A significant performance element in communication and radar systems—as well as wireless devices—is the antenna. It may be defined as a transducer between a guided electromagnetic (EM) wave propagating along a transmission line, and an EM wave propagating in an unbounded medium (usually free space) or vice versa.1 The antenna is required to transmit or receive EM energy with directional and polarization properties suitable for the intended application.
This multi-part tutorial explores the radiation properties of rectangular microstrip antennas—specifically, the radiation method, coupling of the feed structure to the microstrip radiating element (or elements in the case of array structures), and the simple transmission-line model utilized for design and performance estimates. Parts 1 and 2 of the series explore the single-element, rectangular microstrip antenna. Later installments will examine the properties of antenna arrays constructed from the ensemble of single microstrip elements.
Antenna Characterization
Antennas are characterized and described by classification and descriptive parameters. In addition to microstrip or printed antennas, other classes of antennas are wire (e.g., dipole or loop); aperture (e.g., horns); reflector (e.g., parabolic); and lenses. The microstrip antenna may be considered a wire antenna due to the associated property of current on the radiating element. However, microstrip antennas are commonly granted the distinction of a separate antenna classification.
The most notable antenna parameters and definitions are summarized within Table 1.
