A Broadband Radiator and Absorber Based on Tightly Coupled Array

A novel broadband radiator and absorber based on tightly coupled principle is presented. The proposed structure uses orthogonal dipoles and can get a wide operating bandwidth as radiator and absorber. When the tightly coupled dipole is excited, the structure becomes a radiator with a 3.7:1 bandwidth of VSWR<2; when the dipole isn't excited and is loaded with resistors, it becomes an absorber which is polarization insensitive and has a 4:1 absorbing bandwidth of Sii<-10 dB. What's more, the height of the whole structure's profile is 0.086 AL with 2L being the largest wavelength at the operating bandwidth.