METALLIC DELAY LENSES 



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over the reflector antenna. Because electromagnetic waves passing through 

 them are slowed down or "delayed" (as in the glass lenses of optics), they are 

 called delay lenses; and since the elements in the lenses which produce the 

 delay are purely metallic, they are called metallic delay lenses. 



Fig. 1— Waveguide metallic lens having an aperture of 96 wavelengths and a useful 

 bandwidth of 5%. 



PART I— EXPERIMENTAL 



Fundamental Principles 



The artificial dielectric material which constitutes the delay lens was 

 arrived at by reproducing, on a much larger scale, those processes occurring 



