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: Method and apparatus for simultaneously measuring noise power of a two-port device under test (DUT) using a one-port tuner, a low-noise amplifier, a power divider with a plurality of outputs, and a plurality of noise meters. The noise meters are configured to measure available noise power in different frequency ranges which are closely spaced around a selected central frequency, thereby yielding the noise parameters of the DUT at the central frequency.

Abstract: An adapter, having a dielectric substrate upon which are mounted an array of uniformly-spaced, coplanar conductive strips and impedance standards having similarly spaced coplanar leads, facilitates planar transmission line probe measurements of the high-speed electrical characteristics of a package or other interconnect structure for a high-speed integrated circuit. The conductive strips of the adapter are connected to the terminals of the package so as to simulate the integrated circuit connection, that is, with substantially identical length and spacing of bond wires. The planar probe, by contacting the conductive strips of the adapter, is able to measure the electrical characteristics of the package including the bond wires, thereby providing realistic measurements of the integrated circuit's environment. The impedance standards on the adapter are specially designed to enable the effects of the adapter to be removed from the measurements by calibration.

Abstract: A waveguide configuration have a longitudinal ridge directly opposing a longitudinal trough. The ridge provides broadband signal transmission characteristics of ridge waveguides and may extend within the trough to result in a virtually horizontal electric field configuration.

Abstract: A test fixture for testing microstrip assemblies and similar electronic circuit components and assemblies under application of high-frequency signals introduced through launchers whose positions are adjustable in the test fixture to accommodate circuit assemblies of different sizes and different geometry. An easily operated rapid connector positioning mechanism moves connectors which complete electrical connection between outer conductors of the launchers and a ground plane conductor of a microstrip assembly. The connectors also lift the microstrip assembly and support it while electrical connection is completed, without the need for a carrier beneath the test assembly. A lid is moved in coordination with operation of the connector positioning mechanism to provide electrical contact to a third point on the upper face of a circuit assembly to be tested.

Abstract: A method of determining a receiver's noise parameters by measuring one noise power for a first source noise temperature and a plurality of noise powers for another source noise temperature, all at known different source reflection coefficients.

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 method of measuring and compensating for measurement frequency inaccuracies encountered when measuring noise power of a device under test within a desired calibrating frequency range. The method includes sweeping a frequency synthesizer through a frequency range which includes the desired measurement frequency range. Power is measured for different synthesizer frequencies with the noise power meter set to the desired frequency range. Alternatively, the frequency synthesizer may be set to the desired measurement frequency and the noise power meter swept through a range including the desired measurement frequency. The resulting power measurements show the frequency range within which the noise power meter actually measured power.

Abstract: A system for calibrating vector corrected electrical measurements to adjust for distortion due to reactance in the measuring circuit, particularly that caused by variable positioning of a circuit element, such as probe or coupling. Initial error factors for directivity, source match, and frequency response, respectively, normally calculated from assumed reflection coefficients of respective primary impedance standards, are adjusted to correct for such reactance. Reflection coefficient measurements (magnitude and phase) of a further impedance standard, different from the primary standards, are obtained at multiple frequencies and corrected by the initial error factors. The corrected magnitude and phase measurements of the further impedance standard are compared with theoretical magnitude and phase values which very linearly with frequency, and the initial error factors are adjusted so as to minimize any deviation of the corrected measurements from the linear values.

Abstract: A launcher having an outer conductor and a tapered central contact pin within a bore of the outer conductor connects coaxial transmission lines with microstrip transmission lines. The launcher, when used with a microstrip transmission line having a specific dielectric substrate thickness, provides matching of both the characteristic impedance and the electro-magnetic field configuration. The launcher also may be used effectively with microstrip transmission lines having different substrate thicknesses An adjustable stop transversely positions the upper surface of the microstrip transmission line relative to the launcher's outer conductor to counteract capacitive discontinuities caused by different substrate thicknesses. Although such adjustments flex the central contact pin transversely, thus changing the launcher's characteristic impedance, the launcher provides better overall matching between the two types of transmission lines.

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: A wafer probe for accessing bonding pads on a planar device includes contact pads mounted on one edge of the under side of a dielectric substrate board and arranged to align with the bonding pads to be accessed. Coplanar ground and signal conductors deposited on the under side of the substrate board form constant impedance transmission lines for connecting test equipment to the contact pads. A ground contact is mounted on the upper side of the substrate near the end on which the contact pads are mounted, the ground contact being connected by a conductive path to the ground conductors on the under side of the substrate. When two such wafer probes simultaneously access bonding pads on the same planar device, the ground conductors of the two probes are interconnected by a conductive sheet of foil extending between the ground contacts on the upper sides of the substrates of both wafer probes.

Abstract: A wafer probe for testing semiconductor devices brings low impedance connections closely adjacent device bonding pads for bypassing power supply voltages.

Abstract: A wafer probe is provided having metallic transmission lines mounted on a tapered alumina substrate generally surrounded by microwave absorbing material. The probe provides for on-wafer measurements of small planar devices at frequencies from DC to at least 18 GHz with low inductance, and with constant characteristic impedance from the probe external cable terminal to the point of contact on device being probed. The microwave absorbing material absorbs energy propagating along the probe ground preventing this energy from resonating, radiating and re-exciting normal transmission line modes with minimal transmission line mode resonance along the probe ground. The probe, which may be coupled to receive signals from a coaxial cable, is capable of making contact with bonding pads of a device having a center-to-center distance between pads of only 4 mils.