Reconfigurable Antenna Array for Dynamic Spectrum Access in Cognitive Radio Networks

Abstract

Cognitive Radio Networks (CRNs) have come up as a good way to fix the problem of not using all of the available radio frequencies by letting devices use unused parts of the spectrum when needed. A critical enabler for the effectiveness of CRNs is the use of antennas that can change how they send and receive signals on the fly, helping the network adjust to different frequencies as they come up during use. This paper shows how a simple setup made with four PIN diode-controlled antennas can be tested and checked using computer simulations and practical tests, and how it can be used to steer signals in different directions and to change frequencies in real time. The proposed system is set up to find spaces in the spectrum, check how the main users are using the airwaves, and swap antenna setups on its own so that other users can use the airwaves more efficiently. The reconfigurable array can work on three different frequencies (2.4 GHz, 3.5 GHz, and 5.8 GHz) and also let the device point its signals to different directions, thanks to a smart control system that manages how the device uses the spectrum. Full-wave simulations in CST Microwave Studio and cognitive radio behavior modeling in MATLAB show that the system really helps increase how much spectrum is used, cuts down on unwanted interference, and makes the wireless link more stable. These findings show that this antenna system could really work well for real-world CRN uses and other smart wireless communications in the future.