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Wimpie July 2nd 05 08:52 PM

reflectivity of wire mesh (wire screen)
 
Hello,

Wire mesh or parallel bars are often used as a replacement for solid
reflectors.

Is there any practical formula, computer program or graph for
calculating the (plane wave) reflectivity/reflection coefficient of
wire mesh (for example chicken mesh)?

I am thinking of a formula where you have to enter cell/grid size, wire
thickness and frequency.

With kind regards,

Wim Telkamp


Walter Maxwell July 2nd 05 11:27 PM


"Wimpie" wrote in message
oups.com...
Hello,

Wire mesh or parallel bars are often used as a replacement for solid
reflectors.

Is there any practical formula, computer program or graph for
calculating the (plane wave) reflectivity/reflection coefficient of
wire mesh (for example chicken mesh)?

I am thinking of a formula where you have to enter cell/grid size, wire
thickness and frequency.

With kind regards,

Wim Telkamp


If the cell dimension of the grid is 1/20 wl the grid is considered to be
effective as a continuous reflective plane. The same dimension of spacing
between parallel wires is also effective as a continuous reflector for EM waves
whose polarization is parallel with the wires.

Walt, W2DU



Bob McConnell July 3rd 05 04:15 AM

On Sat, 2 Jul 2005 18:27:22 -0400, "Walter Maxwell"
wrote:


"Wimpie" wrote in message
roups.com...
Hello,

Wire mesh or parallel bars are often used as a replacement for solid
reflectors.

Is there any practical formula, computer program or graph for
calculating the (plane wave) reflectivity/reflection coefficient of
wire mesh (for example chicken mesh)?

I am thinking of a formula where you have to enter cell/grid size, wire
thickness and frequency.

With kind regards,

Wim Telkamp


If the cell dimension of the grid is 1/20 wl the grid is considered to be
effective as a continuous reflective plane. The same dimension of spacing
between parallel wires is also effective as a continuous reflector for EM waves
whose polarization is parallel with the wires.

Walt, W2DU


I believe that when the openings in the grid are half of the
wavelength, half the signal ( -3 dB) gets through and half is
reflected. As the gaps get smaller, more signal is reflected. I've
never seen a formula for it.

Bob McConnell
N2SPP



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