Cascade Microtech, Inc.

Tektronix, Inc.

Keith E Jones

K Reed Gleason

Eric W Strid

Warren K Harwood

John Albert Wright

H Erwin Grellmann

Dale E Carlton

Daniel DeLessert

Carl W Laakso

Stephen H Skidmore

Edward M Godshalk

Wesley H Hayward

Thomas A Myers

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.

High-frequency active probe having replaceable contact needles

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.

System for facilitating planar probe measurements of high-speed

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.

Ridge-trough waveguide

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.

Test fixture for microstrip assemblies

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.

Overlap interfaces between coplanar transmission lines which are

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. Thereafter, by positioning the probe or other circuit element relative to a device under test substantially identically to its previous placement relative to the further impedance standard, the adjusted error factors can be used to obtain corrected measurements with minimized magnitude and phase errors due to reactance.

System for setting reference reactance for vector corrected measurements

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. The contact tip of the pin has a cylindrical contact surface coaxial with the pin, thus forming a repeatable line contact with the upper conductor of the microstrip transmission line enabling consistent results. The bore of the outer conductor is at an angle with respect to the coaxial transmission line jack, allowing the tapered pin to extend coaxially with the jack so that the pin can be drilled and tapped on its center axis, simplifying its mass production.

Coaxial transmission line to microstrip transmission line launcher

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.

Microwave wafer probe having replaceable probe tip

Integrated capacitors provide more than one capacitor on a single dielectric substrate. A dielectric substrate has a conductive backplane on one side and two or more conductive capacitor plates on the opposite side. The integrated capacitors may be mounted on a shield wall which has a through hole so that one capacitor is connected to the shield wall and another forms a coupling capacitor via the hole between two stages on opposite sides of the shield wall.

Integrated capacitors for forming components of bandpass filters

A broadband, monolithic integrated-circuit power divider/combiner circuit utilizing gallium arsenide field-effect transistors configured as distributed amplifiers. Two distributed amplifiers include a common merged transmission line element which divides/combines the input signal(s).

Power divider/combiner circuit

A microwave interconnect for integrated or hybrid circuits includes a flexible sheet bearing a flexible conductor which is divided into a plurality of insulated conductive lines, at least some of which make contact with the integrated or hybrid circuit, as well as with a second circuit to which the first is thereby connected. The flexible sheet is backed by a body of elastomeric material and a compression bar which assures good electrical contact of the flexible conductor with the circuits when the compression bar is tightened down on the circuits. The construction allows some degree of misregistration of parts while providing circuit coupling operative at high frequencies.

Microwave interconnect

An improved loop coupled YIG resonator has a coupling loop of three sections, a loop section partially encircling a YIG resonator, and two straight end sections. The end sections together with a ground plane enclosing one end of the resonator cavity form a transmission line, the characteristic impedance of which is determined by the distance of the end section above the ground plane. The characteristic impedance is chosen to match the transmission line input to which the coupling loop is connected.

Loop coupled YIG resonator

A surface mountable microwave IC package uses printed transmission lines on a printed circuit board in lieu of plumbing between milled packages. A backside co-planar waveguide is connected to a topside microstrip line by a through-hole in a carrier substrate. To compensate for inductance added by the hole and transmission line ends, a gap is adjusted to provide compensation capacitance. Hermetic sealing of the package is assured by brazing a lead frame over the through-hole and using a solder sealed lid. The lid provides both a hermetic seal and shielding.

Surface mountable microwave IC package

A capacitive tuning screw comprises a threaded portion with a longitudinal cavity for slidably receiving a plunger shaft. If the capacitive element on the tip of the plunger shaft contacts the corresponding capacitive element on the surface of an electrical circuit board or substrate, further turning of the screw will cause the shaft to slide into the cavity and prevent crushing the circuit board or substrate. A shoulder on the screw stops rotation and longitudinal movement of the screw before the entire length of the plunger shaft slides into the cavity.

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Aloha, OR, United States of America

Keith E Jones