An Equivalent Circuit Model of Miniature Double E-Shaped Meander Line Printed Monopole Antenna

An equivalent circuit model of the UHF miniature double E-shaped meander line printed monopole antenna is presented. The proposed antenna has a simple structure and small antenna size of 46.8 mm x 74 mm or 0.137 Lambda0 x 0.217 Lambda0 at 878 MHz resonant frequency. Advanced Design System (ADS) software is used to develop the antenna circuit model. Each section of the antenna structure is represented by the inductance and capacitance circuit with their values are depending on the width and length of the structure. The circuit model is developed based on common discontinuities in the microstrip line. The performance of the circuit model in terms of return loss is compared with the CST simulation for a validation. The printed monopole antenna is having similar radiation characteristics as an ideal wire monopole where it radiates uniformly in all directions

Efficient discrete modelling of axisymmetric radiating structures

This thesis describes research on Efficient Discrete Modelling of Axisymmetric Radiating Structures . Investigating the possibilities of surmounting the inherent limitation in the Cartesian rectangular Transmission Line Modelling (TLM) method due to staircase approximation by efficiently implementing the 3D cylindrical TLM mesh led to the development of a numerical model for simulating axisymmetric radiating structures such as cylindrical and conical monopole antennas. Following a brief introduction to the TLM method, potential applications of the method are presented. Cubic and cylindrical TLM models have been implemented in MATLAB and the code has been validated against microwave cavity benchmark problems. The results are compared to analytical results and the results obtained from the use of commercial cubic model (CST) in order to highlight the benefit of using a cylindrical model over its cubic counterpart. A cylindrical TLM mesh has not previously been used in the modelling of axisymmetric 3D radiating structures. In this thesis, it has been applied to the modelling of both cylindrical monopole and the conical monopole. The technique can also be applied to any radiating structure with axisymmetric cylindrical shape. The application of the method also led to the development of a novel conical antenna with periodic slot loading. Prototype antennas have been fabricated and measured to validate the simulated results for the antennas