Design and Construction of Smart Antennas to Improve the Security of Communications Links

In this paper, a smart antenna system to be used in moving platforms is proposed. The designed system detects intelligently direction of the other moving platform and communicates with it in a poin to point manner. Compared to omnidirectional transmission, poin to point communication with a high accuracy in the required direction increases the link security and signal to noise ratio (SNR) in the receiver system. The fabricated smart antenna system consists of six sectors, the performance of which is controlled by an intelligent control board. First, the primary moving platform sends a signal to all directions and the second moving platform decides about direction of primary platform, considering the strongest SNR among sectors. In the next stage, aligning operation is performed. Each sector of the proposed smart antenna supports two frequency bands of UHF and C and the implementd adaptive array type is beam-switched. Antenna elements in C and UHF-band are Patch and Rubber duck, respectively. The results show that using the proposed smart antenna in the communication link, increases the security up to 4.7 times.