In this paper, theoretical and experimental study on cylindrical dielectric resonator antenna (CDRA) made of CCTO material is reported. The CDRA with high dielectric constant ( = 55) is fed with aperture coupled 50 ς microstrip transmission line. The mode of CDRA is excited to operate at 5.15-5.35 GHz for wireless local area network (WLAN) application. The electrical model of the aperture coupled CDRA is built to verify the antenna feasibility. The validity of the electrical model is confirmed by comparing the values of the return losses obtained through an electrical model using Agilent Advanced Design System (ADS) against those obtained through antenna geometry using computer simulation technology (CST) and fabricated prototype. Keywords-Cylindrical dielectric resonator (CDRA); microstrip line; electrical model. I.INTRODUCTION With the advent of small size modern communication devices, a small size high gain antenna becomes the requirement of communication industry. Dielectric resonator antenna (DRA) is the best alternative of microstrip patch antenna technology at millimetre wave frequencies. DRA attained the attraction of researchers and communication industry due to its many attractive features. Dielectric resonator (DR) possesses low conductor and surface wave losses at millimetre wave frequencies as compared to patch antennas [1], can be fabricated into different shapes [2], high efficiency (> 95%) [3], can cover the frequency band from 0.7-35 GHz [4] and the performance of DRAs is minimally affected by the presence of nearby noisy objects (such as human bodies) [5]. DRA was first time introduced by Prof Long in 1983 [6]. Before 80's dielectric resonators (DRs) of different shapes with high relative permittivity ε r > 20 have been used in various applications of microwave circuits [7]. Different shapes of dielectric resonators are found in the literature such as rectangular, annular and cylindrical. The cylindrical DRA become the attraction of researchers and communication industry due to its many attractive features. The CDRA is more directional as compare to annular and rectangular DRA [8]. Dielectric material can be easily molded into cylindrical shape by using commercially available rod [9] and it has less edges and simple field structure as compared to rectangular DR [10]. Different modes of DRA, can be excited by selecting the slot position under DRA. It is mentioned in the literature that by placing slot in the middle of the DR hybrid mode can be excited, and by moving away from DR center, TE and TM modes are excited [7]. Various coupling techniques have been used to excite the DRA such as aperture couple microstrip transmission line [11], probe feed [12] and dielectric image line [13]. The microstrip transmission line is easy to fabricate and has a low profile as compared to probe feed and dielectric image line. From the literature it is also proved that rectangular shaped coupling slot is better in performance as compared to the circular shape aperture slot [14].In this paper, mode is excited from...