National metrology standards for scattering parameter calibration at radio frequency

This paper summarizes a load device used as the NMIJ´s primary standards for S-parameter calibrations at radio frequencies. The characteristics of the primary load device were calculated on the basis of microwave transmission line theory after SI traceable measurements of dimensions and resistance / insertion loss of whole parts of the load device. The load device keeps its characteristics for a long time, i.e. approximately within 0.00035 deviation par four months. The expanded uncertainty of approximately 0.001 was achieved at 10 MHz for reflection coefficient of the load device.