SU1429290A1 - Amplifying apparatus - Google Patents

Abstract

The invention relates to radio engineering and provides an increase in accuracy by reducing the level of interference. The input signal is amplified in Kj. times the signal amplifier (CI) 1. The error amplifying amplifier (USO) 2 causes an error voltage between the input and output signals of the device and amplifies it by Ko times. The amplified error signal passes through a filter 3 with a controlled bandwidth to the other input of the CM 1. If the CD 1 introduces linear and non-linear distortions, then the selected error voltage tends to compensate for the error in the output of the amplifying device. Filter 3 prevents the occurrence of undesirable transitional processes in US 1 when the error signal at the output of USO 2 changes abruptly. In USO 2, drift zero is periodically corrected. During the correction by the generator signal of 4 clock pulses, the pass-band of the filter 3 sets-§ with a minimum. In operation mode, | bandwidth filter 3 max-C // on. 1 il. f

Description

fs IND

with to

The invention relates to radio technology and can be used in precision wideband amplifiers: in particular in electroacoustic

; systems, spectrum analyzers ..

The purpose of the invention is to increase accuracy by lowering the noise level.

The drawing shows the structure; on the electric circuit, the circuit of the amplifying device.

The amplifying device comprises an amplifier 1 signal; 2 error signal amplifier, filter 3 with controllable bandwidth, generator 4 such | of these pulses,

1 The device works as follows.

I The input signal is fed to the first input of amplifier 1 of signal 1 and., Amplified Kg 5 times, is removed from the output, (Composed of the output signal of the amplifier, caused by the voltage on the first input of the signal amplifier

Mala,

U X-V-K ,.

; Amplifier 2 error signal, on the hep entrance krtorogo enters the hollow signal Ug, Ug, and the second input

 The output signal of the device is Ug, it separates the error voltage and amplifies it in K oraz,. Increased error voltage, removed: taken from the output of the amplifier 2 signals,

Uo UBx-K, -U ,, K, -U ,,. K, (1)

Where K and K - transfer ratios

amplifier 2 signal

errors on the first and second inputs, respectively,

through filter 3 with a transmission coefficient K ,, is introduced in the appropriate phase into the second input of signal amplifier 1,

Full device output

 l «,, i (UBuy - SK c + Ll. Cf- Kq,

 Wlx Biix In "

t

(2)

 q.

where Ug is the component of the output signal of the device, and is called the amplification of the error signal from the second input K o times. If the balance condition is met

Kq Kn-Krf, Ka,

and, -,

This is the error voltage.

If for one reason or another (for example, as a result of linear 1x or non-linear distortion in the amplifier 1 signal) the output signal of the amplifier signal

(3)

UeMA- Uex Kc + U

where dU is the output component

caused by distortion. Then the balance condition is violated

Ue. K, -Ue ,,, K, o.

The resulting error voltage b is trying to compensate for the error in the output signal of the amplifying device.

Substituted (1), (3) in (2)

, -Ks + 4i + io-K, UexK + dU + U6x K ,. Cf, C Cf-Cd-.

Polaga,, we get the output signal of the device

and-and K + H-K

Ugt.x- b; with +

When K „

Device transfer ratio

 5-ЁМ

UBX KCC. K, - li Sj: K ±: B.

Ik - Kf Kg

during operation of the error signal amplifier 2, the voltage at its output may dramatically change when switching from operating mode to periodic correction mode, and vice versa. This is due to the fact that at high rates of change in the input signal, the final duration of the correction period leads to a significant change in the error signal level U. The occurrence of unwanted transients in the amplifier 1 signal during an abrupt change in the error signal at the output of the amplifier 2 signal error 1-1 is prevented using filter 3 The bandwidth of the filter 3 is changed when it is influenced by its control input voltage from generator 4. During the correction process, amplifier 2 of the error signal and the passband of the filter 3 is minimal and, in an operating mode, is maximal. This provides an effective reduction of the effect of voltage spikes Up at the output of the error signal amplifier 2 and switching interference arising from the imperfect operation of the switching circuits.

error signal amplifier with periodic correction, including control voltage U, time circuits.

control

An atheator with a coefficient (1 transmitting key, I

TO.

TO,

The synchronization with the process of periodic correction of the change-band progrpus TpakTa of the error, which includes the error signal amplifier 2 with the periodic correction and the filter 3, reduces the resulting distortion and improves the accuracy of the device.

When implementing an amplifier, 2 error signals with a normalized ratio of gain factors over the first and second inputs

1 TO,

An amplifier with the same transmission coefficients on both inputs (for example, a differential amplifier) can be used. With this, between the second input of the amplifier 2 error signal and the output of the amplifier 1 signal

Claims (1)

An amplifier device comprising a signal amplifier and an error signal amplifier, wherein the first inputs of the signal amplifier and the error signal amplifier are combined into an amplifier device, the second input of the error signal amplifier is connected to the output of the amplifier signal, and the output of the amplifier device is different that, in order to improve accuracy by reducing the level of interference, between the second input of the signal amplifier and the output of the error signal amplifier is a filter with controlled bandwidth uskani wherein the error signal amplifier is configured with a periodic zero drift correction, which clock pulse generator output is also connected to the control input of the filter with a controllable bandwidth.