subject: What Is A Patch Antenna And What Are They Used For? [print this page] A patch antenna, sometimes referred to as a "microstrip antenna" is a low-profile antenna that a designer can integrate with an electronic assembly. Patch antennas are integrated into the electronic device so that the antenna itself can't be seen, these kinds of antennas are knows as embedded antennas.
Designers like embedded antennas because they are don't interfere with the look and finished ascetics of a product, and they are easy to design into a project, not only because they are small and don't require much space, but also because to mount a patch antenna requires a mounting plate that has the appropriate holes for your patch antenna, making them physically easy to include into the design.
Patch antenna is widely used in many communication systems like GPS satellites which operate at frequency of 1575 MHz, wireless Local Area Network (LAN) -2.4 GHz and 5.2 GHz -,Broadband Stacked Patch Antenna for Bluetooth Applications and in Cellular Networks. The antennas are compact and compatible with microwave integrated circuits (MICs) for high-frequency applications.
The microstrip patch antenna is one of the simplest radiating structures that can be built using printed circuits. Single patch antennas and patch antenna arrays are widely used in communication systems and airborne applications because of their light weight, precise reproduction through photolithographic techniques, conformal properties, suitability to integrate with active circuits, and low cost. The patch antenna can be approximately designed by using the transmission line model. The radiating edges of the patch can be thought as radiating slots connected to each other by a micro-strip transmission line.
The simplest patch antenna uses a patch which is one-half wavelength long, mounted a precise distance above a larger ground plane, sometimes using a spacer made of a dielectric between them. Electrically large ground planes produce stable patterns and lower environmental sensitivity but of course make the antenna bigger.
To eliminate radiation in the unwanted direction, a ground plane is usually employed on that side of the antenna. This ground plane eliminates the problem associated with radiation in two directions.
