Abstract: A return line for a probe station includes a sheet-like conductive strap having a first end connected electrically to a first probe and a self-coiling second end connected automatically detachably to a second probe, as by insertion of the second probe centrally within the coils of the second end. If the spacing between the probes exceeds a maximum distance, the strap harmlessly disconnects. The flat central portion of the strap automatically tracks any reductions in the spacing between the probes, which enables fast probe travel and minimizes noise pickup. Preferably a spindle rotatably engages the coiled probe and has a post member that carries the second end of the strap to a far side of the probe to improve tip visibility and electrical connection during close-in probing.

Abstract: A high-frequency probe comprising a semirigid coaxial line which terminates in an active circuit assembly. The coaxial line's outer conductor is connected to a box while its inner conductor is connected to an active circuit chip. A signal contact needle is attached to the active circuit chip and extends linearly with the coaxial line. The signal needle is held in place with a mass of epoxy filled with silica microballoons, providing a low-capacitance mount. A ground contact needle is connected to a wiper which contacts the box, thus providing a direct, and short, path between the coaxial line's outer conductor and the ground contact needle.

Abstract: An electrical probe tip is yieldably mounted on a probe mount so that, as the probe mount and a device under test are advanced toward each other, the contact force between the probe tip and the device under test first increases gradually and then decreases. This prevents excessive contact force if the probe mount and device under test are inadvertently advanced excessively toward each other, and thereby prevents damage to the probe tip.

Abstract: A high-frequency probe comprising a semirigid coaxial line which terminates in an active circuit assembly. The coaxial line's outer conductor is connected to a box while its inner conductor is connected to an active circuit chip. A signal contact needle is attached to the active circuit chip and extends linearly with the coaxial line. The signal needle is held in place with a mass of epoxy filled with silica microballoons, providing a low-capacitance mount.A ground contact needle is connected to a wiper which contacts the box, thus providing a direct, and short, path between the coaxial line's outer conductor and the ground contact needle.

Abstract: An interface structure, for connecting a pair of coplanar transmission lines in end-to-end overlapping relation to each other, employs dissimilarly-shaped overlapping end portions of the respective signal and/or ground lines of the transmission lines. The dissimilarly-shaped end portions are effective to minimize variations in the impedance of the interface structure due to variations in transverse and/or longitudinal alignment of the overlapping end portions of the respective transmission lines, thereby making the interface tolerant to misalignments.

Abstract: A microwave wafer probe having a replaceable planar transmission line probe tip which detachably connects to a planar transmission line circuit board within the probe head. The circuit board may include passive and/or active electrical circuit components interconnecting its conductors which, due to the detachable interconnection with the probe tip, do not have to be replaced if the probe tip should be damaged. The detachable interconnection between the probe tip and the circuit board is tolerant to misalignment of the two elements because the interconnected end portions of the respective conductors are shaped so as to maintain the impedance between the two elements substantially constant despite misalignment. Preferably, both the circuit board and the detachable tip include coplanar transmission lines interconnected by compressing the overlapping end portions of their conductors together.

Abstract: Improved TRAPATT diodes in which the improvement comprises a high-temperae metallization on silicon from which the diodes are formed.Metallization is applied to a silicon wafer by sputtering a layer of titanium, chromium, tungsten alloy followed by a gold layer. The desired diode shape and size is defined in the gold layer by use of a pattern of the proper shape and size in combination with a photolithographic process. The metallization layers and the silicon are then etched so as to form a plurality of individual shaped (mesa or ring structure) TRAPATT diodes. Such diodes can withstand 610.degree. C. for one hour without degradation.