Documentation discrepency

I am pulling data together to update our internal knowledge base. 

I just downloaded (painfully) the .pdf files: PMP_450_Subscriber_Module-July2014 +  ReflectorDish_Sept2014.

In the PMP_450_Subscriber_Module-July2014 document, the specs for SM Antenna gain say, "8 dBi DUAL SLANT, INTEGRATED PATCH (2.4 GHz, 3 GHz) ".

The specs for Reflector gain say, "+12 dBi FOR 2.4 GHz AND 3 GHz ".

Add those up and you get 20dBi.

In the .pdf document ReflectorDish_Sept2014, the specs for  "TOTAL GAIN (Integrated Antenna + Reflector Dish)" PMP AND PTP 450 3 GHZ = 21DBI

Which figure is it? 20 or 21?

Is it dBi or DBI?

Hi Brian - Thanks very much for pointing this out.... antenna measurements have some amount of error, and sometimes documentation (when located in different places) fails to get updated to the latest or most accurate information.

Our recent testing of the 3 GHz PMP 450 SM with the reflector dish yielded results of 20 dBi at 3650 MHz, but as high as 22 dBi at 3450 MHz.  Because our spec sheet is intended as a quick reference, we try to keep the numbers quite simple, and put 21 dBi as the overall number for 3 GHz (in fact, the gain is 21 dBi across much of the 3.3 - 3.8 GHz band).

If you need additional detail on antenna testing that has been performed, please let me know.

Also, regarding dBi or DBI, we intend decibels (isotropic) in both cases.  (On the "Reflector Dish" spec sheet, I suspect this is an all caps kind of font issue... we can fix it).