Best material to reflect for 35GHz RF

[PhysicBob]

Hello everyone.

This is my first post..

I have been given the task of building some large RF reflectors that will reflect 35GHz RF energy.

Can anyone give me an idea of what material / thickness of material I could use.

For an example.. Would a pyramid made from wooden pallets covered in tin foil do the job?

Thanks in advance..

 

[PhysicBob]

My resources are pretty limited. I have an abundance of pallets and aluminium foil..

 

[Drakkith]

Can you give us more details of your setup? What kind of RF power are we talking about here? How far from the transmitter will your reflectors be? Will you be using this reflected signal for something or do you just want to keep it away from a certain area? Etc.

 

[rootone]

Any special reason for 35GHz?
I know this frequency is used by radar, is the idea to make something which is very radar-obvious?

 

[PhysicBob]

Can you give us more details of your setup? What kind of RF power are we talking about here? How far from the transmitter will your reflectors be? Will you be using this reflected signal for something or do you just want to keep it away from a certain area? Etc.

Unfortunately no I can't say. It's an aircraft mounted radar that's about all I can say. The reflectors will be on the surface of the sea. Does that help?

 

[PhysicBob]

Any special reason for 35GHz?
I know this frequency is used by radar, is the idea to make something which is very radar-obvious?

It's a frequency agile around 35GHz. Yes that's the idea. I'm sorry I can't say much more about it.

 

[davenn]

These type of threads really annoy me
people that come here for help but cant/wont tell us what the project is all about

how do you expect the good people here to give you decent help ??

It's a frequency agile around 35GHz. Yes that's the idea. I'm sorry I can't say much more about it.

well I suggest you go to the engineers within your company that you can discuss the project withDave

 

[Nidum]

Aluminium foil in simple flat sheets does work but sometimes not very well

Traditional solution is a tethered array of Aluminium beer kegs .

Arrays of bin bags or big plastic tubs stuffed with loose foil strips work surprisingly well .

3D objects usually give better targets than flat surfaces where incident signal can come from any direction and especially for airborne radar detection .

See Skolnik - Introduction to Radar Systems . Mc.Graw - Hill

http://www.theradarreflectorsite.org/Articles/MiscellaneousReflectiveMaterials.pdf

 

[Drakkith]

3D objects usually give better targets than flat surfaces where incident signal can come from any direction and especially for airborne radar detection

Makes sense. A flat panel of aluminum foil would probably act like a mirror and just reflect the incoming signal away from the source unless it was aligned almost perfectly towards the source.

 

[berkeman]

Unfortunately no I can't say. It's an aircraft mounted radar that's about all I can say. The reflectors will be on the surface of the sea. Does that help?

Use metallic cube corners that are several wavelengths in size. Cube corners are retro-reflective, so incident RF energy will be reflected back the way it came. You can have several cube corners facing in different directions, so no matter the orientation of the target, you will get a good radar reflection back to the source.

http://www.discovercircuits.com/DAJ-Schematics/corner.gif