A new design and evaluation technique of a microcalorimeter

A new design and evaluation technique of a rectangular waveguide microcalorimeter is presented. Its design is based on the NIST new WR-15 microcalorimeter design^[1], but an important modification was made so that the principle of the measurement was changed. In this design, not only can take the original evaluation technique, but also take the new method to obtain the final data-reference standard´s effective efficiency. By the new evaluation technique, we don´t need measure the S-parameter of the trans-line in the microcalorimeter which is the main uncertainty source in obtaining the thermistor mount effective efficiency.