Digi modules are available with a 1/4 wave integrated wire antenna which is the most economical antenna option available. This option requires the module to be mounted inside a non-metal housing so that the antenna can transmit through the housing and still have good transmission range.
The integrated wire antenna will work best if the antenna can be installed in the final product to extend straight up perpendicular to the RF module. Because it is not always possible to accommodate the antenna in the optimum configuration; follow these guidelines to optimize the performance in any housing:
Extend the antenna directly away from the board in any direction for at least 1 inch before making any bends.
Maximize the distance between the antenna and any ground planes or metal inside the housing.
Antenna can run parallel to the RF module if separated by at least 1 inch.
The antenna may be folded back over the RF module only as a last resort as this configuration will provide the worst performance.
These guidelines will help the OEM accommodate the antenna in their product housing while maintaining as much performance as possible. Note that all of these modifications will adversely affect the performance of the antenna but it will still perform well in many applications.
Any antenna system should be thoroughly tested in real world environments to ensure adequate performance for the application.
Aug 23, 2017