Your Source for New or Used Cisco AIR-ANT5145V-R
Cisco Aironet  Cisco Aironet Antenna AIR-ANT5145V-R 5 GHz 4.5dBi Diversity Omni w/RP-TNC connector
Cisco "AIR-ANT5145V-R" Indoor-Only Diversity Omnidirectional 5 GHz Antenna
The "AIR-ANT5145V-R" antenna is intended for use with the 1200 Series and the
802.11a module (AIR-RM22A). Cisco Aironet Antennas are designed to perform in a
variety of environments. Implementing the antenna system can greatly improve
coverage and performance. To optimize the overall performance of a Cisco
wireless LAN, it is important to understand how to maximize radio coverage with
the appropriate antenna selection and placement. An antenna system comprises
numerous components, including the antenna, mounting hardware, connectors,
antenna cabling, and in some cases, a lightning arrestor.
Cisco "AIR-ANT5145V-R" Indoor-Only Diversity Omnidirectional 5 GHz Antenna
The Cisco Aironet product lines utilize both the 2.4- and 5-GHz bands. In the
United States, three bands are defined as unlicensed and known as the ISM bands.
The ISM bands are as follows:
- 900 MHz (902-928 MHz)
- 2.4 GHz (2.4-2.4835 GHz) IEEE 802.11b
- 5 GHz (5.15-5.35 and 5.725-5.825 GHz) IEEE 802.11a, HIPERLAN/1 and
HIPERLAN/2. This band is also known as the UNII band, and has 3 sub-bands,
UNII1 (5.150-5.250 GHz), UNII2 (5.250-5.350 GHz) and UNII3 (5.725-5.825 GHz)
Each range has different characteristics. The lower frequencies exhibit
better range, but with limited bandwidth and hence lower data rates. The higher
frequencies have less range and are subject to greater attenuation from solid
objects.
An antenna gives the wireless system three fundamental properties?gain,
direction, and polarization. Gain is a measure of increase in power. Direction
is the shape of the transmission pattern. A good analogy for an antenna is the
reflector in a flashlight. The reflector concentrates and intensifies the light
beam in a particular direction similar to what a parabolic dish antenna would to
a RF source in a radio system.
Antenna gain ratings are in decibels which is a ratio between two values. An
antenna rating is typically to the gain of an isotropic or dipole antenna. An
isotropic antenna is a theoretical antenna with a uniform three-dimensional
radiation pattern (similar to a light bulb with no reflector). dBi is used to
compare the power level of a given antenna to the theoretical isotropic antenna.
The U.S. FCC uses dBi in its calculations. An isotropic antenna is said to have
a power rating of 0 dB; for example, zero gain/loss when compared to itself.
Unlike isotropic antennas, dipole antennas are real antennas (dipole antennas
are standard on Cisco Aironet access points, base stations, and workgroup
bridges). Dipole antennas have a different radiation pattern compared to
isotropic antennas. The dipole radiation pattern is 360 degrees in the
horizontal plane and 75 degrees in the vertical plane (assuming the dipole
antenna is standing vertically) and resembles a donut in shape. Because the beam
is "slightly" concentrated, dipole antennas have a gain over isotropic antennas
of 2.14dB in the horizontal plane. Dipole antennas are said to have a gain of
2.14 dBi (in comparison to an isotropic antenna).
Some antennas are rated in comparison to dipole antennas. This is denoted by
the suffix dBd. Hence, dipole antennas have a gain of 0 dBd (= 2.14 dBi).
Note that the majority of documentation refers to dipole antennas as having a
gain of 2.2 dBi. The actual figure is 2.14 dBi, but is often rounded up.
Your Cisco AIR-ANT5145V-R is ready for immediate shipment the same day you place your order in most cases and every product we sell comes with an industry leading One-Year Warranty. Plus, with our ADC Warranty Shield program we can even offer you a Lifetime Warranty. Our relationship doesn't end when the sale is completed. It's just beginning. Free technical support is available toll free by calling (888)872-5619.
| 
