Any Antenna may be Omni antennas or Directional antenna. Omni antennas provide approximately the same amount of profit throughout the entire 360-degree horizontal pattern. Directional antenna, sometimes referred to as sector antennas have the maximum winnings in one direction from the backside, usually 15-25 DB below the maximum benefit.
Antenna gain is a function of the horizontal template, template, vertical and the number of elements that make up the antenna array. The number of elements will be dictate the size of the antenna. Link to vertical and horizontal beamwidths as the number of degrees between the points on the template, which is down 3 dB of maximum benefit.
When selecting the antenna should be aware of the following points:
• The size and weight of the load will affect the antenna tower or the ability to place the antenna in the optimum position.
• Generally, antenna models with narrower horizontally or vertically beamwidths will lead to higher antenna gain, assuming a similar length.
• Vertical and horizontal beamwidths will have an effect on field performance of a site midway between the sectors.
IN large horizontal beamwidths would lead to a duplication of the signal between the sectors. Beamwidths impact on noise, saw (thus affect the number of cells capacity) and with the proper signal level specific area.
• Front to back ratio is also affected by the number of antennas interference seen on other sites and the ability to minimize pilot pollution.
Horizontal and vertical templates provided by the selected antenna needs to be verified to ensure that there will be coverage in the area you want. For example, as a means of improvement direct antenna gain, vertical beamwidth can be reduced. In some situations, the reduction in vertical beamwidth can result in poor signal strong Tower near the site of the antennas, excessive growth of the area to be covered.