Abstract: A microstrip probe includes a microstrip transmission line constructed from a dielectric substrate having a conductive microstrip thereon. The substrate is carried by a carrier which forms the ground plane for the microstrip transmission line. A retractable ground pin projects outwardly from the forward edge of the carrier and also extends past the forward edge of the substrate.

Abstract: A test apparatus has a fixture with upstanding walls and a receiving slot for receiving a substrate holder with a substrate mounted on the holder. Two launchers extend into the receiving slot. Each launcher has two outside contacts and a center pin contact. The pin is electrically insulated from the outside contacts. The center pins contact the two sides of the narrow, central transmission line contact of the substrate, and the two outside contacts of each launcher contact the wider grounded region on the sides of the narrow active region of the substrate. The outside contacts are mounted on a coplanar sleeve that can rotate to some degree so that when the substrate contacts the outside contacts, the coplanar sleeve can rotate so that the surfaces of the electrical contacts against the substrate conform to the surface of the substrate. The holder has two portions. A guide forces the holder to be inserted into the receiving slot such that the substrate does not contact the launcher.