Stream of Knowledge

Microstrip is a type of electrical transmission line which can be fabricated using printed circuit board technology, and is used to convey microwave-frequency signals. It consists of a conducting strip separated from a ground plane by a dielectric layer known as the substrate. The most commonly employed microstrip antenna is a rectangular patch which looks like a truncated  microstrip  transmission line. It is approximately of one-half wavelength long. When air is used as the dielectric substrate, the length of the rectangular microstrip antenna is approximately one-half of a free-space  wavelength . As the antenna is loaded with a dielectric as its substrate, the length of the antenna decreases as the relative  dielectric constant  of the substrate increases. The resonant length of the antenna is slightly shorter because of the extended electric "fringing fields" which increase the electrical length of the antenna slightly. An early model of the microstrip antenna is