Coinciding with its inception before World War II, the face of the microwave industry has largely seemed to hark back to the traditional 1950s white-collar workforce. Peel back the layers, however, and it becomes clear that women and people of color were behind a number of microwave and RF developments. In fact, women have now put their stamp on this industry both in leadership/executive roles and on the technical side.

From the early days of this industry, women inventors were present. Together with Dr. Irving Langmuir, for example, Katherine Blodgett found a way to apply coatings layer by layer to glass and metal. When they were layered to a certain thickness, these thin films would cancel out the reflection from the surface underneath. Blodgett also was the first female scientist hired by General Electric's Research Laboratory in Schenectady, NY (1917) and first woman to earn a PhD in physics from Cambridge University (1926).

Beatrice Alice Hicks got a job at Western Electric in 1942, making her the first female engineer employed at the company. In addition to working on long-distance telephone technology, she developed a crystal oscillator. In 1950, Hicks co-founded the Society of Women Engineers (SWE), which now numbers more than 16,000. (For a current breakdown of women members of the MTT-S, see "Women In Engineering: Current Perspective".)

To avoid network overloads, many communications companies still rely on the principles of the switching system created by Erna Schneider Hoover. She started working at Bell Laboratories in 1954 as a researcher and later became the first female supervisor of a technical department. Hoover created a computerized telephone switching system, which monitored incoming calls and adjusted the call's acceptance rate accordingly. Hoover went on to research radar control programs for the Safeguard Anti-Ballistic Missile System.

In 1968, Dr. Betsy Ancker-Johnson observed a microwave emission from an electron-hole plasma. This was the first observation of microwave emission without the presence of an external field. It was initiated solely by the application of an external electric field. In 1966, she was awarded a patent for "signal generators." Ancker-Johnson discovered that very-high-frequency signals could be generated, as long as a low-density plasma was established in semiconductor material in the presence of both a high-intensity electric field and low-intensity parallel magnetic field.

Screen siren Hedy Lamarr famously developed the concept of frequency hopping. The "Secret Communications System," which she co-invented with George Anthiel, manipulated radio frequencies at irregular intervals between transmission and reception. The resulting code kept classified messages from being intercepted by enemy personnel during World War II. Lamarr was inspired by the idea of radio control, while Antheil, a pianist, envisioned a path to the synchronization device. Just like player-piano rolls, the pair's invention used slotted paper rolls to synchronize frequency changes in both the transmitter and receiver.

More recently, handheld wireless devices have inspired women inventors. Together with Alain Rossman, for example, Celeste Baranski developed an integrated cellular phone, facsimile (fax), and pen input device in 1993. This device became the basis for many personal digital assistants (PDAs). In 1999, Randice-Lisa Altschul was awarded a series of patents for the world's first disposable cell phone.

The flow of women into academia has allowed many of them to pursue various areas of research. (Thanks to the Unknown Editor at microwaves101.com for making sure we had a lot of these folks on our list!) Professor Bharathi Bhat, for example, was part of the team that established the theory and application of Finline. Although Finline resembles slotline, its structure is bounded within a rectangular waveguide.

An authority on electromagnetic (EM) theory, Zoya Popovic is a distinguished professor/Hudson Moore Jr. Endowed Chair at the Department of Electrical, Computer, and Energy Engineering at the University of Colorado, Boulder. Popovic's doctoral thesis was on large-scale, quasioptical microwave power combining. Her research interests include high-efficiency linear microwave power amplifiers, low-loss broadband microwave and millimeter-wave circuits, millimeter-wave and terahertz quasi-optical techniques, intelligent RF circuits, active antenna arrays, voltage standards, near-field EM probing, and wireless powering for low-power sensors. With her late father, Branko, Popovic co-authored Introductory Electromagnetics for junior-level electrical and computer engineering students.

Dana Weinstein, faculty member of the Microsystems Technology Laboratories (MTL) at Massachusetts Institute of Technology (MIT), heads a research group focused on the development of hybrid microelectromechanical-systems integrated-circuit (MEMS-IC) devices for low-power wireless communication, microprocessor clocking, and sensor applications. By harnessing the benefits of acoustic vibrations, they are hoping to enhance the performance of nextgeneration electron devices. They also are pursuing the integration of such hybrid devices into CMOS-based systems including low-power, narrow-bandwidth low-noise amplifiers for transceivers.

Among a string of impressive appointments, Linda P.B. Katehi has been serving as the sixth Chancellor of the University of California, Davis, since 2009. She also holds UC Davis faculty appointments in electrical and computer engineering as well as women's and gender studies. She has been issued 19 US patents and has submitted five more applications. Among Katehi's areas of expertise are the development and characterization of microwave, millimeterwave printed circuits and the computer-aided design of VLSI interconnects. She is a thought leader on the development and characterization of micromachined circuits for microwave, millimeter-wave, and submillimeter-wave applications including MEMS switches, high-Q evanescent mode filters, MEMS devices for circuit reconfigurability, and a variety of other topics.

Dalma Novak is Vice President at Pharad LLCa firm that is developing antenna and RF-over-fiber technologies. She leads the microwave photonic system development efforts. Prior to joining Pharad in 2004, Novak spent 12 years as a member of the academic staff in the Department of Electrical and Electronic Engineering at the University of Melbourne, Australia. During the last six months of that period, she was Professor and Chair of Telecommunications. Since 2004, she has been a Professorial Fellow in that department.

Among the research interests for Kawthar Zaki are microwaves, millimeter waves, and optics, as well as computeraided design. Currently, she serves as Professor Emeritus, Electrical & Computer Engineering Department at the University of Maryland, College Park, MD. Zaki has been awarded six patents and numerous honors and awards. In 1991, for instance, she received the IEEE Fellow Award for contributions to the analysis of dielectric waveguides and resonators and their applications in microwave filters and oscillators.

Credited with having her students design and build real circuits, Almudena Surez joined the Electronics Department at Spain's University of Cantabria, Santander, in 1987. There, she was involved with nonlinear simulation. Since 1993, she has been an Associate Professor with the university's Communications Engineering Department. Surez coauthored Stability Analysis of Microwave Circuits (Artech House, 2003). Her interests include the nonlinear design of microwave circuits.

Also on our "watch" list is Dominique M. M.-P. Schreurs, Associate Professor at Katholieke Universiteit (K.U.), Leuven, Belgium. Among her research focuses have been the use of vectorial large-signal measurements for the characterization and modeling of nonlinear microwave devices.

These achievements, and the drive that led women to reach for them, are certainly daunting in their impressiveness. With limited interest in the study of microwaves and RF technologyespecially for womenit is time to celebrate the achievements of women in microwaves and encourage the next generation of both women and men to join this remarkable industry (see "Calculus: Is It The Key?," below). Please contact nancy.friedrich@penton.com with information on anyone who was not covered here, so that we may feature them in future articles. And don't forget to spread the word on the superb, creative path offered by engineeringparticularly in the RF and microwave market.