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Electron Devices Society [ED-15]

Antenna & Propagation; Microwave Theory & Techniques; Aerospace & Electronic Systems and Electron Devices Societies

3:00 PM, Tuesday, 20 May

Operating Electrically Small Antennas for High Information Bandwidths

Guest Lecturer: Prof. Ramakrishna Janaswamy, University of Massachusetts, Amherst

Location: MITRE (Building C Lobby)

Refreshments served at 2:30pm

You can also attend the meeting from the comfort of your office/home through WebEx. Please see below for login info.

It is well known that electrically small (size to be much smaller than the wavelength at the operating carrier frequency), passive antennas suffer from fundamental limitations on achievable bandwidths. The bandwidth of electrically small antennas could, however, be substantially improved by incorporating lossy matching networks. But this will be at the cost of significantly higher power dissipation in the matching networks, which will tend to decrease the overall radiation efficiency. If, on the other hand, the antenna currents could somehow be made to change rapidly at a rate directly dictated by the message signal, then there is no difficulty in radiating such a rapidly varying waveform from the induced antenna currents, despite its narrow input impedance bandwidth.

In this talk we discuss the theory of operation of a linear, electrically small, time-varying antenna by considering a thin dipole loaded with a fast switching element. Time-variation of antenna structure is achieved by operating the switch via a message signal that has the overall effect of transferring a modulated carrier to antenna currents for subsequent radiation.

Time-domain integral equation and linear state-space theory is used to understand the dynamics of the radiated waveform and the antenna input current. It is demonstrated that the antenna has capabilities of radiating waveforms with an information bandwidth that is an order of magnitude greater than possible with an electrically small traditional antenna. Effect of switch parameters such as the finite OFF resistance and finite switching times relative to the time period of the RF carrier on the operation of the antenna are also presented.

Ramakrishna Janaswamy PhotoBio: Ramakrishna Janaswamy received his Ph.D. degree in electrical engineering in 1986 from the University of Massachusetts, Amherst. He received his Master’s degree in Microwave and Radar Engineering from IIT-Kharagpur, India in 1983 and the Bachelor’s degree in Electronics and Communications Engineering from REC-Warangal (now NITWarangal), India in 1981. From August 1986 to May 1987, he was an Assistant Professor of electrical engineering at Wilkes University, Wilkes Barre, PA. From August 1987-August 2001 he was on the faculty of the Department of Electrical and Computer Engineering, Naval Postgraduate School, Monterey, CA. In September 2001 he joined the Department of Electrical & Computer Engineering, University of Massachusetts, Amherst, where he is a currently a Professor. He was a visiting researcher at the Center for PersonKommunikation, Aalborg, Denmark from September 1997 to June 1998 and spent the Summers of 1994 and 1995 at SPAWARSYSCEN, San Diego, California and NASA Ames Research Center, Moffett Field, California, respectively. His research interests include deterministic and stochastic radio wave propagation modeling, analytical and computational electromagnetics, antenna theory and design, and wireless communications. His research is/was funded by several agencies such as NSF, ONR, ARO, and several Department of Navy laboratories. His personal hobbies include birdwatching and wildlife photography.

Rama Janaswamy is a Fellow of IEEE and was the recipient of the R. W. P. King Prize Paper Award of the IEEE Transactions on Antennas and Propagation in 1995. For his services to the IEEE Monterey Bay Subsection, he received the IEEE 3rd Millennium Medal from the Santa Clara Valley Section in 2000. He is an elected member of U.S. National Committee of International Union of Radio Science, Commissions B and F. He served as an Associate Editor of Radio Science from January 1999-January 2004 and Associate Editor of IEEE Transactions on Vehicular Technology from 2003-2006. He is currently an Associate Editor of IEEE Transactions on Antennas and Propagation and of the IETE (India) Technical Reviews. He is the author of the book Radiowave Propagation and Smart Antennas for Wireless Communications, Kluwer Academic Publishers, November 2000 and a contributing author in Handbook of Antennas in Wireless Communications, L. Godara (Ed.), CRC Press, August 2001 and Encyclopedia of RF and Microwave Engineering, K. Chang (Ed.), John Wiley & Sons, 2005.

For more information, contact:

Raoul O. Ouedraogo, raoul.ouedraogo@ll.mit.edu or

Wajih Elsallal, welsallal@mitre.org, Phone:(319) 775-5296

Foreign nationals should RSVP by contacting Wajih Elsallal no later than 5/15/2014

Direction to MITRE:

Refer to the link below. Please use the lobby at C-building.

http://www.mitre.org/sites/default/files/pdf/bedford-campus-map.pdf

WebEx instruction:

Please login at 2.45pm to give yourself enough time for troubleshooting connection problem.

Meeting information

opic: Operating Electrically Small Antennas for High Information Bandwidths

Date: Tuesday, May 20, 2014

Time: 3:00 pm, Eastern Daylight Time (New York, GMT-04:00)

Meeting Number: 596 891 596

Meeting Password: (This meeting does not require a password.)

To start or join the online meeting

Go to https://ieeemeetings.webex.com/ieeemeetings/j.php?ED=284339862&UID=498391877&RT=MiMxMQ%3D%3D

Provide your phone number when you join the meeting to receive a call back.

Teleconference information

Alternatively, you can call:

Call-in toll-free number: 1-866-2030920 (US)

Call-in number: 1-206-4450056 (US)

Conference Code: 796 395 4371


Life Members; Electron Devices; and Aerospace & Electronic Systems

4:00 PM, Wednesday, 9 April

Anthropogenic Global Warming – Yea or Nay.

Paul H. Carr, Ph.D., AF Research Laboratory Emeritus

Thaddeus Paul Kochanski, Ph.D., (Ted) Sensors Signals Systems

Join the Life Members and the Electron Devices Society in debating: Anthropogenic Global Warming {“APG”} – Yea or Nay. We begin with two opening statements by the two advocates: Paul H. Carr: -- Yea – “Humans Influence Our Climate”; Thaddeus Paul Kochanski – Nay –“Natural Processes Dominate Climate Dynamics“

Humans Influence Our Climate
By Paul H. Carr, IEEE Life Fellow

Fossil fuel burning and agriculture of the exponentially growing population of seven billion are affecting our climate. Fossil fuel emissions include carbon dioxide (CO2) and aerosols. Fossil fuel mining and rice and livestock farming produce methane (CH4).

Increasing CO2 and other noncondensing atmospheric gases like CH4 blanket and warm the earth’s surface via the greenhouse effect. These increases correlate with temperature since the beginning of the industrial era. Carbon dating shows that the CO2 increase is from burning ancient fossil fuels.

The present CO2 rate-increase of 2.5 ppm/year is 300 times greater than that at which the earth recovered from the ice age 18,000 to 10,000 years ago.

If we do not take steps to reduce the 2.5 ppm/year rate, in 240 years CO2 concentrations will reach 1000 ppm. This is what the earth’s atmosphere was 50 million years ago. Then there was no ice, sea levels were hundreds of feet higher, and average temperatures were 11C higher.

The 2014 report of the UN Intergovernmental Panel on Climate Change concluded, “There is a 95 percent or greater likelihood that human activity is the main cause of the ongoing planetary warming.”

Paul H. Carr. BS, MIT, Ph. D. Brandeis. From 1967 to 1995, Paul led the Component Technology Branch, of the Air Force Research Laboratory, Bedford, MA. His branch’s research on surface acoustic waves (SAW) resulted in signal processing filters used in radar, cellular phones, and TV. He has published over 80 technical papers and has 10 patents. After his retirement from AFRL, he taught philosophy courses at U Mass Lowell, which inspired his book Beauty in Science and Spirit. In January 2013, he published “Weather extremes from anthropogenic global warming,” in Natural Science. http://mirrorofnature.org/NS-GlobalWarming.pdf. His web page is www.MirrorOfNature.org

Natural Processes Dominate Climate Dynamics:

Are Climate Data & Models Reliable?
By Ted Kochanski

Before we can get to the ultimate question – we need to address:

My interest began, in the 1980's, while investigating atmospheric effects on low altitude RF propagation for the Navy. I experienced several instances of quality and reliability issues with archived ocean surface water and air temperature data in NOAA's National Climatic Data Center.

In June 1990, I attended a debate at MIT on Global Warming, between Pro -- Dr. Stephen Schneider of the National Center for Atmospheric Research in Boulder, Colorado, and Anti -- Richard S. Lindzen, MIT Sloan Professor of Meteorology. Afterwards, Prof. Lindzen, an atmospheric dynamics and modeling expert, told me that he accepted the surface temperature data. Being an experimentalist, I gave the modelers a “by” on the physics – my problem was with the data. Subsequently, I’ve seen many more examples of problems with: data sources, their interpretation, and modeling [e.g. cloud formation].

The remainder of the meeting will be devoted to members of the audience asking their own questions to further elucidate the topic.

Ted Kochanski, SB MIT, Ph.D. U Texas at Austin, Dr. Kochanski is a consultant, educator, and entrepreneur with a background in experimental physics, and extensive expertise in developing, and utilizing multiple sensor technologies to characterize, monitor and control diverse physical systems. His professional career spans: Tokamaks (University of Texas at Austin); Chair Technical Review Panel on Alpha Particle Diagnostics for Fusion Experiments; Defense System Analysis (MIT Lincoln Laboratory); Sensors Signals Systems – wide range of domestic and international clients in technology, applications, intellectual property; Entrepreneurship (co-founder of several high-tech companies); Engineering Education: university (UNH, WIT, International); continuing education (IEEE Boston Section); informal education (Museum of Science Exhibit Hall Interpretation Volunteer for 20 years).

The meeting will be held at the Lincoln Lab Auditorium, 244 Wood Street., Lexington, MA at 4:00 PM. Refreshments will be served at 3:30 PM. Registration is in the main lobby. Foreign national visitors to Lincoln Lab require visit requests. Please pre-register by e-mail to eception@ll.mit.edu and indicate your citizenship. Please use the Wood Street Gate. For directions go to http://www.ll.mit.edu/. For other information, contact Len Long, Co-Chair, at (781)894-3943, or l.long@ieee.org. or Steve Teahan, Co-Chair at 978-763-5136, or steahan@comcast.net. If you would like to be on the Life Members database so we can inform you of special programs including field trips plus added events like a global warming debate, please send us an e-mail with your contact information. This meeting is cosponsored by Aerospace and Electronic Systems (AESS), and Electron Devices (EDS) Societies.