Host Integration Permissive Changes and Modular Approval Dossier Scope
Host integration of approved radio modules requires strict permissive change assessment and tailored dossier compilation to preserve regulatory market access.
Intermodulation Spurious
Meaning
Unwanted radio frequency emissions generated by the mixing of two or more signals in a non-linear circuit. The presence of intermodulation spurious signals occurs when high-power transmitters operate in close proximity or within the same front-end module. These third-order and fifth-order products often fall within the receive band of the same device.
The boundary of the issue is defined by the linearity of the power amplifiers and the isolation between ports.
Mixing Product
Mathematical combinations of the fundamental frequencies create new signals at predictable intervals. If a 900 MHz and a 910 MHz signal pass through a non-linear component, intermodulation spurious appears at 890 MHz and 920 MHz. These phantom signals can violate regulatory masks for out-of-band emissions.
Filter Rejection
Suppression of non-linear artifacts requires high-performance surface acoustic wave or bulk acoustic wave components. Effective design limits intermodulation spurious by providing steep attenuation at the frequencies where the mixing products are expected to appear. Passive components must also be screened for passive intermodulation which occurs in connectors and cables.
High-quality plating and torque control reduce the generation of these signals at the physical interface.
System Sensitivity
Noise floor elevation caused by internal interference reduces the range and reliability of the wireless link. When intermodulation spurious falls directly on the operating channel of a receiver, it desensitizes the radio. This leads to dropped packets and lower data rates in congested environments.
Maintaining high linearity in the transmit chain is the primary defense against this type of self-interference.