Basic Regulatory Verification of Unaccredited Laboratory Test Reports
Unaccredited lab test reports require rigorous audit of calibration chains, resolution bandwidth settings, and firmware parameters to survive regulatory surveillance.
Log Periodic Antenna
Meaning
Wideband directional arrays utilize logarithmically spaced dipole elements to achieve constant radiation characteristics and impedance across broad radio frequency bands. Deploying a log periodic antenna enables wideband radiated emissions and field immunity testing without swapping transducers during frequency sweeps. Driven element lengths and spacings scale exponentially along the boom axis to maintain consistent directivity.
Scale Factor
Geometric expansion ratios govern the physical dimensions and electrical spacing of successive dipole elements along the central feed line. The constant ratio between element lengths maintains a stable active region that moves along the array as frequency changes. Higher frequencies resonate near the front short elements, whereas lower frequencies engage the longer rear elements.
This self-scaling geometry preserves constant radiation patterns and stable input impedance across multi-octave bandwidths.
Boom Feed
Twin parallel boom structures act as both mechanical support and balanced transmission line for individual dipole elements. Phase reversal between adjacent elements ensures directional radiation toward the smaller elements.
Directivity Profile
Constant front-to-back ratios and predictable beamwidths minimize chamber wall reflections during radiated immunity testing. High directivity concentrates RF power onto the device under test, reducing total power amplifier requirements. Calibration tables store antenna factors across the frequency range to compute precise field strength values.