Advances in Electrical Engineering

Research Article

Design of Tunable Monopole Arm Planar Spiral Antenna for Cognitive Radio

Figure 9

Antenna surface current at (a) 1.93 GHz, (b) 2.79 GHz, (c) 3.47 GHz, and (d) 4.45 GHz.
593194.fig.009a
(a)
593194.fig.009b
(b)
593194.fig.009c
(c)
593194.fig.009d
(d)