No abstract

− This paper presents the design of a single layer, compact, tapered balun with a >20:1 bandwidth and less than / in length at the lowest frequency of operation. The balun operates from 0.7GHz to over 15GHz. It can provide both impedance transformation as well as a balanced feed for tightly coupled arrays. Its performance is compared with that of a full-length balun operating over the same frequency band. There is a high degree of agreement between the two baluns.

A wide bandwidth, ultra-thin, metasurface is reported that facilitates wide angle beam scanning. Each unit cell of the metasurface contains a multi-resonant, strongly-coupled unequal arm Jerusalem cross element. This element consists of two bent-arm, orthogonal, capacitively loaded strips. The wide bandwidth of the metasurface is achieved by taking advantage of the strong coupling within and between its multi-resonant elements. A prototype of the proposed metasurface has been fabricated and measured. The design concept has been validated by the measured results. The proposed metasurface is able to alleviate the well-known problem of impedance mismatch caused by mutual coupling when the main beam of an array is scanned. In order to validate the wideband and wide scanning ability of the proposed metasurface, it is integrated with a wideband antenna array as a wide angle impedance matching element. The metasurface-array combination facilitates wide angle scanning over a 6:1 impedance bandwidth without the need for bulky dielectrics or multi-layered structures.

No abstract

A wide bandwidth, low profile, double sided, wide angle impedance matching metasurface is reported. It alleviates the well-known problem of impedance mismatch caused by mutual coupling when an array is in its scan mode. Each unit cell of the metasurface contains two multi-resonant, tightly-coupled unequal arm Jerusalem cross elements on the top and bottom sides of a thin substrate. Each element consists of two orthogonal capacitively loaded strips. The wide bandwidth of the metasurface is achieved by tightly coupling these multi-resonant elements. The metasurface is capable of facilitating wide angle scanning over a 6:1 impedance bandwidth without the need for bulky dielectrics or multilayered structures.