Abstract: A test fixture is provided for determining electrical characteristics such as the S-parameters of a MMIC package or interconnect. The fixture enables the measurement, in effect, of multiple standards using only the single test fixture and also accommodates variable port-to-port spacings. The test fixture comprises a U-shaped conductive ground plane having parallel arms defining a space therebetween. A center conductor is located in the space and is disposed in spaced relationship to the arms of the ground plane. A beam lead PIN diode is connected to the center conductor at one end thereof and to the ground plane at the other. An external variable DC voltage source is used to vary the bias state of the diode so that when the fixture is inserted into a package or interconnect, reflection coefficient measurements for the different bias states can be obtained by an automatic network analyzer for use in calculations for determining the characteristics in question.

Abstract: Dampening of unwanted resonant modes in a conductive enclosure for microwave circuitry carried on a conductive ground plane is provided by interrupting the ground plane at one or more locations about the microwave circuitry and providing electical resistance by either a resistive film or resistor spanning the one or more interruptions in the ground plane to thereby dampen one or more dominant resonant moded in the enclosure. One or more interruptions or openings for electrical resistance may be preferably located at locations of maximum current flow of the one or more dominant resonant modes excited by the operation of the microwave circuit, or may comprise a single space or gap provided in the ground plane surrounding the microwave circuitry with a plurality of resistors located about the circuitry to dampen the dominant resonant modes. The electrical resistance for dampening can be calculated with the computer program of Appendix 1.

Abstract: A novel transition device is disclosed capable of being used in an integrated circuit comprising a substrate having a first planar surface upon which at least one circuit element is formed and a second planar surface upon which a ground metallization is formed, said first planar surface being spaced from and parallel to the second planar surface, said at least one circuit element being connected to a metal strip and having an open end terminating on said first planar surface, a coplanar grounding station disposed on the first planar surface and situated adjacent to and spaced from said open end, said coplanar grounding station being free of any electrically conducting path between said metal strip and said coplanar grounding station and between said ground metallization and said copolanar grounding station.

Abstract: Compound surface acoustic wave matched filters comprise chirp-biphase and biphase code multiplex transducer pairs on piezoelectric substrates. Both alternatives offer significantly improved processing gain when compared with conventional biphase filters. The advantage is realized by convolving the correlation peak of the chirp or biphase input transducer on the response of the conventional biphase output transducer, thus achieving a large processing gain with a minimum number of transducer electrodes.

Abstract: A temperature stable surface acoustic wave device utilizes a known variation in the power flow angle characteristic of the substrate over a temperature range to vary the response of the device at one or more output transducers in a way which compensates for temperature dependent phase shifts common to prior art devices.

Abstract: Temperature stable cuts of quartz comprise the families of doubly rotated cuts defined by (YXwlt) 0/27/138, 7/27/135.5, 15/40/40, 15/30/38, 12.5/35/130 and rotational equivalents thereof. It is found that SAW devices may be fabricated on these cuts which demonstrate a very high degree of temperature stability and which have other characteristics consistent with practical usage. The sensitivity of the stability to variations in the propagation direction, corresponding to the angle psi, is such that it is advantageous to fabricate several input-output transducer pairs, each slightly rotated with respect to the others, and to chose the most stable for actual use.