3.7 Antenna Reference Designs

Multiple factors affect proper antenna match, hence, affecting the antenna pattern. The particular factors are the board material and thickness, shields, the material used for enclosure, the board neighborhood, and other components adjacent to antenna. The following are the general recommendations that need to be followed when designing the baseboard for the ZigBit module.

General Recommendations:

  • Do not use a metal enclosure. Using a low profile enclosure can also affect antenna tuning.
  • Avoid placing high profile components next to the antenna.
  • Having holes/vias punched around the periphery of the board eliminates parasitic radiation from the board edges also distorting antenna pattern.
  • Do not place the ZigBit module next to consumer electronics that can interfere with the ZigBit module’s RF band frequency.

The board design must prevent propagation of a microwave field inside the board material. Electromagnetic waves of high frequency can penetrate the board, thus, making the edges of the board radiate, which can distort the antenna pattern. To eliminate this effect, metalized and grounded holes/vias must be placed around the board’s edges.