Hybrid Mode Reconfigurable Antenna with V-Shaped Extrudes for Cognitive Radio Applications

Abstract

As the same device may be used for various types of applications, antennas must have the capacity to perform multiple functions. Reconfiguring the polarization, operational frequency, and radiation pattern can create an outcome of multi-functionality. A hybrid, frequency- and pattern-reconfigurable antenna with two V-shaped extrudes in a patch is proposed. To increase the bandwidth of the proposed antenna, the defected ground structure (DGS) phenomenon is presented, which is significant in the bandwidth of 3200 MHz from 2.7 GHz to 5.9 GHz, providing a gain of 3.5 dB. For this design, an FR-4 material was chosen as the substrate, and CST software was used for simulation. Using two p-i-n diodes, the projected antenna illustrates switching for multi-frequency bands such as 1.5, 2.6, 3.2, 5.1, and 8.1 GHz, with a constant radiation pattern and a main lobe direction of 155 degrees. It has C-band, WLAN, cognitive radio (CR), and Bluetooth applications. The proposed antenna displays radiation pattern switching at 3.5 GHz, showing variation between 7°, 158°, 173°, and 175°, and at 4 GHz, it demonstrates switching between 11°, 15°, 165°, and 344°, which defines the hybrid reconfiguration.