Radiation pattern analysis of microstrip fed Yagis placed on a rectangular dielectric plate of finite dimensions

Summary form only given. Printed Yagi or microstrip-fed Yagi-Uda antennas placed on dielectric plates of finite dimensions are a natural evolution of wire Yagis. These antennas can be useful as they are compatible with microstrip circuits. The basic antenna concept involves a printed dipole antenna element fed by a microstrip line to balun transition (Kaneda, N. et al., IEEE Trans. on Antennas and Propag., vol.50, p.1158-60, 2002). This antenna system is a two-element Yagi with a ground plane acting as a reflecting element and the dipole being the feeding element. The concept can be extended to lengthened dielectric slabs with or without the inclusion of parasitics (or directors). Such antennas enjoy good impedance bandwidth and low levels of cross polarization. Director addition introduces multiple resonances extending the pattern bandwidth. The exact form of the radiation pattern solution is found using a simulator. Cross-sectional field values can also be calculated. Given the field inside and its general expression, the orthogonality of modes theorem is applied to extract the values of field coefficients for different propagating modes. Once known, these values can provide insight into an entire mechanism of radiation.