Monish Sai Krishna Namana Journal of Engineering Research and Application www.ijera.com ISSN: 2248-9622 Vol. 10, Issue 02 (Series -III) February 2020, pp 74-79 www.ijera.com DOI: 10.9790/9622-1002037479 74 | Page Design of Microstrip Patch Antenna Characteristics Using Hemispherical and Spherical Dielectric Lens 1 Monish Sai Krishna Namana, 2 S. Santa Kumari 1 Mtech Student, Radar and Microwave, Dept of ECE, AUCE(A), Andhra University, Visakhapatnam. 2 Associate Professor, Dept of Electronics and Communication, AUCE(A), Andhra University Visakhapatnam. Corresponding Author: Monish Sai Krishna Namana ABSTRACT In this paper a study of the directive gain enhancement obtained using a dielectric lens placed in the near field of radiating elements is discussed. The design and results of a single element patch antenna along with hemispherical and spherical lens radiating in rectangular and square antenna are detailed. The design is done using HFSS, which is used for the primary radiator-lens combination. Lenses reduce the size of the composite antenna while providing sufficient collimation comparable to a much larger array of apertures without compromising on the bandwidth. The results obtained are compared in terms of directivity, VSWR, impedance and return loss. The microstrip patch antenna is designed to resonate at a frequency of 5.5GHz (5.35GHz- 5.5GHz) for rectangular patch and frequency of 4.35GHz (4.35GHz-4.5GHz) for square patch with FR4 substrate. Keyword: Microstrip patch antenna, Finite element method, Dielectric Lens, HFSS --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 25-02-2020 Date Of Acceptance: 05-03-2020 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION In wireless applications such as WiMAX, smart antenna, mobile communication and satellite communication applications there is a requirement for high gain antennas[1]. High gain from antenna can be achieved by increasing the number of elements forming an antenna array. The antenna array can be a series array or a parallel array. From the array principles; doubling the number of elements in the array can produce a gain of approximately 3dB is a known fact. If the numbers of elements in the array are increased, then mutual coupling between them increases and gain of the array decreases[2]. The mutual coupling can be controlled by maintaining a distance of half wavelength between the centers of the antenna elements. In applications, where size is the constraint, array with many antenna elements can’t be designed. In such applications the lens antenna is included as a secondary source for increasing the directive gain without compromising the bandwidth[3]. Lenses are primarily used to collimate incident divergent energy to prevent it from spreading in undesired directions[4]. By properly shaping the geometrical configuration and choosing the appropriate material of the lenses, they can transform various forms of divergent energy into plane waves. They can be used in most of the same applications as are the parabolic reflectors, especially at higher frequencies. Their dimensions and weight become exceedingly large at lower frequencies. Lens antennas are classified according to the material from which they are constructed, or according to their geometrical shape[5]. The microstrip patch antenna is simulated with HFSS software and optimized to get a good impedance matching and VSWR at a frequency 5.5 GHz (C Band). The lens antennas are designed such that they can cover the primary radiator exciting it. The size of the hemispherical lens and spherical lens is chosen such that they do not diffract the field of the microstrip patch and same time they cover the single patch antenna. The distance between the patch antenna and the lens is chosen so that at that distance VSWR is minimum. II. HEMISPHERICAL AND SPHERICAL LENS ANTENNAS The major advantage of using a hemispherical or spherical lens antenna [6] is its non-dependency on the focal length. This implies the non-dependency on frequency. Therefore the lens is an inherent broadband which can work up to several GHz. In other words an S-band, X – band and L-band radiators can be placed in front of this lens simultaneously and collimation can be expected. The appropriate number of dividers and other microwave devices must be kept to avoid interferences with other radiators. The restriction of the lens design is the size of the radiator. RESEARCH ARTICLE OPEN ACCESS