Antenna Gain for Aruba AP-315/IAP-315
11-07-2019 10:56 AM
Datasheet for Aruba AP-315/IAP-315 says:
"Four integrated dual-band downtilt omni-directional antennas for 4x4 MIMO with peak antenna gain of 3.6dBi in 2.4 GHz and 6.0dBi in 5 GHz"
"Combining the patterns of each of the antennas of the MIMO radios, the peak gain of the effective per-antenna pattern is 3.1dBi in 2.4 GHz and 3.8dBi in 5 GHz"
At 5 GHz: Can anyone explain me why the peak antenna gain is 6.0dBi and the peak gain of the effective per-antenna pattern goes down to 3.8dB?
Why at 5 GHz the peak gain goes down dramatically to 3.8 dBi compared to 2.4GHz? ... or there is an error in the datasheet?
Thanks for your comments
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Re: Antenna Gain for Aruba AP-315/IAP-315
11-07-2019 01:36 PM
Antenna peaks apply to a particular direction (in 3D) around the AP. The patterns are not homogeneous, and vary a bit (and sometimes a lot) from one antenna to the next.
So since the peaks for each antenna do not typically align, the peak of the average pattern for all antennas in a band can be quite a bit lower than the peak of the individual patterns for each antenna in that band.
Note that total peak gain is the sum of this "peak of average pattern" plus MIMO gain (3dB for 2x2, 6dB for 4x4).
The actual difference depends on the specific patterns and number of antennas.