Effects of the effective efficiency of the thermistor mount with WR-22(33 to 50 GHz) microcalorimeter

In this paper, the effective efficiency of the thermistor mount was evaluated by three WR-22 (33-50 GHz) rectangular waveguide microcalorimeters. Three sets of microcalorimeter were made from the same design drawing. The only difference among them was some key parts (thermal conductive plate and heat isolation section) coming from different manufactures. The relative deviation of measurement results of each microcalorimeter was within one percent. However, the evaluated effective efficiencies of same DUT were highly inconsistent for different microcalorimeters in some frequency points. The preliminary conclusion was that manufacturing process of microcalorimeter would be likely to affect the effective efficiency evaluation of the thermistor mount, and some necessary improvement works have been planned in near future.