Experimental verification of the effect of aperture shape on prompt IRA response

This article presents experimental measurements verifying the relationship between aperture shape and prompt response in an impulse radiating antenna (IRA). Various aperture configurations were realized by constructing a lens IRA with focusing aperture significantly larger than the transverse electromagnetic (TEM) feed structure and then eliminating portions of the aperture with metal blocks. Virtually any prompt response can be realized by a suitable construction. Experimental results agree well with predictions made by evaluating the aperture integral of the TEM mode distribution.