microstrip antenna - RF Cafe Forums

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Qacer
 Post subject: microstrip antenna
Posted: Wed Jan 04, 2006 7:24 pm 
 
Captain

Joined: Sat Apr 23, 2005 2:09 pm
Posts: 17
Location: Tampa, FL
I heard that microstrip antennas are only good from 100 MHz and up. What's the design limitation for lower frequencies in regards to microstrip antennas?
 
   
 
Kirt Blattenberger
 Post subject:
Posted: Thu Jan 05, 2006 8:04 pm 
 
Site Admin
User avatar

Joined: Sun Aug 03, 2003 2:02 pm
Posts: 308
Location: Erie, PA
Greetings Qacer:

The frequency limit is governed by the wavelength of your signal(s) in the substrate. A wavelength calculator is available here. Enter your frequency of interest and the dielectric constant of the substrate.

For example, FR4 has a dielectric constant of around 4.5, so the wavelength of 100 MHz in it is about 1.4 meters (55 inches). If you want to implement any passive circuitry that requires a wavelength shift along the line (as is necessary for filters, power splitters, baluns, etc.), very large substrate would be required.

If all you need is a substrate to implement 50 ohm (or other another impedance) transmission lines to interconnect components, then microstrip can be used at any frequency.

_________________
- Kirt Blattenberger :smt024
RF Cafe Progenitor & Webmaster
 
   
 
new
 Post subject:
Posted: Tue Jan 24, 2006 9:55 am 
an introduction on microstip antenna:

http://www.4shared.com/file/742081/ae5d ... strip.html
 
  
 
Qacer_1
 Post subject:
Posted: Tue Jan 24, 2006 12:17 pm 
Thank you all!



Posted  11/12/2012