Meaning
The engineering task of embedding a pre-certified radio module into a non-wireless system converts a standard product into a connected device. This process is termed host device integration, and it must conform to the conditions of the modular grant.
Compliance Rule
The integrator must respect the boundary conditions set by the original equipment manufacturer during the initial certification. In many cases, the modular grant specifies a minimum separation distance between the transmitting antenna and the human body. Host device integration that violates this distance requires a change in the regulatory approach, shifting the device from the mobile category to the portable category.
This change necessitates specific absorption rate evaluations, which are not covered by the initial modular approval.
Antenna Selection
Selecting an antenna that matches the gain and type used during the module’s certification is necessary to maintain compliance. If an integrator chooses a different antenna type or a higher gain model, they must perform additional transmitter testing. During host device integration, the impedance of the antenna feed line must be controlled to prevent power losses.
Designers often use a co-planar waveguide to route the signal, ensuring that the trace does not pass near noisy digital components.
Radiation Assessment
A final evaluation of the integrated system is performed to ensure that the combination does not generate new unwanted emissions. This process involves testing the host device with the radio active to verify that the digital circuitry has not coupled with the transmitter to produce spurious signals. These checks must be completed before the product can be shipped to distributors or sold to end-users.
Failing to perform this step can lead to market recalls if the finished device is found to exceed the regulatory limits for radiated noise.
