Measurements of Currents and Voltages down to a Wavelength of 20 Centimeters

Bolometric voltage and current (bolovac) standard for high and microwave frequencies

“…), we will allow a conservative width of the electrodes on the disk surface of 15 X 10 -3 cm. The computed [19] equivalent shunt capacity introduced by these electrodes in a 7-mm, 50-0 line is approximately 15 X 10 -3 pF. The effect of the equivalent quadrature shunt reactance at 10 GHz on current measurements employing a 50-0 film will be approximately 0.11 percent.…”

“…Based upon the distance be tween planes Hand C, one may th e refore calculate the value of llf (III = 0.9781 c) with an es timated unce rtainty of 0.2 percent. It is e vide nt from eq (19) that this e rror will be lower as th e heater resistan ce is in c rease d.…”

“…Except for the case of thermistors and other beads (havin g diam e ters of th e ord er of 0.1 to 1 mm ), th e c urrent se nsin g ele me nts are long relative to th e s horter wavelen gth s involved here. The UHF th ermoele ments hav e a glass e nv elope of about 2 c m in diameter and heater diameters startin g at about 10 or 20 J.L (for th e 5 mA c urre nt carrying capac it y); th e heaters are about 1 c m in length [19] . Th e un ce rtainti es in calibrating th ese types of th erm oele m e nts are bri e Ay di sc ussed her e as an illu stration of th e proce dure in error evaluati on.…”

“…(19) Here f x and fA are the respective c urrents entering the planes at x and A; x is the distance from plan e A toward the c urrent source.…”