Radiated Spurious Emissions Mitigation in Multi Radio System Design
Radiated spurious emissions in multi-radio designs demand aggressive board-level isolation and predictive intermodulation filtering to secure market approvals.
Chamber Measurement
Meaning
Electromagnetic characterisation evaluates the radio frequency emission and reception patterns of an assembled wireless device inside a controlled, shielded volume. Conducting a chamber measurement determines the over-the-air performance and electromagnetic compatibility of an integrated product before market release. The evaluation identifies spurious emissions arising from board-level interactions or shielding leaks.
This boundary stops at the physical walls of the test enclosure, which isolate the device under test from external ambient interference.
Environment Control
RF-absorbent foam pyramids line the interior walls to suppress reflections and simulate free-space conditions. An anechoic enclosure isolates the sensitive receiving antenna from cellular signals and wireless networks. The physical dimensions of the space determine the lowest usable frequency of the test setup.
Technical Protocol
Positioned on a multi-axis turntable, the active product rotates through a programmed sequence while the measurement antenna captures the transmitted signal strength at discrete angles. The test software correlates the rotational position with the received power to construct a three-dimensional radiation pattern. Discrepancies between the simulated antenna design and the actual measured performance often originate from passive component traces or nearby metal brackets.
This scanning procedure also reveals the total radiated power and total isotropic sensitivity of the fully integrated module.
System Qualification
Discrepancies in the resulting values require the engineering team to reassess the housing material or revise the trace routing on the printed circuit board. Satisfying the limits of regulatory bodies remains the primary criterion for a successful evaluation. The validated pattern acts as the final benchmark that the assembly meets both carrier requirements and international emissions standards.