×

Noncontact IC card reader/writer

  • US 20050029351A1
  • Filed: 06/29/2004
  • Published: 02/10/2005
  • Est. Priority Date: 06/30/2003
  • Status: Active Grant
First Claim
Patent Images

1. A noncontact IC card reader/writer that communicates data with a noncontact IC card, comprising:

  • a loop antenna, which supplies electric power and a send signal to the noncontact IC card by electromagnetic induction and acquires a receive signal from the noncontact IC card by load fluctuation;

    a first resonance circuit, which resonates the loop antenna with a desired first frequency;

    a radio transmitter, which supplies electric power and send data to the loop antenna via the first resonance circuit; and

    a radio receiver, which acquires the receive signal from the loop antenna via a second resonance circuit connected to the loop antenna via a coupling capacitor and resonated with a desired second frequency;

    wherein the radio transmitter and the radio receiver are respectively connected to CPU; and

    a low-pass filter for removing a high frequency, a class E amplifier and a modulator are connected to the radio transmitter in series.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×