With Plural Amplifier Channels (e.g., Parallel Amplifier Channels) Patents (Class 330/124R)
  • Patent number: 5543752
    Abstract: A microwave amplifier circuit includes a divider having an input connected to an input terminal of the amplifier circuit, dividing an input signal applied to the input terminal into two divided signals, and outputting the divided signals to first and second output ends outputs, respectively. First and second microwave amplifiers having inputs respectively connected to the first and second outputs of the divider. A combiner mixer having first and second inputs and an output as the first input connected to the output of the first microwave amplifier through a 90.degree. phase shifter, the second input connected to the output of the second microwave amplifier, and the output connected to the output terminal of the microwave amplifier circuit. Therefore, the doublet component of the output signal can be suppressed by combining the amplified signal which has shifted the phase of the doublet component by 180.degree. the amplified signal having the same phase as the input signal.
    Type: Grant
    Filed: May 4, 1995
    Date of Patent: August 6, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yoshihiro Tsukahara
  • Patent number: 5539833
    Abstract: An audio signal amplifier device is disclosed, and includes two parallel compass controller circuits (6, 7), each of the circuits (6, 7) having the identical configuration and including a low compass controlling circuit (1, 8) having a plurality of transformers T.sub.1, T.sub.2 connected in series, a medium compass controlling circuit (2, 9) having a capacitor C.sub.2 and a resistor R.sub.3 connected in series, and a high compass controlling circuit (3, 10) having a capacitor C.sub.3 and an amplifier A.sub.2 connected in series, those three compass controlling circuits being coupled in parallel.The parallel compass controller circuits (6, 7) are connected in series through a pre-amplifier PA.sub.1, wherein the post-stage circuit (7) is coupled with an output transformer T.sub.4 through a pre-amplifier PA.sub.3, and the pre-stage circuit (6) is coupled with an input transformer T.sub.3 through a pre-amplifier PA.sub.2.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: July 23, 1996
    Inventors: Osamu Yamashita, Toshimi Furukawa
  • Patent number: 5509078
    Abstract: An operational amplifier is applied with an audio signal at a non-inverting terminal thereof for amplifying the audio signal. A crosstalk cancelling circuit is provided for reducing the output of the operational amplifier to a level of crosstalk generated at the non-inverting terminal. The output of the crosstalk cancelling circuit is applied to an inverting terminal of the operational amplifier so as to cancel the crosstalk.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: April 16, 1996
    Assignee: Pioneer Electronic Corporation
    Inventors: Haruo Hiraoka, Kazuaki Sugawara
  • Patent number: 5481223
    Abstract: A bi-directional spatial power combiner grid amplifier has an array of parasitic elements between the lens and the amplifier. The elements have different impedances to radiation of a first polarization (incident radiation) and of a second polarization which is orthogonal to the first (amplified radiation), thereby providing impedance matching to both the input and the output of the grid amplifier. The elements preferably are separated slots or dipoles (some in each direction of polarization), crossed slots or dipoles, or micropatches.
    Type: Grant
    Filed: September 13, 1994
    Date of Patent: January 2, 1996
    Assignee: Rockwell International Corporation
    Inventor: Sam H. Wong
  • Patent number: 5444417
    Abstract: A self-configurable, dual bridge, power amplifier has a window comparator to sense amplifier signals and control a plurality of configuring switches capable of configuring the amplifier either as a single bridge amplifier driving two loads connected in series or as two distinct bridge amplifiers each driving one of the two loads. When the two amplifier signals remain within a range defined by a negative voltage reference and a positive voltage reference, the amplifier is configured as a single bridge driving the two loads in series, thus reducing power dissipation. Several embodiments of the invention are shown.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: August 22, 1995
    Assignee: SGS-Thomson Microelectronics S.A.
    Inventors: Edoardo Botti, Guido Brasca
  • Patent number: 5438684
    Abstract: A dual-mode RF signal power amplifier combining network is comprised of two branches, each having a power amplifier (200 and 201). The first branch contains a non-linear mode power amplifier (200) while the second branch contains a linear mode power amplifier (201). The non-linear mode branch also has an RF switch (210). Both branches are coupled to a common output node (220). The common node (220) is coupled to a filter (107) before going to an antenna (106). The non-linear mode power amplifier (200) operates when an FM signal is to be amplified, while the linear amplifier (201) is biased in an off state. The linear mode power amplifier (201) operates when a digital signal is to be amplified, while the non-linear amplifier (200) is biased in an off state. The RF switch (210) removes the non-linear amplifier (200) from the circuit to prevent loading the on state linear amplifier (201).
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: August 1, 1995
    Assignee: Motorola, Inc.
    Inventors: Dale G. Schwent, Rashid M. Osmani, Robert N. Weisshappel
  • Patent number: 5434538
    Abstract: A main amplifier has an enhanced gain due to current injection from a replica amplifier which has a similar structure and feedback network to that of the main amplifier. The main amplifier has a transconductance stage and an output resistance stage. A coupling transconductance stage receives the same input signal as that received by the main and replica amplifiers and injects a current to the output node of the main amplifier. The injected current is the same as the current to the output node would have been from the main amplifier's transconductance stage, were the replica amplifier not present. The gain can be obtained without a cascode and with short-channel CMOS technology that operates at a low supply voltage. The gain is increased without causing an increase in the output resistance, and without causing a decrease in the common-mode input range or the output swing.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: July 18, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Hae-Seung Lee, Paul C. Yu
  • Patent number: 5430411
    Abstract: A high frequency amplifying system includes an input coupling circuit having an input terminal for receiving a high frequency signal, a pair of amplifiers, and an impedance mismatch circuit for coupling each amplifier to a respective output terminal of the coupling circuit. The impedance mismatch circuit is controllable by a control signal supplied thereto to produce a selected degree of mismatch between the coupling circuit and the input impedances of the amplifiers, to thereby provide adjustable gain control of the amplifying system. The coupling circuit introduces phase shifts between the input and output terminals thereof which attenuates reflection therebetween of intermodulation products resulting from the presence of interfering signals at any of such terminals.
    Type: Grant
    Filed: February 8, 1994
    Date of Patent: July 4, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Claude Boulic
  • Patent number: 5422595
    Abstract: According to the present invention, a power amplifier with a plurality of power transistors has detection circuitry corresponding to each power transistor which detects the output power of the power transistors and allows this output power to be monitored and modified if desired. The detection circuitry generates a voltage output signal indicative of the rise and fall times achieved by the power transistor. The voltage output signal of the detection circuitry may be monitored by connecting the voltage output signal to a measuring device, such as an oscilloscope of built-in-test-equipment (BITE). Additionally, the voltage output signal of the detection circuitry may be modified by tuning input matching circuitry and/or output matching circuitry accordingly.
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: June 6, 1995
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Joel M. Lott
  • Patent number: 5399986
    Abstract: A multi-output power amplifier is disclosed. The amplifier is divided into two stages. A single voltage amplifier is used as an input amplifying stage and several current amplifiers are used as a second amplifying stage. The inputs to the current amplifiers share a common connection to the output of the voltage amplifier and feedback is provided from the current amplifier outputs to the voltage amplifier input.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: March 21, 1995
    Inventor: Wailit Yen
  • Patent number: 5389890
    Abstract: Directional couplers 7.sup.1 -7.sup.20 are used to couple power from r.f. power amplifier modules 5.sup.1 -5.sup.20 to a transmission line 6 or other type of resonator, from which it is withdrawn by directional coupler 8. The power withdrawn from the continuous transmission line, which is an integral number of wavelengths at the operating frequency of the modules in length, is less than the power circulating around the transmission line 6. The balance load may be removed to enable the output load to be combined with the output of another r.f. power amplifier operating a different frequency so that e.g. sound and vision signals can be combined at an aerial and, in the latter case, means may be provided for improving the resonance of the main loop 6.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: February 14, 1995
    Assignee: GEC-Marconi Limited
    Inventor: Clement P. Burrage
  • Patent number: 5374966
    Abstract: A video amplifier having a reduced noise figure is realized by eliminating the need for a resistive matching termination at the input of the amplifier. A negative feedback loop reduces the effective input impedance of the amplifier by generating an active impedance at the input of the amplifier. Because the input impedance of the amplifier is actively matched to the output impedance of the video signal generator, a noise-generating resistive termination is unnecessary, and the noise figure of the overall impedance-matched amplifier is significantly reduced.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: December 20, 1994
    Assignee: Westinghouse Electric Corporation
    Inventor: Benjamin F. Weigand
  • Patent number: 5365188
    Abstract: A self-configurable, dual bridge, power amplifier has a window comparator sensing the level of input signals fed to the amplifier which drives a plurality of configuring switches capable of configuring the amplifier as a single bridge amplifier driving a first and a second loads connected in series or as two distinct bridge amplifiers each driving one of the two loads. As long as the two levels of the input signals remain comprised between a range defined by a negative voltage reference and a positive voltage reference, the amplifier is configured as a single bridge driving the two loads in series, thus reducing sensibly power dissipation.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: November 15, 1994
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventors: Edoardo Botti, Guido Brasca
  • Patent number: 5349300
    Abstract: A method and apparatus is provided for controlling peak envelope power level in a power amplifier (PA) (10). The method includes the steps of measuring (101) a first peak envelope power value of an input of the PA during a first time period, comparing (102) the first peak envelope power value with a threshold value, and introducing a phase change (103) into a selected signal of a plurality of signals being amplified by the PA when the first peak envelope power value exceeds the threshold. The method further includes measuring (104) a second peak envelope power value during a second time period, comparing (105) the first and second peak envelope power values, and reversing (106) the phase change to the selected signal when the second peak envelope power value exceeds the first peak envelope power value.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: September 20, 1994
    Assignee: Motorola, Inc.
    Inventors: John E. Matz, James E. Mitzlaff
  • Patent number: 5345189
    Abstract: A circuit for combining first and second signals having the same frequency. The signals have a relative phase shift, 2a(t). The circuit generates a signal that is proportional to the sum or difference of signals. The circuit appears to be a resistive load; however, the circuit can be constructed from purely reactive circuit elements, and hence, does not dissipate energy. In one embodiment, the circuit is constructed from a transformer and two LC circuits in which the capacitance is varied in response to a(t). The circuit may be used to construct a high efficiency RF amplification stage.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: September 6, 1994
    Assignee: Hewlett-Packard Company
    Inventors: Thomas Hornak, William J. McFarland
  • Patent number: 5332976
    Abstract: An amplifier for sound signals is made up of an even number of power amplifiers each of which have each an output, wherein each amplifier output can be switched to a first terminal of an associated loudspeaker and in which the second terminals of the loudspeakers can be switched to an output of a buffer amplifier. In order to minimize power losses, the buffer amplifier supplies at its output a DC voltage which is about half the value of the supply voltage of the power amplifiers. In addition, half the power amplifiers supply an output signal that is inverted relative to their input signal.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: July 26, 1994
    Assignee: U.S. Philips Corporation
    Inventor: Joachim Dunnebacke
  • Patent number: 5327095
    Abstract: A method and circuit for increasing the output impedance of an inactive amplifier is provided. The method and circuit allows an increased number of amplifiers to be coupled in parallel to a single transmission line for distributing a plurality of video or other electrical signals to a remote location. The method and circuit increasing the impedance of an amplifier feedback network during inactive operation using a bootstrapping technique (i.e., by driving the feedback network) so as to increase the overall impedance of the amplifier during such operation.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: July 5, 1994
    Assignee: Linear Technology Corporation
    Inventors: William H. Gross, John W. Wright
  • Patent number: 5321710
    Abstract: A predistortion circuit reduces composite second order intermodulation distortion products inherently generated by a laser diode. A radio frequency signal is split into a primary and secondary signal, and the secondary signal is amplified by an amplifier biased at a starvation current level so as to produce intermodulation distortion products having an amplitude relatively large compared to an amplitude of a fundamental generated by the amplifier. The amplitude and phase of composite second order intermodulation distortion products generated by the amplifier are adjusted so as to substantially match those inherently generated by the laser diode by the primary electrical signal, with the products being about 180.degree. out of phase relative to those generated by the laser in response to the primary signal.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: June 14, 1994
    Assignee: Raynet Corporation
    Inventors: Peter W. Cornish, Barry Duncan
  • Patent number: 5315267
    Abstract: A differential amplifier which utilizes a pair of wideband operational amplifiers as output stages for two differential output signals, a pair of high performance DC operational amplifiers to buffer input signals to the pair of wideband operational amplifiers used as output stages and reduce offset voltage error by the amount of the DC gain of the pair of high performance DC operational amplifiers, apparatus for biasing the pair of high performance DC operational amplifiers to provide exceptional DC characteristics and eliminate common mode response from those amplifiers, and apparatus for feeding forward high frequency AC input to the wideband operational amplifiers operating as the output stages without loading the common mode input impedance of the differential amplifier.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: May 24, 1994
    Assignee: Neff Instrument Corporation
    Inventor: William R. Chambers
  • Patent number: 5304943
    Abstract: A system and method for combining RF signals by a series of in-phase combiners. The system uses a series of switched, high efficiency amplifiers which may be selectively operated to obtain a desired output signal, such as an Amplitude Modulated (AM) signal. The output signals of the amplifiers are combined by a series of in-phase combiners. In a high linearity system a feedback loop is used to correct for combiner losses. The RF power normally lost in the combiners is recovered and available to increase the overall combiner efficiency.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: April 19, 1994
    Assignee: Harris Corporation
    Inventor: Floyd A. Koontz
  • Patent number: 5302914
    Abstract: Therefore a method and apparatus for controlling a linear amplifier processing a plurality of carrier signals of a multi channel carrier system alters the phases of one or more sources of the multi-channel signals in response to a detected peak envelope power or of a peak to average power ratio at regular scheduled intervals. This reduces the peak envelope power to average envelope power ratio and enables the reduction in the power rating required by the amplifiers handling the multi-channel signal.
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: April 12, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Bernard J. Arntz, William A. Nitz, Josef Ocenasek
  • Patent number: 5300894
    Abstract: In plural channel amplifier systems processing many phase locked signals of different frequencies as a combined signal, these signals may drift into a phase convergence causing a peak power occurrence in the amplifier which greatly exceeds the rated capacity of the amplifier system. Therefore, in accord with the invention, a dynamic adjustment system is provided to minimize the peak power to which the amplifier is subjected by adjusting the relative phase relationships of the many signals. The dynamic adjustment system includes a peak power detector, a hard wired logic decision circuit and a timing control to control phase shift adjustment steps.
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: April 5, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Robert E. Myer, Clifford W. Schaible
  • Patent number: 5287543
    Abstract: A multichannel communication system carries signals having a different frequency range in each channel. In order to achieve a particular output power level from each channel, an amplifier is associated with each channel to boost the signal level. For reliability, a switching arrangement switches amplifiers among the channels in accordance with a priority, or substitutes a redundant amplifier for a degraded or failed unit in a channel. The amplifier is subject to distortion at the desired output level, and is cascaded with a distortion equalizer or linearizer for reducing the total distortion. In accordance with the invention, each distortion equalizer is fixedly connected in one channel, and is optimized for the relatively narrow frequency range of that channel, rather than being switched together with the amplifier and being optimized over the total or cumulative bandwidth of all the channels.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: February 15, 1994
    Assignee: General Electric Co.
    Inventor: Herbert J. Wolkstein
  • Patent number: 5274342
    Abstract: A microwave monolithic integrated circuit (MMIC) (40), includes a substrate (60), and an input bus (62), output bus (64), ground bus (66) and bias bus (68) formed as striplines of a four-line coplanar waveguide on the substrate (60) with the input bus (62) and output bus (64) disposed between the ground bus (66) and bias bus (68). A plurality of spatially distributed cascode amplifier units (43) are formed on the substrate (60), each including an input heterojunction bipolar transistor (HBT) (42) connected in a common-emitter configuration, and an output HBT (44) connected in a common-base configuration. The input HBT (42) has an emitter (E.sub.1) connected to the ground bus (66), a base (B.sub.1) connected to the input bus (62) and a collector (C.sub.1). The output HBT (44) has an emitter (E.sub.2) connected to the collector (C.sub.1) of the input HBT (42), a base (B.sub.2) connected to the bias bus (68) and a collector (C.sub.2) connected to the output bus (64).
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: December 28, 1993
    Assignee: Hughes Aircraft Company
    Inventors: Cheng P. Wen, Chan S. Wu, Cheng K. Pao
  • Patent number: 5264803
    Abstract: A system for increasing the voltage handling capacity of an amplifier circuit coupled to a transformer output comprises a transformer secondary winding divided into n sub secondary windings, where n is an integer. A first terminal of a first of the sub secondary windings is coupled to a reference potential. n amplifiers, numbered sequentially 1.ltoreq.m.ltoreq.n as they appear in the amplification circuit with an output terminal of the nth amplifier comprising an output terminal of the amplification circuit, each have an input terminal and an output terminal. An input terminal of the first amplifier is coupled to a second terminal of the first sub secondary winding. An output terminal of each of the n amplifiers is coupled to a first terminal of the next adjacent higher numbered sub secondary winding, except for the nth amplifier, the output of which comprises the output of the amplifier circuit.
    Type: Grant
    Filed: June 26, 1992
    Date of Patent: November 23, 1993
    Assignee: Radian Research, Inc.
    Inventor: Glenn A. Mayfield
  • Patent number: 5264807
    Abstract: A high frequency amplifier containing: a constant envelope signal generation circuit for transforming an input signal to form two constant envelope signals where phases of the constant envelope signals correspond to an amplitude of an envelope of the input signal; two amplifying circuits for separately amplifying two constant envelope signals; and a power synthesizing circuit for synthesizing the first and second amplified signals to generate an amplified signal of the input electric signal, and reflecting remaining components of the first and second amplified signals which remaining components remain in the above synthesizing operation, toward the first and second amplifying circuits.
    Type: Grant
    Filed: August 13, 1991
    Date of Patent: November 23, 1993
    Assignee: Fujitsu Limited
    Inventors: Naofumi Okubo, Yoshihiko Asano, Hiroshi Kurihara, Yoshimasa Daido, Kazuhiko Kobayashi, Shuji Kobayakawa, Toru Maniwa
  • Patent number: 5233634
    Abstract: An automatic gain control circuit (AGC) in a receiver for a digital radio telephone. Most of the total gain control of the received signal is accomplished in the base band frequency sections, i.e. in the I and Q branches, where the signal amplification is controlled step by step, and only a minor part of the total gain control is performed in the RF stage. High amplification steps are formed with amplifiers (9a, 10a, 11a, 12a; 9b, 10b, 11b, 12b), wherein the desired amplifier is activated with a digitally controlled (A, B) multiplexer (13a, 13b), and low amplification steps are formed with a resistance attenuator (14a, 14b), in which a signal of desired level is selected by a digitally controlled (C, D, E) multiplexer (15a, 15b). In addition, the RF amplifier (2) has two amplification levels and the desired amplification is selected with a digital control (F). With the different digital control combinations (A, B, C, D, E, F) the entire gain control range required of the receiver can be covered.
    Type: Grant
    Filed: October 5, 1990
    Date of Patent: August 3, 1993
    Assignee: Nokia Mobile Phones Ltd.
    Inventor: Risto Vaisanen
  • Patent number: 5227735
    Abstract: The invention relates to a circuit for driving a transformer coupled line amplifier. The present invention uses a high impedance differential negative feedback from the secondary of the transformer and uses positive feedback from the primary winding of the transformer. This enables the transformer to be smaller in size while still reducing the harmonic distortion, improving the frequency response, eliminating ringing, lowering the output impedance, improving the longitudinal balance, and also improving the overall stability and phase response of the transformer.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: July 13, 1993
    Assignee: Sony Corporation of America
    Inventor: John L. Lumsden
  • Patent number: 5223800
    Abstract: A distributed array of microelectronic triodes constitutes a series of banks of triodes arranged in a concentric configuration. Each triode in the bank is a microelectronic triode fabricated by semiconductor integrated circuit techniques. Triodes in each individual bank are arranged in a parallel or other configuration whereby each of the triodes operate to provide increased power in regard to input signals applied to each bank. The array of triodes is capacitively coupled so that each of the banks contributes to the total output power. The coupling is provided for by capacitive coupling with biasing being accommodated by resistor biasing networks which are also integrated circuit components.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: June 29, 1993
    Assignee: ITT Corporation
    Inventors: Kenneth S. Karsten, Jr., Frank F. Francisco
  • Patent number: 5218317
    Abstract: A transmitter which includes N amplifiers connected together by a common signal input and which output to a common load. The transmitter also includes N identical series LC circuits, each connected between an amplifier output and the common load, with the common points between each inductance and capacitance connected together. The extremely modular nature of the device makes the transmitter easy to reconfigure if one of the amplifiers fails.
    Type: Grant
    Filed: December 4, 1991
    Date of Patent: June 8, 1993
    Assignee: Thomson-CSF
    Inventors: Guy Boulzaguet, Guy-Arnaud Penet
  • Patent number: 5208554
    Abstract: A Class A high power amplifier having an operating frequency in the range of less than substantially 2 GHz and suitable for aircraft use, is all solid state in that gallium arsenide field effect transistors are utilized. These are mounted in a large copper heat sink which is air cooled to provide for overall cooling by conduction and convection. By the use of microstrip matching circuits, the relatively low impedance of the gallium arsenide FET units is matched to the required higher system impedance. At the same time a 40% band-width is provided due to the superior matching.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: May 4, 1993
    Assignee: Systron Donner Corporation
    Inventors: Harvey Endler, Hadi Mojaradi
  • Patent number: 5206604
    Abstract: A broadband high power amplifier for multifrequency signal applications comprises an N-way power combiner that is arranged to combine a plurality of multi-frequency input signals and provide a combined (complex) signal at its output. The output of the N-way combiner is amplified in a preamplifier stage and supplied therefrom to an M-way power divider. The M-way power divider has a plurality of M output ports from which M subdivided versions of the combined (complex) output signal from the preamplifier are derived. Each of these effectively identical subdivided signals is coupled to a respective one of a plurality of M signal amplifier stages that drive the radial power combiner. Each amplifier stage is a relatively low to moderate gain amplifier stage, so that its amplitude and phase characteristics may be matched with those of the others of the M amplifier stages.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: April 27, 1993
    Assignee: Harris Corporation
    Inventor: Roy A. Vaninetti
  • Patent number: 5200708
    Abstract: Apparatus is provided for the virtual expansion of the power providing capacity of a power supply, e.g., for a stereophonic audio system with a given number of channels which may be selectively increased to provide a surround audio system. A plurality of amplifiers, each having an adjustable gain, are powered from the power supply. The current drawn from the power supply is sensed. When additional amplifiers are activated, the total amount of power drawn by all of the amplifiers can exceed a predetermined level which corresponds to the original plurality of amplifiers. However, when it is sensed that the total amount of power drawn exceeds the predetermined level, the gain of all of the amplifiers is reduced so that the power drawn from the power supply does not exceed the predetermined level. Thus, the virtual power providing capacity of the power supply is expanded to power the additional amplifiers.
    Type: Grant
    Filed: September 11, 1991
    Date of Patent: April 6, 1993
    Assignee: Thomson Consumer Electronics, Inc.
    Inventors: Robert E. Morris, Jr., Mark R. Anderson
  • Patent number: 5191298
    Abstract: A isolation amplifier circuit comprises: an operation amplifier provided with a first and second input terminals, an output terminal, and a feedback resistor for connecting the output terminal and second input terminal; a first emitter follower, for inputting a signal, connected to the first input terminal; a second emitter follower connected between the output terminal and the feedback resistor; a third emitter follower connected between the second input terminal and a first ground impedance; and a fourth emitter follower connected between the first input terminal and a second ground impedance. In the isolation circuit, dynamic resistances of the first, second, third, and fourth emitter followers are made identical with one another.
    Type: Grant
    Filed: November 21, 1991
    Date of Patent: March 2, 1993
    Assignee: Rohm Co., Ltd.
    Inventors: Hiroyuki Funahashi, Chung C. San
  • Patent number: 5187447
    Abstract: A planar interdigitated microstrip coupler comprises a plurality of adjacently disposed transmission lines being spaced such that the transmission lines gradually diverge from a close spacing to a wider spacing. The planar interdigitated microstrip coupler provides equal power split and either 0.degree. or 180.degree. differential phase shift over a multi-octave bandwidth. Further, the interdigitated coupler, when used as a power combiner, provides increased cancellation of second order intermodulation products normally generated by non-linear devices, such as amplifiers, which may be fed to the inputs of the coupler. This increase in second harmonic cancellation, known for distorting signal fidelity, is particularly useful for monolithic circuit applications using amplifiers and mixers.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: February 16, 1993
    Assignee: Raytheon Company
    Inventor: Ming-Chi Tsai
  • Patent number: 5161198
    Abstract: An audio system for use with a mobile radio. More particularly, a microprocessor controlled audio system capable accepting multiple audio input signals and providing an amplified audio signal to a local speaker and a remote speaker without the use of transformers or relays, and capable of driving the speakers either individually or simultaneously. The system provides for increased versatility in output configurations, and allows for microprocessor-controlled muting and power output level switching.
    Type: Grant
    Filed: May 15, 1991
    Date of Patent: November 3, 1992
    Assignee: Allied-Signal Inc.
    Inventor: Scott W. Noble
  • Patent number: 5157348
    Abstract: The Smart Programmable Amplifier System provides a microprocessor based aification system which uses programmable gain amplifier (PGA) techniques. It is used in remote data acquisition systems where it must cover a wide signal range, but the actual measurement range is much smaller during a given time interval. The system interfaces to a host computer to provide complete operator control and to relay continuous status information. The system provides automatic and programmable gain control to meet individual test requirements.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: October 20, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: David M. Deveau
  • Patent number: 5150071
    Abstract: A differential output stage for electronic equipment, the output stage comprising a two-port network having two paths, each connecting an input terminal to an output terminal, and comprising means for generating a negative feedback voltage from each path for application to the other, and means for providing an output voltage in each path equal to an identical linear combination in each path, of the input voltage to the path and of the negative feedback voltage from the other path.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: September 22, 1992
    Assignee: Alcatel Cit
    Inventor: Jean-Pierre Bouzidi
  • Patent number: 5144257
    Abstract: A distributed array of microelectronic triodes constitutes a series of banks of triodes arranged in a concentric configuration. Each triode in the bank is a microelectronic triode fabricated by semiconductor integrated circuit techniques. Triodes in each individual bank are arranged in a parallel or other configuration whereby each of the triodes operate to provide increased power in regard to input signals applied to each bank. The array of triodes is capacitively coupled so that each of the banks contributes to the total output power. The coupling is provided for by capacitive coupling with biasing being accommodated by resistor biasing networks which are also integrated circuit components.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: September 1, 1992
    Assignee: ITT Corporation
    Inventors: Kenneth S. Karsten, Jr., Frank F. Francisco
  • Patent number: 5136256
    Abstract: A radio fequency amplifier-combiner using series fed directional couplers in an input distribution network each coupler having an amplified output to a respective coupler in an accumulator providing a high energy output with low accumulator losses. The invention can be used in waveguide with capabilities of output power levels reaching hundreds of watts and more.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: August 4, 1992
    Inventor: Edward Salzberg
  • Patent number: 5101171
    Abstract: A system for extending the frequency range of an RF amplifier by improving the VSWR, and power handling capability of the amplifier, comprising a broadband reversing transformer, a first and a second amplifier coupled by means of a first and a second through-line quadrature coupler with the first quadrature coupler being connected to the inputs of the two amplifiers and the second quadrature coupler being connected to the outputs of the two amplifiers. The broadband reversing transformer is inserted in series with one of the two amplifiers enabling a signal at frequencies out of the passband of the quadrature couplers to pass through the through-lines port of the quadrature couplers, and thereby greatly extending the frequency range over which quadrature couplers may be used while, at the same time, retaining the usual combining and VSWR advantages of the couplers within their passbands.
    Type: Grant
    Filed: November 23, 1990
    Date of Patent: March 31, 1992
    Assignee: Advanced Systems Research, Inc.
    Inventor: Kevin Redmond
  • Patent number: 5083094
    Abstract: A circuit for selecting and combining power signals of a pair of parallel amplifiers (3,4) using phase shifters (5,6) having fixed phase. Either amplifier (3,4) may be selected to produce a power signal of power P at the circuit output (9), where P is the power at the output (11,12) of each amplifier (3,4). Alternatively, power from the two amplifiers (3,4) may be combined to produce a signal of power 2P at the circuit output (9). By using a passive circuit to achieve the selection and combination, the use of heavier and less reliable relay switches is avoided.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: January 21, 1992
    Assignee: Space Systems/Loral, Inc.
    Inventor: Bjorn G. Forsberg
  • Patent number: 5081425
    Abstract: An adaptive power amplifier system for use with VSWR loads includes an adaptive power supply that indirectly monitors the power dissipated by a RF power amplifier and adapts bias conditions of solid state components in the RF power amplifier to protect the components from excessive power dissipation typically experienced with VSWR loads, even while maintaining full forward power output.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: January 14, 1992
    Assignee: E-Systems, Inc.
    Inventors: Charles R. Jackson, Douglas R. Burke
  • Patent number: 5070304
    Abstract: An improved distributed amplifier usable, for example, in the gigahertz frequency range for radar and electronic warfare applications is disclosed. In the amplifier stage a combination of optimum amplifier stage loading, a reflection cancelling output network, and an amplifier capacitance hiding input arrangement are employed. The disclosure includes specific component values for one embodiment of the invention.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: December 3, 1991
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Mike L. Salib, Marvin Cohn
  • Patent number: 5066924
    Abstract: A pulse amplifier has a driver stage and a following splitter/combiner stage for power division onto two output stages connected in parallel as well as a further splitter/combiner stage that combines the output signals of the output stages. The two splitter/combiner stages each comprise a respective further decoupled port each of which is respectively connected to a switch-over device. The further ports are connected to terminating impedances in a first switch position of the switch-over devices and are connected to one another via an additional signal path in a second switch position and the output stages can be respectively terminated with low impedances at their input sides and output sides via switch elements.
    Type: Grant
    Filed: February 25, 1991
    Date of Patent: November 19, 1991
    Assignees: Siemens Aktiengesellschaft, Siemens Aktiengesellschaft
    Inventor: Peter Wendt
  • Patent number: 5066926
    Abstract: A cascode transistor configuration includes an input terminal for receiving the input signal, an output terminal for outputting the output signal and bass and emitter terminals connectable to ground. Each of a predetermined plurality of common-base heterojunction bipolar transistors (HBTs) has a base coupled to the base terminal, and a collector coupled to the support output terminal. Each of the predetermined plurality of common-emitter HBTs is associated with one of the common-base HBTs. Each common-emitter HBT also has a base coupled to the input terminal, an emitter coupled to the emitter terminal, and a collector coupled to only the emitter of the associated common-base HBT.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: November 19, 1991
    Assignee: Pacific Monolithics
    Inventors: Ravi Ramachandran, Allen F. Podell
  • Patent number: 5028880
    Abstract: A microwave power amplifier includes first and second circuits each having first, second, third and fourth terminals. Each of the first and second circuits has functions of distributing an input signal to the second and third terminals and generating first and second output signals 180.degree. out of phase with each other through the second and third terminals, respectively, adding a first pair of 180.degree. out-of-phase input signals to the second and third terminals and outputting a first resultant signal through the first terminal, and adding a second pair of in-phase input signals to the second and third terminals and outputting a second resultant signal through the fourth terminal.
    Type: Grant
    Filed: February 14, 1990
    Date of Patent: July 2, 1991
    Assignee: Fujitsu Limited
    Inventor: Fuminori Sakai
  • Patent number: 5017888
    Abstract: A broadband nonlinear drive control network for linear amplifiers with several amplifier channels has a first branch (Z1) with an adjustable amplitude limiter (A) connected to a signal source (S) through an impedance inverter (B), whereby an increasing impedance is produced at the signal source (S) when the limiter is activated. A variable resistor (C) is connected to the signal source (S) in a second branch (Z2). The resistor (C) begins to conduct only above an adjustable high frequency signal voltage. The amplitudes at the limiter (A) and at the resistor are tuned to each other so that the load impedance at the signal source (S) remains constant. Linear branch signal combinations provide the drive control voltages for the individual channels (K2 . . . Kn). A portion of the power output of the branch (Z1) directly drives the amplifier channel (K1).
    Type: Grant
    Filed: March 1, 1990
    Date of Patent: May 21, 1991
    Assignee: Messerschmitt-Boelkow-Blohm GmbH
    Inventor: Karl Meinzer
  • Patent number: 5012200
    Abstract: The amplification efficiency is increased in a system for linear amplification of signals, especially in satellite transponders, by connecting at least three amplifier impedance inverter units in parallel to each other between an input signal control network and a common load. The reactive loading of the individual amplifiers is compensated by shunt susceptances at the output ports of the individual amplifiers.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: April 30, 1991
    Assignee: Messerschmitt-Boelkow-Blohm GmbH
    Inventor: Karl Meinzer
  • Patent number: 5008631
    Abstract: Apparatus and method for extending the effective dynamic range of pulse measure and pulse display devices by providing dynamic gain switching, with an associated gain or attenuation coefficient that assumes one of a plurality of two or more values, depending on the instantaneous magnitude of the signal received or upon the choice of an external controller. The amplification path may be one of a plurality of mutually exclusive parallel paths. Alternatively, the amplification path may be a serial combination of an arbitrary subset of a collection of amplification paths. The choice of amplification path may be made automatically by a fast-acting sensor such as a signal comparator or may be made by an external control provided by a human operator or computer and may be overridden by an externally produced control override signal.
    Type: Grant
    Filed: August 16, 1989
    Date of Patent: April 16, 1991
    Assignee: Hewlett-Packard Company
    Inventors: Dieter Scherer, William E. Strasser