Broadband transmitting antenna for test chamber

Claim 1

A broadband transmitting antenna adapted for electromagnetic interference testing of objects within a test chamber of physical dimensions smaller than the quarter-wavelength of the longest wave signal transmitted, the antenna comprising, in combination: first conducting means associated with the floor of said test chamber and effective to establish a ground plane thereat; and second conducting means comprising a plurality of tuned quarter-wavelength monopole antenna elements of progressively decreasing length, said elements being joined at one end in a common feed point and fanning out in a triangular array suspended above and in a plane substantially parallel to the first conducting means, whereby said antenna operates as a tuned quarter-wavelength array for transmitted electromagnetic signals having quarter-wavelengths no longer than the longest monopole antenna element and further operates as a capacitive antenna device in the volume between the first and second conducting means by generating a varying electric field therein having components with quarter-wavelengths longer than the longest monopole antenna element.