Top Loaded Wideband Electrically Small Antenna and Its Quality Factor Analysis

This work presents a top-loaded wideband electrically small antenna (ESA). Here a 2D metallic (PEC) strip is loaded at the top of the conventional monopole to design an electrically small antenna. The bandwidth enhancement mechanism of the proposed antenna is analyzed by considering fringing field capacitance between the ground plane of the CPW feed and radiating element. In addition, to support the effectivity of the proposed method, the lower bound Quality factor (Q.F lb ) of the proposed antenna is estimated by considering the theoretical limitations of an electrically small antenna. The overall surface area of the antenna is 0.2λ×0.15λ, where λ is the wavelength at 4.4GHz. The antenna exhibits −10 dB impedance bandwidth of 1950 MHz for the intended 5G WLAN and new radio (n79) applications. Furthermore, it offers more than 85% efficiency with an omnidirectional radiation pattern over the operating band. The achieved impedance response and radiation characteristics validate the suitability of the proposed antenna for indoor wireless applications.