Fig.1 (a) Geometry and configuration of proposed antenna, (b)
geometry of unit cell split ring resonator (SRR)
microstrip transmission line of length Lf=5 mm and width
Wf=3 mm which is terminated with a sub miniature version
A (SMA) connector for the measurement purpose. On the back surface of
the substrate a ground plane of dimension
(LgndxWgnd) 15x2.75
mm2 is printed. An open-ended rectangular slot is
created at the middle of the ground plane of dimension
(Lgndslotx Wgndslot) 4.5x2.5
mm2.The distance between the circular radiating
element and the ground plane is Lgr=2.25 mm. A square
shaped slot is cut at the middle of the circular radiating patch of
dimension (LslotxWslot) 7x7
mm2. A rectangular stub of dimension
(LstubxWstub) 4x5mm2is protruding down from the top middle edge of the square slot towards
the center of the square slot created in the circular radiating patch.
An open-ended square slit (slot with small thickness) ring of dimension
(LslitxWslit) 1x1 mm2is created on the top of the protruding stub. On the left side of the
feed line on the front surface of the substrate, a SRR is embedded. The
magnified version of unit cell split ring resonator (SRR) is also shown
in the figure1 (b). The dimension of the outer side of the SRR is
(LSRRxWSRR) 2x2 mm2and the dimension of the inner side is (fxe) 1x1mm2.
Both the sides are open ended. The Ansoft HFSS [25] is employed to
perform the design and optimization process of this antenna. The design
parameters are mentioned in the table I.