Semiconductor device and position detecting method using the semiconductor device

• US 8,364,077 B2
• Filed: 04/17/2007
• Issued: 01/29/2013
• Est. Priority Date: 04/28/2006
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): Anderson, Matthew
• Assistant Examiner(s): Hanidu, Ganiyu A
• Application Number:
  US11/785,292
• Publication Number:
  US 20070252208A1
• Time in Patent Office: 2,114 Days
• Field of Search: 455/41.2, 455/41.3, 455/41.1, 340/436, 340/471, 340/475, 340/10.1
• US Class Current: 455/39
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

An object of the present invention is to solve a problem of a conventional semiconductor device in that although information such as whether the semiconductor device exists in a predetermined space and information on an ID and the like included in the semiconductor device can be obtained, a position where the semiconductor is located in the predetermined space cannot be identified. The semiconductor device includes a signal sorting portion which sorts a signal based on a signal output from the outside and a signal detecting portion for detecting the signal output from the outside. In a structure of the semiconductor device including the signal sorting portion and the signal detecting portion, a position detecting system is developed base on signals from a plurality of interrogators.

Claims

1. A semiconductor device comprising:

an antenna circuit receiving signals from a plurality of interrogators, the antenna circuit being configured to transmit a signal;

an amplifier circuit for amplifying the signal to transmit, the amplifier circuit being configured to change amplification degree;

a signal sorting portion for sorting the signals from the plurality of interrogators; and

a signal detecting portion for detecting intensity of the signals sorted by the signal sorting portion, the signal detecting portion including a rectifier circuit, an A/D conversion circuit and a central processing unit,

wherein the central processing unit is configured to calculate a distance between the semiconductor device and each of the plurality of interrogators, based on intensity of a signal output from the rectifier circuit for input to the central processing unit through the A/D conversion circuit, and

wherein the antenna circuit is configured to transmit, to the nearest interrogator to the semiconductor device among the plurality of interrogators, a signal including information on the intensity of the signals from the plurality of interrogators.

2. A semiconductor device according to claim 1, wherein the signals from the plurality of interrogators are different in frequency.

3. A semiconductor device according to claim 1,

wherein the signal sorting portion includes a frequency mixer, a bandpass filter, an oscillation circuit, and an oscillation frequency control circuit;

and

wherein signals with different frequency, which are generated in the frequency mixer based on the signals from the plurality of interrogators and a signal from the oscillation circuit, are output to the rectifier circuit through the bandpass filter, so that the signals from the plurality of interrogators are sorted.

4. A semiconductor device according to claim 1, wherein the signal detecting portion includes a demodulation circuit and a baseband signal processing circuit which are for decoding the signals from the plurality of interrogators, which are sorted by the signal sorting portion.

5. A position detecting method for detecting position information of a semiconductor device, comprising the steps of:

receiving signals from a plurality of interrogators by an antenna circuit;

sorting the signals received by the antenna circuit by a signal sorting portion;

detecting intensity of the signal sorted by the signal sorting portion by a signal detecting portion wherein the signal detecting portion includes a rectifier circuit, an A/D conversion circuit and a central processing unit;

calculating a distance between the semiconductor device and each of the plurality of interrogators, based on intensity of a signal output from the rectifier circuit for input to the central processing unit through the A/D conversion circuit,

detecting intensity of signals from the plurality of interrogators;

amplifying a signal including information on the intensity of the signals from the plurality of interrogators at amplification degree based on intensity of signal from one of the plurality of interrogators;

transmitting, to the nearest interrogator to the semiconductor device among the plurality of interrogators, the signal including information on the intensity of the signals from the plurality of interrogators.

6. A position detecting method according to claim 5, wherein the signals from the plurality of interrogators are different in frequency.

7. A position detecting method according to claim 5,

wherein the signal sorting portion includes a frequency mixer, a bandpass filter, an oscillation circuit, and an oscillation frequency control circuit;

and

wherein signals with different frequency, which are generated in the frequency mixer based on the signals from the plurality of interrogators and a signal from the oscillation circuit, are output to the rectifier circuit through the bandpass filter, so that the signals from the plurality of interrogators are sorted.

8. A position detecting method according to claim 5,

wherein the signal detecting portion includes a demodulation circuit and a baseband signal processing circuit;

and

wherein the signals from the plurality of interrogators, which are sorted by the signal sorting portion are decoded.

9. A semiconductor device comprising:

an antenna circuit;

an amplifier circuit for amplifying a signal to transmit, the amplifier circuit being configured to change amplification degree;

an oscillation circuit;

a frequency mixer configured to multiply a signal from the antenna circuit by a signal from the oscillation circuit;

a bandpass filter configured to filter a signal from the frequency mixer;

a rectifier circuit configured to rectify the signal from the frequency mixer through the bandpass filter;

an A/D conversion circuit configured to convert a voltage of the rectified signal into a digital signal;

a central processing unit configured to calculate a distance between the semiconductor device and source of a signal received by the antenna circuit, based on the digital signal; and

an oscillation frequency control circuit configured to control an oscillation frequency of the oscillation circuit,

wherein the antenna circuit is configured to transmit, to the nearest interrogator to the semiconductor device among a plurality of interrogators, a signal including information on an intensity of signals from the plurality of interrogators.