November 8, 2012 “Antenna Testing in Less Than One Second: Very-Near-Field Techniques for Far-Field Measurements by Cedric Caudron of EmScan
Cedric Caudron is an application engineer with EMSCAN, a Canadian company that makes sensors for making electromagnetic measurements for EMC testing and antenna testing.
The talk gave a brief history of EMSCAN including a description of their first product, an array of sensors to provide rapid determination of emissions from circuit boards and other electronic devices. They then adapted the sensor array to allow determination of far field characteristics of antennas based on very near-field measurements. The RFXpert is a desktop scanner that characterizes antennas without the need for a chamber. The device provides far-field patterns, bisections, EIRP and TRP in less than two seconds. Novel near-field results,including amplitude, polarity and phase give insights into the root causes of antenna performancechallenges and help troubleshoot far-field radiation patterns. RFXpert can also integrate with a network analyzer to measure gain, efficiency and S11 of an antenna,
A demonstration of one of the units was made to show the results in near real-time.
October 18, 2012 “Antenna Synthesis: A New Way to Approach Antenna Design” by Dr. Jason Lohn
Dr. Lohn is an Associate Research Professor in Electrical and Computer Engineering at Carnegie Mellon University. He led a team of scientists and engineers to successfully evolve, develop and fly three evolved X-band antennas in space aboard NASA’s Space Technology 5 mission in 2006. His main interests are to research and develop search algorithms that can automatically design and optimize hardware systems to achieve increased performance and reliability in application areas such as antenna design, microelectromechanical systems, robotics, and spacecraft design.
Current methods of designing and optimizing antennas by hand are time and labor intensive, limit complexity, and require significant expertise and experience. AI search algorithms can overcome these limitations by automatically searching the design space and finding effective solutions that are closer to limits imposed by physics. For example, our algorithms have discovered counter-intuitive antenna designs that out-perform traditionally designed systems. While optimization modules are commonly available in commercial RF CAD tools, they are typically simple parametric methods, and no system yet offers an antenna synthesis capability. We described the antenna synthesis system we are developing and its use in a variety of applications, including a project that produced antennas that flew in space on NASA’s Space Technology 5 (ST5) mission.
July 19, 2012: “Single Antenna Measurement using a Mirror and Time Domain” by Mike Hillbun, President Diamond Engineering
The talk presented a technique utilizing the IFFT and high power processing capability of a modern Vector Network Analyzer to enable broadband single antenna measurement.
June 21, 2012: “Antennas I Have Known” by John Hill, Retired
The talk presented descriptions of many types of antennas including aircraft antennas, spacecraft antennas, ground based antennas, rocket antennas, and space shuttle antennas that John Hill worked on or designed over the course of 42 years.
January 12, 2012: “Who is the Father of Electrical Engineering?” by Tapan Sarkar, Professor of Electrical Engineering, Syracuse University
According to Sir James Jeans: In his hands electricity first became a mathematically exact science and the same might be said of other larger parts of Physics. He did develop almost all aspects of Electrical Engineering. To start with, as Sir Ambrose Fleming pointed out he provided a general methodology for the solution of Kirchoff’s laws as a ratio of two determinants. He showed how a circuit containing both capacitance and inductance would respond when connected to generators containing alternating currents of different frequencies. He developed the phenomenon of electrical resonance. He showed that between any four colors an equation can be found, and this was confirmed by experiments. Secondly, from two equations containing different colors a third may be obtained. A graphical method can be described, by which after fixing arbitrarily the position of three standard colors that of any other color can be obtained by experiments. Finally, the effect of red and green glasses on the color-blind was presented, and a pair of spectacles having one eye red and the other green was proposed by him as assistance to detect doubtful colors. He was the first to show that in color blind people, their eyes are sensitive only to two colors and not to three as in normal eyes. Typically, they are not sensitive to red. He perfected the ophthalmoscope to look into the retina. At the point of the retina where it is intersected by the axis of the eye there is a yellow spot, called the macula. The macular degeneration of the eye affects the quality of vision and is the leading cause of blindness in people over 55 years old. Today, the extent of macular degeneration of the retina is characterized by his yellow spot test. He also developed the fish eye lens to look into the retina with little trauma. He provided a methodology for generating any color represented by a point inside a triangle whose vertices represented the three primary colors that he chose as red, green and blue. He took the first color photograph. The experimental set up was to take three pictures separately using different colors and then project the superposed pictures to generate the world’s first color photograph. Today, color television works on this principle, but his name is rarely mentioned.
He wrote the first paper on control theory showed for the first time that for stability the characteristic equation of the linear differential equation has to have all its roots with negative real parts. He not only introduced the first statistical law into physics but also introduced the concept of ensemble averaging which is an indispensable tool in communication theory and signal processing. He also did other significant works including introducing the concept of relativity which made Albert Einstein remark: One scientific epoch ended and another began with him –, and, From a long view of the history of mankind – seen from, say, ten thousand years from now – there can be little doubt that the most significant event of the nineteenth century will be judged as his discovery of the …… – Richard Feynman.
He always delivered scientific lectures for the common people using models. He also was very prolific in writing limericks, as we will see. Yet, very few electrical engineers know who this person is and his contributions!
This meeting was co-sponsored by the SCV MTT.