A wideband circularly polarized (CP) slot array with high radiation efficiency is proposed. The cavity-backed square slots are designed to achieve wideband CP radiation with a unidirectional pattern. The slotted waveguide is adopted to feed the array with high efficiency. The square slot, cavity and feeding slot in the waveguide can be viewed as a radiating element. A CP slot array can be conve...

The generalized dual series solution to the scattering of an E-polarized (E-pol) plane wave from an infinite circular cylinder having ?n infinite axial slot and enclosing an infinite concentric impedance cylinder is presented. This solufion explicitly exhibits the correct edge behavior, and it can handle cylinders that are either electrically small or large without special considerations. The a...

Microperforated panel (MPP) absorbers are promising as a basis for the next-generation of sound absorbing materials. A microperforated panel absorber is backed by an air-cavity with a rigid-back wall and its typical use is for a sound-absorbing ceiling. However, MPPs have some limitations and disadvantages: its sound absorbing mechanism is limited to a Helmholtz resonator caused by perforations...