“Introduction to Antennas” – an antenna training DVD

Understanding antenna characteristics and how they are effected by their surroundings is essential to obtaining the best performance from communications assets. Communications personnel responsible for the choice, configuration and orientation of antennas, and/or frequency management, rely on this knowledge for daily performance of their duties. The HMAS Cerberus Radio Frequency Management Course regularly delivers such training to a wide range of students, both from Australasia and South East Asia. Students have diverse academic backgrounds and experience, and may not have English as a first language. Because of this, teaching of underlying concepts needs to be addressed with a minimum of detailed mathematics. A comprehensive range of image-based training material developed privately by the author has been captured on a DVD entitled “Introduction to Antennas”. This paper discusses the DVD and some of the material. Background. For over a decade, the author has been a guest presenter at a range of conferences and courses in Australia, in particular the HMAS Cerberus Radio Frequency Management (RFM) Course. The RFM course, unique in the Southern Hemisphere, provides training for Australian and New Zealand Defence Communications personnel, as well as corresponding personnel from South East Asia. The transient nature of tactical communications implies a need to “get it right first time”, and this is promoted by a thorough conceptual understanding of the issues involved an antenna intuition. Because RFM students have a wide range of academic backgrounds, and many do not having English as a first language, material needs to be presented so that it can be easily understood and remembered by students at all levels. Explanation of electromagnetic concepts using images rather than detailed mathematics is key to the success of this work. The images are the product of fifteen year’s involvement with electromagnetic visualisation. They include still images and animations of data from NEC and basic mathematics, as well as “artist’s impressions”, and cover electromagnetics, electromagnetic interactions, propagation, and performance of antennas in the real world. Since 1990, the author has been developing NEC graphical interfaces. Initially, AutoCAD was customised to provide both a powerful 3D model creation environment, and display of 3D radiation patterns and near field contours [1]. Acquisition of 3D Studio (DOS) added “realistic” 3D rendered images of radiation patterns as animations, or suites of still images for use in antenna training aids [2]. With the need to run up to 30000 NEC models in a single batch, NEC was modified to read command line arguments for input, output and Sommerfeld file names. Input and batch file creation as well as post-processing was handled by purpose-written applications. Data compression techniques were developed to provide efficient storage and retrieval of radiation pattern data [3]. This allowed interactive display of radiation patterns as traditional graphs, and together with a modest ionospheric model, as skywave footprints. Reference [4] gives more detail of this work. In 2002, Defence’s Navy Video Unit (NVU) were tasked by the RFM course to prepare a series of DVDs containing this course material. The first DVD “Introduction to Antennas” has been completed. Preparation of DVD material The 82-page DVD script evolved from several of the author’s scripts for various courses and presentations. Because of its DOS origins, all image material had to be reworked for the higher resolution DVD format using the Windows version of 3D Studio – 3DMAX. Creation of the animations in the DOS environment made extensive use of an embedded language to provide software generation of keys to manipulate scene entitites, often up to several thousand per animation frame. This capability was not available in 3DMAX, and while the DOS animation files could be imported, some of the more extensively used animation keys either were not transferred or were modified. As a consequence, a significant amount of manual rework was required in 3DMAX – a time-consuming and error-prone process.