Design and Analysis of Antennas Operating At Different Frequency Bands Using CST

Abstract

Spherical microstrip antenna arrays have a great practical interest because they can direct a beam in an arbitrary direction throughout the space. The characteristics i.e. without limiting the scan angles, differently from the planar antenna behaviour makes them very suitable for use in communication satellites and telemetry. As far as circular array antennas are concerned, the quality of the radiation pattern will not be impaired when scanned in the full azimuthal axis. Spherical array antennas have the unique property of scanning their beam with no deterioration in full spherical coverage (i.e. azimuth and elevation axes). In this work a spherical microstrip antenna array of 16 elements has been designed. The basic element of this array is a rectangular patch antenna with operating frequency at 5.35 GHz. All the 16 elements were mounted on spherical surface in order to design the spherical microstrip antenna array with an operating frequency of 5.35 GHz. Power dividers are one of the key components in many microwave circuits and subsystems. The most useful power divider is Wilkinson divider that has excellent isolation between two ports. A basic Wilkinson power divider has two in-phase output ports. The Wilkinson power divider can be matched at all 3 ports. It is loss less if the output ports are matched, reciprocal and largely isolated. In this thesis work a 2-way, 4-way and 8-way equal and 4-way unequal power dividers are designed using the conventional Wilkinson topology. Two more designs were included in this work. One is ultra-wide band antenna and other is Zigzag antenna. First one is designed for ultra-wideband (UWB) body area network (BAN) applications to operate with in the 3.1 to 10.6 GHz frequency band. Second one Zigzag antenna is designed for a Radio telescope antenna. The high directivity of the Zigzag antenna can be utilized advantageously in the VHF and UHF ranges. All the designs were done using electromagnetic simulator, CST Microwave Studio