Abstract: A device for measuring the power in a microwave transmission and for providing a measuring port at the output of a microwave signal generator or transmitter. First and second quarter wavelength transmission line sections, coupled in series with one another and having characteristic impedances Z.sub.2 and Z.sub.1 respectively, where Z.sub.2 >>Z.sub.1, are coupled at the first section to a predetermined point on a transmission line to be monitored. A port at the free end of the second section allows for the connection of two independent measuring circuits to the transmission line.