Abstract: A highly directive, broadband, bidirectional distributed amplifier has a series of FETs connected between input and output lines which have their effective transconductances scaled in accordance with binomial coefficients along the distributed amplifier to maximize the directivity of the amplifier. Directivities on the order of -25 to -35 dB are obtained over as much as an octave in frequency. The effective binomial scaling may be achieved by insertion of appropriately sized capacitors in the gate lines of each of the FETs. The minimization bandwidth may be shifted to lower frequencies by incorporating passive impedances between the active devices in both the gate and drain lines. These impedances preferably comprise T-section inserts composed of serially connected lumped inductors and a capacitance from the junction between the inductors to ground.

Abstract: The disclosure relates to a circuit to reduce the gate loss in a semiconductor travelling wave power amplifier using series capacitors on the gate feeding lines for a distributed amplifier design. The circuit arrangement significantly increases the gate width of the amplifier with a resultant increases of the broadband output power and efficiency.

Abstract: Transversal and recursive filters having an input propagation lumped element network with a band pass filter response, a low pass filter response, or a high pass filter response, and an output propagation network having a low pass frequency response, a high pass frequency response, or a band pass frequency response are described. Weighting means including a plurality of field effect transistors are used to successively couple the input propagation network and the output propagation network. The general shape or response of the transversal filter is provided by choosing the characteristics of the input and output propagation networks in relation to the desired filter response. With the general shape provided by the propagation networks rather than only by the transversal elements, fewer transversal elements are required to provide a desired response.

Abstract: A radio frequency matrix amplifier includes an input propagation network for successively connecting input electrodes of a first plurality of transistors. Output electrodes are successively coupled by an intermediate propagation network. The amplifier also includes a second plurality of transistors, having input electrodes successively coupled by the intermediate propagation network and output electrodes successively coupled by an output propagation network. A bias circuit for the amplifier includes an inductor connected between a last one of the second plurality of transistors and the intermediate propagation network and a plurality of capacitors disposed to connect reference electrodes of the second plurality of transistors to a reference potential. With this arrangement stages are connected in series for D.C. potentials and in cascade for r.f. potentials.

Abstract: A distributed amplifier has a plurality of amplifying sections which are connected between input and output lines comprising artificial transmission line sections. Input line attenuation compensThis invention was made with U.S. Government support awarded by the Department of the Navy, Contract No.: N00014-87-C-0157. The U.S. Government has certain rights in this invention.

Abstract: A double balun circuit is provided by connecting two pairs of circut types. The first circuit, a distributed divider circuit, includes first and second pluralities of field effect transistors, a common input transmission line, and a first and second output transmission lines. The common input transmission line is disposed to successively couple the input electrodes of each transistor of both the first and second pluralities of transistors. The output lines are disposed to successively couple the output electrodes of the respective ones of the plurities of transistors. Each output transmission line is coupled to one of the pair of output terminals of the circuit.

Abstract: An apparatus and method are disclosed for performing impedance transformations on the order of 4:1 to 8:1 or more over extremely broad bandwidths. The transformations are performed in an apparatus having a plurality of n distributed amplifiers having one common synthetic transmission line sharing inductive elements and a second transmission line connected in parallel to the other transmission lines. The transmission lines incorporate active elements preferably in the form of FET cascode pairs. In one embodiment, the second transistor of each cascode pair is replaced with n smaller gate FETs to decrease DC power requirements and provide additional doncution paths for impedance reduction.

Abstract: Distributed amplifiers in integrated circuit form wherein dielectric matel and electrically conductive material combine to form field emitter cathodes, grids, and anodes in a module forming one or more amplifier cells embedded in a matrix of reactive impedances that form companion stripline-like transmission lines in a vacuum or sufficiently low pressure gas such that electrons remain unscattered during travel over trajectories from cathode to anode in a cell.

Abstract: A high-frequency circuit includes a field-effect transistor having a gate electrode for receiving a high-frequency input signal, a source electrode and a drain electrode. Substantial improvements in both maximum gain and high-frequency performance are achieved by providing an input or output terminal at one end of each electrode, and terminating at least one of the electrodes with an appropriate impedance at its second end.

Abstract: A distributed circuit includes a plurality of field effect transistors (FETS), each one of such FETS having gate, drain and source electrodes, with a first portion, or a first channel, of such FETS having gate electrodes and drain electrodes successively coupled between a first input terminal and a first ouput terminal, and a second like portion or a second channel of such FETS having gate electrodes and drain electrodes successively coupled between the first input terminal and a second output terminal. Separate bias circuits are provided to the input electrodes and the output electrodes of the first and second channels. Bias signals fed to the input bias circuits and coupled to the input electrodes to place the FETS in an "on" state to provide gain to r.f. input signals fed thereto, or in a "pinch-off" state to isolate r.f. signals fed to the input electrodes of the FETS. Accordingly, a 1.times.2 signal splitter or a 1.times.2 switch which provides gain to a signal is provided.

Abstract: The invention relates to a variable gain distributed amplifier for use at microwave frequencies, and fabricated in a monolithic microwave integrated circuit format. In the amplifier, the attenuation is varied, based upon digital control of a dual gate segmented FET. The amplifier has a nearly flat insertion phase and amplitude response, and an insertion phase response that varies only slightly between gain settings. The amplifier employs segmented dual gate field effect transistors as the gain elements, having their signal input and signal output electrodes which provide shunt capacities (C.sub.G1S, C.sub.DS) interconnected with serial inductances to form separate low pass transmission lines having relatively high cut-off frequencies. The amplifier has means to insure stability and uses Chebyshef equal ripple techniques to linearize the amplitude and insertion phase response.

Abstract: The requirements of extreme miniaturization, remote operation, wide bandwidth, good reproducibility in high quantities, low cost and low insertion loss are met with an incrementally adjustable distributed network arrangement in the general configuration of a distributed amplifier. The arrangement comprises delay elements (Z.sub.Dm, Z.sub.Gm) and a plurality of controlled sources (T.sub.n-2, T.sub.n-1, T.sub.ni VCCS), a signal input (E) and a signal output (A). The controlled sources (T.sub.n-2, T.sub.n-1, T.sub.ni VCCS) may be selectively turned on and off. Dual gate FETs (T.sub.1, . . . T.sub.n) are employed as controlled sources, whose first gate (G.sub.1) is connected to the input signal voltage through delay elements (Z.sub.Gm) and whose second gate (G.sub.2) is maintained at suitable dc voltages for turning the respective FETs on and off.

Abstract: Distributed amplifiers in integrated circuit form wherein dielectric material and electrically conductive material combine to form field emitter cathodes, grids, and anodes in a module forming one or more amplifier cells embedded in a matrix of reactive impedances that form companion stripline-like transmission lines in a vacuum or sufficiently low pressure gas such that electrons remain unscattered during travel over trajectories from cathode to anode in a cell.

Abstract: Logarithmic amplifiers which have a logarithmic transfer characteristic may be used in microwave instrumentation. Such an amplifier includes a series of MESFET distributed amplifiers (DA1-DA8) connected in cascade, with each of the MESFET distributed amplifiers (DA1-DA8) having a gate transmission line (G1-G8) and a drain transmission line (D1-D8) which share a common ground or source line (5), and a number of MESFETs (1-4) connected in parallel with their gate electrodes (g) connected at spaced intervals along the gate transmission line (G1-G8) their drain electrodes (d) connected at spaced intervals along the drain transmission line (D1-D8) and their source electrodes (s) connected to the source line (5). A low pass filter (LPF1-LPF8) is connected to the downstream end of the gate transmission line (G1-G8) of each distributed amplifier (DA1-DA8) with each low pass filter (LPF1-LPF8) passing only the rectified component of the travelling wave passing along each gate transmission line (G1-G 8).

Abstract: A distributed amplifier which increases gain by increasing transconductance comprises a plurality of amplifying elements. Each element includes a darlington amplifier connected in cascade with a FET (field effect transistor) amplifier. The darlington amplifier includes an RC (resistance/capacitance) feedback loop from the drain to the gate. Each of the amplifying elements are coupled in parallel between an input transmission line and an output transmission line. The output transmission line operates as a recombining network as the input signals pass through the amplifying elements. To further increase gain and power output, a time delay line is coupled to each end of the output transmission line. The time delay line simulates the terminating elements normally associated with distributed amplifiers, and collects unguided signals from the output transmission line to recombine them with guided signals at the output.

Abstract: A high-frequency power synthesizing apparatus having a plurality of distributors arranged in a plurality of stages, a plurality of amplifiers which are supplied with outputs from a final stage of said power distributors and which amplify these outputs to a predetermined level, and a power synthesizing unit including initial-stage power synthesizers supplied with outputs from said amplifiers and a final-stage synthesizer which outputs power to an external load. The final-stage power distributors and the initial stage synthesizers are constituted by 0.degree.-hybrid modules. The output level of each amplifier is regulated and made constant by being compared with a predetermined level. The output levels of the amplifiers can be displayed on an external display.

Abstract: A distributed amplifier having an on chip DC biasing network including a spiral inductor. The spiral inductor has a low resistance for providing a minimal resistance path for the DC biasing, while also having a high inductance for isolating the RF signal from the DC bias sources. Additionally, an inductive lead connected between the spiral inductor and the amplifier has a predetermined inductance such that this inductance is matched with the inherent capacitance of the spiral inductor in order to provide a substantially same impedance as that of the amplifying stages.

Abstract: An optical gain control circuit for controlling the gain of a GaAs MMIC dributed amplifier having a dc gain control is provided. Variable intensity light from a controlled LED is directed to the surface of a GaAs multi-finger FET by means of an optical fiber. The FET is gate biased to a point near pinch-off to maximize its light sensitivity and the drain and source of the FET are serially connected with a fixed resistance in a dc voltage divider circuit so that the output of the voltage divider circuit changes as a function of the change in light intensity of the LED. A MMIC operational amplifier connected in an inverter mode is coupled between the output of the voltage divider circuit and the dc gain control of the distributed amplifier to control the gain of that amplifier.

Abstract: An input signal for a travelling wave or distributed amplifier having input and output transmission lines is supplied to one end (1) of the input line and an output signal is derived from one end (4) of the output line. Conventionally, the other end (2, 3) of each line is terminated in a respective matched load, but three ports of the amplifier may be employed. The travelling wave amplifier may be used to replace a circulator (CIRC, FIG. 2) in an FMCW radar having a single transmitting/receiving antenna (ANT) (TWAMP1, FIG. 3), to replace a directional coupler (DC) for supplying a local oscillator signal to a mixer (MXR) (TWAMP2, FIG. 4), and in combination with a mixer diode (D) to form a mixer amplifier (TWAMP3, FIG. 3), giving the possibility of the larger-scale integration of RF circuits.

Abstract: A distributed FET amplifier comprising an array of FET elements each having a gate terminal, a drain terminal and a source terminal. The gate terminals of the adjacent FET elements are connected by a first inductor, and the drain terminals of the adjacent FET elements are connected by a second inductor. Between the source terminals of each of the FET elements and the ground is connected a parallel circuit comprising a capacitor having a capacitance greater than the gate-source capacitance of the FET element and an impedance element connected in parallel to the capacitor for grounding the direct current. A bias voltage supply circuit for supplying a bias voltage to such as distributed amplifier is also disclosed.

Abstract: In order to supply a d.c. bias to the drain electrodes of MESFETS (1-4) in a distributed amplifier operating in the 500 MHz to 20 GHz or above, a d.c. source (15) is connected to the drain line (5,9,11,14) via a feed component (16) which comprises a ferrite bead (17) having an axial aperture (18). A coil (19) comprising, for example, four turns of 20 micron gold wire is wound on the bead in toroidal fashion. The bead may be of the kind which is used for low-frequency interference suppression or for encircling the emitter lead-out wire of a bipolar transistor operating in the lower megahertz range. At these relatively low frequencies in the conventional use of the bead, the bead material will exhibit low magnetic losses and high permeability. However, in the present invention, due to the microwave signal in the coil, the bead operates over a frequency band which is many times higher than its normal operating band. At these high frequencies the bead material exhibits quite large losses.

Abstract: A monolithic semiconductor having an on-chip DC biasing including a plurality of series connected spiral inductors connected between the respective biasing and the semiconductor circuit. The spiral inductors provide a low resistive path for the DC biasing while also having a high inductance for isolating the RF signal from the bias sources, thereby improving the low frequency response. The capacitance associated with the individual spirals, however, is significantly less than the capacitance associated with a single spiral inductor having an equivalent inductance of the small series connected spirals; thus the higher frequency response is not degraded while the low frequency response has been improved.

Abstract: The present invention provides a modified distributed amplifier which is capable of providing push-pull operation without the loading losses of conventional push-pull combining. The modified distributed amplifier comprises a distributed amplifier configuration and with signal inverting means, such as a wide bandwidth transmission line transformer, interconnected into both the input and output lines. The signal inverting means are most effectively placed at the electrical centers of the lines, but may be placed at any positions in the individual lines to produce optimum performance to specific applications. The separate segments of the distributed amplifier separated by the signal inverting means operate in opposed phase but the signals output to the load add in phase thus providing push-pull operation.

Abstract: A multifunction monolithic microwave integrated circuit composed of a pluity of dual gate FET amplifier sections connected between a pair of transmission lines which are adapted to receive one or two input signals. The circuit can be configured, by selective external connections and biasing voltage levels, to function in a number of different modes, such as an amplifier, a mixer, modulator, a variable amplifier, an attenuator, a temperature compensation chip, a frequency multiplier and a phase shifter.

Abstract: A distributed amplifier includes a plurality of field effect transistors, each having gate, drain, and source electrodes, successively coupled between an input terminal and an output terminal. The gate electrode of each one of successively coupled FETS is coupled to the input terminal through a corresponding one of a plurality of capacitors and selected ones of the drain electrodes of the FETS are coupled to the output terminal through one of a corresponding second plurality of capacitors, with said capacitors being coupled to an output coupling means comprising a plurality of transmission line sections. By providing the second plurality of capacitors to couple the drain electrodes to the output terminal, the output impedance of each one of the field effect transistors is concomitantly increased thereby permitting the periphery of the transistors to be correspondingly increased and thereby providing increased output power and gain from the amplifier circuit.

Abstract: The disclosed microwave distributed amplifier includes a plurality of cascaded field emission triodes, each having a field emission element for emitting electrons, a grid disposed downstream from the field emission element along the electron flow path and an anode disposed further downstream along the electron flow path. A series of inductive strips interconnect successive grids to form a grid transmission line, while another series of inductive strips interconnect successive anodes to form an anode transmission line. Small electron transit times over integrated circuit distances in a vacuum environment and low interelectrode capacitance allow extremely large gain-bandwidth products to be achieved.

Abstract: A distributed circuit includes a plurality of field effect transistors (FETS), each one of such FETS having gate, drain and source electrodes, with a first portion, or a first channel, of such FETS having gate electrodes and drain electrodes successively coupled between a first input terminal and an output terminal, and a second like portion or a second channel of such FETS having gate electrodes and drain electrodes successively coupled between a second input terminal and said output terminal. Separate bias circuits are provided to the input electrodes of the first and second channels. Bias signals fed to the bias circuits and coupled to the input electrodes place the FETS in an "on" state to provide gain to r.f. input signals fed thereto, or in a "pinch-off" state to isolate r.f. signals fed to the input electrodes of the FETS. Accordingly, a 2.times.1 switch or a two way active r.f. combiner which provides gain to a signal is provided.

Abstract: A radio-frequency (rf) power combiner or divider structure containing distributed amplifier components and having broadband operating characteristics, and operable with net gain or practically no insertion losses. The divider structure includes an input transmission line having series-connected impedances that interconnect with active devices, such as field-effect transistors to form a practically lossless line. The active devices provide gain between distributed points in the input transmission line and distributed points in multiple output transmission lines, which are similarly structured as series-connected impedances. Each output transmission line supplies one of the divider outputs. In the combiner form of the device, there is a single output transmission line and multiple input transmission lines, coupled to the output line in a distributed manner by active devices.

Abstract: A broadband distributed amplifier comprised of a plurality of field effect transistors whose gates are connected to junctions between serially-connected inductors forming a gate transmission line, whose drains are connected to junctions between serially-connected inductors forming a drain transmission line, and whose sources are connected to ground. The distribution of the amplifier stages along the gate and drain transmission lines is effected such that these transmission lines are periodically loaded by their own impedances and by the transistor gate and drain capacitances, thus forming artificial lines, and such that a microwave frequency input signal applied to the input of the gate transmission line effects the production of an amplified microwave frequency output signal at the output of the drain transmission line. The gate and drain transmission line output and input, respectively, are terminated by loads.

Abstract: A microwave amplifier that both multiplicatively and additively amplifies microwave frequency signals. The amplifier, herein coined a matrix amplifier, is a distributed amplifier with two or more tiers (rows) of transistors. Each tier has a plurality of transistors which additively amplify the signal entering that row of the amplifier, and each row multiplicatively amplifies the output of the previous row. The gates of the transistors in each row are sequentially coupled to an input transmission line having a series of transmission elements. The outputs of all the transistors from each row are sequentially coupled to the input transmission line of the next tier, except that the outputs of the last tier are coupled to an output transmission line for transmitting the output of the amplifier to an output node. Furthermore, each transmission lines has (1) at least one line termination at one of its ends for absorbing signals incident on that end of the transmission line, and (2) biasing means for d.c.

Abstract: A monolithic distributed mixer includes a plurality of dual gate field effect transistors (FETs) and first and second corresponding pluralities of T shaped constant K-filters connected respectively to first and second gates of the dual gate FETs for delaying in time the LO and RF voltages applied thereto whereby the phase shift is the same at each filter and the phase difference between the LO and RF at each FET is equal. Thus, the IF energy developed at each drain is in phase. The plurality of dual gate FETs have their drains commonly connected for summing the IF outputs thereof to provide a flat response throughout the bandwidth which is limited only by the cutoff voltages of the FETs or first and second pluralities of K-filters which act as low pass filters.

Abstract: A robust amplifier consists of two delay lines linked by a number of discrete amplifiers. Distortion correction is carried out by distortion feed forward. This is achieved by sampling the output of each amplifier at a coupler and then subtracting this sample from the input signal to later amplifiers along the delay line at directional coupler. As a result each discrete amplifier's distortion is corrected by all of the following discrete amplifiers in the amplifying circuit.

Abstract: A travelling-wave transistor structure (50) with the input and output transmission lines (54,58) terminated with unmatched impedances (70,72,74;80,82,84) to improve high-frequency response by reflection and phase shift to provide constructive interference is disclosed. Preferred embodiments include a .pi.-gate (52,56) MESFET structure travelling-wave transistor with many periodically spaced gate feeding fingers (56) connecting gate (52) to gate transmission line (54) which parallels gate (52). This provides a compact structure and has large advantages at millimeter wave frequencies. Source (60) may be grounded by vias (61) or may pass over gate transmission line (54) by air bridges to a ground on the same surface as the MESFET.

Abstract: Structures (30) with IMPATT type diodes (34) located periodically along a transmission line (38-32) to simulate a distributed diode are disclosed. Preferred embodiments include incorporation of the periodic diode structures as the gain element of microwave amplifiers and oscillators. Preferred embodiments also place capacitors between the diodes to fix nodes in the electric field and increase the effective structure size.

Abstract: The present invention includes an apparatus and a method for connecting at least a pair of stages in DC series between a pair of power-supply potentials so as to provide economical utilization of the power supply. The stages are connected so as to maintain their AC independence.

Abstract: A 2-18 gigahertz monolithic distributed amplifier using dual-gate gallium arsenide field effect transistors for maximum gain over the design bandwidth.

Abstract: An integrated amplifier circuit for monolithic fabrication is disclosed. circuit includes a plurality of amplifier stages between an input transmission line and an output transmission line. Each stage includes a FET formed on the surface of a semi-insulating substrate such as gallium arsenide (GaAs). The gate of each FET is connected to the input transmission line, while the drain is connected to the output transmission line. The source is connected through the semi-insulating substrate to a conductive layer. A received signal propagates as a traveling wave along the input transmission line, and is amplified by each of the FETs. The phase delay between the gates is the same as that between the drains, so that the amplified signal adds constructively on the output transmission line. Each of the transmission lines is terminated in its own characteristic impedance, which may be equal to the load.

Abstract: A power combiner has been described incorporating N transmission lines each having a quarter wavelength or multiple thereof for a frequency within a predetermined frequency range where the input of each transmission line has a resistor coupled thereto with the other ends of the resistors coupled together using inductance and capacitance to compensate for the distances between the resistors to provide a floating node which is low impedance in the predetermined frequency range. A composite amplifier is described on gallium arsenide wherein a power divider and power combiner are coupled to a plurality of MESFET's and wherein each input and output of the power combiner and power divider have a resistive load with respect to the MESFET while including a matching circuit and wherein each input of the combiner has a resistor coupled to a first floating node and each output of the divider has a resistor coupled to a second floating node.

Abstract: A broadband distributed amplifier capable of amplifying frequencies from zero to 20 Gigahertz is disclosed having a singly terminated output. The singly terminated construction of the amplifier precludes the need for a termination resistor on the output and thereby enables substantially all of the output power to be utilized.

Abstract: A high power amplifier arrangement utilizes a configuration which is similar to that of a distributed amplifier in which the capacitances of a plurality of individual amplifying devices form part of a delay line which couples together the amplifying device, so as to sum the output power. The invention enables amplifying devices, such as vacuum tubes or field effect transistors which have significant electrode capacitances, to be used to amplify wide band high frequency signals. Each amplifying device is provided with an associated output impedance having a value which is matched to that of the output delay line on to which it fits. The output delay line consists of a number of stages separated by power combiners connected to different respective amplifying devices. This configuration can be more efficient than a conventional distributed amplifier, and its use is more acceptable in conjunction with loads, such as antennas whose actual input impedance can differ somewhat from a nominal design value.

Abstract: A distributed amplifier having a plurality of successively coupled field effect transistors with cascaded gate electrodes and cascaded drain electrodes. A first one of such transistors has the gate electrode thereof coupled to an input terminal adapted to receive an input radio frequency signal and the drain electrode thereof coupled to a dc drain electrode bias circuit. The last one of the successively coupled field effect transistors has the gate electrode thereof coupled to a dc gate electrode bias circuit and a drain electrode coupled to a radio frequency output terminal which produces an amplified radio frequency signal. The source electrodes of the plurality of transistors are coupled to ground. A drain bias voltage source is coupled between ground and the drain electrode bias circuit, such bias circuit providing a direct current path between such drain bias voltage source and the drain electrodes of the transistors.

Abstract: A parallel channel microwave amplifier comprising a plurality of amplificon channels interconnecting a power-dividing matrix and a power-combining matrix. Each amplification channel includes a phase shifter, an attenuator and a power amplifier connected in series. The device functions as a combination of amplifier and an r.f. attenuator/modulator.

Abstract: A device combining a certain number of elementary amplifiers formed on the same semiconductor wafer having a very high frequency (about 10 GHz), thus obtaining a monolithic amplifier with a high power and a wide pass band. This amplifier comprises at the input a first transmission line of the microstrip type, bent in such a way that it has an input branch and a tap branch where the waves reflected as a result of mismatches are absorbed in a resistive load. The bent region of line is connected to a row of elements of the impedance transformation lines passing to the gates (case of field effect transistors). It comprises at the output a second microstrip line parallel to the first and bias connected to a row of elements identical to those of the amplifier input.

Abstract: The invention relates to a radio power distributor. The distributor comprises a plurality of dividers D(i-1), D(i) . . . mounted in cascade-like manner and each having a primary branch A(i-1, A(i) . . . which is divided up into secondary branches, whereof one, the main secondary branch B(i-1) is connected to the primary branch A(i) of the following and whereof the others (C) are terminated on the utilization points. All the branches (C) are connected to the same point a of the line B of the same rank i by resistance members. This makes it possible to absorb the reflected powers in these lines when mismatchings occur, even when the latter are identical. A phase changer .phi. is optionally placed in the primary branch.

Abstract: The present invention provides a modified distributed amplifier which is capable of accepting two or more independent inputs and amplifying them without giving rise to a large number of significant intermodulation products. This modified distributed amplifier effectively comprises two or more unmodified distributed amplifiers (as V.sub.11 to V.sub.18 and V.sub.21 to V.sub.28) joined so as to have a common output line (10) but individual, independent, input lines (111 and 211). The join is preferably "back-to-back" (in a parallel sense) so that the individual distributed amplifiers are in some sort of interleaved arrangement.

Abstract: For many applications it is desirable that electronic amplifiers have good linearity (a typical such application is in the field of high frequency radio transmission). Various arrangements and designs have been employed to ensure that the desired linearity is attained, but some types of amplifier have proven rather difficult in this respect: such a type is the distributed amplifier, where the correction of amplification errors has proven particularly difficult because of the relatively large time delay (and thus signal phase difference) "across" the amplifier. The present invention seeks to provide a distributed amplifier system allowing the easier correction of amplifier errors.

Abstract: A distributed amplifier is provided with an output filter line with the output terminals of a plurality of individual amplifying devices connected to different points along the output filter line. Instead of dimensioning the impedance of the output filter line to provide a perfectly uniform frequency response, it is arranged as a wide band multiple quarter wave impedance transformer. The use of this kind of output filter line provides superior performance when the amplifier is used with mismatched loads and the frequency response can still be very good.

Abstract: The amplifier comprises two input and output transmission lines connected together by means of a plurality of active quadripoles mounted in parallel across the transmission lines, the elements for matching the quadripoles being inserted between the lines. In a solid state design, the active quadripoles are formed in a gallium arsenide substrate and the lines are constituted by metallic deposits formed on the substrate by means of the microstrip technique. The matching elements comprise inductance coils between which are placed coupling capacitors.