Use a stub matching network.

Regards,

Jim KA9QHR 

-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
Of Zik Saleeba
Sent: Wednesday, June 20, 2007 6:50 PM
To: Microcontroller discussion list - Public.
Subject: [EE] Feeding a dipole

I have an RF question which has been bothering me for a while. I have a
900MHz 1W transceiver module which I'm planning to put in a model plane
for telemetry purposes. Every gram counts so rather than using an
off-the-shelf antenna I'm planning to make a dipole from conductive foil
tape stuck to the wing. I have a small amount of experience with VSWR
meters so I think I can get that part of the system working pretty well.

My problem is that the output of my transceiver is 50 ohms unbalanced
and dipoles are an inherently ~73 ohm balanced antenna. I want to
connect the transceiver to the antenna in the lowest loss way I can so
I'd prefer to avoid using a balun if at all possible. Weight is also a
consideration here.

Is it "good enough" to connect the signal and ground to the two arms of
the dipole or is there some better low-loss, low-weight way I can do
this?

Incidentally this is a for-fun project, not a hugely important
commercial application so some bodginess is fine.

Cheers,
Zik VK3MHZ
--
http://www.piclist.com PIC/SX FAQ & list archive View/change your
membership options at http://mailman.mit.edu/mailman/listinfo/piclist

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist