Binary-Coded Frequency Reconfigurable Antenna for Cognitive Radio

There is a need of antennas which can dynamically reconfigure themselves for cognitive radio (CR) application. This article illustrates an frequency reconfigurable antenna whose modes of operation follow a binary sequence. By using two positive-intrinsic-negative (PIN) diodes, electrical switching is used to toggle between the frequency bands. The possible combination of ‘
$\text{ON}=1$
’ and ‘
$\text{OFF}=0$
’ conditions of these two diodes are giving rise to 00,01,10 and 11 coded modes. These four modes covers the frequency band from 2.43 to 6.23 GHz. Ten different tunable frequencies within the above band with different modes of operation is achieved. The antenna is designed over a FR-4 substrate of thickness 1.6 mm with an overall dimension of
$10\ \text{mm}\times 17\ \text{mm}$
.