Shaping of flat-topped element patterns in a planar array of circular waveguides using a multilayered disk structure. II. Experimental study and comparison

For pt.I see ibid., vol.51, no.5, p.1040-47 (2003). A symmetrical 19-element K_a band breadboard corresponding to the array considered in part I, as well as a similar X band breadboard with dipole exciters arranged in waveguides, are studied experimentally. In both breadboards the central ports are connected to microwave sources, while all the other ports are terminated with matching loads. The multilayered periodic structures placed above the waveguide apertures are composed of thin polymer films with conducting disks deposited by ion-beam. It is shown that the calculated and measured element patterns of the K_a band breadboard are in good agreement within the flat-topped main lobe. The edge effects and design elements explain some of the disagreement in the side lobe area. The measurement of the X band breadboard gives similar results, and confirms the desirable properties of the disk structures for application in limited-scan arrays.