Managing Dual Band Radio Laboratory Testing under Chinese Regulatory Frameworks
SRRC approval for dual-band radios demands locked firmware power tables, local agent coordination, and strict host radiated spur compliance to avoid re-test delays.
5.8 GHz Power Spectral Density
Meaning
Power distribution limits specify how much transmitter energy may be packed into any single slice of the operating band. For devices utilizing the upper industrial band, the 5.8 ghz power spectral density defines the maximum conducted power permitted in any five hundred kilohertz segment.
Signal Concentration
Regulators restrict this concentration to maintain a fair sharing of the shared radio spectrum among unlicensed products. In many territories, the 5.8 ghz power spectral density must not exceed thirty decibel-milliwatts per five hundred kilohertz when a device operates as a point-to-point bridge. When designers employ wider channel bandwidths, the total power is spread over a larger frequency range, lowering the density.
Board Design
Engineering teams adjust the output stages of the radio-frequency front end to prevent local saturation of the spectrum. If the 5.8 ghz power spectral density exceeds permitted levels, the power amplifier must be throttled or the modulation scheme altered to distribute the energy more evenly. This balance affects the thermal budget of the transceiver because inefficient power settings generate waste heat that must be dissipated by the enclosure.
High-density signals can also cause non-linear behaviors in the mixing stages of the transceiver, creating unwanted harmonic products.
Validation Protocol
Laboratory technicians verify these emissions by connecting the antenna port directly to a calibrated spectrum analyzer. The test program configures the transmitter to send a continuous, maximum-rate stream of packets while the analyzer measures the power in the specified bandwidth. Failure to stay within the 5.8 ghz power spectral density limits during these sweeps requires a firmware adjustment before the module can be sold.