Modeling of cable for measurements of small monopole antennas

Coaxial cable is often used for measurements of antennas inside anechoic chambers. In the measurement of a monopole antenna with a small ground-plane, the finite-sized ground causes the current to flow back from the radiator to the outer surface of the coaxial cable. This results in secondary radiation which introduces errors to the measured radiation pattern. To reduce the unwanted secondary radiation, the coaxial cable can be covered with EMI suppressant tubing materials. However, this introduces errors to the measured efficiency. In this paper, the models of the coaxial cable with and without suppressant tubing are developed and used for computer simulation. The cable effects on the measured results of a small monopole ultrawide band (UWB) antenna are studied by using the antenna measurement equipment Satimo StarLab and the EM simulation tool CST. The results show great agreements between the simulated and measured results. © 2011 IEEE.published_or_final_versio

An accurate and computationally efficient tool using UTD on large meshed geometries

Asymptotic (GTD) analysis of antenna farms and of the scattering from complex and electrically large geometries is commonly used to predict installed antenna patterns on satellites and space platforms, ships, planes, and other vehicles or antennas operating in urban environments. Yet the overwhelming majority of existing commercial tools requires dedicated models or incurs in very large computational costs when a meshed geometry, like those used for integral methods, is used. Besides other possible problems, the fact alone of being forced to use several different electromagnetic models of the same object poses traceability issues and requires duplication of effort, making a complete analysis quite expensive. The Astigmatic Beam Tracer (ABT) has been updated to improve its performance with large meshed geometries (aircrafts, satellites, ships) achieving a unique modelling capability. The numerical modelling of the environment based on beam tracing (ABT) and SATIMO measurements capability have been combined in SATSim software. The updated tool has been tested on several scenes with increasing complexity and the corresponding computational cost has been evaluated, confirming the expected speed and accuracy

An accurate and computationally efficient tool using UTD on large meshed geometries

Asymptotic (GTD) analysis of antenna farms and of the scattering from complex and electrically large geometries is commonly used to predict installed antenna patterns on satellites and space platforms, ships, planes, and other vehicles or antennas operating in urban environments. Yet the overwhelming majority of existing commercial tools requires dedicated models or incurs in very large computational costs when a meshed geometry, like those used for integral methods, is used. Besides other possible problems, the fact alone of being forced to use several different electromagnetic models of the same object poses traceability issues and requires duplication of effort, making a complete analysis quite expensive. The Astigmatic Beam Tracer (ABT) has been updated to improve its performance with large meshed geometries (aircrafts, satellites, ships) achieving a unique modelling capability. The numerical modelling of the environment based on beam tracing (ABT) and SATIMO measurements capability have been combined in SATSim software. The updated tool has been tested on several scenes with increasing complexity and the corresponding computational cost has been evaluated, confirming the expected speed and accuracy