Chip antenna

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” (

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?