The novelties of a reflectarray antenna: A legitimate child of a reflector and an array antenna

Summary form only given. Broadly speaking a reflectarray antenna is a legitimate child of a reflector and an array antenna. Reflectarray´s major role is to synthesis any desired scattered wavefront from a given incident wavefront. Both reflector and phased array antennas do this as well. In reflector antennas one typically utilizes curved surfaces and in phased arrays one uses the element phasing to achieve the desired radiating wavefront. A reflectarray will do this by first being a planar structure rather than a curved structure and secondly by creating the desired element phases through the element topology instead of phase shifters. These two unique features make a reflectarray antenna a potentially very interesting and useful radiating device. In this overview talk with a personal historical perspective the following topics will be addressed: (a) The origin and history of reflector and array antennas leading then celebrating the birth of reflectarrays resulting from the marriage of a reflector and an array antenna, (b) Understanding the fundamental concepts behind their functionality, (c) The design approaches and performance characterizations including novel graphical visualizations, (d) Bandwidth limitations and other potential short comings, (e) Diverse applications in mimicking performance of conventional curved reflector antennas, elliptical or hyperboloidal subreflectors, wavefront correcting mirrors and others, (f) Reconfigurable reflectarray designs using MEMS, (g) Novel simulation and measurement results, and (h) Recent advances and future applications in microwave, mm-wave and optical regimes.