Automated antenna trim for transmitting and receiving semiconductor devices

• US 6,806,812 B1
• Filed: 04/26/2000
• Issued: 10/19/2004
• Est. Priority Date: 04/26/2000
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Cathey, David A.
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/558,581
• Time in Patent Office: 1,637 Days
• Field of Search: 340/572.1, 340/572.2, 340/572.3, 340/572.4, 340/572.5, 340/572.7, 343/745, 343/746, 343/747, 343/748, 343/749, 343/750, 343/752, 343/751, 343/723, 343/844, 324/708, 324/605, 324/76.14, 324/76.74, 324/691, 324/707, 324/713, 324/699
• US Class Current: 340/572.7
• 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 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• 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: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• 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 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

A radio frequency communication device and methods of testing and tuning an antenna attached thereto are disclosed. A radio frequency communication device according to the present invention is disclosed comprising internal circuitry and an antenna having a plurality of antenna segments associated therewith. Each antenna segment is associated with the antenna in either series or parallel relation through at least one of a fuse and an antifuse. In testing and tuning, a comparison is made to indicate whether the antenna is too short or too long. If the antenna is too short, an antenna segment may be attached to the antenna by initiating an antifuse. If the antenna is too long, an antenna segment may be detached from the antenna by blowing a fuse. If it is indeterminate whether the antenna is too short or too long, an antenna segment may be either attached or detached, the test repeated, and the results of the repeated test compared with the prior test to determine whether the correct action was taken. If the results improved, the correct action may be repeated if needed. If the results did not improve, an opposing action may be initiated. Tuning the antenna by adjusting its length rather than adjusting the values of impedance elements coupled to the antenna reduces power consumption and heat, and simplifies tuning of antennas for high frequency applications.

Claims

1. A method of tuning an antenna of a radio frequency communication device, the method comprising:

evaluating an antenna response to at least one test signal; and

in response to an evaluation result;

if the evaluation result meets first criteria, accepting the radio frequency communication device;

if the evaluation result meets second criteria, rejecting the radio frequency communication device;

if the evaluation result meets third criteria, coupling an antenna segment to the antenna using an antifuse; and

if the evaluation result meets fourth criteria, detaching an antenna segment from the antenna using a fuse.

2. The method of claim 1, wherein accepting the radio frequency communication device occurs if the evaluation indicates the antenna meets specified criteria.

3. The method of claim 1, wherein rejecting the radio frequency communication device occurs if the evaluation indicates the antenna is too long and there is no antenna segment coupled to the antenna through a fuse.

4. The method of claim 1, wherein rejecting the radio frequency communication device occurs if the evaluation indicates the antenna is too short and there is no antenna segment associated with the antenna through an uninitiated antifuse.

5. the method of claim 1, wherein coupling the antenna segment to the antenna occurs if the evaluation indicates the antenna is too short and there is an antenna segment associated with the antenna through an uninitiated antifuse.

6. The method of claim 1, wherein coupling the antenna segment to the antenna occurs if the evaluation is indeterminate as to whether the antenna is too short, too long, or meets specified criteria.

7. The method of claim 6, further comprising:

re-evaluating the antenna response with the coupled antenna segment in response to at least another test signal;

comparing a re-evaluation response with the evaluated antenna response; and

doing one of;

accepting the radio frequency communication device;

rejecting the radio frequency communication device;

coupling an antenna segment to the antenna if the comparison indicates that the re-evaluation response improved but the antenna response is still not within the specified criteria; and

detaching an antenna segment from the antenna if the comparison indicates that the re-evaluation response did not improve.

8. The method of claim 1, wherein detaching the antenna segment from the antenna occurs if the evaluation indicates the antenna is too long and there is an antenna segment coupled to the antenna through a fuse.

9. The method of claim 1, wherein detaching the antenna segment from the antenna occurs if the evaluation is indeterminate as to whether the antenna is too short, too long, or meets specified criteria.

10. The method of claim 9, further comprising:

re-evaluating the antenna with a coupled antenna segment in response to at least another test signal;

comparing a re-evaluation response with the evaluated antenna response; and

doing one of;

accepting the radio frequency communication device;

rejecting the radio frequency communication device;

coupling an antenna segment to the antenna if the comparison indicates that the re-evaluation response did not improve; and

detaching an antenna segment from the antenna if the comparison indicates that the re-evaluation response improved but the antenna response is still not within the specified criteria.

11. The method of claim 1, further comprising evaluating an antenna response to at least another test signal if the evaluation of the antenna response to the at least one test signal did not indicate that the radio frequency communication device was accepted or rejected.

12. The method of claim 11, further comprising, in response to an evaluation result from the evaluation of the antenna response to the at least another test signal, doing one of:

accepting the radio frequency communication device;

rejecting the radio frequency communication device;

coupling an antenna segment to the antenna; and

detaching an antenna segment from the antenna.

13. A method of testing a radio frequency communication device, the method comprising:

comparing at least one characteristic of an antenna response to at least one test signal with at least one specification value; and

responsive to the comparison, initiating a fuse blow sequence to detach an antenna segment associated with an antenna if the comparison yields a first criteria, and initiating an antifuse initiation sequence to attach an antenna segment associated with the antenna if the comparison yields a second criteria.

14. The method of claim 13, further comprising accepting the radio frequency communication device if the comparison indicates that the at least one characteristic is within an acceptable variance from the at least one specification value.

15. The method of claim 13, further comprising rejecting the radio frequency communication device if the comparison indicates that the at least one characteristic is not within an acceptable variance and an appropriate adjustment to a length of the antenna is unavailable.

16. The method of claim 13, wherein if the comparison does not indicate whether the at least one characteristic is within an acceptable variance of the at least one specification value, after initiating one of the fuse blow sequence and the antifuse initiation sequence, the step of comparing at least one characteristic of an antenna response to at least one test signal with at least one specification value is repeated, a result of a repeated comparison is compared with a result of a first comparison, and a determination is made as to whether the result of a second comparison is better than the result of a first comparison.

17. The method of claim 16, further comprising, if the result of a second comparison is better than the result of a first comparison, initiating another fuse blow sequence if the fuse blow sequence was initiated in response to a first comparison, and initiating another antifuse initiation sequence if the antifuse initiation sequence was initiated in response to a first comparison.

18. The method of claim 13, further comprising, if the at least one characteristic was not within an acceptable variance of the at least one specification value:

comparing the at least one characteristic of the antenna response to at least another test signal with at least one specification value; and

again initiating one of the fuse blow sequence to attach and the antifuse initiation sequence to detach an antenna segment associated with the antenna in response to the comparing the at least one characteristic of the antenna response to the at least another test signal.