Abstract
The rate at which wireless communication technology application is becoming an indispensable part of our daily lives, demands advances research and development activities. This wireless communication technology offers an attractive way to carry out the mobility and capability of the information while enduring the good, easy, and flexible way of communication among many devices. Currently, satellite communication is one of the potential wireless communication technology. The antenna is one of the indispensable components of wireless communication technology. Therefore, it demands the search for novel techniques/approaches capable of enhancing the gain, bandwidth and directivity of the planar antenna. The development of a microstrip patch antenna creates a firm contender for communication system application. In this thesis, we have designed microstrip planar antennas with complete numerical computation, model results, comparison, and validation with reported literature. Further, the simulation has been performed with two advanced computer-aided software such as Computer Simulation Technology Microwave Studio (CST-MWS) software and Ansoft High-Frequency Structure Simulator (HFSS). These commercial electromagnetic simulators can accommodate complex and straightforward designs producing high percentage accuracy. This research focuses on different techniques for improving bandwidth, gain, and directivity.
Inner configuration of modernizing quadrilateral microstrip antenna is loaded with double rectangle-shape slot (DRSS) for radio astronomy receivers. The slot addition has an actual high impact on performance with the control of the antenna, the goal is to improve bandwidth that is conveyed around the slot when loaded side-by-side on the rectangular patch and is fed by the microstrip feeder line. It is understood that stacking of slot in this fragment of the antenna without degradation, cutting the edge cross-polarization performance brings good results than conventional microstrip cases. The reconfigurable antennas emerge to address design complexity, high cost, and the use of several antennas. Introducing reconfigurable antennas provides a single compact size solution, low-cost, turns operation frequency over a wide bandwidth, low-loss, and serves multiple purposes. However, it remains clear that the antenna used in this communication system is limited to low-frequency bands, more switches mechanisms, few resonances, and a wide antenna area. Therefore, to have a small antenna, two-switch mechanisms still function efficiently, with more resonances and high bandwidth, an innovative design for frequency-domain reconfigurable antennas at Ku, K-bands frequency for satellite applications. The re-configurability is realized with the procedure of the switching
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mechanism. The two switches modify resonance frequency to Ku also K-bands on the antenna at four stages. The design of a spherical ring with a tilted rectangular resonator frequency selective surface (FSS) for gain with bandwidth improvement of the Ku-band satellite communication antenna. The frequency selective surface (FSS) as superstrate for rectangular microstrip antenna is used. A unique tilt rectangular and circular ring element was introduced to motivate the degree of liberality in the configuration, growing the length and rectangular tilt at 45 degrees to change the band stop. The dielectric material is incorporated alongside. In increasing the bandwidth partial ground plane techniques, gain amplified with the loop FSS from an antenna gain of 3.74 dB to 6.25dB at 12 GHz. Directivity from 4.09 dBi to 6.62 dBi and at 18 GHz the gain enhanced from 3.60 dB to 5.86 dB with the directivity from 3.78dB to 6.63dB correspondingly for satellite applications.
The design concept of tilted-ring model implementing the serial array for direct broadcast satellite application. The proposed novel antenna design consists of seven radiating elements incorporating sixteen circular rings tilted resonator frequency selective surface (FSS). Further, the sequential feed network techniques are used to improve the gain and enhance the directivity.
There is a need to compare appropriate designs for a specific purpose in a communication system, for this purpose, the feed networks such as series feed (SF), corporate feed (CF), and corporate-series feed network (CSFN) in the task of antennas play a vital role. Therefore, the designed rectangular microstrip antenna with inner ring slot, two semi-circular slots on both sides of the microstrip, and two director elements. These proposed antennas are in four sets with different shapes for satellite communication operating at the Ku-band frequency. We have used copper (annealed) as material for the ground plane. The substrate material of the proposed antenna is Rogers RT5880, with a dielectric constant at 2.2. Moreover, we have used the probe feed technique in this antenna, further followed by SF, CF, and CSFN networks. The presented design is simple, compact, and very economical with optimal gain and bandwidth. The structure parameters of this proposed antenna are numerically computed.
An in-depth design of advanced beam steering inner ring structure (ABS-INS) with high gain for satellite communication was model. This design consists of a novel forty-two compacted network elements unit cells in a composite system. Antennas are essential for various applications, specifically in communication. Several antennas have been designed for this purpose, it remains clear that there is a need for beam steering antennas to solve high path loss challenges, low gain, attenuation of objects, and misalignment of antennas. This design of an antenna array is model to feeds on a dielectrics image line with a transferrable reflector plate. Moreover, unlike other reported antenna designs which feed on image lines only, the serial beam gets more signal coupling to dielectric image line after waveguide with the transition to allow appropriate propagation and desired frequency range. The radiation beam angle steer when the propagation is constant. The array's beam direction is controlled by a perturbation distance change in the dielectric image line and the detachable plate. The models were all designed with the aid of CST. With the help of 3D electromagnetic computer simulation technology (CST) studio suite because of the flexibility, exactness, and ability to accommodate the multifaceted design. We designed the projected antenna for the satellite applications, performed the optimization with a time-domain solver of microwave studio, validation of the model was done with ANSYS HFSS simulator. The simulation results and validation results are both in agreement.