March 5, 2016

Antennas and Passive Components 101

This blog entry illustrates basic definitions of antennas and passive components for in-building distributed antenna system (DAS).

An antenna is a passive device which does not offer any added power to the signal. Instead, an antenna simply redirects the energy it receives from the transmitter. The redirection of this energy has the effect of providing more energy in one direction and less energy in other directions. An antenna has two fundamental properties: gain and direction. Gain is a measure of increase in power that an antenna adds to a radio frequency (RF) signal with respect to an isotropic antenna (dBi) or a dipole antenna (dBd). Direction is the shape of the transmission pattern. As the gain of an antenna increases, the angle of radiation decreases. This provides a greater coverage distance, but with a reduced coverage angle. Antennas can be broadly classified as directional and omnidirectional antennas, depending on the directionality.

Directional/Donor Antenna:

directional antenna is an antenna which radiates or receives greater power in specific directions allowing for increased performance and reduced interference from unwanted sources. Directional antennas are typically mounted on the roof of a structure where a clear line-of-sight path exists to the distant radio tower as strategic placement can dramatically reduce interference. ADRF’s donor antennas (AD-PA-700-900-DIN and AD-PA-1900-2600-DIN) are considered one of the industry’s finest with its narrow beamwidth, and high front-to-back ratio and gain ( The Donor Antenna is crucial to obtaining the optimal signal and coverage for your repeater system.



Omnidirectional Antenna:

Omnidirectional antennas provide a 360 degree horizontal radiation pattern, often described as “doughnut shaped”. Omnidirectional antennas are very easy to install and they provide perfect coverage for an indoor environment. ADRF’s Low PIM SISO and MIMO antennas are the perfect solution to your in-building coverage needs (


Passive Components:

By offering our customers a wide variety of passive components to perfectly complement our repeaters, DAS, and other active products, we eliminate risks arising from potential sourcing or interoperability issues. These components are manufactured to ADRF’s high standards and are part of our total wireless integrated solution. ADRF’s Passive Components product suite includes:

  • Channel Combiners
  • Splitters
  • Couplers
  • Multi-plexers
  • Attenuators
  • Adapters
  • External Modems
  • Battery Backups
  • RF Jumper Cables


The selection of antenna and passive components should be strictly determined by a correct and proper site survey. Advanced RF Technologies, Inc. has been generating a lot of buzz in the wireless industry with the recent price reduction of all of our passive components and antennas. As of February 1, 2016, ADRF reduced the pricing of our industry-leading antennas and passive components by up to 50 percent. For more information, please contact us at today.