Meaning
RF measurement instruments employ specialized sensors to reconstruct three-dimensional electric field vectors from multiple scalar measurements. A pseudo vector probe uses closely spaced dipole elements to calculate the magnitude and direction of the electromagnetic field at a specific point. This configuration provides a cost-effective alternative to true vector probes in automated test environments.
Operating Principle
The probe sequentially measures the field components along pre-defined orientations to estimate the vector field. In a typical scan, the pseudo vector probe gathers data from three orthogonal sensors and uses a mathematical algorithm to resolve the final field vector. This sequential acquisition requires the source signal to remain coherent and stable during the measurement process.
It reduces the complexity of the receiver hardware while still providing the essential spatial field information needed to evaluate the device performance.
Measurement Protocol
Automated test systems move the sensor through a pre-programmed grid to map the emissions of the device under test. When utilizing a pseudo vector probe, the system must account for the physical spacing between the individual sensor elements. The control software applies a correction factor to align the measurements to a single reference point.
Calibration Method
The sensor must undergo regular calibration in a known reference field to maintain its measurement accuracy. Calibrating the pseudo vector probe involves exposing it to a uniform field inside a TEM cell or waveguide. This process defines the sensitivity and correction factors for each dipole element, which are stored in the probe’s memory.
