Antennas are basically devices that launch energy into the air, or receive energy that has already been launched. They are usually connected to some form of transmission line such as a coaxial cable that guides energy to or from the antenna in the form of electrons. The energy that is being launched or received from the antenna is in the form of photons, so visible light is just one form of electromagnetic energy that happens to be much higher in frequency then what we usually employ for radio systems. Antennas are basically devices that convert electrons into photons and vice versa. As such they can be considered a form of transducer just as a light bulb converts electricity into light or our eyes convert photons into signals for our brain to interpret as images.

The three most important features of an antenna are bandwidth, directionality, and polarization.

Bandwidth describes that part of the electromagnetic spectrum in which the antenna is capable of operating. For example, the PCS band for cell phone communication has been defined as 1850 MHz to 1990 MHz which, when you take the difference, is 140 MHz of bandwidth. Antennas vary widely in their bandwidth, as well as their efficiency across the bandwidth. Voltage Standing Wave Ratio (VSWR) is a measure of how well an antenna is able to convert a signal at a particular frequency into photons that are actually launched when transmitting. It is important to note that all common forms of antennas work equally well whether they are transmitting or receiving signals. A VSWR of 1.0 is the absolute best that an antenna can be and from that the value rises as the energy that cannot be converted into photons is reflected back into the transmission line. A VSWR of 1.5 indicates that 96% of the energy is converted, for a VSWR of 2.0 it drops to 89%, and for 3.0 it is 75%.

Directionality describes the ability of antenna to radiate in a particular direction, much like a bare light bulb is considered omni-directional as it radiates in all directions, whereas a flashlight has a reflector that causes the light to be directed in a particular direction. This directionality is also described as gain for an antenna when its efficiency is also considered. A gain of 3 dB indicates the energy level is twice that of an omnidirectional or isotropic radiator, and 6 dB is 4 times that of an isotropic radiator, and this doubling continues for every additional 3dB of gain, so that at 9 dB the level is 8 times that of an isotropic radiator.

Polarization is the plane that the electric wave is oscillating in. So a vertically polarized antenna would be acting in the vertical plane and a horizontal would be acting parallel to the ground. There is also circular polarization in which the plane is actually rotating resulting in a helical shape much like a coiled spring. If the transmitting antenna is operating with vertical polarization then it would be most efficient for the receiving antenna to also be vertically polarized.

Accurate Electronics takes into consideration all of these factors to produce embedded antennas that are superior in quality and performance.