SNIFT

The accurate and highly stable SNIFT software transforms measured spherical near-field antenna data to far fields, accounting for the full characteristics of the measuring probe.

Features

      Allows full sphere or partial sphere input data
      Full correction for m=±1 probes
      Fast Fourier Transformation and self-stabilizing recurrence relations allow handling of even very large antenna structures
      Industry standard for spherical near-field to far-field transformation with probe correction
      Independent of the actual measurement system implementation

Rotation of the spherical wave coefficients

If only a certain region of the antenna pattern has interest, it is possible to perform truncated measurements and still use SNIFT for the transformation. The transformed data are referred to the measurement coordinate system, but if, for example, the region of interest does not coincide with this system (e.g. a scanned beam), the supplementary program ROSCOE can be applied to do the appropriate coordinate transformation into a system centered around the peak.

Accurate determination of spherical harmonics

Well-founded choice of numerical implementation ensures a very stable algorithm, also for high-order harmonics. Antennas with diameters exceeding several hundred wavelengths are handled within seconds on a standard PC with accurate determination of all involved spherical harmonics.

Values

       Fast transformation time
      Mathematically exact pattern transformation
      The output pattern may be given in coordinate system rotated to peak direction of the far field
      Non-Maxwellian measurement inaccuracies are averaged to physically correct output
      Noise reduction by means of high-order spherical mode filtering