Skip to main content
. Author manuscript; available in PMC: 2021 Apr 27.
Published in final edited form as: IEEE Trans Med Imaging. 2021 Apr 1;40(4):1147–1156. doi: 10.1109/TMI.2020.3047354

Fig. 1.

Fig. 1.

Modification steps involved in converting a dipole antenna (a) to a symmetric sleeve antenna (b) then to an asymmetric sleeve antenna (c). The basic structures of a dipole and a symmetric sleeve antenna are equivalent (b). However, the sleeve antenna is an end-fed structure (b and c) while the dipole antenna is a center-fed structure (a). The sleeve portion of the sleeve antenna is a part of the antenna which acts as the ground. The architecture of the sleeve antenna leads the freedom to modify the length of the antenna part, which consists of the monopole, and sleeve portion, leading to an asymmetric sleeve antenna (c-e). Photograph (d) and schematic diagram (e) of an asymmetric sleeve antenna. The sleeve portion of the antenna is mechanically fixed in position, remains electrically floating without any direct contact to conductors of the coaxial cable.