Abstract: A CMOS transmission line equalizer is provided for receiving distorted signals transmitted through a transmission line and for compensating for the signal distortion. The equalizer has a transfer function characteristic with a single pole and a single zero. The transfer function includes a mirroring ratio circuit (CMR) for controlling the ratio between the single pole and the single zero. The mirroring ratio circuit is controlled by transistor size ratio. The single zero serves to cancel the dominant pole in the transfer function of the transmission line so as to compensate for the signal distortion caused by the transmission line.

Abstract: A distributed transmission line structure (10) includes a ground plane (26) affixed to a substrate (12). The substrate (12) is formed of a generally nonconductive material. A first metallic strip (14) is affixed to the substrate (12) and is electrically connected to the ground plane (26) through a first through-hole (34). A second metallic strip (16) is affixed to the substrate (12) and is spaced apart from the first metallic strip (14) by a gap (28) and is electrically connected to the ground plane (26) through a second through-hole (38). A dielectric layer (20) overlies the substrate (12), the first metallic strip (14), and the second metallic strip (16). A third metallic strip (18) is affixed to the dielectric layer (20) and is disposed to overlie the gap (28). The third metallic strip (18) has a width less than the gap (28). The impedance of the distributed transmission line structure (10) is substantially constant over a predetermined range of thickness of the dielectric layer (20).

Abstract: A compact high-power RF load comprises a series of very low Q resonators, or chokes ?16!, in a circular waveguide ?10!. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer ?12! at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications.

Abstract: A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power.

Abstract: An apparatus for the propagation of microwaves, particularly ultrahigh frequency waves. A substrate has formed therein a cavity open on one of the sides of the substrate. A membrane is deposited on the substrate above the cavity. At least one transmission line is located on the membrane which is able to propagate an ultrahigh frequency wave. An integrated circuit for rigidifying the membrane is fixed to the transmission line or to the membrane on the side where the line is located.

Abstract: In a CATV housing:the main RF circuit, a coupler circuit and splitter circuit are located respectively on a platform board, coupler board and splitter board respectively. The coupler board is between and perpendicular to the platform board attached to the housing and to the splitter board attached to the lid. The coupler circuit has a main RF circuit input and output near the bottom of the coupler board and a tap output to the splitter at the top of the board. A ground plane on the coupler board approximates, relative to the coupler circuitry, transmission line impedance. In combination with ground planes on the platform board and splitter board, the ground planes provide approximate transmission line impedance to both the main RF path and to the path through the coupler to the splitter output.

Abstract: In high frequency apparatus such as for example an rf resonant cavity or a waveguide, it is often necessary to include a slot to permit a probe or other member to be located in the high frequency region and be moveable along the slot. Sealing means arranged adjacent to the slot and around the probe permits movement of the probe whilst minimising the open aperture area of the slot, hence preventing or reducing leakage through it. In one embodiment of the invention, the sealing means comprises a metallic mesh and in another it includes an elastomer material which is loaded with metallic material and/or carries a metallic mesh.

Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.

Abstract: A variable impedance coaxial transmission line having a center conductor of constant cross-section, an outer conductor surrounding and coaxial with the center conductor and spaced radially therefrom, and a variable dielectric constant material between the center conductor and the outer conductor. The variable dielectric constant material has a plurality of alternating elements of high dielectric material and low dielectric material arranged along the center conductor from a first end to a second end of the center conductor. The invention also includes a reduced size, high-power broadband power/divider incorporating the variable impedance coaxial transmission line.

Abstract: The present invention is directed to an electrical connector for blocking direct current while permitting transmission of alternating currents. The connector includes a first connector member and a second connector member for matingly receiving the first connector member. The first connector member includes a first conductor and the second connector member having a second conductor. The first and second conductors are positioned adjacent to one another and spaced apart by a layer of dielectric material. The dielectric material provides capacitive coupling of alternating currents from one conductor to the other while preventing coupling of direct current from one to the other. It is an object of the present invention to provide an improved electrical connector with an integral dielectric coating for direct current blockage.

Abstract: An equaliser circuit arrangement for compensating for the frequency-dependent characteristics of a transmission line such as an untwisted pair, for lines of lengths up to, say, 125 meters and at data rates up to, say, 155MBits/sec., in which signals from the transmission line are applied by way of a unity gain path and a frequency-selective path including a first wide-band amplifier of variable gain to a summing node. The signals at the summing node may be further amplified by a second wide-band variable gain amplifier using gain control signals derived for the first amplifier.

Abstract: A duplex dielectric filter is disclosed in which plural elements of the filter are merged into a single element to thereby simplify the manufacturing process and product handling, and automatize assembly. The conventional three separate shunt capacitors are simplified into a single dielectric substrate. A brass shim which was conventionally inserted between the shunt capacitors and the dielectric substrate to adjust the height of the shunt capacitors is eliminated. A dielectric substrate having load capacitors is extended to substitute for the brass shim. A through hole is formed through electrode patterns which are formed on both sides of the dielectric substrate to connect an input terminal to the shunt capacitors.

Abstract: A spacer is indicated for a high-frequency coaxial cable with an inner conductor, a tube-shaped outer conductor and a dielectric cavity located between the two conductors which, through the use of different materials, has a higher thermal load capacity in the inner conductor area than in the outer conductor area. When installed, the parts, which are composed of different materials and are superimposed in the radial direction, are mechanically interconnected.

Abstract: A combiner/divider is provided which includes a common output/input port and a plurality of N input/output ports and a plurality of N isolation ports. A 90.degree. phase shifter interconnects each of the N input/output ports with the common port. N transmission line balun transformers are provided with each interconnecting an input/output port with one of the N isolation ports. Each balun transformer serves as a two-way power splitter.

Abstract: A power divider/combiner which can be installed flexibly, with small changes either as a divider/combiner or as a lossless transmission line. The configuration of the power divider/combiner into a lossless transmission line is realized by a parallel connection of two non-symmetrical transmission lines which usually have different impedances. One of the transmission lines is a branch present in a Wilkinson divider, and the other is an extra branch formed inside the divider/combiner.

Abstract: A differential nonlinear transmission line (NLTL) circuit has anti-parallel diode pairs along a balanced transmission line to generate well defined high-speed pulses with sharp positive and negative transitions from a time varying input signal. The input signal may carry an arbitrary DC bias voltage component that is suitable for digital logic circuits, such as current mode logic (CML) employing differential inputs.

Abstract: A device (1) for correcting the amplitude/frequency characteristic of an input signal (FI), particularly from transmission cables (40), having a minimal frequency f1, a center frequency f0 and a maximal frequency f2, the input signal (FI) having an attenuation as a function of frequency characteristic that increases between f1 and f2, the correction device (1) supplying a corrected output signal (). The correction device includes two cascaded filters (41, 42), the first of the filters receiving the input signal (FI) and supplying a filtered signal (SFI) to the second of the filters, the second of the filters supplying the corrected output signal (). One of the filters is a band-stop filter (41) having a center frequency f3 less than or equal to f1, the other of the filters being a band-pass filter (42) having a center frequency f4 greater than or equal to f2. The center frequencies f3 and f4 satisfy the equation:f3.times.f4=f0.sup.

Abstract: A spacer is indicated for a high-frequency coaxial cable with an inner conductor, a tube-shaped outer conductor and a dielectric cavity located between the two conductors, which has a higher thermal load-carrying capacity in the inner conductor area than in the outer conductor area, due to the use of different materials. The parts of the spacer which are made of different materials are radially superimposed and are solidly interlocked with each other by means of injection molding.

Abstract: An impedance matching circuit disposed on one of input and output sides of an element to be evaluated matches I/O impedances of the element. The impedance matching circuit includes a matching substrate having a surface, a main line on the surface, passive circuits having stubs and FETs alternatingly connected in series and electrically connected to the main line to change impedance of the main line, and a plurality of switching FETs connected in series between the main line and the respective passive circuits switched on and off in accordance with characteristics of the element. The impedances of the matching substrate can be changed as required by electrically connecting the passive circuit to the main line by switching of the FETs. Even when a considerable change occurs in the I/O impedances of the element due to fabrication variations and in large signal (non-linear) operation of a power FET, I/O impedances of an evaluating object can be matched easily and promptly by appropriate switching of the FETs.

Abstract: An active device, such as a field effect transistor ("FET") or MMIC, converts microwave signals between a microstrip transmission line ("microstrip") and a coplanar wave guide ("CPW"). In microstrip-to-CPW conversion using a simple FET, a gate connection is made to the microstrip signal conductor. A drain connection is made to the center conductor on the CPW. Two FET source terminals are connected respectively to each CPW ground strip. The ground strips are electrically coupled to the microstrip ground plane with a minimum length connection so the inductance common to the FET input and output is minimized. The FET can be reconnected so as to reverse the input and output, providing for conversion of signals from CPW to microstrip. Conversion from microstrip to an intermediate CPW and back to microstrip provides for mounting an intermediate circuit, such as an amplifier or other MMIC, directly on the CPW.