Replacing omni antennas with directional patch

[Bandit]

Has anyone tried to replace the omnidirectional antenna with a simple patch antenna to increase the power transmitted in any one direction? This would be useful in a room or to target the area to jam. A different antenna would be required for each band of interest as microstrip patch antennas are quite narrowband.

[nova]

you can make a patch antenna with fr4 board, but you need to calculate dimensions based on center frequency( lots of calculation!!!!). I wonder if a yagi antenna would work also for what you are trying to do?

I hope this helps!

[Bandit]

I know how to make the patch, I was just curious to see if anyone has tried it with a directional antenna to see how much the effective range of the wave bubble is. A yagi should provide more gain but at the expense of size. If I design a patch Ill do a back of the envelope calculation and then use a program like CST to simulate, and optimise it. When I get round to it Ill post the details.

[nova]

the directional antenna idea you are trying is similar to a cell phone tower antenna. they are directional too.
it would be hard to prevent cell phones in all directions around you from working. only the cell phones in the antennas patch will be affected. also the antennas in cell phone towers are pcb antenna with low VSWR and high gain.

I hope this helps.

[amigomaxwell]

Can't wait to try my Yagi-Uda microstrip antenna with the Wave Bubble !

[Bandit]

AmigoMaxwell, have you simulated that antenna to get radiation patterns? Id be interested to see how well it works. Im gonna make a patch antenna, but try to make it as compact as possible. Also will try to make it work well at 900 and 1800 MHz since 1800Mhz should be the 2nd resonance if 900 MHz is the fundamental mode of the antenna. The patterns will be different but it should still work (will have to be careful with the matching though).

[whitey]

I'd definitely be interested to see the results of your work. I'm a relative newb to this. I've built a simple cantenna for my wifi and I was thinking about the same thing for the wavebubble. It'd be great if an experienced individual does this and shares the details. It's kind of hard juggling school with my hobbies

[amigomaxwell]

Hi guys, sure, no prob ! I'll post them as soon as I have some time to dive into the deeps of my hard disks ! (I designed those antennas a long time ago... )

[amigomaxwell]

AmigoMaxwell, have you simulated that antenna to get radiation patterns? Id be interested to see how well it works. Im gonna make a patch antenna, but try to make it as compact as possible. Also will try to make it work well at 900 and 1800 MHz since 1800Mhz should be the 2nd resonance if 900 MHz is the fundamental mode of the antenna. The patterns will be different but it should still work (will have to be careful with the matching though).

Bandit, the problem with this will be that the antenna will take a big dimension due to the frequency scaling. The antenna I designed was about 20cm long @ 2.4GHz. Or either you will have to use a PCB with a very high dielectric constant (I used standard FR4 substrate)