There is an extensive body of theory relating the maximum possible bandwidth and efficiency to antenna size, i.e. ka factor, for electrically small antennas. Using this theory, we can establish limits for the gain and bandwidth performance for electrically small antennas. This is important for developing reasonable performance requirements and expectations for antennas and systems, especially those operating at lower frequencies. From the ka factor for a particular antenna, theory permits us to calculate the Q, or quality factor, of the antenna. The Q of an antenna is defined as the ratio of the stored magnetic and electrical energy to the radiated energy from the antenna. The importance of antenna Q is that it is approximately equal to the inverse of the bandwidth of the antenna. Full article coming soon!
Using a 3D Fused Deposition Modeling (FDM) part printer in the antenna design process
Fused deposition modeling is a technology developed by Stratasys which uses a nozzle to deposit molten polymer onto a support structure layer by layer, transforming 3D CAD files into functional prototypes. By leveraging this technology, antenna prototypes may be designed, printed and tested in a very rapid fashion, leading to a quicker time to market. Additionally, rapid prototyping techniques such as FDM unleash the designer's ability to create unconventional, cutting edge designs which result in extremely high performance antennas. Full article coming soon!
CST Microwave Studio (CST MWS) enables the fast and accurate analysis of high frequency (HF) devices such as antennas, filters, couplers, planar and multi-layer structures and SI and EMC effects. Exceptionally user friendly, CST MWS quickly gives you an insight into the EM behavior of your high frequency designs and is quickly becoming the industry standard 3D electromagnetic design tool.
Microwaves101 is a practical web resource covering the fundamental principles of microwave design. The site provides a wealth of microwave design theory and information in hypertext encyclopedic format that includes practical rules of thumb, microwave formulae presented in "enter-and-click" formats and design details of various antenna designs such as microstrip patches, Vivaldi antennas, horn antennas, parabolic reflector arrays and phased arrays.
Radio Electronics is aimed at providing useful information and overviews for the radio and electronics engineering industries. The site provides a variety of information for the electronics industry including tutorials covering the basic aspects of technology with a number of deeper studies on various topics. We also provide our new magazine section giving insight into various industry sectors with case studies, articles about industry trends and topics, as well as exhibition reports. We also provide up to the minute electronics industry news, pages for job information, and pages covering the forthcoming exhibitions. The site is an excellent resource for Antennas and Propagation.
RF Cafe is a collection of links to various application notes, RF equations, technical data sheets, math notes, and engineering articles and is one of the most highly rated engineering websites on the Internet. The site is full of useful design information, links and component vendor information.
Useful Videos
We often are asked "How is the performance of your mudflap antenna impacted by the presence of mud?"
This video demonstrates how the presence of mud on GreenWave Scientific's MAX-1160 Mudflap Antenna has little to no effect on its performance.
Stratasys FDM technology is an additive fabrication technology used by many in the rapid prototyping community. No special setup is required for Stratasys printers and production system. This video describes the FDM process:
Step 1: Pre-Process
From 3D CAD data, pre-processing software automatically slices, calculates support structures, and creates toolpaths that are optimized for the system.
Step 2: Produce Part
Parts are built layer by layer in an additive process. Extrusion heads lay down thermoplastic build and support material to create each layer.
Step 3: Remove Supports
Temporary support structures are easily removed. Soluble support material automatically dissolves in a water-based solution. Break-away supports simply snap off by hand.
Although a few years old, this video provides a great overview of CST's electromagnetic field simulation tool CST STUDIO SUITE 2009 with CST MICROWAVE STUDIO 2009. Researchers and design engineers use CST STUDIO SUITE™ for the analysis, design and optimisation of EM based components.
More information about CST EM simulation products available at http://www.cst.com.
Mark Saffian from AWR presents iMatch, a submodule of iFilter that delivers automated impedance matching capabilities to AWR's MWO software. The wizard allows users to quickly compare different matching topologies and choose among the best solution based upon certain, user-specified requirements.
This video was developed at Purdue University and is an array of 3.2 GHz patch antennas connected to a rectifier into an LED. This allows direct visualization of the antenna pattern. The effect of a polarization mismatch is shown. Also an array with Elevation Delta, Sum, and Delta-Delta patterns is shown.
SPAWAR Systems Center Pacific has developed a technology that uses the magnetic induction properties of sodium chloride (salt) in sea water to create UHF/VHF/HF antenna. The system uses a pump that shoots electrolytic fluid through center of current probe. The height and diameter of the fluid stream determine the frequency and bandwidth. The system also provides for use of multiple heads and current probes to cover a variety of frequencies and bandwidths.
The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. Often the significance of the decibel is misunderstood, or at least, under-appreciated.
