Abstract: An impedance transformation comprising a plurality of elementary tranformers which can be used as impedance converters for radio frequency antennas of a nuclear magnetic resonant tomograph system. At least one combination of a parallel circuit and a series circuit using inner conductors and the outer conductors exists at the primary side of the transformer and at the secondary side of the elementary transformers. Nearly all arbitrary transformation ratios can be obtained with the line transformers of the invention.

Abstract: The invention is an improved integrated circuit chip assembly which provides enhanced heat transfer from active electronic devices of the integrated circuit by significantly reducing the thickness of the substrate and providing the necessary structural support through a thermally conducting spacing segment between the substrate and a ground plane in the region of the active electronic devices. This improvement further permits added flexibility in the design of transmission lines by permitting adjustment of the distance between the transmission line and the ground plane and furthermore by permitting the introduction of a second dielectric material such that the impedance of the transmission line may be controlled.

Abstract: A carrier for high power solid state devices in particular monolithic microwave integrated gallium arsenide circuits includes a dielectric carrier surface comprised of aluminum nitride having disposed over a first surface thereof, a plated ground plane conductor and having disposed over a second surface thereof a ground plane conductor disposed in selected regions of said second surface, connected to the underlying ground plane conductor by via holes. The aluminum nitride carrier provides a dielectric for transmission lines which are supported by said carrier, and a support for resistor and capacitor devices formed over said carrier by thin film techniques. A high power active device such as a FET or gallium arsenide MMIC is bonded to the selective ground plane regions of the second surface of the aluminum nitride carrier. With this approach, a separate metal carrier having separately mounted components such as resistors, capacitors, and transmission lines is eliminated.

Abstract: A resonance absorption-type microstrip line isolator including a ground conductor; a magnetic member provided on the ground conductor; and a central conductor provided on the magnetic member, portions of the magnetic member on both sides of the central conductor being magnetized oppositely. The magnetic member may be replaced by a composite member constituted by at least two magnetic members and at least one nonmagnetic dielectric member. Further, to achieve the miniaturization of the isolator, the central conductor may be in a meandering shape.

Abstract: A millimeter wave microstrip oscillator utilizing either a pulsed or CW IMPATT diode as the active element provides relatively high power output not available with a GUNN diode. The circuit comprises a block of a conductive metal having a channel of rectangular cross-section formed therein and including a cylindrical well formed inwardly in the block from the floor of the channel. A packaged IMPATT diode of either the pulsed or CW variety fits into the well with the cap portion of the package coplanar with the microstrip circuit pattern when the microstrip rests on the floor of the channel. The pattern includes a shunt open circuit stub and an impedance transformer connected to the terminals of the IMPATT diode for effectively matching the diode's complex impedance with the load. A conductive cover is secured to the block and a laterally and vertically movable tuning screw passes through the cover for fine tuning the oscillator's output frequency and power.

Abstract: A stripline structure has a stabilized resonant frequency against temperature variations. It includes a lower and an upper substrate of ceramic materials, each substrate having opposing inner and outer surfaces. Each of the outer surfaces are covered with a layer of conductive material constituting ground planes. Resonator strips of conductive material are situated on each of the inner surfaces, and each have one end connected to the ground, while the opposite end is an open circuit. The upper and lower substrates are bonded together along the length of their respective resonator strips, thereby producing the stripline structure. The length of the resonator determines the resonant frequency of the stripline structure. The two substrates are made of materials having opposite dielectric temperature coefficient.

Abstract: A miniature circulator which is compatible with integrated circuits is described. The circulator includes a substrate which supports three copolanar waveguide transmission lines which are connected at a common junction. The common junction provides a coupling structure between the coplanar waveguide transmission lines. A ferrite disc having a conductive layer disposed thereover is provided over the intersection of the three coplanar waveguide transmission lines. A magnet is then disposed over the ferrite disc to direct a D.C. magnetic field through the disc. An alternative coupling structure having interwoven, balanced lines disposed on the substrate is also described. An alternative arrangement for the ferrite disc having a hexangular shape, which carries a beam-lead node metalization is also described.

Abstract: A process for forming a stripline interface conductor. A stripline interface conductor receives a circuit element and provides spaced-apart connections to each of the closely spaced leads of the circuit element. A first ground plane layer and an attached dielectric layer are perforated to create a first access opening and a plurality of second access openings. The plurality of second access openings are spaced at a distance from the first access opening so that closely spaced leads of the circuit element can be attached to signal traces at the first access opening and electrical connection can be made to the leads in a spaced-apart geometry at the plurality of smaller access openings. A second dielectric layer including top and bottom metallic layers is attached to the exposed side of the first dielectric layer. Before this attachment the top metallic surface of the second dielectric is etched to form the signal traces and a third access opening is formed through all three layers.

Abstract: A fixture for measuring the static characteristics of microwave active components has mechanical devices for supporting two dielectric substrates. Two terminals of the components under test are separately connected to electrical circuits constructed on said dielectric substrates. This fixture can be adapted to geometric sizes of component case and allows it to be submitted to thermal tests, without mechanical stresses due to expansion. The electrical circuits constructed on the dielectric substrates ensure circuit stability avoiding spurious oscillations during static characteristic measurement.

Abstract: The invention relates to a stripline circuit comprising a stripline structure of a high-conductive material disposed on the surface of a board of a dielectric material, as well as a method for regulating such a stripline circuit. The invention is characterized in that a metallic or metal coated cover (4) is non-conductively provided in the vicinity of the stripline structure (2), the distance of the cover from the stripline being adjustable to regulate the characteristic impedance of the stripline. The distance of the cover from the stripline is preferably adjusted by bending the cover (4).

Abstract: Disclosed is a tunable circuit for an integrated circuit device and a process for making such circuit.

Abstract: A voltage-controlled oscillator (VCO) especially designed for use in the millimeter wave frequency band (Ka-band) and which exhibits an adjustable tuning sensitivity. A low tuning sensitivity is easily obtained, making it suitable for narrow-band FMCW applications. It comprises a Gunn diode as a negative resistance device and a voltage variable capacitance diode (varactor) as a tuning element. A fixed capacitance element is coupled in RF series with the varactor and microstrip transmission lines are configured to function as impedance matching, resonating and filtering elements. By incorporating the fixed capacitance in RF series with the varactor, the tuning sensitivity, measured in volts/Hz is markedly reduced. The VCO uses a novel RF structure which puts the fixed capacitance in RF series with the varactor, without introducing the fixed capacitance element in the varactor bias circuitry.

Abstract: A broadband interconnection between a microstrip and a coplanar waveguide is provided without use of via holes by using anisotropic etching to form a sloped surface between connection points. The sloped surface is then metallized to provide the interconnection.

Abstract: An electrical circuit interconnect system employs an electrically conductive enclosure (57) and cover (64) which completely encompasses, hermetically seals (54) and electrically isolates from the outside environment a component (18) mounted on first surface of an insulating substrate (16) of a microwave circiut (56). A plurality of conductors (12) mounted on the first surface of the insulating substrate (16) electrically connect the component (18) to the outside electrical circuitry by passing under a corresponding plurality of pass-through bores (58) within the base of the enclosure (57). Specifically, within each respective passthrough bore (58), a corresponding glass encased conductor (60 and 62) electrically connects each conductor (12) within the enclosure to a conductor outside of the enclosure (57).

Abstract: A suspended substrate rat-race coupler utilizes an elliptic configuration of the usual circular rat-race coupler on a circuit card positioned within below cut-off suspended substrate housing channels. The channels within the suspended substrate housing are positioned to receive the arms of the elliptical rat-race coupler. The longitudinal axis of two of the suspended substrate channels are offset with respect to each other to accommodate the rat-race arms and are positioned either on the same side of a primary suspended substrate channel or on opposite sides of the primary suspended substrate channel. Connections to the four ports of the rat-race can thus be made without disrupting the TEM propagation mode within the suspended substrate device.

Abstract: A circuit board configuration for I/O devices and logic devices, wherein the I/O devices have current levels substantially higher than the current levels associated with the logic devices. The I/O devices are grouped adjacent a connector, and a ground return plane surrounds the I/O devices coupling the ground terminals of the I/O devices to the ground pins of the connector. The logic devices are spaced some distance away from the connector where the ground terminals of the logic devices are connected through vias to a ground plane. The ground return plane, forming a strip line with the ground, plane, is effective for isolating the I/O devices and reducing signal distortion on the board.

Abstract: The present invention relates to a transition wherein a microstrip line, formed on one major surface of a substrate, is capacitively coupled to a reduced-height waveguide, comprising a predetermined width-to-height ratio, by means of a T-bar conductive pattern formed on a substrate at the end of the microstrip line. Such T-bar transitions can also be connected on opposite end of the microstrip line to provide connections between two waveguide sections.

Abstract: The present invention incorporates a specially-designed low-pass filter into the feedthrough of a monolithic microwave integrated circuit (MMIC) to provide compensation for discrepancies from the impedance required for an MMIC package to be matched to a transmission line. The compensation allows all parameters to be adjusted and the complete filter to be printed.The main features of the invention include minimum width for the under-wall conductor and brazing metallization, two open-circuited stubs at the package-die interface for wire bonding ease, and metal-filled vias connecting the ground plane base and the lid sealing ring to bring the lid sealing ring to RF ground.The present ivention also includes a method for designing the desired feedthrough that obviates the need for scale-model feedthrough design before printing, a prior art method that requires precision in the scale model. An electrical model of a feedthrough is first derived.

Abstract: A strip line circuit assembly consisting of a first and second strip line ch comprised of three dielectric layers having conductor strips on either side of the center layer and ground planes on the outsides of the outer layers which sandwich the center layer except for an open central portion which turns through a 180.degree. curved bend. The three layer first and second layer strip lines are separated by the single layer central portion and are sandwiched between three holding plates. The center holding plate has a curved end extension containing axially spaced channels which receive the conductors of the center dielectric layer on the inside of the end. One of the outer two holding plates is placed upon each of the outer dielectric layers in contact with the ground planes on the outer surfaces of each layer.

Abstract: A low temperature cofired monolithic ceramic package (10) for use with microwave and millimeter wave gallium arsenide integrated circuits, or the like. In situ buried passive components (28), including capacitors, resistors, couplers and inductors are incorporated within a cofired substrate structure (12). Fields of interconnected staggered or stacked vias (56, 58) are provided in the substrate below the integrated circuit for efficient heat transfer and electrical connection to a ground plane that eliminates complicated heat sink strucutres. At least one cavity (24) is provided in the top surface to confine integrated circuit chips. A plurality of connectable electrical conductors (34,36,38,40,42) including RF input and output leads and DC bias leads for the chip extend from the edge of the substrate (12) to the edge of the cavity (24). A sidewall 14 is extends around the periphery of the cavity (42) and comprises a low temperature cofired structure which is cofired with the substrate (12).

Abstract: Apparatus and method are provided for making rf contact between the ground plane surface of a microwave-monolithic-integrated-circuit chip and a test fixture. The test fixture includes a chip support with a planar surface, a chip stop with a wedging surface, a clamp-release lever with a wedging surface, and a spring. The conductive ground plane surface of a MMIC chip is pressed against a planar surface with a contacting force that is a function of a clamping force that is applied to one of the wedging surfaces, and that is a function of angles of the wedging surfaces. Heat applied to the MMIC chip cooperates with the contacting force to provide a suitable rf connection between the ground plane surface of the chip and the planar surface of the test fixture.

Abstract: A semiconductor device includes a Si substrate, a compound semiconductor layer selectively formed on one main surface of the Si substrate, a hole formed in the Si substrate to expose a portion of a back surface of the compound semiconductor layer, a microwave monolithic integrated circuit formed on a portion of an upper surface of the compound semiconductor layer just above the exposed portion of the back surface, and a metal layer covering the back surface of the Si substrate, the side walls of the hole and the exposed portion of the back surface of the compound semiconductor layer. A Si device may be formed on the portion of the upper surface of the Si substrate where the compound semiconductor layer is not formed. GaAs may be used for the compound semiconductor layer and the metal layer is connected to the ground line.

Abstract: Packaging techniques are described which provide electrical, thermal, and mechanical advantages. A low-profile semiconductor package is described in which the leads are flat and are present in the same plane. The leads are arranged and positioned in order to eliminate inductance. A semiconductor die is secured to a ceramic substrate, and a plurality of bond wires are secured between the pads on the die and the leads of the package.

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 fully monolithic solid state device compatible with standard semiconduc processing for amplifying radio frequency (RF) microwave and/or millimeter wave signals is disclosed. The device includes an input microstrip transmission line which capacitively couples an input RF signal to input underlying grating fingers which, in turn, mode-couple the signal to an interaction grating region by way of an input finger taper region. The RF is amplified in the interaction grating region through its interaction with a space charge wave. Then the amplified RF signal is mode-coupled to output underlying grating fingers by way of an output finger taper region before it is capacitively coupled to an output microstrip transmission line.

Abstract: A nearly square waveguide below cutoff has a microstrip substrate disposed diagonally therein. A first shunt capacitance is provided by either a conductor formed on the microstrip substrate or a conductor disposed in the waveguide perpendicular to the microstrip substrate. A dielectric window is disposed in the end to provide a shunt capacitance at the opposite end of the waveguide.

Abstract: A broadband balun, suitable for feeding a spiral antenna, has a balanced port (20) comprising two adjacent strip conductors (16,17; 36,37) which are coupled to the unbalanced port (6) by respective paths of the same effective electrical lengths. The paths comprise respective strip transmission lines (9,10) having a common ground conductor (3; 44) which terminates in a transition to the balanced line (19), and further comprise slot line means (11; 21) and strip transmission line-to-slot line coupling means (14,15) so arranged as in operation to provide in the two strip conductors (16,17; 36,37) from an RF signal at the unbalanced port (6) signals of mutually opposite phases with respect to the common ground conductor (3; 44).

Abstract: A microstrip nonreciprocal latching phase shifter has a ferrite rod with ramp-shaped dielectric waveguide members at the ends thereof mounted on one surface of a microstrip dielectric substrate having a ground plane on the opposite surface thereof. The dielectric constants of the ramp members and the rod are substantially the same and the substrate dielectric constant is substantially less than the dielectric constant of the ramp members. A dielectric plate is on top of the rod. A microstrip conductor mounted on the substrate, the ramp members and the plate in axial alignment with the rod extends between the ends of the substrate. The rod has a rectangular longitudinally-extending passageway therein filled by a dielectric core insert having a dielectric constant greater than the dielectric constant of the rod. A single control wire is disposed in and aligned with the core insert.

Abstract: A microwave switch comprises a transmission line section which separates into two arms, at least one of which can go from a normal state to a superconductive state at a critical temperature, a junction rejoining the two arms in a second microwave transmission line section, and means to control the normal or superconductive state of one arm or of the two arms. The difference in length between the two arms is chosen to be substantially equal to an odd of half wavelengths of operation of the switch in such a way that the switch is off or on when the two arms are respectively in the same state, namely normal or superconductive, or in a different state. The state of the arms can be controlled by a magnetic field which causes the critical temperature to vary.

Abstract: An improved transmission line filter element allows a higher difference between even and odd mode impedances than previously obtainable from planar structures. The filter element comprises a U-shaped gap formed in the strip conductor of a strip line transmission line, a microstrip structure or a suspended strip line structure. The internal transmission line filters can be cascaded to produce electromagnetic energy filters with deeper notches and steeper skirts than previously obtainable from other planar structures with the same number of elements.

Abstract: The invention relates to a microstrip to stripline transition which achieves good electrical performance and permits easy, solderless disconnection. The upper portion of the stripline is omitted permitting a flying lead bonded to the microstrip conductor, and which extends across a gap, to be held in contact with the stripline conductor by a removable filler block, which replaces the omitted upper portion of the stripline. The air gap, and the width of the stripline and microstrip conductors adjacent the air gap are dimensioned to form the electrical equivalent of a pi network to achieve a desired response.The filler block is held in place, in one embodiment, by an elongated conductor bridging the upper and lower ground planes of the stripline and which is cut away to form a short waveguide section encircling the transition. The waveguide section is dimensioned to favor only a desired TEM stripline mode and suppress undesired waveguide modes for increased transition efficiency over a desired band.

Abstract: Tuning elements are mounted on a coplanar waveguide probe adapted to be used for on-wafer microwave noise measurement of integrated circuit devices. Each of the tuning elements is a capacitive varactor which is connected between a respective position on the input signal line of the probe and a respective capacitor to ground for the injection of bias voltage. The input signal line carries a gate voltage for the wafer device under test, and the differential voltage between the gate voltage and the bias voltage applied to the respective varactor determines the capacitance presented to the signal line by the varactor. The impedance of the signal line at the point where the probe contacts the wafer can be varied by adjusting the bias voltages applied to the varactors. The position at which each of the varactors is connected to the input signal line depends upon the wavelength of the input signal and is normally less than two wavelengths of the input signal from the end of the probe that contacts the wafer.

Abstract: Integratable microwave devices such as a tuneable band reject filter or an r.f. switch are provided on a gallium arsenide substrate having a (100) orientation. Each of the devices includes a layer of a ferromagnetic material having a pair of easy axes which lie in the plane of said (100) orientated substrate and a layer of a conductive, nonmagnetic material disposed thereover. The ferromagnetic material has a ferromagnetic resonant frequency related to the applied DC magnetic field, the anisotropy field, the saturation magnetization, and gyromagnetic ratio. Such devices are provided by utilizing the ferromagnetic resonant properties of the ferromagnetic material disposed on the (100) substrate.

Abstract: In a 1/2 wavelength side coupling filter, a plurality of resonance lines (4) are arranged on a board (20) in parallel to each other in a staggered manner so that respective ends thereof have step portions. An input coupling line (3) is arranged in parallel to the plurality of resonance lines, with an input end (5) formed opposed to an intermediate position of the adjacent resonance line and one end portion (6) formed aligned with one end portion of the adjacent resonance line. An adjusting line (7) is formed extending from one end portion (6) on the input coupling line, and the filtering characteristics adjusted by the adjusting line.

Abstract: An adjustable band filter comprising a conductive screening body (10, 11) made of two parts (10 and 11) joined to each other on either side of a separation plane (13), a cavity (12) inside said body, said cavity containing a half wavelength resonant line (15) carried on a first face (16) of a suspended substrate (14), the substrate being end-coupled and received in grooves (17) made in the walls of the first portion (10). The first face (16) of the substrate (14) divides the cavity (12) into two asymmetrical volumes in such a manner as to enable the passband of said filter to be modified.

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 four-pole or three-pole structure adapted to propagate an electromagnetic wave, such as an electrical line or cable or electronic component, comprises a lossy non-linear dielectric material distributed in a wave propagation direction. This material has a non-linear conduction characteristic whereby it is substantially non-conductive at any rated applied voltage of the structure and substantially conductive at any abnormally high applied voltage. It consists of a polycrystaline material comprising thin interstitial layers procuring a tunneling or Schottky type effect in response to a high electric field resulting from such abnormally high applied voltages. It absorbs both voltage surges (varistor effect in the time domain) and high-speed transients (lowpass filter effect in the frequency domain). The structure can be used to provide protection against lightning strikes, nuclear electromagnetic pulses, electrostatic discharges and radio-frequency interference in general.

Abstract: Disclosed herein is an N-way, broad band planar power divider/combiner circuit for dividing or combining RF signals which includes a tapered strip of electrically conductive material having a plurality of conductor fingers which define a plurality of ports at the wide end of the taper, and having a narrow end which defines single port. The tapered metal strip is mounted onto a dielectric slab, and isolation resistors connect adjacent fingers. A single RF signal can be fed into the single port which will be divided into a plurality of signals of equi-amplitude and equi-phase. Conversely, a plurality of RF signals can be fed into the ports at the wide end which will be combined into a single signal.

Abstract: The dielectric resonator apparatus is characterized in that electric walls exist on one plane or two including the central axis of the electromagnetic field distribution in the using mode of a dielectric resonator, a dielectric resonator with either of dielectrics between the electric wall being removed in shape is provided by plurality, an equivalent axis is common to the central axis of each of the dielectric resonators, with the dielectric resonators being inductively coupled in the axial direction. A dielectric resonator which prevents the current from being concentrated on the central axis of the electromagnetic field distribution, is collectively smaller in the Joule loss and is higher in Q. The dielectric resonator of the present invention is characterized in that the dielectric close to the central axis is removed, wherein electric walls exist on one plane or two including the central axis of the electromagnetic field distribution in a dielectric resonator using, for instance, a TE.sub.01.delta.

Abstract: A connector arrangment (13) for electrically connecting first and second microstrip structures (15,15') carrying for example RF and DC voltage values therebetween, the groundplates of the connector arrangement (13) and said microstrip structures (15,15') establishing an offset stripline arrangement, the dielectric layer of the connector arrangement (13) being substantially thicker and the dielectric constant thereof substantially lower in value than the corresponding values of the dielectric layers of said microstrip structures (15,15'), thereby enabling the metalization lines (18, 20 and 21) in the connector arrangement (13) to be relatively wide to enable effective alignment of microstrip structures (15,15') and connector arrangement (13).

Abstract: A microstrip IMPATT circuit tuning mechanism for use with RF producing IMPATT diode combinations including a microstrip circuit board and a external load line connected by a coupling spring attached to the load line and separated from the microstrip circuit by a dielectric layer, the coupling spring being manipulated by a dielectric screw inserted through the housing containing the microstrip board and further having a metallic frequency controlling screw extending through the housing and terminating before the microstrip board.

Abstract: A device fixed on a measuring instrument provides access to the terminals of a microwave component in order to measure scattering, noise or output power parameters. In order to minimize the length of connections between the access lines of the device and the input and output terminals of the component to be measured, two access blocks which carry the access lines are positionally adjustable with respect to the component to be measured in such a manner as to permit two degrees of freedom in relative-spacing displacement and in lateral translational displacement. Irrespective of the type of component to be measured (chip, package, or hybrid circuit), the component is carried by an insert block placed between the two access blocks and having dimensions equal to those of the component.

Abstract: A microstrip type transmission line connects RF signals between separate spaced microwave components and defines a RF connecting strip having a flexible insulator base and a ski slope shaped geometry.

Abstract: A tuneable microwave filter comprises two branches of the same type each of which is connected to ground (22, 24) at each end and each of which includes a series-connected variable capacitance diode (13, 13A) controlled by a D.C. signal (V), said filter being disposed on the first face (9) of a plane substrate (8), with each branch comprising in series:a micro-strip transmission line (11, 11A);a second variable capacitance diode (12, 12A) situated between the first diode (13, 13A) and the micro-strip transmission line (11, 11A); andthe input (E) and the output (S) of said filter taking place at the points interconnecting the micro-strip transmission lines (11, 11A) and the second variable capacitance diodes (12, 12A) of respective ones of the first and second branches. The filter is applicable, in particular, to space telecommunications.

Abstract: A shielded printed circuit board system is described in which a microstrip transmission line secured to the surface of a dielectric substrate between ground planes is shielded to isolate the microstrip and inhibit the escape of electromagnetic radiation. This system reduces crosstalk in printed circuit boards and also reduces coupling of external fields into the signal path, thus allowing more sensitive measurements. The shield member is conductive and includes a body section and downwardly depending leg members. The leg members are secured to ground planes on each side of the microstrip transmission line. In another embodiment a dimensionally stable support plate (e.g., an aluminum plate) is secured over the shield member.

Abstract: A DC cutting circuit for passing a signal having a selected wavelength from input side circuitry to output side circuitry while cutting from said signal any DC component therein, which includes a resonator electrode having an electrical length of 1/4 wavelength and formed at a forward open end of a strip line connected to an input side circuitry, and another resonator electrode also having an electrical length of 1/4 wavelength and formed at a forward open end of a strip line connected to an output side circuitry, with said resonator electrodes being disposed in a parallel spaced relation to each other so as to couple the input side circuitry with the output side circuitry by the two resonator electrodes.

Abstract: A directional coupler includes a main line (1) and two conductive pads (2a, 3a) which are capacitively coupled to the main line (1) in a lumped constant fashion. The conductive chips (2a, 3a) are separated by a distance of .lambda.g/4. Signals on the conductive pads (2a, 3a) are transferred, through first and second conductive patterns (B1, B2) narrower than the main line, to an output terminal. The first conductive pattern and the second conductive pattern are different in length by 80 g/4, and a loose and directional coupling signal is obtained at the output terminal.

Abstract: A tunable coupled transmission line band reject filter for use in the microwave frequency range includes a coupled transmission line having first and second line sections. Each line section has an input end and an output end. A transmission line exhibits a natural notch at a particular frequency. A first varactor is coupled between the input ends of the first and second sections. A second varactor is coupled between the output ends of the first and second sections. A D.C. bias voltage across the varactor diodes controls the center frequency of the resulting notch filter.

Abstract: Programmable attenuators including DPDT relays or pairs of SPDT relays with terminals which are interconnected through conductors and attenuator sections disposed on opposite sides of grounded isolation elements, and so configured and supported by printed circuit boards or the like as to provide very high isolation while obtaining flat response characteristics up to very high frequencies, in the megahertz range.

Abstract: An ultra high frequency circuit constructed in hybrid or integrated form whose parasite capacities are greatly reduced. The ultra high frequency circuit has, besides the components, at least one component fixing metallization and at least one microstrip formed by a metal track, on a first face of a dielectric substrate and, a ground plane metallization on a second face of the substrate. The ultra high frequency circuit is fixed to the base of a case. In order to reduce the parasite capacities formed between metallizations, the second metallized face of the substrate is locally demetallized, in line with the fixing metallization, and an air layer is introduced between the demetallized substrate and the base of the case.