RU2168264C1 - Controllable power amplifier - Google Patents

Abstract

FIELD: radio engineering, radio transmitting devices with controllable radiation power. SUBSTANCE: amplifier includes N amplification stages 1.1-1. N of first amplification path with own power supply units 2.1-2.N and switches 3.1-3.N, control unit 4, M amplification stages 5.1- 5.N of second amplification path with own power supply units 6.1-6.N and switches 7.1-7.M, power divider 8, power division bridge 9, power addition bridge 10, two phase detectors 11.1 and 11.2, two controllable phase inverters 12.1 and 12.2, ballast load 13. Amplification stages are based on amplitrons. Output power is controlled by supply of power to those amplification stages which ensure required power across output of controllable power amplifier and by turning off supply to unused amplification stages without break of SHF path. EFFECT: enhanced reliability of amplifier with increase of number of control stages without loss of information. 2 dwg

Description

 The invention relates to radio communications technology and can be used in microwave transmitting devices.

 Known adjustable power amplifier containing N amplifier modules, a controlled power adder, switchable matching transformer and control unit. The power control in it is carried out by changing the number of active (working) amplifier modules with the subsequent addition of the capacities of these modules in a controlled adder (see A.S. USSR.N 131924, MKI H 03 F 1/30 from 06.23.87, Bull. N 23). The disadvantages of this amplifier are a small number of power gradations, determined by the number of amplifier modules, the need to use an N-channel controlled adder, which complicates the device, and the presence of RF switches in it reduces the technical reliability of the adjustable power amplifier.

Known low-noise microwave amplifier containing N amplification stages connected to each other through controlled switching units (controlled switches), power switches of the amplifier stages and a control unit. The adjustment of the output signal level in it can be carried out by changing the number of amplification stages used (see Pat. RF. N 210858, IPC ⁶ H 03 G 3/20 of 04/10/98, Bull. N 10). The disadvantages of this device are a small number of output power levels, determined by the number of amplification stages, low technical reliability due to the serial connection of amplifiers through controlled microwave switches.

 The closest in number of similar features is an automatic gain control device containing a multistage amplifier, in which controlled switches are installed between the cascades to ensure the inclusion of one stage or another in the amplification path, or to exclude it from the path, a power source, and power switches that provide power to amplifiers included in the amplification path, and disconnecting power from amplifiers excluded from the amplification path and a control unit for controlling the above annymi switches. By means of interstage switches and lines connecting one of the outputs of the previous switch to the input of the subsequent switch, the excluded amplification stage is bypassed (see AC.SSSR, N 1617622, MKI H 03 G 3/20 dated 10.08. 1990 Bull. N 48).

 We will take this device as a prototype.

The disadvantages of the prototype include:
1. Low technical reliability due to the presence of series-connected interstage switches
2. Loss of information during switching related to gain control
3. A small number of gradations of the output power, equal to the number of amplification stages.

 The aim of the invention is the development of a device that provides control of the output power of the amplifier while increasing technical reliability, increasing the number of gradations of the output power, without losing information passing through the adjustable amplifier with changes (adjustments) of the output power.

This goal is achieved by the fact that in a known device containing an N-cascade amplification path, N power supplies, N power switches and a control unit, the power supply unit of each stage connected to the power input of its cascade through a power switch, the control input of which is connected to the control output of the control unit, a second multistage amplification path is additionally introduced, containing M amplification stages, M power supplies, M power switches, a power divider, a power division bridge, two phases x detector, two controlled phase shifter, the phase shifter 90 ^o and the ballast load, the input power divider is the input of the controlled amplifier, the first output of the power divider via a first controllable phase shifter is connected to the input of the first stage of the first (N-cascade) amplifying path and the second the output of the power divider is connected to the input of the first stage of the second (M-cascade) amplifier path, the output of the Nth stage of the first amplifier path is connected to the first input of the bridge of power division and the first input the house of the first phase detector, the output of the Mth cascade of the second amplifier path is connected to the second input of the power sharing bridge and to the second input of the first phase detector, the output of which is connected to the control input of the first controlled phase shifter, the first output of the power sharing bridge through the second controlled phase shifter is connected to the first the input of the power addition bridge and with the first input of the second phase detector, the output of which is connected to the control input of the second controlled phase shifter, the second output of the power division bridge awns coupled to a second input of the power summation of the bridge and through the phase shifter 90 ^o to a second input of the second phase detector, a first output capacity of addition of the bridge is the output of the adjustable power amplifier, and the second is connected to the ballast load blocks cascades are connected in with supply inputs their cascades through corresponding power switches, the control inputs of which are connected to the corresponding additional control outputs of the control unit, amplifier stages are made on amplitrons.

Thanks to a new set of essential features due to the introduction of a second multistage amplification path with power supplies and power divider power switches, dividing and adding power bridges, two phase detectors, 90 ^o phase shifter and two controllable phase shifters, the proposed device will provide the possibility of discrete control of the amplifier output power with increasing technical reliability and without loss of information (due to the direct connection of cascades in amplification paths as a result of using amplitrons as amplifying elements), increasing the number of output power control stages with the same number of amplifying stages as the prototype (due to the introduction of a second multi-stage amplifying path, a power divider, and division and addition bridges). The analysis of the prior art made it possible to establish that analogues that are characterized by a combination of features identical to all the features of the claimed technical solution are absent, which indicates the compliance of the claimed device with the patentability condition of "novelty". Search results for known solutions in this and related fields of technology in order to identify features that match the distinctive features of the claimed device from the prototype showed that they do not follow explicitly from the prior art. The prior art also did not reveal the popularity of the impact provided by the essential features of the claimed invention transformations to achieve the specified technical result. Therefore, the claimed invention meets the condition of patentability "inventive step".

The claimed device is illustrated by diagrams:
FIG. 1 is a functional diagram of an adjustable power amplifier;
FIG. 2 is a diagram of a control unit.

An adjustable power amplifier (see Fig. 1) consists of a first amplifier path containing N amplifier stages 1.1 ... 1.N, N power supplies 2.1 ... 2N, connected via power switches 3.1 ... 3.N to power the inputs of its amplifier stages, the second amplifier path, containing M amplifier stages 5.1 ... 5M, M power supplies 6.1 ... 6M connected via power switches 7.1 ... 7M to the power inputs of their amplifier stages, control unit 4, power divider 8, power division bridge 9, power addition bridge 10, phase detectors tori 11.1 and 11.2, phase shifter 90 ^o 14, controlled phase shifters 12.1 and 12.2 and ballast load 13. The input of the power divider 8 is the input of an adjustable power amplifier. The first output of the power divider 8 is connected to the input of the first amplifier stage 1.1 of the first amplifier path through a controlled phase shifter 12.1, and the second output of the power divider 8 is connected directly to the input of the first amplifier stage 5.1 of the second amplifier path. The output of the Nth amplifier stage 5.N of the first amplifier path is connected to the first input of the power sharing bridge 9 and to the first input of the first phase detector 11.1. The output of the Mth amplification stage 5.M is connected to the second input of the power dividing bridge 9 and to the second input of the phase detector 11.1. The output of the phase detector 11.1 is connected to the control input of the controlled phase shifter 12.1. The first output of the power sharing bridge 9 through the second controlled phase shifter 12.2 is connected to the first input of the power addition bridge and to the first input of the second phase detector 11.2. The second output of the power sharing bridge 9 is connected to the second input of the power addition bridge 10 and through the phase shifter 90 ^o 14 with the second input of the second phase detector 11.2, the output of which is connected to the control input of the second controlled phase shifter 12.2. The first output of the power addition bridge 10 is the output of an adjustable power amplifier, and the second is connected to the ballast load 13. The control outputs of the control unit 4 are connected to the control inputs of the corresponding power switches 3.1 ... 3N, 7.1 ... 7.M.

 The control unit 4 (see Fig. 2) in its composition contains a constant voltage source 15 and N + M switches 16.1.1 ... 16.1.N, 16.2.1 ... 16.2. M. A constant voltage source 15 is connected to the inputs of the switches 16.1.1. . . 16.1. N, 16.2.1 ... 16.2.M, the outputs of which are connected to the corresponding control outputs of the control unit 4. As switches 16.1 ... 16.N + M, in the case of manual control, rocker switches (such as the Toggle switch) can be used (see Reference book of the developer and designer of REA. Elemental base. Maslennikov M.Yu., Sobolev B.A., Sokolov G.V. et al. M .: ITAR TASS, 1993, p. 33.).

 As a power divider 8, six-terminal T-or Y-shaped connection can be used (see J. Buduris, P. Schenevier. Microwave chains. Translated from French. Edited by A.L. Zinoviev. - M. : Sov.Radio, 1979, p. 165 - Fig. 6.2.1 and 6.2.2, p. 169. Fig. 6.2.7). As the bridges for dividing 9 and adding 10 powers, you can use the slotted waveguide bridge device described in the book: Devices for adding and distributing high-frequency oscillation powers / V.V. Zaitsev, V.M. Katushkina, S.E. London, Z.I. Model; Under. ed. Z.I. Model. - M .: Sov.radio, 1980 .-- 296 p., Fig. 6.24 on p. 97, Fig. 6.26 on p. 98.

 As controlled phase shifters 12.1 and 12.2, the Regia-Spencer controlled ferrite phase shifter described in the book by Sazonov D.M., Gridin A.I. and Mishustina B.A. Microwave devices. Textbook / Ed. D.M.Sazonova - M .: Higher School, 1981, - 295 p., Fig. 9.15 and 9.16 p. 282, 283.

As a phase shifter at 90 ^o 14 can be used a line segment (coaxial cable or waveguide) with a length that provides a phase delay of the signal at 90 ^o .

 As phase detectors 11.1 and 11.2, you can use the device described in the book: J. Buduris and P. Schenevier. Chains of superhigh frequencies Per. with french / Under. ed. A.L. Zinoviev.- M .: Sov.radio, 1979.- 288 p., Fig. 7.3.4. on page 198.

 As amplification paths (1.1 ... 1, N; 5.1 ... 5.M), for example, circuits of amplification devices on a two-stage amplitron chain described in the book of M. B. Zeitlin, M. A. Fursaev, O.V. Betsky. Cross-field microwave amplifiers. / Under. ed. M.B. Zeitlina. -M .: Sov. radio, 1978-280 s, fig. 8.15 on page 234 and fig. 8.16 on page 235.

 As the power switches 3.1 ... 3.N, 7.1 ... 7.M, the relays described in the Reference manual of the developer and designer of REA can be used. Maslennikova M.Yu., Soboleva E.N., Sokolova G.V. et al. - M.: ITAR-TASS, 1993, on pages 36-51.

 A distinctive feature of an amplitron is its slight attenuation in the "cold", that is, off state, so that for discrete control of the output power, there is no need to use switches and additional connecting lines to bypass the amplifier stages in the amplification paths. For a step-wise change in the output power of an adjustable amplifier, it is enough to simply turn on the anode power to the used cascades and disconnect it from the unused cascades. Due to this, discrete (stepwise) regulation of the output power in each amplifier path is carried out without breaking the microwave path.

Adjustable power amplifier operates as follows. A microwave signal is received at the input of power divider 8, for example, from the output of a preliminary amplification stage (not shown in the diagram) made on a traveling wave lamp. From the outputs of the power divider 8, microwave signals with equal powers P _{output.dm 1} = P _{output 2} = 0.5P _input.dm are fed to the input of the first amplification stage 1.1 of the first amplifier path through a controlled phase shifter 12.1, and to the input of the first amplification stage 5.1 of the second amplifier path - directly. The amplified microwave signals are supplied from the output of the Nth amplification stage 1.N of the first amplifier path to the first input (input 1) of the power division bridge 9, and from the output of the Mth amplification stage 5. M. of the second amplifier path to the second input ( input 2) of the power sharing bridge 9. At the inputs Вх.1 and Вх.2 of the power sharing bridge 9 microwave signals are received, in the general case with different powers and with different phases. In order to irrespective of the ratio of power and phase of the microwave signals supplied to the inputs Vkh.1 and Vkh.2. power dividing bridge 9, the entire microwave signal power equal to the sum of the output powers of both amplifier paths was supplied only to the first output of the power addition bridge 10, i.e., the output of an adjustable power amplifier, the necessary ratio of amplitudes (powers) and phases of microwave signals at the bridge inputs should be provided addition 10. If you select quadrature type bridge devices as division bridge 9 and addition bridge 10, to add microwave power only at the first output (output 1) of addition bridge 10, microwave signals at its inputs Must have equal amplitudes (power) and a phase difference of 90 ^o . The phase difference of 90 ^o at the inputs of addition bridge 10 provides a phasing system consisting of a phase detector 11.2, a controlled phase shifter 12.2 and a phase shifter of 90 ^o 14. Equal amplitudes (powers) of microwave signals at the inputs of the addition bridge 10 provide a power division bridge 9 and a phasing system, consisting of a phase detector 11.1 and a controlled phase shifter 12.1. The phasing system 11.1 and 12.1 ensures the equality of the phases of the microwave signals at the inputs (Input 1 and Input 2) of the division bridge 9. When applying microwave signals to the inputs of a quadrature-type bridge device with any (arbitrary) ratio of amplitudes (powers), but with the same phases , at its outputs there will be microwave signals with equal amplitudes (powers), but different phases. These microwave signals are fed to the inputs of addition bridge 10 through a phasing system (blocks 11.2, 12.2 and 14), due to which their amplitudes and phases have the ratios (U _in1 = U _in2 , ΔΦ = 90 ^o ) necessary to isolate the total power of both amplifier paths at the first exit (Exit 1) of addition bridge 10.

 The output power is regulated by turning on the power to those amplification stages that provide the necessary power at the output of the adjustable amplifier, and turning off the power to unused stages. Switching the power on and off of the respective stages is carried out using the switches 16.1. . . 16.N + M of the control unit 4, providing the supply or disconnection of control voltages from the voltage source 15 of the control unit 4 to the control inputs (relay windings) of the power switches 3.1 ... 3N and 7.1 ... 7.M.

In the mode of using the full power of the adjustable amplifier, power is supplied to all amplification stages 1.1 ... 1.N of the first amplification path and to all amplification stages 5.1 ... 5M of the second amplification path. In this case, a microwave signal with a power equal to the output power of the Nth amplification stage 1.N of the first amplifier path is fed to the first input (Bx.1) of division bridge 9, and a microwave signal to the second input (Bx.2) of division 9 with a power equal to the output power of the Mth amplification stage 5.M of the second amplification path. At the output of the adjustable power amplifier (bridge Out.1 addition capacity 10) receive the microwave signal power P _out = P _{vyh.um. 1.N} + P _{out. 5.M.}

If it is necessary to reduce the output power, the power to the amplification stage 1.N of the first amplifier path is turned off, or to the amplification stage 5.M of the second amplifier path. In the first case, the output of the adjustable power amplifier will be the power P _o. = P out. _1.N-1 + P _{out. 5.M} , and in the second P _out = P _{out. 1.N} + P _{out. 5.M-1} . If it is necessary to further reduce the output power, turn off the power to the amplification stages 1.N and 1.N-1, 5.M and 5. M-1 and so on. When you turn off the power from all stages of the amplification of the first and second amplification paths, the power of the microwave signal at the output of the adjustable amplifier will be equal to its input power, P _o = P _I. .

 We will evaluate the effect obtained from the proposed technical solution, in comparison with the prototype.

 1. Since changes in the number of amplification stages used are carried out without breaking the microwave paths, the claimed technical solution provides output power control without loss of information passing through an adjustable power amplifier. The regulation of the output power in the prototype is carried out with a rupture of the microwave path, which leads to loss of information during adjustments of the output power.

 2. The presence of two amplifier paths and the exclusion of interstage switches provides an increase in the technical reliability of the claimed adjustable power amplifier compared to the prototype.

 3. With the same number of cascades of amplification in the prototype and in the claimed technical solution, the latter provides a greater number of stages for regulating the output power.

Compare the number of stages of regulation at four amplification stages (let both amplification paths of the claimed device have two stages, N = 2 and M = 2, and in the prototype there are 4 series stages). Then, in the prior art is provided a 5-speed regulating output power: P _out = P _{vyh.um4; P _ex.um3 ; P _ex.um2 ; P _out.um1 and P _in }. The claimed adjustable power amplifier provides 9 stages of output power regulation. Let us designate: R _dm1 , R _dm2 - microwave power at the first and second outputs of the power divider 8, P _{dm 1.1} , R _{dm 1.2} - microwave power at the outputs of the first and second stages of the first amplifier path, R _{dm 2.1.} , R _{mind. 2.2} - power at the outputs of the first and second stages of the second amplification path. Then the set of output powers for the claimed device will have the following meanings:
P _out = {1) P _{dm. 1} + P _dm . ₂ ; 2) P _{d. 1.1} + P _{dm. 1.2.} ; 3) P _{d. 1.2.} + P _{mind 1.2.} ; 4) P _{d. 2.1.} + R _dm . ₁ ; 5) P _{d. 2.2.} + R _dm . ₁ ; 6) P _{d. 1.1.} + P _dm . _2.1 ; 7) P _{d. 1.1.} + P _mind.2.2 ; 8) P _{d. 1.2.} + P _dm . _2.1 ; 9) P _{d. 1.2.} + P _{mind 2.2} }

Claims (1)

An adjustable power amplifier comprising an amplification path of N series-connected amplification stages, each of which has its own power supply connected to the power input of the corresponding amplification stage through a controllable power switch, and a control unit whose outputs are connected to the control inputs of the power switches of the respective amplification stages, characterized in that a second amplification path of M consecutively connected cascades is additionally introduced into it, each of which has its own Lok supply connected to the supply input of the respective amplifier stage via a controllable switch, power divider bridge power division capacity addition bridge, the first and second phase detectors, first and second controllable phase shifters, phase shifter 90 ^o and the ballast load, wherein the control inputs are driven power switches of additional amplification stages are connected to the corresponding additional outputs of the control unit, the input of the power divider is the input of an adjustable power amplifier Ti, the first output of the power divider through the first controlled phase shifter is connected to the input of the first amplification stage of the first amplifier path, the output of the last amplification stage of this path is connected to the first input of the power division bridge and the first input of the first phase detector, the second output of the power divider is connected to the input of the first stage the amplification of the second amplifier path, the output of the second amplifier path is connected to the second input of the power dividing bridge and to the second input of the first phase detector, the output of which connected to the control input of the first controlled phase shifter, the first output of the power sharing bridge through the second controlled phase shifter is connected to the first input of the power addition bridge, the first input of the second phase detector is connected to the first input of the power addition bridge, the output of which is connected to the control input of the second controlled phase shifter, the second output the power dividing bridge is connected to the second input of the power addition bridge, the second is connected to the second input of the power addition bridge through a 90 ^o phase shifter the second input of the second phase detector, the first output of the power addition bridge is the output of an adjustable power amplifier, and the second is connected to the ballast load, the amplification stages are made on amplitrons.

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