Wide-band RF signal power detecting element and power detecting device using the same

A wide-band RF signal power detecting device comprising:

• a wide-band RF signal power detecting element comprising a substrate, a resistor formed on said substrate, electrodes formed on one surface of said substrate and connected to two ends of said resistor, and a thermocouple for outputting a signal corresponding to heat generated by said resistor, and set such that transmission impedance between said electrodes has a predetermined value;
• and
• a module substrate made larger than said substrate of said wide-band RF signal power detecting element, and comprising a central conductor and a ground conductor formed by patterning on one surface of said module substrate to guide a signal to be measured, and mount portions formed, in one-to-one correspondence with said electrodes of said wide-band RF signal power detecting element, at a distal end of said central conductor and in a portion of said ground conductor in the vicinity of the distal end of said central conductor, said module substrate fixing said wide-band RF signal power detecting element to the one surface with said electrodes of said power detecting element joined to said mount portions, supplying a signal to be measured to between said electrodes of said power detecting element, and outputting a signal corresponding to power of the signal to be measured,
• wherein a transmission impedance between said central conductor and said ground conductor of said module substrate is made substantially equal to a transmission impedance between said electrodes of said wide-band RF signal power detecting element, and wherein said central conductor is given an inductance component corresponding to a capacitance component increased by junctions between said mount portions and said electrodes of said wide-band RF signal power detecting element.