It was known that the resonant length of a rectangular microstrip antenna is approximately one-half wavelength with the effective dielectric constant of the substrate taken into account. Following the introduction of the microstrip antenna, analysis methods were desired to determine the approximate resonant resistance of a basic rectangular microstrip radiator. The earliest useful model introduced to provide approximate values of resistance at the edge of a microstrip antenna is known as the transmission line model, introduced by Munson. The transmission line model provides insight into the simplest microstrip antenna design, but is not complete enough to be useful when more than one resonant mode is present. In the late 1970s Lo et al. developed a model of the rectangular microstrip antenna as a lossy resonant cavity. Microstrip antennas, despite their simple geometry, proved to be very challenging to analyze using exact methods. In the 1980s, the method of moments (MoM) became the first numerical analysis method that was computationally efficient enough so that contemporary computers could provide enough memory and CPU speed to practically analyze microstrip antennas.

An analysis of the circular microstrip antenna, which is very useful for engineering purposes, has been undertaken by Derneryd and will be utilized here.

Dual-band microstrip antennas are generally of two types: 1) separate microstrip resonators coupled to a transmission line, or 2) perturbed microstrip resonators where their original resonant frequencies are shifted by geometrical alteration of a basic resonator. Dual-band microstrip antenna designs which allow for independent frequency selection have the most design utility. A good overview of dual-band microstrip antennas is given by Maci and Gentili.

Microstrip antennas have a large number of applications despite their limitations. In some cases, pattern or bandwidth requirements can only be met with planar antennas, which are not a traditional microstrip configuration. These are generally referred to as printed or planar antennas. In some cases, microstrip transmission line may be integrated with an antenna, and often these are still called microstrip antennas. In this chapter we will investigate a number of useful printed/microstrip antenna designs.

This appendix covers the topics in numerical integration, evaluation of sums, fixed-point iteration, and bisection algorithm.

This appendix cover the topics in Friis transmission formula, wireless link range, antenna gain and directivity, receiving antennas and transmitting antennas.