Abstract: A radio-frequency switch of planar construction for connecting N input signals to M output signals in a broadcast switch mode or a matrix switch mode. The switch includes a single substrate or circuit board (49) and M output switches (50) disposed in a row on one face of the board, each output switch having N input ports. In the broadcast mode, there are N rows of distributed power dividers (such as 60, 62, 64 and 66), each row providing M outputs from a single input port, the outputs being connected by conductors (such as 90) to the output switches (50). The conductors effecting these cross-connections are formed for the most part on the reverse face of the circuit board, to avoid intersection between the cross-connections and the distributed power dividers. In the matrix mode, the power dividers are replaced by switches (110).

Abstract: A companding digital to analog converter (DAC) of a digital input and exponential output is utilized to drive a PIN diode having a logarithmic attenuation characteristic. An RF signal applied to the diode is linearly attenuated by the diode and variably controlled by digital means through the DAC.

Abstract: A signal input circuit comprising a control member for the controllable attenuation of the input signal and firmly set reactances for the selection of the input signal, wherein the reactances are connected and dimensioned in such a way that there exists a circuit point which has a large impedance compared to the impedance of the signal source, and the control member acts upon this circuit point.

Abstract: An equalizer circuit for use in a communication unit comprises a variable amplitude equalizer (VAE) and a variable group delay equalizer (VDE). The variable amplitude equalizer (VAE) is able to vary only an amplitude frequency response continuously without varying a group delay frequency response, while the variable group delay equalizer (VDE) is able to vary only a group delay frequency response continuously without varying an amplitude frequency response, both being able to adjust the amplitude and group delay frequency responses, respectively, in an independent manner. Preferably, the variable group delay equalizer (VDE) includes an amplitude correcting portion and is structured such that amplitude distortion caused in a delay portion can be corrected by a signal from the amplitude correcting portion.

Abstract: A ladder-type signal attenuator comprises a ladder network (50) storing a ladder resistor circuit of a plurality of stages (n-1) each having an input resistor (2R) and an output resistor (R) and a ladder portion of the final stage (n) having an input resistor (8) and an output resistor (7) and coupled to the ladder resistor circuit. The resistance value (RB) of the input resistor (8) of the ladder portion of the final stage is different from 2R and/or the resistance value (RA) of the output resistor (7) is different from R. A bias voltage (Vb) or an analog input signal (Sin) is selectively applied to a corresponding signal input terminal of the ladder circuit (50) by means of switches (S.sub.1 to S.sub.n) in response to control data (b.sub.1 to b.sub.n) of n bits. At least one of the resistance values of the two resistors (7, 8) of the final stage ladder portion is changed as a function of the state "0" or "1" of the final bit (b.sub.

Abstract: A ladder network includes a plurality of cascaded prototype network sections connection in cascade and terminated with a termination resistor. The sections each provide gains of 1/2, 2/5, 1/5 and 1/10. Linear circuits are also disclosed which utilize at least one amplifier and the ladder network in a feedback loop.

Abstract: A termination device for absorbing RF energy waves in the termination chamber of a traveling wave tube. The termination device is formed by modifying two wedge shaped termination devices of the prior art. Specifically, two well known single wedge termination devices are sliced in half to produce two wedges each one half the thickness of the prior art single wedge device. The two halves are positioned with their newly formed surface, formed by the slicing, in opposed facing contact. The new double wedge thus has the same thickness as the prior single wedge and is readily accommodated within the termination chamber. The double wedge termination device greatly reduces small signal gain variations across the operating frequency band of the traveling wave tube.

Abstract: A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

Abstract: Disclosed is an apparatus having a signal attenuating portion for setting the gain or loss in amplitude of an electrical signal received by the apparatus, and alternatively, provides a gain of unity without a change of setting. The apparatus employs a plurality of switching devices which may be selectively opened and closed to provide the apparatus with a fixed gain of unity and alternatively predetermined losses or gains to the input signals.

Abstract: A microwave switching device replacing PIN diodes and operating at higher eeds requires reduced switching current. A field effect controlled device is utilized with no ground plane, for elimination of source-ground and drain-ground capacitance. Massive source and drain structures reduce terminal inductance. A low resistance active region provides dynamic switching capability improving over prior art devices in operating frequencies and speeds.

Abstract: An attenuator for high-power, low frequency RF signals including two .pi.-section low-pass filters is well matched to the transmission line characteristic impedance. Each of the four loss branches of the attenuator includes a power resistor and a PIN diode. The attenuator is made electronically variable by controlling the dc bias across the PIN diodes, which respond to increased voltage by exhibiting lowered resistance. At any setting of the dc bias, only a fraction of the attenuated RF power is dissipated by the diodes. When the bias voltage is tuned for high attenuation, virtually all of the power is dissipated by the power resistors.

Abstract: A high-frequency input circuit for two inputs has a pair of first and second pi variable attenuation circuits each composed of three P-I-N diodes, some of which are shared by both of the circuits. The P-I-N diodes serve as attenuator elements in the attenuation circuits and also as switching elements for switching between the first and second attenuation circuits.

Abstract: A prescription attenuator comprising a plurality of cascaded L-pad sections coupled together to form an attenuator network wherein each cascaded section includes a single pole switch for activating its respective section. The network impedance values are selected so that single L-pad section activations produce actual attenuations slightly more than an ideal level of attenuation wherein multiple section activations tend to keep the error evenly distributed about the ideal level of attenuation.

Abstract: A noise trap circuit which suppresses noise in a communication system of the type used in hotels and motels to transmit encoded communication signals such as room status information. The communication signals are transmitted on the neutral and ground lines of the AC power distribution network of the building. The noise trap circuit is an LCR circuit connected between the hot and neutral lines. The capacitor and inductor of the LCR circuit pass the communication signal band width, and the resistor has an impedance equal to the line impedance with the offending noise sources active. The communication system normally has a remote controller in each room of the building, and each remote controller is equipped with a noise trap circuit.

Abstract: A remote control precision step attenuator for providing a desired amount of attenuation in the transmission channel of an audio signal. The attenuator includes a counter which provides a binary output count representative of the desired attenuation. An input applied to the counter can cause a stepwise increment or decrement to the output count of the counter. A control circuit responds to the binary output count in order to produce an attenuation control signal. Attenuation circuitry, coupled within the transmission channel is controlled by the attenuation control signal in order to apply the desired amount of attenuation into the channel. The attenuation circuit can be a resistance pad having sections each of which are switched into and out of the transmission channel by relays responding to the counter binary count output.

Abstract: A complex RF weighter provides an RF output signal controlled in amplitude and phase with respect to an input signal. The input signal is applied to a quadrature hybrid that is terminated with two PIN diodes, one of which is one-eighth wavelength farther from the hybrid than the other. Independent control of the bias on the PIN diodes provides control of the relative amplitude and phase of the output signal.

Abstract: An attenuator for IF and RF electrical signals is disclosed comprising a digital mapping means which transforms a digital control word representing the amount of attenuation desired to a current gain control word and a voltage gain control word. The current gain control word causes a current gain means to impart a specific current through a control diode. A first voltage follower is used to measure the voltage imparted across the control diode. The voltage gain control word causes a voltage gain means to output a specific voltage to a summer which combines the specific voltage with the output voltage of the first voltage follower. The summed voltages are taken by a second voltage follower to the cathode of an attenuating diode, whose anode is connected to the signal to be attenuated.

Abstract: A microwave attenuator consists of a plurality of variable attenuation PIN diodes connected in a serial path. At least one of the diodes forms part of a feed-back loop so that the attenuation level it provides can be adjusted to correspond with a reference signal. The effective level of the reference signal is modified in accordance with correction factors, by means of which non-linearities in the performance of the remaining diodes can be compensated.

Abstract: A variable pi RF attenuator includes shunt input and output branches, between which is connected a series branch. Each branch includes a voltage controlled variable impedance PIN diode. The level of a d.c. control input voltage is converted into a first d.c. current source having a magnitude proportional to an exponential function of the level. A first d.c. bias circuit supplies current of the first source as a d.c. bias for the series branch diode, while isolating the d.c. current of the first source from the diodes of the shunt branches. The control voltage is converted into a second d.c. current source having a magnitude proportional to the source voltage. A second d.c. bias circuit supplies current from the second source as d.c. biases for the diodes for both shunt branches, while isolating the d.c. current of the second source from the diode of the series branch.

Abstract: A CATV subscription service control device has a switched buffer to prevent jamming signals from a switched attenuator from propagating throughout the system. The attenuator uses mutual inductance to achieve a high degree of attenuation.

Abstract: This disclosure relates to an electronic circuit which has a controllable impedance. This type of circuit is well suited for application in noise suppression circuits or in signal compression/expansion circuits. The circuit has two stages. The first stage is a voltage to current converter. The second stage is a variable gain current amplifier. The output of the second stage is connected by a feedback loop to an input of the first stage. The circuit has a variable impedance which can be controlled by an external signal. The imput impedance of the circuit is linearly related to the applied control signal.

Abstract: Four PIN diodes are connected, two in parallel oppositely directed at each f two ports of a 3 dB, quadrature hybrid which equally divide the power from an input port. The mismatch produced by the PIN diode resistance in parallel with the matching load resistance reflects part of the power, which combines at the two ports and exits at a fourth port of the hybrid. Direct-current bias to the PIN diodes is adjusted to vary the attenuation. There is also variable resistance and capacitance which serves as variable adjustments on the terminations of the hybrid when the diodes are unbiased.

Abstract: A step adjustable attenuator comprising a silicon substrate on one face of which are deposited thin film-type resistors and electrical conductors by which the resistors are interconnected. Contact points are arranged at the periphery of the substrate and connected to the resistors. However, the attenuating sections are not interconnected on the substrate. A conductive pattern prepared from a conductive film forms finger-like leads of which inner portions are bonded to the contact points. By its shape, the pattern ensures the interconnections between the sections and forms two rows of outputs, one for the connections on the printed-circuit board on which is implanted the attenuator and the other being associated with displaceable straps enabling attenuation to be adjusted.

Abstract: A high-impedance cascade attenuator device includes a plurality of attenuator stages mounted on a single substrate by means of metallization and thick film processes. The attenuator stages are conventional frequency-compensated voltage dividers designed for high-frequency operation; however, the capacitive compensation is included in the thick film process, and the attenuator components may be trimmed to provide precise impedance ratios so that calibration or circuit adjustments are never required.

Abstract: A structure with a surface portion of dielectric material which passes electromagnetic radiation and with a portion below the surface which includes material that absorbs the radiation, the face of the structure being formed with numerous steep ridges. The steepness of the dielectric material results in a high proportion of the electromagnetic energy passing through the surface for absorption by the absorbing material under the surface. A backing of aluminum or other highly heat-conductive and reflective material lies under the face and has very steep protuberances supporting the absorbing and dielectric materials.

Abstract: Attenuation of a signal is achieved by biphase modulating the signal with an asymmetrical duty factor rectangular wave. In one embodiment of the invention an input signal is applied to a phase reversal switch having as its second input thereto an asymmetrical duty factor rectangular wave.

Abstract: A main resistance element and an elongated conductor are arranged coaxially and a plurality of secondary resistance elements are arranged radially and connected between the main resistance element and the conductor. A slider is ohmically movable on the main resistance element to provide a variable attenuator with low impedance and logarithmic attenuation to at least -60 db. An auxiliary resistance element may be provided coaxially with the main resistance element and the conductor with another set of secondary resistance elements connecting the auxiliary resistance element with the conductor, the ends of the main and auxiliary resistance elements being connected together.

Abstract: An attenuator for use in filtering high-frequency waves propagated in a transmission line, comprising ferrite beads having a conductor passed therethrough which are enclosed firmly within a mixture having powder of ferrimagnetic material dispersed in an organic high polymer.

Abstract: Step attenuators wherein a number of individual attenuators are connected in series, with a switch across each individual attenuator, are well known. By opening and closing particular combinations of the switches, any one of a number of different values of attenuation may be selected. Each individual attenuator has in the past, as well as in the present invention, had a characteristic impedance equal to the impedance of both the signal generator (which feeds the input of the step attenuator) and the load (connected across the output of the step attenuator). However, the switches for selecting the individual attenuators may have substantial resistance especially where solid state switching diodes or mercury wetted reed relays are employed. The latter type switches display resistances caused by skin effect at highter frequencies. This causes inaccuracies of the attenuation steps due to mismatch, in prior art systems of the type described above.

Abstract: A high-impedance programmable attenuator utilizing field-effect transistor (FET) switching in both the high-impedance and low-impedance sections. In the high-impedance section, hybrid passive attenuator elements are employed to provide attenuation of electrical signals, and both series and shunt forms of active switching are employed to align the appropriate signal paths. The low-impedance amplifier section includes a FET-switched resistive network.

Abstract: The invention relates to a card-type attenuator having a flat insertion loss from DC to 2 GHz or higher. A rectangular card has two ground conductors extending along its longitudinal side edges and an inner conductor extending along a first face of the card midway between said ground conductors. The outer conductor comprises two main parts: First, a metal trough into which the card is placed with the two ground conductors, and secondly, an inverted U-shaped metallic spring which has its free ends pressing against the ground conductors respectively to hold them firmly in the trough. The inner conductor is accurately positioned a distance from the bottom of the trough which is small compared to the distance that the U-shaped spring is above the inner conductor. Hence, most of the electromagnetic field exists between the inner conductor and the bottom of the trough. Accordingly, the exact size and shape of the U-shaped spring is not critical.

Abstract: A constant impedance, constant phase PIN diode attenuator uses PIN diodes in a double pi configuration. A control voltage is applied simultaneously thereto thus attaining 40 dB attenuation without substantially varying phase and amplitude characteristics.

Abstract: A substantially constant power level is derived over a predetermined frequency band, in each of a plurality of relatively widely spaced power ranges, from a microwave load having a predetermined amplitude versus frequency response, such as an antenna. A microwave source of substantially constant amplitude drives a forward path connected between the source and the load. The forward path includes a voltage controlled, PIN diode, variable microwave attenuator. A feedback path responsive to the microwave power level in the forward path derives a control voltage for the PIN attenuator. The feedback path includes a microwave equalizer attenuator having an amplitude versus frequency response corresponding substantially with the amplitude versus frequency response of the load. The equalizer attenuator drives a linear, crystal amplitude detector.

Abstract: An attenuator, which can readily provide balanced as well as unbalanced attenuation in a plurality of external circuits, includes first and second circuit substrate devices and an actuating device associated with the circuit substrate devices. The first and second circuit substrate devices each provide variable magnitudes of attenuation to respective ones of the external circuits such as, for example, signal transmission lines. The actuating device couples the first in the alternative, and second circuit substrate devices simultaneously or the first and second circuit substrate devices separately to their respective external circuits so as to produce desired magnitudes of balanced or unbalanced attenuation in the external circuits.

Abstract: A switchable attenuator assembly includes a housing, a plurality of rocker arms mounted for pivotable movement within the housing, and a pair of shorting bars associated with each rocker arm. Each shorting bar of the pair of shorting bars associated with each rocker arm is coupled to a respective end of the rocker arm and is aligned with electrical connectors which extend from an attenuator circuit aligned with and adjacent to the housing. The rocker arms are selectively pivoted to cause the shorting bars coupled thereto to move into and out of engagement with their respective electrical connectors to provide attenuation of selected magnitudes to an external circuit.

Abstract: A switchable attenuator includes a split housing assembly formed of interlocking cover and support members. A plurality of rocker arms are mounted for pivotable movement between the cover and the support members and each rocker arm has lugs formed on opposite ends thereof which receive respective ones of a pair of shorting bars. Electrical circuit connectors, coupled to an attenuator circuit mounted adjacent to the support member, are aligned in pairs with each pair being positioned to receive a respective one of the pair of shorting bars associated with each rocker arm. The rocker arms are selectively pivoted to cause the shorting bars to move into and out of engagement with the electrical circuit connectors aligned therewith to selectively provide attenuation of different magnitudes to an external circuit.

Abstract: A spring contact element is soldered to the end section of a plate holder hub in a high frequency tuneable cavity. The spring contact extends outwardly transverse to the shaft's principle direction and terminates in a plurality of radially extending contact fingers inclined toward and in contact with a wall of the cavity at the end of the hub. Attachment of the spring contact electrically at the plate holder hub and consequent moving contact between the cavity wall and the spring contact member at a circumference considerably larger than that at the hub provides reduced current densities in the vicinity of the moving contact between the wall and the spring contact and consequently considerably reduced power loss at high frequencies above 100 MHz.

Abstract: A corrective network for obtaining a desired overall frequency response comprises a plurality of tunable, non-active resonant circuit stages, each connected with a source and operative for modifying the frequency response over a respective portion of the frequency spectrum. Each resonant stage comprises a variable differential capacitor having a rotor plate terminal and two stator plate terminals. Each stage further includes a series circuit branch constituted of a resistor and an inductor which has one end which is connected to the respective rotor terminal of each stage. The network further includes a common terminal at which the other ends of the series circuit branches are all connected. The source may be a transformer having a tap intermediate its end terminals, and an output impedance is located between the common terminal and the tap of the transformer. The stator plate terminals of at least some of the stages are connected to respective ones of the end terminals of the source.

Abstract: A digital level comparison device having a digitally controlled switching network for adding or removing attenuation from a signal channel is described. The device includes a binary counter having an input for pulses corresponding to the received signal level and a timing input for receiving clock pulses corresponding to a predetermined nominal level. The counter is graduated in stages, each of which has an output leading to the aforementioned switching network. Within each stage interval, on one side thereof, there is a first additional interval, and on the other side of that stage interval there is a second additional interval. If the counter reading falls within a first additional interval the predetermined nominal level value is reduced by a given value, and if the counter reading falls within a second additional interval the nominal level value is increased by a given value.

Abstract: Support for foam absorber for electromagnetic waves. The support is constituted by one or more filaments impregnated with a plastic material which may be either thermohardening or thermoplastic. The support has a generally pyramidal form. The plastic material employed for the impregnation of the wound filaments has a dielectric constant less than six.

Abstract: Gain control circuits in the base and emitter circuits of a common-emitter transistor amplifier stage each include pluralities of resistors and electrically conductive screw-type switches which are connected together such that the net changes in decibel values of gain provided by closing individual switches are cumulative. Resistors in the emitter gain control circuit are electrically connected in parallel with the emitter resistor in the AC equivalent of the amplifier in various configurations by closing screw switches to decrease the effective emitter resistance and thereby increase the decibel value of amplifier gain in steps of prescribed magnitudes. The switches are selectively closed in a prescribed manner to provide step changes in the decibel value of the net gain of the stage in discrete consecutive steps of the same magnitude. Transistor amplifiers with emitter gain control circuits may be connected in series to provide additional steps and range of voltage gain.

Abstract: An integrated voltage-controllable RF-signal attenuator having a pair of signal input terminals and a pair of signal output terminals, comprising a first signal transmission path connected between a signal input terminal and a signal output terminal, which attenuator includes a first pair of PIN-diodes which are arranged in series opposition and which have a RF-signal impedance which is variable by passing a variable forward bias current through them, and a signal discharge path connected between the signal input terminals, said discharge path comprising a second pair of PIN-diodes arranged in series opposition, which attenuator also includes a special circuit of pairs of PIN-diodes, arranged in series opposition, by means of which the distortions can be kept lower within the normal attenuation range than is possible with the known attenuators which are provided with the same pairs of PIN-diodes, arranged in series opposition.

Abstract: This device essentially comprises a resistive element connected between two conductor elements one of which is attached to one of the two walls between which the waves requiring attenuation appear, and the other of which is located opposite the other wall, constituting a capacitor in relation thereto; such devices are disposed in regions of high frequency tubes such as magnetrons or tetrodes devoided of useful waves.

Abstract: A low loss corrective network for obtaining a desired overall frequency response comprises a plurality of tunable resonant circuit stages which are operative for modifying the frequency response over respective portions of the frequency spectrum. Each resonant stage comprises a variable differential capacitor having two stator plate input terminals and a rotor plate output terminal. Each stator plate input terminal is connected to respective end terminals of a source. A single voltage divider common to all of the stages has two end terminals which are connected with the source and which are also commonly connected with all of the respective stator plate input terminals of the individual stages, and a tap point located intermediate the end terminals of the divider which is commonly connected with all of the respective rotor plate output terminals of the individual stages. Moreover, matching resistors and inductors are employed to compensate for the capacitive loading presented by the differential capacitors.

Abstract: A transformer circuit is arranged to attenuate spurious signals at undesired frequencies and substantially reduce the distortion of signals coupled through the transformer. The transformer circuit includes an iron core transformer and an active circuit arranged to simulate a lumped element having a frequency dependent magnitude which resonates with the transformer impedance at a desired frequency.

Abstract: In a tuner for a television receiver, an attenuator circuit coupling a signal input to a signal output network includes a series connected controllable impedance and amplifier stage connected to a source of AGC potential whereby increased signal strength causes an increased AGC potential which reduces current flow through and increases the impedance of the controllable impedance while reducing the gain, and consequently the noise, of the amplifier stage coupled to the signal output network.In another aspect of the invention, a second attenuator circuit includes a second controllable impedance series coupling a signal input to the attenuator circuit and a third controllable impedance coupling the junction of the first and second controllable impedances to circuit ground for effecting an additional increased attenuation of a received signal.

Abstract: A device for suppressing parasitic oscillations in electronic power tubes of coaxial structure. It is constituted by an electrically conductive component of cylindrical form with a flange, containing an odd number of resonant circuits of the RLC type, with distributed constants. Each circuit comprising at least one inductance coupled to at least one capacitor. The latter are respectively constituted by an opening and a slot in said component. The circuits are tuned to the range of frequencies of the parasitic oscillations.

Abstract: Disclosed is a solid state signal controller designed to be inserted in a radio frequency transmission line or path between a source and a signal utilization device to allow the control by external means of signal amplitude ratio and polarity, with a minimum of distortion of the signal. This invention has a dynamic range of more than 100 db and is capable of greater power handling capacity than the prior art signal controllers. It employs a plurality of semiconductor diodes, commonly known as PIN diodes, each cooperating with an energy coupler and having their respective impedances controlled to effect a reflection of energy with either positive or negative polarity toward an output terminal.In one embodiment employing a single channel, a pair of control elements are employed. In the second embodiment, four impedance elements are employed to produce a pair of quadrature signals, each independently controllable in amplitude and polarity.

Abstract: Gain control circuits associated with the base and emitter electrodes of a common-emitter transistor amplifier stage include pluralities of electrically conductive screw-type switches and resistors. The net gains provided by the associated gain control circuits are cumulative and determine the net gain of the stage. The gain changes provided by individual switches of the base and emitter gain control circuits are also cumulative, the switches being selectively closed in a prescribed manner to provide step changes in the decibel value of the net gain of the stage in discrete steps of the same magnitude. A plurality of transistor amplifiers with associated emitter gain control circuits may be connected in series, with the decibel values of voltage gains thereof also being additive, to provide additional steps and range of voltage gain. Series resistors in the base gain control circuit are selectively short-circuited by screw switches to decrease the input resistance of the amplifier stage.

Abstract: A device for attenuating very short parasitic waves which create surface currents at the surface of a conductive wall of a high frequency circuit, said device comprising within an opening provided in the wall, a highly resistive element exhibiting magnetic losses; the surface currents which form a loop around said element, generate therethrough an alternating magnetic field providing magnetic losses which attenuate said parasitic waves.