US 6,173,899 B1 · Method and system for contactless energy transmission and data exchange between a terminal and IC card

Abstract

The present invention relates to methods and systems for power and energy transfer for non-contact IC cards, which is capable to communicate with an external device such as a host terminal. The disclosed method and system give the possibility to combine inductive coupling for remote power and data transmission, and capacitive coupling while IC card is attached to terminal, in order to transfer a large amount of energy. The new in the art is that bidirectional data and energy transfer from a terminal into an IC card is performing at two different carrier frequencies of an energy-transmitting alternating field. Herein the remote data transmission and energy transfer into the IC card is provided at first, lowest, frequency, utilizing the inductive coupling between a terminal transmitting-receiving coil and a IC card transmitting-receiving coil. Additionally, the close contactless energy and data transmission into the IC card is provided at second, higher, frequency utilizing the capacitive coupling between a terminal and IC card capacitive pads while IC card is attached to the terminal. The first frequency is designed to be a frequency of a parallel resonance combined by parallel alignment of an IC card inductive coil and a distributed capacitance of an IC card capacitive pads. The second frequency is designed to be a frequency of a series resonant circuit associated with series alignment of additional terminal inductance and joint capacitance of a terminal capacitive pads and IC card capacitive pads, when card is attached to terminal.

Claims7

Dependent claims

A method for contactless energy transmission and data exchange between a host terminal and integrated circuit IC card, which is powered via an energy-transmitting alternating field at a different frequencies which are modulated with data signal to provide bidirectional data transfer, comprising the steps of:

the remote bidirectional data transmission and energy transfer into the IC card at first, lowest frequency, utilizing the inductive coupling between a terminal transmitting-receiving coil and an IC card transmitting-receiving coil while IC card is separated from terminal,
the close coupling bidirectional data transmission and energy transfer into the IC card at second frequency, higher than first frequency, utilizing the galvanically contactless capacitive coupling between terminal capacitive pads and IC card capacitive pads while IC card is attached closely to the terminal,
wherein first frequency is designed to be a frequency of a parallel resonant circuit combined by parallel alignment of an IC card inductive coil and a distributed capacitance of IC card capacitive pads,
wherein second frequency is designed to be a frequency of a series resonant circuit associated with additional inductor of terminal and joint capacitance of a terminal capacitive pads with the IC card capacitive pads, when card is attached closely to terminal, and
the second frequency is selected to be as higher than first frequency where an equivalent impedance of IC card inductive coil is significantly large to load the series resonant circuit combined by serial alignment of joint capacitance created by mating of terminal capacitive pads with IC card capacitive pads with an additional inductance of terminal when IC card is attached closely to terminal.

2 more elements

A system for contactless energy transmission and data exchange between a host terminal and IC card, which is powered via an energy-transmitting alternating field at a different frequencies which are modulated with data signal, which system containing:

the IC card comprising first capacitive pads, diode bridge, voltage regulator with smoothing capacitor, data detector, clock conditioner and modulating means, microprocessor unit having internal memory, and wherein IC card additionally comprising inductive coil,
the host terminal comprising second capacitive pads designed to combine associated joint capacitors with corresponding first capacitive pads of IC card when last is attached closely to terminal,
additional inductor connected in series alignment with one of second capacitive pads of terminal, and additionally host terminal comprising:
antenna for power radiation and data transmission and receiving at first, lowest frequency of energy-transmitting alternating field,
wherein the inductor of host terminal combines a series resonant circuit with associated joint capacitors fabricated by mating of second capacitive pads with corresponding first capacitive pads when IC card is attached closely to host terminal,
wherein first capacitive pads of IC card combine a distributed self-capacitance,
wherein the inductive coil of IC card combines a parallel resonant circuit with distributed self-capacitance of first capacitive pads of the IC card when card is separated from host terminal, and
wherein a frequency of series resonant circuit differs from frequency of parallel resonant circuit.

5 more elements

Dependencies are inferred from the claim text.

Method and system for contactless energy transmission and data exchange between a terminal and IC card

Life of this patent

Method and system for contactless energy transmission and data exchange between a terminal and IC card

Life of this patent

Abstract

Claims7