A major portion of 'stealth design' is to deflect the radar signal in
directions away from the transmitter [i.e. deflect the echo]. Hence, the
many flat panels on the F-117.

A secondary feature of the design is absorbent material.

A third feature is the hex filter designs in the windows/turbine
aperture etc [allow rf in but keep it from getting out].

But, your basic absorbing material is found in numerous graphite epoxies
whose composition is classified.

You may find useful information on basics by checking out 'space cloth'.
Space cloth is used for radar dummy loads and is available in Zo that
provide VSWRs from 5:1 to 1:1. At 1:1 there is no reflection.

Frank Alforo wrote:

Anybody have any info the material used on the stealth aircraft to absorb
radar signals?

Dave wrote:

A major portion of 'stealth design' is to deflect the radar signal in
directions away from the transmitter [i.e. deflect the echo]. Hence, the
many flat panels on the F-117.

A secondary feature of the design is absorbent material.

A third feature is the hex filter designs in the windows/turbine
aperture etc [allow rf in but keep it from getting out].

But, your basic absorbing material is found in numerous graphite epoxies
whose composition is classified.

You may find useful information on basics by checking out 'space cloth'.
Space cloth is used for radar dummy loads and is available in Zo that
provide VSWRs from 5:1 to 1:1. At 1:1 there is no reflection.

I read somewhere that the absorbant material had an impedance of 377 ohm per
square. J Kraus showed that space cloth of this impedance reflects 30
percent of the incident wave.
Is space cloth still manufactured? A google search turned up zero hits.

Tnx es 73, Frank

Frank Alforo wrote:

SNIP

I read somewhere that the absorbant material had an impedance of 377 ohm per
square. J Kraus showed that space cloth of this impedance reflects 30
percent of the incident wave.
Is space cloth still manufactured? A google search turned up zero hits.

Tnx es 73, Frank


I last purchased 'space cloth' [122 ohm/square] in 1990. I don't know if
it's still manufactured.

W1MCE

Frank Alforo wrote:
"J. Kraus shower that space cloth of this impedance reflects 30 percent
of the incident wave."

There must be an impedance discontinuity. Not 377 ohms?

Kraus said sheets of space cloth backed by a reflecting plate are
sandwiched between plastic layers. Kraus has an appendix "D" on
absorbers.

Searching on "Salisbury screens" got me 4578 hits.

Best regards, Richard Harrison, KB5WZI