Prof. James K. Breakall of Penn State University

The half-wave dipole is one of the most widely used and practical antennas in amateur radio and various communication applications. Its foundational principles make it a staple in early studies of antenna technology, often being one of the first antennas covered in academic courses dedicated to the subject. Professor R.W.P. King, a prominent figure in the field, dedicated most of his 100-year career to meticulously measuring dipoles and monopoles. His groundbreaking research led to measurements of unprecedented accuracy, benchmarks in validating antenna modeling software even today. Another significant contributor to the understanding of dipole antennas is Professor John Kraus. His influential book, *Antennas*, published in 1950, inspired countless antenna engineers and enthusiasts, including myself, to delve deeper into the science of antenna design and application. This presentation aims to delve into various aspects of the half-wave dipole, a classical antenna, while proposing new perspectives on commonly accepted facts and practices. We will first investigate the accuracy of multiple antenna modeling codes using the half-wave dipole as a benchmark. A unique surface model was developed in the FEKO software to serve as a reference dipole. This model will be compared to results from several other codes that utilize the wire method of moments (MoM), providing insight into the strengths and weaknesses of different modeling approaches. Additionally, we will analyze the well-known formula 468/f, which calculates the length of a half-wave dipole in feet, with 'f' representing the frequency in megahertz (MHz). This formula is well-remembered by hams and often featured as a test question for obtaining an amateur radio license. We will discuss the effectiveness of this formula in practice, exploring its historical context and debunking common myths surrounding its application. It is worth noting that this formula does not consistently provide accurate tuning for resonating an antenna at a desired frequency across all wire or tubing diameters. We will introduce a straightforward interpolation method to facilitate precise adjustments that can significantly enhance tuning accuracy. Finally, we will present a novel design methodology for constructing a half-wave dipole antenna independent of the conductor’s diameter, whether solid wire or tubing. This innovative approach aims to simplify the design process and improve the overall performance of the antenna across various frequency ranges, ensuring better adaptability and efficiency in real-world applications. Through this presentation, we hope to offer a deeper understanding of the half-wave dipole antenna and its relevance in modern communications.

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Address:Professor, Electrical Engineering , 225 Electrical Engineering East Penn State University , University Park, Pennsylvania, United States, 16802

Jack L. Burbank of Advanced Communications Technologies at Sabre Systems

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Address:141 Warren St, New Jersey Institute of Technology, The Lewis and Julia P. Kieman Conference Room, Newark, United States, 07102

Steve Floyd

The HAARP Research Facility is a state-of-the-art project focused on ionospheric research located in Alaska. It was jointly funded by the U.S. Air Force, U.S. Navy, and the Defense Advanced Research Projects Agency (DARPA). Designed and built by a team from APTI/BAE Systems based in Washington, D.C., the facility aims to analyze the Earth's ionosphere and explore the potential for developing ionospheric enhancement technologies for radio communications and surveillance, as well as new radar and radio communications research. Construction of the HAARP facility took place in three stages, starting in 1993, with research operations commencing in 1996 and final completion in 2007. In 2015, the HAARP program and all its assets were officially transferred to the University of Alaska Fairbanks (UAF), where it continues to operate today. The most prominent instrument at the HAARP Research Station is the Ionospheric Research Instrument (IRI), which features a phased array of 180 antennas and 180 individual radio transmitter systems. These operate in the high-frequency (HF) band, generating an adequate radiated power of 5 gigawatts. The HAARP IRI is recognized as one of the highest-powered HF transmitting systems in the world and is used to temporarily excite a limited area of the ionosphere for scientific study. Other instruments at the facility include VHF and UHF radars, a fluxgate magnetometer, a Digi-sonde (an ionosphere sounding device), an induction magnetometer, and low-light CCD camera optics systems. These tools are all employed to investigate the physical processes that occur in the excited ionosphere region. Additionally, the HAARP facility houses a 15-megawatt diesel engine-based power generation plant and a modern operations center. The HAARP program is acknowledged as a highly successful research initiative that has overcome numerous unique and challenging radio engineering design obstacles. This presentation will provide an in-depth view of how the HAARP systems were designed, constructed, installed, and operated, with a focus on the unique engineering aspects of building this modern research facility. Examples of scientific research conducted at the facility will also be included.

Biography:

Steve Floyd is a BSEE graduate of Virginia Tech and obtained his MSEE (with emphasis on RF and Microwave Engineering and Radar Systems Engineering) from Johns Hopkins University in 1991.  He became a licensed Amateur Radio operator at 12 and is active as W4YHD.  Steve began his professional career designing high-power RF communications and Radar systems at E-Systems Inc., then became Chief RF Systems Design Engineer for HAARP, working at APTI/BAE Systems.  As Chief Engineer for the HAARP facility, he was responsible for all hardware systems designs, equipment installation, and site operations until 2014 when he became a part-time Chief Engineer and consultant to the program.  His current responsibilities are primarily in designing high-power SDR-based Radar systems, including EW and Communications systems, at Ultra Electronics. Steve is also active in the broadcast industry, an SBE member of DC Chapter 37, and has a lifelong love of radio broadcasting and amateur radio.

Address:United States

Prof. (Dr. Ing. Habil) Ulrich L. Rohde

Rod antennas, commonly used in portable (manpack) radio systems, ensure reliable communication links in amateur and military contexts. These systems often need to function effectively under varying environmental and ionospheric conditions, where signal propagation is highly dependent on the frequency. A key principle in high-frequency (HF) communications is the concept of an optimum working frequency (OWF). This frequency, or a narrow band of frequencies, allows maximum signal stability and minimal path loss between two communicating points. The optimum frequency remains relatively stable for several hours, particularly under quasi-static ionospheric conditions. To take full advantage of this phenomenon, it is essential to align the antenna system with the dynamic characteristics of the propagation medium. Traditional rod antennas often suffer from impedance mismatch across a wide frequency range, which results in suboptimal radiation efficiency and poor signal quality. This presentation introduces an innovative hybrid impedance matching strategy that combines passive and active components, such as adaptive tuners, broadband baluns, and variable reactive networks. This method aims to improve the matching of the antenna and transmitter within the OWF range. Experimental and simulation results show that this adaptive matching technique significantly enhances the Voltage Standing Wave Ratio (VSWR) and adequate radiated power (ERP) across the target frequencies. Field tests further indicate that the optimized antenna system achieves a greater communication range, lower error rates, and improved link quality compared to traditional matching techniques used in legacy manpack systems. This approach holds particular promise in situations where operators have limited control over antenna geometry or deployment environments, such as during on-the-move tactical operations or with backpack-mounted configurations. Overall, this method represents a practical advancement in portable HF communications, with significant implications for emergency communication networks, expeditionary forces, and low-power field operations in civilian and military contexts.

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Prof. Dr. Ing. habil Ulrich L. Rohde, an IEEE Fellow,  is a Partner of Rohde & Schwarz, Munich, Germany; Chairman of Synergy Microwave Corp., Paterson, New Jersey; President of Communications Consulting Corporation; serving as an honorary member of the Senate of the University of the Armed Forces Munich, Germany honorary member of the Senate of the Brandenburg University of Technology Cottbus–Senftenberg, Germany.  Dr. Rohde is serving as a full Professor of Radio and Microwave Theory and Techniques at the University of Oradea and several other universities worldwide, to name a few: Honorary Professor IIT-Delhi, Honorary Chair Professor IIT-Jammu, Professor at the University of Oradea for microwave technology, an honorary professor at the BTU Cottbus-Senftenberg University of Technology, and professor at the German Armed Forces University Munich (Technical Informatics). Rohde has published 400+ scientific papers, co-authored over dozen books with John Wiley and Springer and hold 50 plus patents; received several awards, to name a few recent awards: recipient of 2023 IEEE Communications Society Distinguished Industry Leader Award, 2023 IEEE Antennas and Propagation Society Distinguished Industry Leader Award, 2022 IEEE Photonics Society Engineering Achievement Award, 2021 Cross of Merit of the Federal Republic of Germany, 2020 IEEE Region 1 Technological Innovation Award, 2019 IETE Fellow Award, 2019 IEEE CAS Industrial Pioneer Award; 2017 RCA Lifetime achievement award, 2017 IEEE-Cady Award, 2017 IEEE AP-S Distinguish achievement award, 2017 Wireless Innovation Forum Leadership Award, 2016 IEEE MTT-S Applications Award, 2015 IEEE-Rabi Award, 2015 IEEE Region-1 Award, and 2014 IEEE-Sawyer Award. Dr. Rohde is recognized in the list of Divine Innovators of November 2011, Microwave Journal. In 2006, Dr. Rohde was selected to be part of the Microwave Legends:  Through innovation and invention, these 45 people, places, and things have shaped the microwave industry, Microwave & RF Magazine. IEEE recognized his five decades of scientific research contributions by establishing three awards in his name: (1) IEEE Ulrich L. Rohde Innovative Conference Paper Awards on Antenna Measurements and Applications, (2) IEEE Ulrich L. Rohde Innovative Conference Paper Awards on Computational Techniques in Electromagnetics, and (3) IEEE Ulrich L. Rohde Humanitarian Technical Field Project Award. Dr. Ulrich Rohde is the recipient of the “2021 Cross of Merit of the Federal Republic of Germany. The Order of Merit of the Federal Republic of Germany, also known as the Federal Cross of Merit, is the highest tribute the Federal Republic of Germany can pay to individuals for services to the nation. In December 2022, The Indian National Academy of Engineering (INAE) inducted Dr. Ulrich Rohde as a fellow during ceremonies for "outstanding contributions to engineering and also your dynamic leadership in the engineering domain, which has immensely contributed to the faster development of the country." Dr. Rohde is only the third foreign fellow elected by the INAE, preceded by Dr. Jeffrey Wineland, who won a Nobel Prize in Physics.

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Address:52 Hillcrest Drive, , Upper Saddle River, United States, 074584

David Bart, President Emeritus, Radio Club of America

The Radio Club of America was founded in 1909 by enthusiastic young experimenters in wireless telegraphy. It quickly became a magnet for innovators, entrepreneurs, inventors, industry leaders, and historians interested in all aspects of communication without wires. Our pantheon of legendary members continues to hold major roles in developing radio, television, mobile communication, satellite, space research, mmWave, and digital technologies. We are a forum, a gathering place for professional, scientific, and amateur practitioners of these arts. Join us for a collegial discussion about how history meets innovation. 

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David has a BA and MBA from the University of Chicago. He is a Senior Member of IEEE and the long-time Treasurer of the IEEE Historical Committee. He is significant with the Milestones Program and serves on the Global Museum Subcommittee. He was recently inducted into IEEE  Eta Kappa Nu’s Eta Chapter. David is President Emeritus of the Radio Club of America and Editor of the Proceedings of the Radio Club of America. His primary interests focus on the history and evolution of wired and wireless communication innovation.He is a Vice President and a Life Member of the Antique Wireless Association, and a former Co-Editor of the AWA Review. David serves on the Collections Committee of the Board of Directors of the Adler Planetarium in Chicago, and he is the former Vice President of the Museum of Broadcast Communications in Chicago. David has published extensively and provided numerous museum exhibits and designs regarding the history of wired and wireless electronic communications for over 25 years.  He has published in and/or presented in/at: the Proceedings of the IEEE, IEEE Global History Network, IEEE Canadian Review, IEEE History Center Newsletter, Proceedings of the RCA, RCA Technical Symposium, AWA Conference, AWA Review, AWA Journal, New York Historical Society, and the American Association of Physics Teachers Joint AAPT/AAAS Meetings. David has received numerous awards for his work in publications, historical preservation, and museum exhibit development. He holds an amateur radio license, is a Life Member of the American Radio Relay League, and is the former President of the Antique Radio Club of Illinois.

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Address:United States