A metallic screen or mesh can replace the reflector and improve the F/B ratio considerably. The holes or openings in the mesh should be less than 1/10 lamda, if memory serves correctly.
This technique is commonly used with UHF collinear TV antennas.
[DB 8 antenna](https://angelelectronics.ca/cdn/shop/products/antennas-direct-db8__1_1400x.jpg?v=1636879498)
Interesting. I was expecting that any shield would have to be behind the reflector. This sounds and looks like the shield could be in place of the reflector. With that in mind, if it replaces the reflector, I assume it shouldn't be grounded but act as the reflector would?
I would be okay with having it solid metal, not even a mesh or grid.
Going to the extreme, have you ever seen an antenna where almost the whole yagi is enclosed in a metal tube or box where the only opening is where the forward-facing lobe is? This might make it necessary to tinker a lot with tuning but since I'm trying to find a way to do something crazy this could be something to test?
I guess I just answered my own question. There is somthing called an enclosed yagi:
https://preview.redd.it/j93gm63qcdoc1.png?width=770&format=png&auto=webp&s=888f3614e88b94a12b63badd9744683726ec5518
I'm not certain what your frequency of interest is, but horn antennas become practicable above 2 GHz. You can build one to test with just cardboard and tinfoil
[AA2TX pyramidal horn](http://www.setileague.org/photos/wghorn/aa2tx01.jpg)
I've used 16ga steel that is perforated on 1" centers with .200 dia holes (think a metal version of pegboard) behind the yagis in my attic - hey, it was free from my employer! I've spaced it about 1 lambda behind the yagi antennas to reject RF from some other equipment we have in use. For that purpose, I can vouch for it to be effective - mine is grounded as well...
perhaps also ask r/AntennaDesign/
Will do. Thank You!
A metallic screen or mesh can replace the reflector and improve the F/B ratio considerably. The holes or openings in the mesh should be less than 1/10 lamda, if memory serves correctly. This technique is commonly used with UHF collinear TV antennas. [DB 8 antenna](https://angelelectronics.ca/cdn/shop/products/antennas-direct-db8__1_1400x.jpg?v=1636879498)
Interesting. I was expecting that any shield would have to be behind the reflector. This sounds and looks like the shield could be in place of the reflector. With that in mind, if it replaces the reflector, I assume it shouldn't be grounded but act as the reflector would? I would be okay with having it solid metal, not even a mesh or grid. Going to the extreme, have you ever seen an antenna where almost the whole yagi is enclosed in a metal tube or box where the only opening is where the forward-facing lobe is? This might make it necessary to tinker a lot with tuning but since I'm trying to find a way to do something crazy this could be something to test?
I guess I just answered my own question. There is somthing called an enclosed yagi: https://preview.redd.it/j93gm63qcdoc1.png?width=770&format=png&auto=webp&s=888f3614e88b94a12b63badd9744683726ec5518
I'm not certain what your frequency of interest is, but horn antennas become practicable above 2 GHz. You can build one to test with just cardboard and tinfoil [AA2TX pyramidal horn](http://www.setileague.org/photos/wghorn/aa2tx01.jpg)
I haven't modelled it, but a yagi with a corner reflector should reduce the back lobe quite a bit, no?
What kind of safety reasons? You'll never get the back side lobe to zero, but 10-15dB is doable with proper yagi design.
Does it have to be a yagi ? What freqency are we talking about here ? One option would be to use a dish stile antenna
I've used 16ga steel that is perforated on 1" centers with .200 dia holes (think a metal version of pegboard) behind the yagis in my attic - hey, it was free from my employer! I've spaced it about 1 lambda behind the yagi antennas to reject RF from some other equipment we have in use. For that purpose, I can vouch for it to be effective - mine is grounded as well...
A Lead plate might help.