Abstract: An RF wattmeter is disclosed of the type using an "insertion-type" pick-up element to produce a voltage wave signal corresponding to the measured power in the coaxial transmission line. The induction loop in the pick-up element is connected to a principal detector, and a secondary detector is connected in opposition to the principal detector. Both detectors are located in close proximity to each other and are subject to the same thermal environment. A sine wave generator supplies a wave signal to the secondary detector in opposition to the wave signal supplied to the principal detector from the inductive loop. The d.c. portion of the resulting signal representing the difference between the opposed signals is integrated, and the integrated output is used as the amplitude in the generated sine wave. When the circuit is in balance, the integrated output matches the amplitude of the inductive wave form and can be used as an output indicating measured power in the coaxial transmission line.

Abstract: An electronic instrument is disclosed for measuring directional RF power levels and power function levels on a coaxial transmission line. The instrument includes an inductive sensing loop for sensing the RF voltage level on the transmission line and producing a voltage level proportional thereto. An analog-to-digital conversion means is connected to the sensing loop for converting the voltage level from the sensing loop to binary voltage data. A microcomputer means is associated with the conversion means for performing arithmetic operations upon the binary voltage data to calculate power data and power function data. Means connected to the microcomputer means are also provided for displaying the calculated power data and power function data. The instrument provides a direct readout in digital form of RF power data and data for various power and voltage functions such as VSWR.