Tuning Interactions of Cascaded-Frequency Selective-Slot Arrays

Experimental and theoretical results are presented which consider placing a number of slotted arrays inside a halfwave dielectric, to give a high-strength material which exhibits a narrow passband transmission response. Array spacings of lambda/4 were found to be optimum for narrow bandwidths. Passband widths can also be reduced by choice of element; additionally reducing secondary responses produced by array interactions. The dielectric causes a shift of band centre between TE and TM planes for embedded biplanar arrays, while also causing passband ripple in the general case. This can be reduced by matching skins and results for a matched triple-array panel exhibit a highly selective passband response, stable over a wide range of incidence angles.