SU686142A1

SU686142A1 - Null-filter

Info

Publication number: SU686142A1
Application number: SU752165896A
Authority: SU
Inventors: Ася Мироновна Лер; Евгений Пантелеймонович Соголовский
Original assignee: Львовский Ордена Ленина Политехнический Институт
Priority date: 1975-08-15
Filing date: 1975-08-15
Publication date: 1979-09-15

Description

(54) НУЛЕВОЙ ФИЛЬТР(54) ZERO FILTER

II

Изобретение относитс к технике измерений и может использоватьс дл определени спектрального состава сложных элект| гаескнх сигналов , в том числе шумовых, что позвол ет исследовать вибрации мшшн и механизмов.The invention relates to a measurement technique and can be used to determine the spectral composition of complex electrons | Gaeshnh signals, including noise, which allows to investigate the vibrations of the mechanisms and mechanisms.

Известеи нулевой фильтр, содержащий две параллельно включенные ветви, состо щие из основной RC -структуры с обшей емкостью и пополнительной КС-структуры с емкостными входом выходом, и о&цим сопротивлением, заземленным с обоих концов.Lime filter containing two parallel-connected branches, consisting of a basic RC-structure with a common capacitance and a supplementary KS-structure with a capacitive input output, and an impedance grounded at both ends.

Однако известный нулевой фильтр обладит ннзкой точностью настройки и низким козффкацентом подавлени .However, the known zero filter will have lower tuning accuracy and low kozfftsentsent suppression.

Целью изобретени вл етс повышение точности настройки нулевого фильтра на заданную частоту и повышение коэффициента подавлени .The aim of the invention is to improve the accuracy of the zero filter setting at a given frequency and increase the suppression ratio.

Дл зтого в нулевой фильтр, содержащий две параллельно включенные ветви, состо щие из основной RC-структуры с общей емкостью и дополнительной RC-структуры с емкостными входом и выходом и общим сопротивлением, заземленным с обоих концов, последовательно с одной из ветйей, со стороны входа нулевогоFor this purpose, a zero filter containing two parallel-connected branches consisting of a main RC structure with a common capacitance and an additional RC structure with a capacitive input and output and a common resistance grounded at both ends, in series with one of the branches, from the input side zero

фильтра, включен четырехполюсник с регулируемым коэффициентом передачи, причем четырехполюсник с регулируемым коэффициентом передачи включен в цепь основной ВС-с.труктуры и выполнен в виде делител , или tюtыpexдoлюcник с регулируемым коэффициентом 1№редачи включен в цепь дополнительной RC-структуры и выполнен в ввде усилител .filter, a quadrupole with an adjustable transmission ratio is included, and a quadrupole with an adjustable transmission coefficient is included in the main VS-c. structure of the circuit and made in the form of a divider or variable amplifiers with an adjustable transmission ratio of 1 is included in the additional RC structure .

На чертеже кведена функциональна электрическа схема предложенного устройства.In the drawing, a functional circuit of the proposed device is coded.

Нулевой фильтр содержит две параллельно включенные ветви, состо щие из основной RC-структуры 1 и дополнительной КС-структуры 1, к четырехполюсник с регулируемым коэффициентом передав, выполненный в виде усилител 3.The zero filter contains two branches connected in parallel, consisting of a basic RC structure 1 and an additional CS structure 1, to a quadrupole with an adjustable transfer coefficient, made in the form of an amplifier 3.

Claims

The device works as follows. The zero filter works on the principle of zero circuits with current resonance. The introduction of amplifier 3 into the circuit of the additional CC structure 2 changes the resonance condition in such a way that the asymmetry of the amplitude response branches is shifted and the zero frequency is shifted towards the low frequencies, with an imbalance in the circuit balance. Each value of the gain corresponds to its own value condition balance (coefficient A). Thus, the introduction of the amplifier 3 in an ideal circuit leads to the same effect as the mismatch of parameters in the real circuit. Consequently, in the scheme of an additional RC-structure 2, the presence of an amplifier with an amplification factor K, which is obviously of great influence, the variation of the parameters of the elements of the structures, is necessary. When the relation between the time constants of the additional BC-p) of Tour 2 and the basic RC-structure 1 (coefficient A) is fulfilled in such a way that the balance condition corresponds to the increase of K in the real gain factor circuit is reduced by the amount of the total alias of the parameters, resonance condition corresponding to the ideal circuit with a 3 Cc loop. Thus, tuning and balancing the zero filter reduces only to reducing the gain before obtaining a transmission zero, and the relationship between the coefficients A and K O1 is reduced by the formula A 0.5766 - 0.0353 Zero frequency of the zero filter is equal Use of the proposed device simplifies setting zero filter at a given frequency and increases the suppression rate, which distinguishes it from the known device. Claim 1: A null filter comprising parallel-connected branches consisting of a basic RC structure with a total capacitance and an additional RC structure with capacitive input and output, and a common resistance grounded by HbfM at both ends, characterized in that increasing the accuracy of adjusting the zero filter to a predetermined frequency and increasing the suppression coefficient, in series with one of the branches, on the input side of the zero filter, a quadrupole with an adjustable transmission key is turned on. 2. 1ltr according to claim 1, characterized in that a quadrupole with a regulable, peredrazdny factor is included in the circuit of the main YAS-page) and the "1" in the form of a divider. 3. A filter according to Claim 1, characterized in that a quadrupole with an adjustable transmission coefficient is included in the chain of an additional RC structure and is made in the form of a yi line.