Radio IC device

• US 9,077,067 B2
• Filed: 12/30/2010
• Issued: 07/07/2015
• Est. Priority Date: 07/04/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ikemoto, Nobuo
• Primary Examiner(s): ALAM, MIRZA F
• Application Number:
  US12/981,582
• Publication Number:
  US 20110090058A1
• Time in Patent Office: 1,650 Days
• Field of Search: 340/10.1, 340/572.7, 340/572.5, 340/539.23, 340/547, 340/572.1, 340/568.1, 340/10.4, 340/10.51, 340/5.8, 340/539.21, 340/572.4, 343/855, 343/857, 343/866, 343/700, 343/873, 343/895, 343/853, 343/867, 343/728, 343/751, 235/492, 235/441, 235/451, 235/380, 235/487, 235/449, 235/493, 310/365
• US Class Current: 1/1
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• 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: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: G06K 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• 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 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A radio IC device that can be used in a plurality of frequency bands for RFID tags and that is compact and has superior radiation characteristics is provided. A spiral line electrode portion and a first side electrode, extending from an inner end thereof, of a capacitor electrode portion are provided on a top surface of a sheet-shaped substrate, and a second side electrode arranged to face the first side electrode and a crossing line electrode are provided on a bottom surface of the substrate. A first radio IC chip is arranged at a location in the line electrode portion, and a second RFID tag radio IC is arranged so as to be connected to a front-to-back connection portion and an end of an electric-field radiation electrode portion. The radio IC chip rectifies an RF signal in a first frequency band and outputs and supplies power to the second RFID tag radio IC.

Claims

1. A radio IC device comprising:

a first radiation electrode;

a second radiation electrode;

a first radio IC electrically connected or electromagnetically coupled to the first radiation electrode and arranged to receive a first RF signal through the first radiation electrode; and

a second radio IC electrically connected or electromagnetically coupled to both of the first and second radiation electrodes and arranged to transmit and receive a second RF signal through both of the first radiation electrode and the second radiation electrode;

wherein

a first frequency band of the first RF signal is different from a second frequency band of the second RF signal;

the first radio IC includes a circuit arranged to rectify the first RF signal and to supply power to the second radio IC to transmit and receive the second RF signal; and

the first frequency band is lower than the second frequency band, and the first radiation electrode includes a magnetic-field radiation electrode portion having a resonant frequency lower than the second frequency band and arranged to function as a magnetic-field radiation electrode for the first RF signal.

2. The radio IC device according to claim 1, wherein the first radio IC and the second radio IC are disposed in a common package.

3. The radio IC device according to claim 1, wherein the magnetic-field radiation electrode portion is arranged to receive the first RF signal and to transmit and receive the second RF signal.

4. The radio IC device according to claim 1, wherein the resonant frequency of the first radiation electrode is lower than the second frequency band.

5. The radio IC device according to claim 1, wherein the magnetic-field radiation electrode portion includes a line electrode and capacitor electrodes defining a capacitor between ends of the line electrode.

6. The radio IC device according to claim 5, wherein the capacitor electrodes include a first side electrode and a second side electrode arranged opposite to each other with a dielectric layer there between in a thickness direction, the line electrode includes a spiral portion extending spirally around the capacitor electrodes, the first side electrode is electrically connected to an inner end of the spiral portion of the line electrode, and a crossing line electrode is arranged so as to connect an outer end of the spiral portion of the line electrode and the second side electrode.

7. The radio IC device according to claim 6, wherein the line electrode includes an electrode-removed region, the first radio IC is arranged so as to be connected between ends of the line electrode in the electrode-removed region, and the second radio IC is arranged so as to be connected to the crossing line electrode near the outer end of the line electrode.

8. The radio IC device according to claim 1, wherein a pair of the magnetic-field radiation electrode portions are provided, and the first and second radio ICs are electrically connected or electromagnetically coupled to the pair of magnetic-field radiation electrode portions.

9. The radio IC device according to claim 1, wherein the second radiation electrode includes an electric-field radiation electrode portion paired with the magnetic-field radiation electrode portion to define an equivalent dipole antenna together with the magnetic-field radiation electrode portion, and the second radio IC is electrically connected or magnetically coupled to the magnetic-field radiation electrode portion and the electric-field radiation electrode portion.

10. The radio IC device according to claim 9, wherein the electric-field radiation electrode portion is arranged outside a spiral portion of a line electrode.

11. The radio IC device according to claim 1, wherein each of the first radio IC and the second radio IC is electrically connected to the first radiation electrode.

12. The radio IC device according to claim 1, wherein the first radio IC or the second radio IC is an electromagnetic coupling module including a feed circuit board that includes a matching circuit including at least one inductor and a radio IC chip mounted on a top surface of the feed circuit board and electrically connected to the matching circuit.

13. The radio IC device according to claim 1, wherein a battery or a capacitor is provided and is arranged to accumulate power output from the first radio IC.

14. The radio IC device according to claim 1, wherein a sensor is provided;

and the first radio IC or the second radio IC includes a circuit arranged to transmit detection results from the sensor.

15. The radio IC device according to claim 1, wherein the second radio IC is electrically connected to both of the first and second radiation electrodes.

16. The radio IC device according to claim 1, wherein each of the first and second radiation electrodes is a dipole element of a dipole antenna.

17. The radio IC device according to claim 16, wherein the first radiation electrode includes a magnetic-field radiation electrode portion, and the second radiation electrode includes an electric-field radiation electrode portion.