Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

How to design a embedded FM radio antenna?

Status
Not open for further replies.

stephen168

Electrical
Nov 4, 2004
6
Is it possible to design a small build in antenna for FM radio? (87.5MHz to 108MHz)
For example, patch antenna.
 
Replies continue below

Recommended for you

FM radio antennas are not necessarily tuned or optimized for the actual band they operate in. A 1/4 wave whip needs to be ~30 inches long. Many hand-held radios compromise on size for style. A patch antenna at this frequency would be the size of a suitcase.

Dielectric loading could reduce the size of a patch but would narrow the bandwidth. "F" antennas are used to reduce size for frequency bands just above the FM band (Orbcomm and aircraft).

Previous pointers found in this earlier thread may help.
thread247-75816
 
In addition, many modern FM broadcast band radios have FET front ends. The high input Z and relatively high gain of the FET RF amplifier makes lambda/4 antennas unnecessary and in high RF environments a detriment.

Unfortunately, in todays marketplace, often cheaper is better.

I am probably one of the very few people out there who would spend the extra money for an FM radio/receiver with decent selectivity and sensitivity...That's why the FM tuner in my home stereo is an ancient Sherwood monaural unit (The tuning indicator is a magic eye tube) with a home brew PLL FM MPX decoder and a home brew tunable SCA unit too...

Now that I think about it, the reason I use the old stuff might be because I'm really cheap...[ponder]

I remain,
The Old Soldering Gunslinger
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor