SU625301A1

SU625301A1 - Cascade amplifier

Info

Publication number: SU625301A1
Application number: SU762427472A
Authority: SU
Inventors: Владимир Михайлович Артеев; Олег Николаевич Папуцкий
Original assignee: Предприятие П/Я М-5619
Priority date: 1976-12-07
Filing date: 1976-12-07
Publication date: 1978-09-25

Description

(54) КАСКОДНЫЙ УСИЛИТЕЛЬ(54) CASCADE AMPLIFIER

Изобретение относитс к радиотехнике и может использоватьс в высокоскоростных системах св зи с импульсно-«одовой модул цией в качестве входного или промежуточного усилител в оконечном обо- рудованни линейного тракта системы.The invention relates to radio engineering and can be used in high-speed communication systems with pulse-type modulation as an input or intermediate amplifier in the terminal equipment of the linear path of the system.

Известен каскадный усилитель, содержащий первый и второй транзисторы, вклю ченные соответственно по схеме ойдий эмиттер-ойца база flj.A cascade amplifier is known, containing the first and second transistors, included respectively according to the scheme of emitter-emitter base flj.

Однако в таком усилителе входное сопротивление зависит от частоты.However, in such an amplifier, the input impedance is frequency dependent.

Цель изобретени - стабилизаци входного сопротивлени и расширение полосы пропускани .The purpose of the invention is to stabilize the input impedance and bandwidth expansion.

Дл этого в каскодном усилителе, содержащем первый и второй транзисторы, включенные соответственно по схеме общий эмиттер - обща база, параллельно первому транзистору включена дополнительна пара транзисторов, включенных каскодно по схеме обща база - общий эмиттер.For this, in the cascode amplifier containing the first and second transistors, connected respectively according to the common emitter scheme - common base, an additional pair of transistors connected in cascade according to the common base - common emitter scheme is connected in parallel with the first transistor.

На чертеже изображена принципиальна электрическа схема предложенного каскодного усилител .The drawing shows a circuit diagram of the proposed cascode amplifier.

Он содержит первый и второй транзисторы 1, 2 и дополнительные транзистору 3, 4, резистор 5, корректирующий двухполюсник 6, нагрузочный резистор 7, разделительные конденсаторы 8 - 1О, резисторы 11-15.It contains the first and second transistors 1, 2 and additional transistors 3, 4, resistor 5, correcting two-terminal 6, load resistor 7, coupling capacitors 8 - 1О, resistors 11-15.

Устройство работает следующим образом .The device works as follows.

Claims

The input pulse signal is fed from the input simultaneously to the base of the transistor 1, connected according to the common emitter circuit, and to the emitter of the additional transistor 3, connected according to the common base circuit. When the additional transistor 3 is turned on according to the common base circuit, there is negative capacitance in the input impedance, and when the transistor 1 is turned on according to the common emitter circuit, the positive capacitance is approximately equal in absolute value. The nature of the dependencies of the absolute values of capacitances on the frequency is the same. The active component of the input impedance of the transistor 1, connected according to the circuit with both vihm emitter, decreases with increasing frequency, and increases according to the common base circuit, both of them (sotampym ™ tends to the volume of opposite base {transistor 1 of transistor 1). ) As a result of the proposed connection of transistors 1 (3), compensation of reactive components and changes in the active components of the input pedals of transistors 1 and 3 takes place, and with an appropriate selection of modes of transistors 1 (3) With a minus 16 signal, an approximately constant input impedance of the pulse amplifier can be achieved in a wide range of operating frequencies.The amplification of a part of the energy of the input signal arriving at the input of the additional transistor 3 is performed by the introduced additional transistor 4 with opposite polarity, connected in a symmetrical pattern paired with the cascode transistor 1. Transistors 1 and 4, to the bases of which the INPUT signal is received respectively, directly from the input of the amplifier and through the transistor 3, have a direct connection Speaker wiring | operating on the total load served by the cascode transistor 2, in addition, for transistors 1 and 4, each separately, dynamic loads are created, thereby increasing the gain area of the amplifier. In particular, the dynamic load of transistor 1 and 2, and the dynamic load of transistor 4 is a combination of transistors 1 and

2. Transistor 2, connected according to a circuit with a power supply base, along with the main function of amplification, plays the role of an integration barrier eliminating the influence of voltage variations and current at the output of the cascode on the value of the stabilizing input impedance amplifiers. If additional correction of the amplitude-frequency characteristic of the amplifier is necessary, a frequency-dependent correction two-pole 6 can be introduced into the emitter circuit of transistor 4. The proposed amplifier allows stabilizing the input impedance and broadens the passband. Claim amplifier containing the second transistors connected respectively by the common emitter circuit, characterized in that, in order to stabilize the input impedance and expand the half-pass, an additional pair of transistors connected cascadely according to the base-lean-emitter circuit is included in parallel with the first transistor . Sources of information taken into account during the examination: 1. French Patent No. 2194079, cl. N OZ F 3/04, 11 ..