Abstract: A method is described for measuring the noise parameters of field effect transistors (FETs) while still in the wafer stage. Instead of conducting lengthy testing of each individual device at the operating frequency of interest after the devices have been diced, mounted and bonded, each of the devices on a wafer is automatically probed to obtain the standard S-parameters and also the FET's output noise power P.sub.n at a frequency at which parasitic probe effects are avoided. The various noise parameters can then be calculated for higher operating frequencies of interest from FET equivalent circuit parameters derived from the S-parameters, and from P.sub.n, either before or after dicing.

Abstract: A power divider/combiner assembly is provided which matches the impedance seen at the input/output port with the impedance seen at the peripheral end of each of plural radial transmission lines. Impedance matching is accomplished through the use of an inverted microstrip on a substrate suspended over an air dielectric. The thickness of the air dielectric is varied along each transmission line in discrete steps from the common dividing/combining end to the peripheral end of each transmission line. The air dielectric thickness can be chosen independently for each section of line so that a characteristic impedance of from 40 ohms to greater than 130 ohms is achieved.