Hi there
The radiation pattern for the XBee chip antenna seems to have a severe null on the module’s right side, as shown on page 7 of “XBee & XBee‐PRO OEM RF Module Antenna Considerations” (http://ftp1.digi.com/support/images/XST-AN019a_XBeeAntennas.pdf)
Is there an explanation for why the right side has this null? (I would have guessed that a null (if any) would be to the rear, rather than to one side.
Or is there an inconsistency between plots and the module orientation shown on page 5?
Regards