PERFORMANCE ANALYSIS OF SOFTWARE-DEFINED RADIO BASED RECONFIGURABLE ANTENNA ARRAY IN THE MILLIMETER WAVE WIRELESS COMMUNICATIONS

Abstract

The SDR-based reconfigurable antenna array over multiple-frequency bands and radiation patterns is very important to wireless communication. SDR components are attached to RA by using the RF front-end. This is to help the antenna to change user demands and wireless environment requirements through different configurations. In this thesis, we designed an eight element reconfigurable rectangular microstrip antenna array for millimeter-wave wireless communication, which was suitable for SDR. This was achieved by using a microstrip feed connection. The design considered the combination of frequency and radiation pattern reconfigurable antenna to improve the gain and bandwidth of the antenna. The work was important to minimize the generated interference to nearby users. The operating frequency band was Ka-band, which was 34.5-36.5GHz. This frequency was used to improve communication efficiency and high-speed broadband access. The type of Pin diode designed between antenna elements was MACOM MAAM-011275-DIE. It was very important to switch the frequency and radiation pattern in ON and OFF conditions for reconfigured purposes. The dielectric material of RT Duroid Rogers5880 with a dielectric constant (εr) of 2.2, substrate height (h) of 0.254mm, and low loss tangent tan of 0.002 was used in this research. ANSYSHFSS electronics desktop software tool was used to design a reconfigurable antenna array and simulate reconfigurable frequency and radiation patterns. The simulated reconfigurable frequency based on the operating frequency was 35.2GHz, 36.2GHz in an ON state, and 34.6244GHz, 35.0022GHz, 35.4467GHz, 35.7667GHz, and 36.4556GHz in OFF states, with good return loss and VSWR. The radiation pattern was simulated with main lobe direction and main lobe magnitude in ON and OFF states. The simulated results were -10º with 5.0196dB and 0º with 4.8810dB, respectively. Good performance analysis was obtained based on gain, bandwidth efficiency, radiation power efficiency, and energy efficiency. For this antenna, the efficiency was 97.3% (ON) and 97.4% (OFF), and the high directivity was 9.71dB (ON) and 9.65dB (OFF). Based on these parameters, an eight-element reconfigurable rectangular microstrip antenna array was presented. This is applicable for radar systems, 5G and beyond, satellite communications, wireless backhaul, research and development, point-to-point wireless links, wireless local area networks, and the Internet of Things (IoT).