ABSTRACT

Antennas play a dominant role part in the transmission and reception of signals in wireless communication, and their development make a significant impact on the speed of a wireless link. Microstrip antennas are the most common antennas widely implemented in different communication systems due to its small size, low profile, and conformity to planar and non-planar surfaces. However, the inherent characteristics of a conventional microstrip antenna, like low gain, narrow bandwidth and wider beamwidth, limits their wide applications and makes it necessary for designs to have array configuration. In this research work, the design and simulation of microstrip patch array antenna for improving signal reception in wireless communication systems is presented. The application is for X-band frequency range of 8-12GHz. All designs and simulations were carried out using HFSS (v.15) software. The design procedure started with the design of a single element Rectangular Microstrip Patch Antenna (RMPA), and then the linear RMPA array designs of 1x2 array (2-elements), 2x2 array (4-elements) and 4x2 array (8-elements) configurations. The proposed RMPA design used an operating frequency of 10GHz, a Rogers RO4350 substrate material with dielectric constant of 3.66, and a substrate height of 31mil, to achieve a compact RMPA with a patch size small enough to fit onboard an aerial system. The patch dimensions were calculated using the transmission line model and excited using inset-fed microstrip line feeding method. The feeder networks for the array designs used a corporate feeding network, with an optimized inter-element spacing of 0.52λ. Antenna parameters such as return losses, VSWR, gain etc. of the designed antennas were obtained from HFSS software. The performance parametric results of the designed antennas were compared in terms of the stimulated antenna parameters. Based on the simulation results, all the designed antennas resonated at the desired resonant frequency of 10GHz which indicates good antenna designs. The simulation results of the single element RMPA achieved a good return loss of -19.61dB at 10GHz, with a narrow bandwidth of 2.26%, VSWR of 1.82, low gain and directivity of 6.58dBi and 6.83dBi respectively, wide beamwidth of 115.2^o and an efficiency of 94.2%, while the final 4x2 array RMPA achieved an improved return loss of -28.96dB, wider bandwidth of 5.82%, VSWR of 1.14, significant high gain and directivity of 11.45dBi and 11.83dBi respectively, narrow beamwidth of 47.4^o and high radiation efficiency of 91.6%. Thus, the proposed 4x2 array RMPA significantly increased the narrow bandwidth of the single element antenna by 157.1% (355.4 MHz), and greatly improved the gain of the single element RMPA by 74.0%. These results show that the proposed 4x2 array RMPA has an improved performance over the single element RMPA, and meets the main objective of improving signal reception for the X-band application in a wireless communication system. The designed antennas can be embedded in wireless devices for commercial WLAN and WiMAX applications and also for onboarding in radar and satellite wireless communication systems for various surveillance and communication purposes.