Abstract: An optimized transmission line switch comprises a first high frequency diode and means for counteracting the capacitive component of the first diode. Unpackaged diode chips are utilized to avoid parasitics introduced by diode packages. A two diode switch installed in a reduced height waveguide section provides isolation comparable to prior art switches while providing greatly improved insertion loss.

Abstract: Either an input signal of a combining network or an output signal of an inverter arranged on a main path is fed to a side path through a mode switch in a switchable signal compressor/signal expander. Since an input terminal of a control amplifier is connected to a variable filter without passing through a signal amplifier, the deviation of the detection characteristic of a rectifier and integrator attributed to D.C. offset voltages of the signal amplifier and the control amplifier can be reduced. On the other hand, a switchable signal compressor/signal expander in another aspect of performance has a reference voltage generator for producing a D.C. reference voltage, and the output D.C. level of the control amplifier is maintained at a level approximate to the D.C. reference voltage. The other ends of first and second capacitors of the rectifier and integrator are also supplied with the D.C.

Abstract: a dielectric waveguide is used as a connecting medium in a rotary joint tsmitting waveguide energy in the 3 mm region. The dielectric waveguide is fastened within a ball bearing race to provide relative motion between the gimballed and stationary waveguide structure. Launch horns are used to enhance transmission through said dielectric waveguide.

Abstract: A transducer for coupling to an antenna with a first polarizing duplexer for working in a low-frequency band, a between-guide transition element formed from a variable-section guide and a second polarizing duplexer for working in a high-frequency band. In the polarizing openings of the first duplexer are placed dipoles resonating at the mean frequency of the high band which cause a short-circuit for the high frequencies and let the low frequencies pass. A set of quasioptical filters, situated in the body of the first duplexer, between the polarizing openings of this first duplexer and the transition element, causes a short-circuit for the low frequencies and lets the high frequencies pass.

Abstract: The IF section of a television receiver includes an amplifier having an input terminal for receiving an IF signal and an output terminal at which an amplified version of the IF signal is developed and a SAW filter having two input terminals, one of which is connected to AC signal ground, for receiving the amplified IF signal and an output terminal for providing a modified IF signal having a bandpass characteristic determined by the SAW filter. An impedance transformation network is coupled between the output terminal of the amplifier and the input terminal of the SAW filter for increasing the effective load impedance of the amplifier and for decreasing the output impedance of the drive arrangement. The former aspect of the impedance transformation network allows a transistor with lower current supplying capabilities to be employed. The latter aspect of the impedance transformation network tends to reduce undesired voltages developed in response to reflections between the transducers of the SAW filter.

Abstract: A coaxial transmission line to waveguide transition is formed of two waveguide portions disposed on opposing sides of, and enclosing a portion of, a flat plate structure. The enclosed portion of the flat plate structure includes a tapered slot extending through the flat plate structure leaving portions of the flat plate structure protruding into the waveguide as loading ridges which provide impedance matching (transformation) between the coaxial line and the unloaded waveguide. The flat plate structure has a hollow therein and an inner conductor passing therethrough forming a coaxial line. The inner conductor crosses the tapered slot within the waveguide enclosure.

Abstract: A touch sensitive variable speed tuning selector is disclosed. A rotary tuning selector knob includes a finger contact coupled to touch sensitive circuitry. Tuning selector rotation causes a shaft encoder to provide a first pulsed output to tuning circuitry for normal frequency change increments. When the touch sensitive circuitry detects the presence of a finger on the contact, a signal is provided to the tuning circuitry causing each pulse from the shaft encoder to change frequency in larger increments for fast, or coarse, tuning. In a preferred embodiment, a change in the capacitance of a touch sensitive capacitive network changes the timing of input pulses provided to a flip-flop which, in turn, changes the flip-flop output to the variable speed tuning circuitry resulting in an increase in frequency change increments.

Abstract: A phase shifter has two sections, a gyromagnetic section and a switching section connected in series. The gyromagnetic section provides fine increments of phase shift and the switching section provides larger increments of phase shift.

Abstract: A low VSWR, high isolation microwave matched coaxial transmission line power divider/combiner compensates for parasitic reactances with lumped compensating elements to yield a compact, densely packable structure.

Abstract: A 1/4 wave length coaxial resonator comprises an outer cylindrical portion, an inner cylindrical portion positioned coaxially in the outer cylindrical portion, with the outer and inner cylindrical portions connected at one end by a radial connecting portion, and a dielectric unit disposed therebetween. The outer cylindrical portion and the inner cylindrical portion and the radial connecting portion are formed with a unitary member of a metallic extruded material formed by means of an impact extruding process so that the inner cylindrical portion is positioned coaxially in the outer cylindrical portion. As a result, a space is formed between the outer cylindrical portion and the inner cylindrical portion to allow for insertion of a hollow cylindrical dielectric unit.

Abstract: In an optical fiber connector component including a tubular housing and three round rods supported longitudinally side by side within the tubular housing and defining between them an intersticial space for reception of an optical fibre or optical fibres, the tubular housing is of a material having a greater coefficient of thermal expansion than that of the material of the rods. In use, prior to introducing optical fibre into the intersticial space, the tubular housing is heated to cause it to expand radially outwardly to permit radial separation of the rods and introduction of the optical fibre into the intersticial space. The tubular housing is then cooled or permitted to cool to cause the housing to contract radially inwardly to compress the rods inwardly and cause them to grip the optical fiber so that it is aligned axially in the intersticial space.

Abstract: A frequency selective limiter comprising a plurality of LC series-resonant filters having resonant frequencies uniformly spaced over the passband. Each filter is formed of two identical LC series-resonant sections with a diode limiter coupled between the two sections. The filters are coupled in parallel between the limiter input and the load to form two groups having alternate resonant frequencies with signals passing through one group being shifted in phase by 180.degree. relative to signals passing through the other group.

Abstract: The plasma switching stage of a radar receiver protector is simplified and improved by the utilization of a halogen gas filled quartz container and a "keepalive" electron source. The container is configured as a capillary stem filled with low pressure chlorine gas and provides the active switching element in the signal waveguide portion of the receiver protector. An enclosed r.f. energy source in combination with the capillary stem creates a copious and steady free electron supply. The r.f. exciting field used to activate the "keepalive" plasma is enhanced by a coaxial re-entrant cavity located on the top wall of the receiver protector waveguide.

Abstract: A two-terminal-pair circuit which simulates an inductance includes input and output terminal pairs and a first ohmic resistor. The voltage-carrying terminal of the input terminal pair is connected to one terminal of the first ohmic resistor. The circuit includes a bridge circuit having bridge branches and two opposite bridge diagonal terminals, two capacitors each connecting a respective one of the two bridge diagonal terminals to a respective one of the terminals of the first ohmic resistor, and a difference amplifier having two inputs each connected to a respective one of the two bridge diagonal terminals. The output of the difference amplifier is connected to the base of a transistor whose collector-emitter path is connected in one of the bridge branches in series with an effective resistor or with a parallel circuit comprising a capacitive reactance and an effective resistor.

Abstract: A microwave apparatus comprises a waveguide section including a stepped septum. The septum is positioned so as to divide the waveguide into two channels. The steps comprise a plurality of first steps which advance progressively in one direction and at least one second step, or the equivalent, which follows the first steps and which returns in an opposite direction. The invention is intended to enable the production of a circularly polarized microwave signal without requiring the use of phase adjustment techniques.

Abstract: Transmission line directional coupler directivity is improved by providing compensation for even and odd mode phase velocity differences. Teeth are added to the edges of the coupler electrodes remote from the coupling region separating the electrodes, so that the phase velocity of even mode and odd mode waves is made similar over a wide frequency band. The compensation approach is applicable to both suspended substrate and stripline type directional couplers, where the uncompensated odd mode velocity is less than the even mode velocity.

Abstract: A millimeter-wave odd-harmonic frequency multiplier comprising a block member having an RF output port and an RF input port at right angles to one another with a pair of nonlinear resistance type diodes positioned at the intersection of the RF input port and the RF output port.

Abstract: A microstrip microwave circuit having embedded therein at least one suspended substrate stripline region for high Q circuit elements is disclosed. Each suspended substrate region includes an upper ground plane formed by covering the microstrip circuitry of each region with a metallic housing having holes in the sidewalls thereof to permit passage therethrough for the interconnecting circuit paths of the region and by connecting the housing to the top surface of the microstrip ground plane substrate; and a lower ground plane formed by removing the section of substrate lying substantially underneath each high Q region to form openings in the bottom surface of the substrate which are covered by an individual cover plate. The upper and lower ground planes are separated from their corresponding high Q regions by an air spacing dimensioned as a function of the RF impedance desired.

Abstract: A 0.degree. and 180.degree. hybrid power divider/combiner includes a first quadrature hybrid and two other quadrature hybrids arranged in tandem with one output port of the first hybrid connected to an input port of the tandem arrangement and the other output port thereof connected to a delay of electrical length equal to that of the tandem arrangement. When an input signal is applied to one input port of the first hybrid with the other port terminated, two signals of reduced amplitude which are either in phase or of opposed phase (dependent on which input port receives the input signal) are produced at the output of the tandem arrangement and delay.

Abstract: A search tuning type channel detector system for television receivers. When AFC voltage of a tuner has attained a first predetermined voltage level, frequency sweeping direction for tuning is reversed and stopped thereby to tune the tuner at an optimum tuning frequency. Means are provided to allow the inversion as well as stoppage of the frequency sweeping only when AFC voltage has attained a second predetermined voltage level, thereby to exclude possible erroneous operation due to noise or the like spurious signal components.