📄 578.htm
字号:
<html> <head> <title>RFID-Bulletin Board: Re: 13.56 MHZ antenna , Reinier Gerritsen at 7/20/2002 13:25</title> <!-- Anfang Header --><!-- Ende Header --> </head> <BODY BGCOLOR="#fffcf4"><!-- Anfang BeitragsseitenKopf --><!-- Ende BeitragsseitenKopf --><!-- AnfangBanner --><!-- EndeBanner --> <blockquote> <center> <h1>Re: 13.56 MHZ antenna </h1> </center><!-- Anfang BeitragsNavigationsLeisteOben --><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><center><P><B>[ <a href="../index.htm">RFID-Bulletin Board</a> ]</B></P></center><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><!-- Ende BeitragsNavigationsLeisteOben --><p>Written by <a href="mailto:r.gerritsen@IDcircuits.com">Reinier Gerritsen</a> at 20 Jul 2002 13:25:38:<p>As an answer to: <a href="577.htm">13.56 MHZ antenna </a> written by amin at 20 Jul 2002 12:25:04:<p>>Dear Sirs,<br>>Could anybody help me on micro strip antenna ( 13.56 MHZ ):<br>>1- why antenna coil surrounded with two metal ground plain ? does this ground plain destroy coil feild ?<br>>2- why and how should we use magnetic ferrit in antenna ?<br>>regards<p>I don't know understand your first question. In general, you should make a loop antenna with one or a few turns. This loop is resonated with a capacitor. There should be no ground plane under the loop antenna because the current in the loop antenna induces an equal current in the ground plane and the effect is that they cancel each other. That is the same principle as a shielded box. There are some good application notes available from Texas Instruments (Tag-it, www.ti.com). You could also look for Atmel, Microchip or Philips (I-code). These application notes tell you how to make antennas.<br>As far as I know, ferrite antennas are not used, though you may need a ferrite core to do impedance matching. I could help you, but not for free.<br>Success,<br>Reinier<br><ul><li><a href="http://www.IDcircuits.com" target=_top>RFID and Electronics</a></ul><br><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><form method=POST action="../wwwforum.cgi?formular"><input type=hidden name="followup" value="577,578"><input type=hidden name="origname" value="Reinier Gerritsen"><input type=hidden name="origemail" value="r.gerritsen@IDcircuits.com"><input type=hidden name="origsubject" value="Re: 13.56 MHZ antenna "><input type=hidden name="origdate" value="20 Jul 2002 13:25:38"><input type=hidden name="subject" value="Re: 13.56 MHZ antenna "><input type="submit" name="abschicken" value="Write an answer"> <br><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><p><a name="followups"><B>List of answers:</B></a><br><ul><!--insert: 578--></ul><!--end: 578--><!-- Anfang BeitragsNavigationsLeisteUnten --><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><center><P><B>[ <a href="../index.htm">RFID-Bulletin Board</a> ]</B></P></center><!-- AnfangLinie --><center><p><HR></p></center><!-- EndeLinie --><!-- Ende BeitragsNavigationsLeisteUnten --></blockquote> <!-- Anfang BeitragsseitenFuss --><!-- Ende BeitragsseitenFuss --></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -