On 4/29/19 8:24 PM, Matthias Schiffer wrote:
This is just the factor of 1/2/3/4 (approximated) in dB:
10^0.0 = 1
10^0.3 ≈ 2
10^0.5 ≈ 3
10^0.6 ≈ 4
I've seen these numbers being used in WLAN drivers to account for the
antenna array gain, so at least this part of the TX power computation might
already be working as expected.
Kind Regards,
Matthias
On 4/30/19 12:39 AM, Vincent Wiemann wrote:
Hi Matthias,
thank you for the hint. That's funny, because someone from the German Federal
Network Agency
said that when radios have multiple antennas, the aggregated EIRP of the
antenna array must not exceed the
EIRP limits of a single antenna, but I've assumed this is done in hardware and
not in software.
Can you hint me to the source for this lookup table?
Regards,
Vincent Wiemann
On 29.04.2019 08:50, Matthias May wrote:
On 25/04/2019 17:54, Vincent Wiemann wrote:
First EIRP is by definition ERP + antenna gain - cable loss.
Hi
Small detail: Don't forget the antenna array gain.
So EIRP as:
Antenna Port Power
+ Antenna Gain
+ Antenna Array Gain
- Cable Loss
The Array Gain as a simple lookup table:
1 Antenna: 0
2 Antennas: 3
3 Antennas: 5
4 Antennas: 6
BR
Matthias
A concern could be a simple count of antennas may over estimate EIRP and
reduce enabled power below what is allowed. A cheap example of simple
diversity, only one antenna is used for TX based on which of the other
antennas RX the best connection to a client (gain=0). Even with beam
forming, a few antennas may be included in TX phased array and others RX
monitors.
- Eric
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