Branka Jokanovic was born in Uzice, Serbia, where she finished grammar school as the best pupil of her generation and the winner of Vukova Diploma. She received the Dipl. Ing. degree from the Faculty of Electrical Engineering, University of Belgrade, in 1977. She received her MSc (1988) and PhD (1999) degrees in the field of microwave mixers and baluns from the same Faculty. In 2008, she was elected the Research Professor at the Faculty of Electrical Engineering, University of Belgrade. From 1978 until 2009, she worked at the Institute for Applied Physics, today the IMTEL Institute (Institute for Microwave Techniques and Electronics), doing research and development of ultra-wideband radar detectors, waveguide slot antenna arrays, high-efficiency printed antenna arrays and image rejection mixers for low-noise receivers in microwave and millimeter-wave frequency range. Since 2003 she held the position of director’s counselor for science. In October 2009, she joined the Photonics Center of the Institute of Physics, University of Belgrade, where she is involved in the research of microwave and photonic metamaterials for communications and sensors.
In 1989, B. Jokanovic was a guest researcher at the University of Virginia, Semicondactor Device Laboratory, Charlottesville, USA. In 2000, she completed a postdoctoral study at the Department for Electrical and Electronic Engineering, University of Stellenbosch, South Africa. In 2008, she was an invited guest scientist at Heart Sensing Laboratory, Department of Electrical Engineering, University of Hawaii, USA and in 2009 and 2010 at the Department for Electrical and Electronic Engineering, University of Stellenbosch, South Africa.
During 1992-2000 B. Jokanovic managed the development and serial production of the first Yugoslav microwave link at 23 GHz. The link helped the Institute IMTEL become known on the radio relay devices market. She also managed two army projects and five projects co-financed by the Ministry of Science and Technological Development. She published over 100 papers in peer reviewed journals and at international conferences, 3 chapters in international monographs, 1 domestic monograph and over 60 papers at domestic conferences. Her papers have been cited more than 600 times in prominent international journals, books and patents. All published papers are based on the development of innovative units for real radars and communications devices.
B. Jokanovic was the chairperson of the Scientific Board of the Institute IMTEL (1991-2009). She was a member of the Advisory Board of the State Agency for Telecommunications-RATEL (2006-2009). She co-founded the Yugoslav IEEE MTT-S Chapter (1989) and organized the first IEEE sponsored conference in Yugoslavia: The First Scientific Meeting of Microwaves in Medicine’91, held in Belgrade in 1991. In the period 1989-2000, she was the chairperson of the Yugoslav IEEE MTT-S Chapter and in 1991 she was elected a member of the Administrative Committee of the IEEE MTT-Society as a representative of Region 8 (Europe, Near East and Africa). In 1994, she founded the Yugoslav Association for Microwave Technique and Technology - YuMTT and was its chairperson until 2000. She established the only national journal for microwave technique and technology published in English: Microwave Review and was its editor in the period 1994-2004. Today, this journal is among the top national periodicals.
B. Jokanovic is a Specialist Editor for Electromagnetics and Antennas SAIEE Africa Research Journal and a member of review boards of the most important journals in the field of microwave technique: IEEE Transaction on MTT, IEEE Microwave and Wireless Components Letters, Electronics Letters, Modern Physics Letters B, Journal of Electromagnetic Waves and Applications (JEMWA). She is a member of the Technical Program Review Committee of the IEEE MTT-S International Microwave Symposium since 2007 (Subcommittees: Transmission Lines, Filters, Phase Arrays and Integrated Beamformer). B. Jokanovic has been the reviewer of the South African National Research Foundation (NRF) since 2012.
B. Jokanovic received the Award of Institute IMTEL for her scientific contribution (1996), the IEEE Third Millenium Medal (2000), the Award of the Yugoslav Association for Microwave Technique and Technology-YU MTT for her outstanding contribution to the development of the Yugoslav IEEE MTT section (2005), Aleksandar Marincic Award in 2013 and Prof. Dr Ilija Stojanovic award in 2015, both for the best journal papers. B. Jokanovic is a full member of the Academy of Engineering Sciences of Serbia (AINS), since 2018.
B. Jokanovic’s scientific activity includes research in the field of radio communications at microwave and millimeter wave ranges, especially microwave mixers, direct QPSK modulators, waveguide and printed filters and diplexers and broadband transitions from symmetrical to nonsymmetrical lines. She gave a special contribution to the design of mixers with symmetrical frequency suppression which are a key unit of any microwave transceiver. These mixers have been integrated in infantry radars, surveillance systems and the unmanned aerial vehicle developed at the Institute for Applied Physics, as well as in all radio relay devices produced at Institute IMTEL. B. Jokanovic is the co-author of a new class of miniature wideband transitions from balanced to unbalanced line (balun), introduced in microwave technique under the title Double-Y balun. These baluns are presented in two books by foreign authors, published by Artech House and Wiley-Interscience, John Wiley and Sons Inc. and were the theme of a doctoral dissertation at the School of Electrical and Computer Engineering, Georgia Institute of Technology, Georgia, USA, under the title: “Investigation of the Double-Y Baluns for Feeding Pulsed Antennas”. At the Institute IMTEL, her double-Y baluns were applied in the original design of a number of mixers, as well as in the design of a miniature wideband waveguide-microstrip transition. In 2001, B. Jokanovic developed an integrated microwave transceiver with direct QPSK modulator at 23 GHz that was integrated in several hundred of RRU23A radio links manufactured at the Institute IMTEL. To our best knowledge, IMTEL’s links are the first commercial links in which direct modulation of the microwave range transmitting signal was applied, with no need of an upconverter or a filter.
Since 2005, B. Jokanovic has been researching metamaterials and their application in design of miniature filters and antennas. She has suggested several original super compact resonators and filters based on metamaterials consisting of grounded spirals, such as: ForeS, S-spiral and Single-spiral, whose dimensions are in the range from λg/13 to λg/76, making them the most miniature microstrip filters published so far. She also proposed extremely compact multi-band resonators and filters consisting of multiple split-ring resonators as well as a de-tuning technique for determining inter-ring coupling coefficients. This technique was later used to obtain several tunable and reconfigurable compact filters with PIN and varicap diodes. Her research of ENZ (epsilon-near-zero) waveguide resulted in a novel technique for tuning the zero-order resonance (ZOR) and Fabry-Perot resonance (FP) by means of short longitudinal or inclined slots. The method is suitable not only for joint adjustment of resonances, but also for their independent adjustment and can be used in the design of tunable multi-band filters.