SU1748228A1 - Frequency-dependent two-terminal network - Google Patents

Description

The invention relates to electronic engineering and electronics and can be used in alternating current circuits with a constant component in the synthesis of complex filters, correction circuits in automation, communication, radio engineering, as well as in cybernetics in the creation of predicting and smoothing devices.

The purpose of the invention is to increase the linearity and accuracy of the transfer function.

The drawing shows a diagram of the frequency-dependent two-terminal.

The frequency-dependent two-port network contains a passive quadrupole 1, a transistor 2, the first 3 and the second 4 resistors.

Frequency-dependent two-terminal works as follows

The instantaneous value of the voltage at the inputs of a two-pole device should not change its polarity. Thus, for an n-pn-type bipolar transistor shown in the drawing, the inequality UAB O must always be satisfied

For definiteness, the input value of a two-port network is the variable component of the voltage at its input UAB, and the output value is the value of the variable component of the current of the two-pole I. Then the transfer function of the two-pole will have the dimensionality of conductivity or in -operator form,

W (P) Y (P) (1)

The variable component voltage Uoo1 at the output of the quadrupole is defined as

Ugo (p) W (p) .UAB (p). (2)

where W (p) is the transfer function of the quadrupole

For the variable component of the base current 16, we have.

U

Re

(3) 45

. „

where Re is the resistance of the circuit branch between points O and C, including the base-emitter junction

0

five

0

In the first approximation, you can write

Kb gb-e + (/ 3 + 1) Ve, (4)

where gb-e differential resistance of the base-emitter junction at the operating point;

/ - current transfer coefficient of the transistor.

Since the current value of the two-pole device is determined in the first approximation by the current of the emitter, we can write

Te Te 1b (+1). (5)

Thus, the substrates (2) and (3) in (5), we have in operator form

pyo (p) fi + 1 Re

Cr) (0 + 1

five

0

five

five

W (P) UAB (P)

Re (6) or finally

Y (p) (p)

To synthesize a frequency-dependent two-pole network, using the specified operator expression for the impedance Z (p) (conductivity Y (p) from equation (7), the first approximation determines the expression for the transfer function of the four-pole network W (p), which takes into account the bias circuit circuit of the quadrupole from the corresponding reference tables.

Claims (1)

The invention is a frequency-dependent two-port network, comprising a transistor and a frequency-dependent quadrupole, whose inputs are frequency-dependent inputs. The two-pole and the output is connected to the control electrode of the transistor, characterized in that, in order to increase the linearity and accuracy of the transfer function, the first and second resistors are inserted, the transistor is made bipolar, the collector and the emitter of which are connected to the first terminals of the first and the second resistors, respectively, the second terminals of which are connected to the inputs of the frequency-dependent bipolar, and the frequency-dependent quadrupole is made in the form of a passive RC circuit