Non-contact IC card having an active attenuation circuit
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorAtsuo Yamaguchi
Life of this patent
Estimating the term…
Abstract
The present invention provides a microcomputer in which an input signal is input via a resonance circuit, a CPU for processing data, an input circuit for detecting the input signal, a decoding circuit for demodulating the input signal and supplying a demodulated signal of a predetermined length to the CPU when the input circuit detects the input signal, an attenuation circuit for attenuating oscillation in the resonance circuit when said input circuit detects the input signal, and an output circuit for outputting an output signal from the CPU. A non-contact IC card utilizing the microcomputer includes an antenna circuit for transmitting and receiving data and incorporating the resonance circuit.
Claims6
A non-contact IC card comprising:
- an antenna circuit for transmitting and receiving signals and for producing an output signal in response to a received signal;
- a CPU for processing data;
- a receiving circuit connected to said antenna circuit for detecting a receive signal in an output signal produced by said antenna circuit;
- a decoding circuit connected to said receiving circuit for demodulating a receive signal detected by said receiving circuit and outputting a demodulated signal having a predetermined length to said CPU when said receiving circuit detects the receive signal;
- an attenuation circuit connected to said receiving circuit for attenuating oscillation in said antenna circuit when said receiving circuit detects the receive signal;
- and
- a transmitting circuit connected to said CPU and said antenna circuit for coupling a transmit signal to said antenna circuit from said CPU.
Dependencies are inferred from the claim text.