User's Manual

CT-EM2506 ZigBee Ready RF Transceiver Modules

16. Antenna Design Considerations

The CT-EM2506 module includes an integrated PCB trace antenna. An optional MMCX

connector can be specified, enabling connection to a 50-ohm external antenna of the user’s

choice..

The PCB antenna employs an F-Antenna topology that is compact and supports an

omni-directional radiation pattern. To maximize antenna efficiency, an adequate ground

plane must be provided on the host PCB. If positioned correctly, the ground plane on the host

board under the module can contribute significantly to antenna performance.

The position of the module on the host board and overall design of the product enclosure

contribute to antenna performance. Poor design effects radiation patterns and can result in

reflection, diffraction, and/or scattering of the transmitted signal.

Here are some design guidelines to help ensure antenna performance:

• Never place the ground plane or route copper traces directly underneath the antenna

portion of the module.

• Never place the antenna close to metallic objects.

• In the overall design, ensure that wiring and other components are not placed near the

antenna.

• Do not place the antenna in a metallic or metallized plastic enclosure.

• Keep plastic enclosures 1cm or more from the antenna in any direction.

Test at 2440MHZ

__ Vertical Polarization Gain

(dBi)

Avg : -14.8

--- Horizontal Polarization Gain

(dBi)

Avg : -3.4