Wireless tag, its manufacturing and its layout

• US 6,795,025 B2
• Filed: 03/14/2003
• Issued: 09/21/2004
• Est. Priority Date: 05/24/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Saito, Takeshi
• Primary Examiner(s): Chen, Shih-Chao
• Application Number:
  US10/387,376
• Publication Number:
  US 20030169204A1
• Time in Patent Office: 557 Days
• Field of Search: 343/700.MS, 343/829, 343/830, 343/848, 343/846, 343/905
• US Class Current: 343/700.0MS
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00
• 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 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

To provide a wireless tag having a wide band, a microstrip-line of a half wavelength type is used and an IC is built in between an antenna and a ground conductor, and a middle point of the antenna and the ground conductor are connected.

Claims

1. A wireless tag comprising:

an antenna;

a logic circuit;

a memory circuit;

a transmitter and receiver for rectifying a signal from said antenna and supplying an electric power to the logic circuit and the memory circuit through an electric power line; and

an LED, the LED being coupled between the electric power line and a around in the forward direction,

wherein the LED prevents a voltage formed by the transmitter and receiver from exceeding a voltage limit of the logic circuit and the memory circuit when a distance between the antenna and a source of the signal is small.

2. The wireless tag according to claim 1,

wherein the transmitter and receiver, the logic circuit and the memory circuit are constituted by a single chip.

3. The wireless tag according to claim 1, wherein the transmitter and receiver comprise a rectifying circuit, the rectifying circuit being coupled between the electric power line and a ground.

4. The wireless tag according to claim 1, wherein the LED dissipates the supply voltage by a light emission when a voltage between the electric power line and ground excesses a predetermined voltage.

5. The wireless tag according to claim 4, wherein the predetermined voltage is a withstand voltage of the logic circuit.

6. The wireless tag according to claim 1, further comprising:

a dielectric member;

a ground conductor;

wherein the dielectric member is disposed between the antenna and the ground conductor;

the middle point of the antenna is connected to the ground conductor;

the LED is arranged on a side of the antenna; and

a side of the ground conductor is used as a contacting face to an article when the wireless tag is arranged to the article.

7. A wireless tag comprising:

an antenna;

a logic circuit;

a memory circuit; and

a transmitter and receiver for rectifying a signal from said antenna and supplying an electric power to the logic circuit and the memory circuit;

an LED;

wherein said LED is driven by a modulated signal from the logic circuit and transmits an optically modulated signal to an interrogator.

8. A wireless tag comprising:

an antenna;

a logic circuit;

a memory circuit; and

a transmitter and receiver for rectifying a signal from said antenna and supplying an electric power to the logic circuit and the memory circuit;

an LED;

wherein said LED is driven by a signal from the logic circuit and transmits an optically modulated signal to an interrogator.