A Compact Dual-band CPW-fed Slotted-ring Monopole Antenna with Circular Fractal Elements for WiMAX and C Bands Applications

Abstract

This paper presents a new compact dual-band slotted-ring monopole antenna (SRMA) with circular fractal elements (CFEs) design for WiMAX and C bands applications. Good improvements are obtained in widening the upper-frequency band of the proposed antenna and in miniaturizing its overall size. Antenna miniaturization is accomplished by employing a coplanar waveguide (CPW)-fed fractalshaped SRMA loaded at its inside and outside of the ring's peripherals by two types of CFEs, namely, CFE1 and CFE2. The dual-band capability of antenna is realized by introducing in its ring's center a circular slit to act as a key parameter for band rejection characteristic. The design procedure starts from a conventional circular monopole antenna (CMA), and evolution steps of antenna are performed until achieving the proposed CPW-fed SRMA with aforementioned features. The simulated results in terms of reflection coefficient, gain, efficiency, and radiation patterns are obtained by using CST MWS and HFSS programs. Due to the agreement between the CST and HFSS simulated results, the prototype of the antenna is fabricated on one side of an FR4 substrate with a volume of 20 × 22 × 0.8 mm 3 . Then the measured reflection coefficient is conducted, and it agrees well with the simulated counterpart. As observed from measurement, the antenna operates at two distinct bands of 3.15-3.75 GHz and 5.02-7.58 GHz that exhibits the proposed antenna to cover WiMAX, WLAN, C-, 4G LTE, 5G, and Sub-6 GHz bands. Also, the proposed antenna exhibits an acceptable gain and efficiency across the operating bands along with omnidirectional radiation pattern.