Introduction to antenna theory. Hertzian dipole. Applications of electrically small antennas. The linear dipole antenna. Radiation field of arbitrary antennas. Directivity, gain, radiation resistance, effective height. Image theory, images of antennas. Travelling-wave antennas. The small circular loop. Antenna arrays. The rhombic antenna. Uniform, end-fire, and broadside arrays. Phase detection. Polynomial array theory. Superdirective arrays. Radiation-pattern synthesis, basics of array design. The reciprocity theorem in electromagnetic theory. Current and voltage sources, principle of duality. General formulas for the calculation of self- and mutual antenna impedance; application to dipole antennas. Dipole quality factor and bandwidth. Array antenna feeds. Baluns, stub matching, the folded dipole. Yagi-Uda arrays. Antennas as receivers. Identity theorems on transmit and receive. Receiver equivalent circuit. Effective area-to-directivity ratio. Received power. Lecturers:Christos Capsalis , Panagiotis Cottis , George Fikioris Course Website:http://mycourses.ntua.gr/courses/ECE1116 , http://www.antenna.ece.ntua.gr/