Radio Wave Propagation: Effects of Metal Objects

[barry.haworth]

Hi I wonder if anyone could advise how a radio wave would propagate around a metal object? Basically, I have a GPS antenna and due to mechanical issues the antenna is obscured by a mounting screw that sits in front of the antenna by about 2~3cm. I understand that the radio wave would become reflected/refracted/diffracted/scattered to some greater or lesser degree and is wavelength dependant. I wondered if anyone could advise how much an effect this screw would have and advise any approximations or assumptions that could be made?
Many thanks

 

[Simon Bridge]

Welcome to PF;

Hi I wonder if anyone could advise how a radio wave would propagate around a metal object?

Much the same way a water-wave does.

Basically, I have a GPS antenna and due to mechanical issues the antenna is obscured by a mounting screw that sits in front of the antenna by about 2~3cm. I understand that the radio wave would become reflected/refracted/diffracted/scattered to some greater or lesser degree and is wavelength dependant. I wondered if anyone could advise how much an effect this screw would have and advise any approximations or assumptions that could be made?
Many thanks

Diffraction effects are important if the screw is similar in size to the wavelength of the signal.
If the screw is large compared with the wavelength, then you get more of a shadow effect.

Unless you are very unlucky, or you've left something out, the screw should have almost no effect.

 

[barry.haworth]

Thank you for your reply Simon, very helpful!