Radiation characteristics of the various types of the printed circuit radiators electromagnetically coupled to microstrip feed lines are measured and compared with the theoretical values based on the cavity model. Some configurations which have wider bandwidths are investigated. The characteristic impedance of a dielectric-covered microstrip is calculated and a coaxial-to-microstrip connector is characterized to obtain an accurate input impedance in the measurements.
Additionally, necessary data in the design of the planar arrays of microstrip dipoles, such as self-impedance, mutual coupling, and radiation currents are measured as functions of the dipole length and transverse offset. The input impedance of an isolated dipole is measured as a function of the dipole width, longitudinal offset, and the thickness of the upper substrate and parameters critical to the flexibility in the design of an array antenna are identified.
