Research Article

Rectangular Ring Antenna Excited by Circular Disc Monopole for WiMAX System

Figure 4

The resonant frequency relative to for various ( = 7.20 cm, = 2.60 cm, and = 2.40 cm).
(a) The minimum frequency of resonance at 2.3 GHz by varying
(b) The maximum frequency of resonance at 2.3 GHz by varying