Directional transmitting antenna?

[distendo]

I want to install a wireless CCTV camera at the end of our garden to cover the gate and various sheds, etc., with the receiver antenna poking through the eaves at the rear of the house. I'm fairly confident I can get a transmitter which will cover the 45 metres or so between Tx and Rx.
However, I don't really want to provide a TV channel featuring our back yard for anyone with a scanner or a similar receiver. Basically I was wondering if it is possible to screen the antenna to confine its output to a narrowed beam of say 10 degrees towards the house, instead of the 360 degrees broadcast it normally would produce.
I imagine that simply wrapping a tin can with a split in the side around the transmitter antenna might cause harmonic interference from internal reflections, and that a more complex screen design might work. I can find nothing about RF-absorbent materials.
So there it is, the latest crack in my pot. Anyone got any ideas about the viability of the basic idea?
Thanks!

[iStorm]

What wireless camera and reciever are you using? And on what frequency? Why not just put a cable in and have it wired? Will stop a lot of heart ache in the long run!! Believe me.

[codemonkey]

You could try using some type of YAGI antenna, if your transmitter supports that. Mainly though, as long as your system operates on a frequencey not normally used for regular TV receivers (2.4GHz or 5.8GHz), you should be fine. The only person who will be able to receive will be ones actively looking for it, and have a receiver of the right type tuned to the exact right frequency.

I agree with Iain, though. If you are really concerned with someone snooping about, hardwire the thing, and you'll be golden.

[distendo]

Thank you for the replies.
I agree about the wiring thing, and am currently installing a wired cctv system & burglar alarm in the house for precisely the reasons you give. However, the garden is about 50 metres long, and at some point I intend to run an armoured cable (and other stuff like phone/ethernet) to the other end, which is when I'll dig the trench. At this point it's just too much to contemplate to dig one specifically for a camera. Then I'm thinking of mounting the camera on a pole, so any cable would need some serious protection, and so on...
So for the time being I'm thinking of using an existing zero-lux b&w camera on a pole and feeding it into a 2.4GHz transmitter (maybe with wet-cell battery and small solar power panel to maximise recharging cycles).
The tx/rx kits you get on Ebay etc. all have those stubby aerials, and I'm not sure I'm technically up to adapting one, but now you've mentioned it, I'm looking into the yagi idea. Any recommendations about what to look for in a (cheap-ish) tx/rx set-up are welcome.
Thanks very much both for your time and attention!

[distendo]

Ok, I've looked at a lot of yagi antennas, most of which look like overkill for my application (and v expensive). But I also found this patch antenna:
TL-ANT2406A
and I'm wondering if it'd be worth buying a couple (or just one for the transmitter) and hacking the aerial off the tx and soldering this one on instead...?
Observations/corrections gladly received!

[distendo]

Moderator!
I thought this the best way to contact you...
Sorry about the multi-posting!

I just didn't see the notice about moderators viewing posts first, so kindly delete my first two attempts to post the reply outstanding (about the yagi TL-ANT2409A patch antenna) and this one, and by all means edit out the line in my third attempt about it being my 3rd attempt. Are posts with a URL in them moderated?

KRs
Harry

[brian]

Apologies for that.