Miniaturizing a VHF antenna
I'm trying to design an antenna in VHF band to receive NOAA's images. The center frequency is 137.5 MHz and I need to make an small antenna. I think that a printed antenna is the best choice, so I searched some information and I found some type of antennas, like meander-line and spiral antennas,which can work in that band. Do you know other technologies to make the antenna? If you have some information about the antenna it'd be nice. I need to make it planar, that's the most important requirement.
Thanks.
Hi,
An important starting point will be to first chose the antenna type for your design. Printed monopole antennas are widely used in the 700 MHz + range which are then miniaturized by shaping, reactive element loading, use of novel materials etc. Other antennas like slot antenna and patches with defect in grounds are also used where slots/defect in ground plane are used for miniaturization. I have seen most of these designs in 700 MHz to 5.8 GHz range but I think the same concept should work for lower frequencies in VHF bands.
I suggest you to read the book 'Small Antennas : Miniaturization Techniques & Applications' by Volakis. You should also look into the papers of Dr. Richard Ziolkowski in which he has used metamaterial inspired techniques to design small antennas for VHF bands.
Here is the link ;
http://www2.engr.arizona.edu/~ziolko...0Antennas.html