Chapter 1: Introduction

Antennas are essential components of wireless communication systems such as radio and television broadcasting, radar, mobile phones, satellite communications, airborne navigation, Bluetooth devices, RFID tags, wireless computer networks, to name just a few (Kraus and Marhefka, 2002). Design of modern antennas is a challenging task where an important step is adjustment of geometry and material parameters of the structure so as to satisfy given performance requirements concerning return loss, radiation pattern, gain, etc. (Gautam et al., 2013; Nguyen et al., 2013; Kuwahara, 2005). In many cases, geometrical constraints have to be taken into account because — for some applications (e.g., handheld and wearable devices; Guo et al., 2012; Chahat et al., 2011) — achieving compact designs might be of primary concern. For the sake of reliability, the process of dimension adjustment (also referred to as design closure; Koziel and Ogurtsov, 2014a) has to be based on accurate evaluation of antenna performance. The latter can only be ensured by full-wave electromagnetic (EM)-simulation. This is particularly important for compact antennas as well as other cases where EM couplings between the antenna itself and its environment (connectors, housing, feeding circuitry) may affect the device’s operation. However, EM analysis of realistic and finely discretized antenna models might be computationally expensive. Typically, this is not a problem for design validation, but it may be prohibitive from the point of view of parametric optimization which requires multiple simulations of the antenna structure at hand…