Wideband Microwave Absorber based on Triangle Folded Dipole Element

In some extent, a microwave absorber can be seen as an antenna array, while the captured signal by the absorber are dissipated but not transmitted to the loading system. Therefore, to get a broadband absorber, one can make the design from an ultra-wideband antenna array. Based on a closed-form formula of the radiation impedance, the bandwidth of a classical folded dipole can be made optimally broadband, with just a few steps of manual manipulation on the frequency locus of the folded-dipole in the Smith chart. With this method, a wideband triangle folded dipole array is carried out firstly in this work. Then by replacing the excitation ports of the antenna with lumped resistors, we can get a broadband absorber with a relative bandwidth of 116% at the center frequency of 9GHz.