Antennas are in the news this week, with these few examples reflecting the many innovations in recent years. Driven by the needs of multiple wireless bands and services, antenna designers have learned to pack what once required three or more separate and often large antennas into a single compact design. And there is no doubt that these antenna designers have benefitted from the availability of and improvements in planar and three-dimensional (3D) electromagnetic (EM) simulation software. (Some credit is also due to improvements in microprocessors, which now allow these EM simulators to run simulations in hours instead of weeks.)
Because of their complex field patterns, in both azimuth and elevation planes and with near-field and far-field behavior, antenna designs are not trivial--even with fast computers equipped with the latest EM simulation engines and models. Add the demands of modern communications systems and customer desires for multiple wireless services in a single device, and the design of a broadband antenna that can fit within a pocket-sized device becomes a challenge. Fortunately, as one of the items below indicates, EM software developers have a real passion for antenna design. Their tools have made what seemed impossible some years ago to something that is almost taken for granted today.