What are common WiFi Antenna FAQs?

How do I choose the correct WiFi antenna? The two main types of antennas are Omni-directional and directional. Omni-directional antennas radiate RF signal in a 360 degree pattern and directional antennas emit the RF signal in a focused beam similar to the headlight of a car. If your application is a point to point WiFi link like from one building to another you would use a Directional antenna. If you need to send the WiFi signal 360 degrees then you would use and Omni directional antenna. If you have a point to multi point application, such as a campus environment then you would use a combination of Omni directional and Directional antennas.

What is antenna polarity? The polarity of an antenna is the orientation of the electric field of the radio wave with respect to the Earth's surface. Antennas can have vertical polarization, horizontal polarization or both.

What is antenna gain? Antenna gain is a relative measure of an antennas ability to direct or concentrate radio frequency energy in a particular direction or pattern. WiFi antenna gain is typically measured in dBi or dBd.

What is 802.11? 802.11 is an IEEE standard for implementing wireless local area network (WLAN) communications in the 2.4, 3.6 and 5 GHz frequency bands. Previously released 802.11 standards include 802.11a, 802.11b, 802.11g, and 802.11n. The latest pre-release standard is 802.11ac which promises wireless speeds over 1 Gbps.

What is a Decibel ( dB )? A Decibel is a logarithmic representation of magnitude relationships commonly used in radio and sound measurement. A Decibel is 1/10 of a Bel.

What is dBi ? dBi are Decibels relative to an isotrope.

What is Fade Margin? Fade margin is the loss in signal along a signal path, measured in dB, caused by environmental factors such as terrain, atmospheric conditions, etc.

What is Frequency? Frequency is the number of cycles of alternating current in one second, measured in Hertz (Hz).

What is an Isotrope? A theoretical "isotrope" is a single point in free space that radiates energy equally in every direction similar to the Sun.

What is a Microwave? A Microwave refers to all radio frequencies above 1 GHz or so.

What is Multipath Interference? Multipath interference is signal reflections and delayed signal images that interfere with the desired un-delayed and larger desired signal. Multipath causes picture ghosting for over the air analog TV and errors in digital transmission systems.

What is Path Budget? Path Budget is a mathematical model of a wireless communications link that accounts for a wide variety of factors that affect operating range and performance. Path Budget is sometimes referred to as "link" budget.

What is Path Loss? Path Loss is the weakening of a signal over its path of travel due to various factors such as terrain, obstructions and environmental conditions. Path Loss is measured in dB.

What is a Point-to-Point network? A point to point architecture is a communications channel that runs from one point to another. Directional antennas would be used in a point to point wireless link.

What is a Point-to-Multipoint network? A point to multipoint architecture is a communications channel that runs from one point to several other points. For this type of network you would use both Omni directional and directional antennas.

What is Radio Frequency (RF)? Radio frequency is typically a frequency from 20 kHz to 100 GHZ. RF is usually referred to whenever a signal is radiated through an enclosed medium like a transmission cable or air.

What is a Radio Wave? A radio wave is a combination of electric and magnetic fields varying at a radio frequency and traveling through space at the speed of light.

What is Ultra High Frequency (UHF)? Ultra high frequency radio waves that are in the range of 300 to 3,000 MHz.

What is Very High Frequency (VHF)? Very high frequency waves that are in the range of 30 to 300 MHz.