John N. Sahalos received B.Sc. degree in Physics, M.Sc. degree in Electronic Physics, BCE & MCE degrees in Civil Engineering, and Ph.D. in Electronic Physics from the Aristotle University of Thessaloniki, (AUTH) Greece. Prof. Sahalos is with the Radio-Communications Laboratory at the AUTH, and with the Department of Engineering at the University of Nicosia, Cyprus. For eight years he was a Professor in the ECE Department, University of Thrace, Greece, and Director at the Microwaves Laboratory. He was a visiting faculty member at Ohio State University, the University of Colorado, and the Technical University of Madrid. He was also on the board of directors of the National Research & Technology Committee of Greece and on the Board of Directors of OTE S.A., the largest telecommunications company in Southeast Europe. For more than 10 years, Prof. Sahalos was the president of the Greek committees of URSI. Also,he was a member of the committee and internal auditor of EurAAP (European Association of Antennas & Propagation). Besides his academic duties, he is now a Coordinator of the R&D advisory board at a high tech industry. Prof. Sahalos is an IEEE Life Fellow, an Honorary Fellow of the Electronic Physics Society, a Fellow of the Physical Society, and a member of the Technical Chamber of Greece. He is the author of four books, one in English (Wiley), and of more than 450 articles published in scientific literature. His research interests include antennas, radio communications, EMC/EMI, RFIDs, Microwaves, and Biomedical Engineering. With his colleagues, he designed innovative products like the EIT, the MLS, the ORAMA simulator and the SMS-Kmonitoring system.George A. Kyriacou was born in Famagusta, Cyprus, on March 25, 1959. He received his Electrical Engineering diploma and Ph.D. degree, both with honors, from the Democritus University of Thrace, Xanthi, Greece, in 1984 and 1988, respectively. Since January 1990, he has been continuously with the Department of Electrical and Computer Engineering, Democritus University of Thrace, where he is currently Professor and Director of the Microwaves Laboratory. From 2005 to 2010 he has been Director of the Graduate Studies of the department. He has authored over 250 journal andconference papers and supervised 7 Ph.D. and 11 M.Sc. theses and more than 90 Diploma theses. His main research interests include microwave engineering, open waveguides and antennas in anisotropic media, software-defined and cognitive radio, computational electromagnetics, and biomedical engineering. Dr. Kyriacou is member of IEEE since 1990 and senior member since 2000. He is also a member of the Technical Chamber of Greece and the European Microwave Association (EuMA).

• List of Figures.- List of Tables.- Preface.- Acknowledgments.- Ferrites and Ferroelectrics.- Tunable Materials--Characteristics and Constitutive Parameters.- Finite Ferrite Samples.- Multiferroics: Ferrite--Ferroelectric Composites.- Planar Transmission Lines.- Authors' Biographies .

John N. Sahalos received B.Sc. degree in Physics, M.Sc. degree in Electronic Physics, BCE & MCE degrees in Civil Engineering, and Ph.D. in Electronic Physics from the Aristotle University of Thessaloniki, (AUTH) Greece. Prof. Sahalos is with the Radio-Communications Laboratory at the AUTH, and with the Department of Engineering at the University of Nicosia, Cyprus. For eight years he was a Professor in the ECE Department, University of Thrace, Greece, and Director at the Microwaves Laboratory. He was a visiting faculty member at Ohio State University, the University of Colorado, and the Technical University of Madrid. He was also on the board of directors of the National Research & Technology Committee of Greece and on the Board of Directors of OTE S.A., the largest telecommunications company in Southeast Europe. For more than 10 years, Prof. Sahalos was the president of the Greek committees of URSI. Also,he was a member of the committee and internal auditor of EurAAP (European Association of Antennas & Propagation). Besides his academic duties, he is now a Coordinator of the R&D advisory board at a high tech industry. Prof. Sahalos is an IEEE Life Fellow, an Honorary Fellow of the Electronic Physics Society, a Fellow of the Physical Society, and a member of the Technical Chamber of Greece. He is the author of four books, one in English (Wiley), and of more than 450 articles published in scientific literature. His research interests include antennas, radio communications, EMC/EMI, RFIDs, Microwaves, and Biomedical Engineering. With his colleagues, he designed innovative products like the EIT, the MLS, the ORAMA simulator and the SMS-Kmonitoring system.George A. Kyriacou was born in Famagusta, Cyprus, on March 25, 1959. He received his Electrical Engineering diploma and Ph.D. degree, both with honors, from the Democritus University of Thrace, Xanthi, Greece, in 1984 and 1988, respectively. Since January 1990, he has been continuously with the Department of Electrical and Computer Engineering, Democritus University of Thrace, where he is currently Professor and Director of the Microwaves Laboratory. From 2005 to 2010 he has been Director of the Graduate Studies of the department. He has authored over 250 journal andconference papers and supervised 7 Ph.D. and 11 M.Sc. theses and more than 90 Diploma theses. His main research interests include microwave engineering, open waveguides and antennas in anisotropic media, software-defined and cognitive radio, computational electromagnetics, and biomedical engineering. Dr. Kyriacou is member of IEEE since 1990 and senior member since 2000. He is also a member of the Technical Chamber of Greece and the European Microwave Association (EuMA).

• List of Figures.- List of Tables.- Preface.- Acknowledgments.- Ferrites and Ferroelectrics.- Tunable Materials--Characteristics and Constitutive Parameters.- Finite Ferrite Samples.- Multiferroics: Ferrite--Ferroelectric Composites.- Planar Transmission Lines.- Authors' Biographies .

John N. Sahalos received B.Sc. degree in Physics, M.Sc. degree in Electronic Physics, BCE & MCE degrees in Civil Engineering, and Ph.D. in Electronic Physics from the Aristotle University of Thessaloniki, (AUTH) Greece. Prof. Sahalos is with the Radio-Communications Laboratory at the AUTH, and with the Department of Engineering at the University of Nicosia, Cyprus. For eight years he was a Professor in the ECE Department, University of Thrace, Greece, and Director at the Microwaves Laboratory. He was a visiting faculty member at Ohio State University, the University of Colorado, and the Technical University of Madrid. He was also on the board of directors of the National Research & Technology Committee of Greece and on the Board of Directors of OTE S.A., the largest telecommunications company in Southeast Europe. For more than 10 years, Prof. Sahalos was the president of the Greek committees of URSI. Also,he was a member of the committee and internal auditor of EurAAP (European Association of Antennas & Propagation). Besides his academic duties, he is now a Coordinator of the R&D advisory board at a high tech industry. Prof. Sahalos is an IEEE Life Fellow, an Honorary Fellow of the Electronic Physics Society, a Fellow of the Physical Society, and a member of the Technical Chamber of Greece. He is the author of four books, one in English (Wiley), and of more than 450 articles published in scientific literature. His research interests include antennas, radio communications, EMC/EMI, RFIDs, Microwaves, and Biomedical Engineering. With his colleagues, he designed innovative products like the EIT, the MLS, the ORAMA simulator and the SMS-Kmonitoring system.George A. Kyriacou was born in Famagusta, Cyprus, on March 25, 1959. He received his Electrical Engineering diploma and Ph.D. degree, both with honors, from the Democritus University of Thrace, Xanthi, Greece, in 1984 and 1988, respectively. Since January 1990, he has been continuously with the Department of Electrical and Computer Engineering, Democritus University of Thrace, where he is currently Professor and Director of the Microwaves Laboratory. From 2005 to 2010 he has been Director of the Graduate Studies of the department. He has authored over 250 journal andconference papers and supervised 7 Ph.D. and 11 M.Sc. theses and more than 90 Diploma theses. His main research interests include microwave engineering, open waveguides and antennas in anisotropic media, software-defined and cognitive radio, computational electromagnetics, and biomedical engineering. Dr. Kyriacou is member of IEEE since 1990 and senior member since 2000. He is also a member of the Technical Chamber of Greece and the European Microwave Association (EuMA).

• List of Figures.- List of Tables.- Preface.- Acknowledgments.- Ferrites and Ferroelectrics.- Tunable Materials--Characteristics and Constitutive Parameters.- Finite Ferrite Samples.- Multiferroics: Ferrite--Ferroelectric Composites.- Planar Transmission Lines.- Authors' Biographies .