Rapid technological developments demand compact, lightweight, and high-performance wireless communication components, necessitating efforts to optimize multiband antenna technology that ensures affordable access across a wide range of modern applications. Multiband antennas can operate at several different frequencies in a variety of applications, reducing the number of antennas used, saving space and costs. This study compares five models of microstrip Log-Periodic Antenna (LPA) using modified rectangular geometry, namely model 1 (U-shaped), model 2 (S-shaped), model 3 (O-shaped), model 4 (full rectangle), and model 5 (rhombus-shaped). The five antennas were constructed with identical substrate dimensions, differing just in the configuration of the patch radiator, and were simulated using a full-wave electromagnetic solver (CST Studio Suite) at a frequency range of 3-11 GHz, utilizing a dual- layer Rogers RO4003C substrate to enhance radiation efficiency and stability. Analysis is carried out on parameters such as return loss, surface current, radiation pattern, and directivity. Antenna models 1 to 5 produce 4,7,5,5, and 8 different Multiband frequencies. Model 5 provides eight resonance frequencies at 2.4, 3.0, 3.7, 5.7, 7.6, 10.0, 10.5, and 10.9 GHz, with a minimum reflection coefficient of −37.86 dB at 5.7 GHz and a peak directivity of 9.21 dBi at 4 GHz. Additionally, the results of measurement and simulation of the Model 5 were compared, with some fulfilling the specified criteria. The findings indicated that all five antennas are capable of functioning at multiband frequencies, rendering them appropriate for diverse communication technologies and applications such as, IoT, UAVs, radar, and others.
Fauzan et al. (Mon,) studied this question.