A microstrip antenna is a kind of antenna used to process ultra-high frequency signals. It is often used as a satellite radio or cell phone receiver or is mounted on an aircraft or spacecraft. This type of antenna has the advantage that it costs little to make but the disadvantage that it has limited bandwidth.
An antenna is a device designed to transmit or receive electromagnetic waves. It is used in radio equipment to convert radio waves into electrical currents or electrical currents into radio waves. The only difference between a transmitting antenna and a receiving antenna is the direction the signal is traveling. A microstrip antenna is used to transmit or receive signals in the ultra-high frequency spectrum. These are waves with frequencies between 300 MHz and 3000 MHz (3GHz).
The most common type of microstrip antenna is the microstrip patch antenna. It is made by etching the antenna pattern into metal trace. This etching is bonded to a layer of insulating material, such as plastic, certain ceramics, glass, or certain types of crystal, then the insulating layer, known as the dielectric substrate, is bonded to a layer of metal. It is possible to create this type of antenna without a dielectric substrate. The resulting antenna is not as strong but gets better bandwidth, meaning it can process more information at once.
A microstrip antenna can also be printed directly onto a circuit board. Since the antenna requires few materials, it is low cost, easy to manufacture and light weight. These characteristics make these antennas ideal for use in cell phones and other small electronic devices.
The size of the microstrip antenna is inversely proportional to its frequency. That means the larger the antenna, the lower the frequency it is able to detect. For this reason, these antennas are generally used for ultra-high frequency signals. A microstrip antenna capable of sensing frequencies lower than microwave would be too large to use.
The microstrip concept was first proposed by G.A. Deschamps in 1953. The concept did not become practical to implement until the 1970s, when soft substrate materials, such as plastics, became readily available. At that time, the idea was further developed by Robert E. Munson and John Q. Howell. Research is still being done to improve these antennas. Scientists are especially looking for ways to reduce the size of the antennas to allow for their use in even smaller electronic devices.