An antenna is a semi-metallic structure that radiates or capture propagating electromagnetic waves. Antennas are different shapes and sizes from small point to big reclector types. Generally give the shape of radiation (pattern), polarization and impedance matching.
A frequency-selective surface (FSS) is mainly periodic shaped surface which designed to reflect, transmit or absorb electromagnetic waves based on the desired frequency bands.
A ground-penetrating radar is a system designed to detect electromagnetic reflections in the soil layers. Mainly transmits wide band wave forms and collects reflected electromagnetic waves.
Imaging radar is a group of application which is used to construct one-two-three dimensional responces. Imaging radar illuminate an area and collect reflected response of scene.
