larger than the dynamic antenna. 
     
     
         20 . The method of  claim 15 , the passive antenna boosts a communication range of the terminal independent of interfering with operations of the mobile host device or the terminal.