Design and Analysis of Miniaturized Broadband Microstrip Patch Antenna for Aircraft Surveillance Applications

In this work, a miniaturized, broadband, coaxially fed rectangular microstrip patch antenna (MPA) is designed for the traffic alert and collision avoidance system (TCAS) application. The TCAS is a legally mandated aircraft surveillance system that is installed in all aircraft to prevent accidents. A novel structure is proposed to minimize the overall size of the conventional TCAS antenna while increasing the bandwidth (BW). Many methods, such as multiple symmetrical slits, parasitic patches, and defects on the ground structure, have been incorporated into the conventional design to achieve miniaturized broadband antenna. The proposed antenna structures are designed and simulated using the High-Frequency Structure Simulator (HFSS) software. For the proposed design, antenna parameters such as impedance, VSWR, BW, reflection coefficient, gain, and radiation pattern are evaluated. The conventional antenna resonates at 1.06 GHz with 31.30 MHz BW (1.07–1.04 GHz), VSWR of 1.18, and a maximum gain of 4.68 dB, whereas, the proposed TCAS antenna operates at 1.07 GHz with 75.4 MHz BW (1.1–1.03 GHz), VSWR of 1.12, and a maximum gain of 3.31 dB. In the proposed design, the antenna gain is reduced by 1.38 dB, and it is mainly due to the reduced antenna size. The proposed antenna has improved the impedance BW from 31.3 to 75.4 MHz, which is more than double the BW of a conventional antenna. Furthermore, the overall antenna size has been reduced by 30.77%, making it an excellent choice for aircraft surveillance/TCAS applications.