SU744952A1 - Pulse duration selector - Google Patents

Description

The invention relates to radar, an antechamber, and can be used in signal processing devices of pulsed telemetric systems.

According to the main author. St. No. 434586 is known for a multi-limiting pulse selector with a duration that contains output stages with one capacitor during the master C-chain and several series-connected resistors (1. This selector has one input and several outputs corresponding to different thresholds of selection. On admission, to the input multi-limit selector of a stream of pulses, the duration of which is within the change of the selection threshold, at the outputs of the selector, pulse flux of different intensity is formed, and the higher the threshold is projections, the lower the intensity (the number of pulses per unit time) of the output stream.

If the pulse stream consists of useful pulses and interference pulses, and the average duration of useful pulses is longer than the average duration of pulsed noise, with an increase in the selection threshold in the output stream,

the ratio of the number of useful igushuls to the number of pulses nOjMex. However, at the same time, the probability of loss of useful impulses increases. The optimal value of the selection threshold can be determined by analyzing the pulsed flows at all outputs of the multi-pioneer selector and choosing which of the short-circuit outputs at the acceptable level of loss of useful pulses the interference level will be minimal.

However, such a multi-limit selector

to does not automatically select the optimal selection threshold when the duration of the useful pulses at the input of the selector is changed, which does not allow the device to achieve the maximum noise immunity. The purpose of the invention is to increase the noise stability of the pulse selector in duration.

This goal is achieved by the fact that a pulse selector with duration, containing output stages with one capacitor during the master C-circuit and several series-connected resistors, has AND elements, triggers and OR element, all inputs of which, except the last one, are AND, and the last

directly connected to the corresponding outputs of each selector E, the second inputs of the elements And are connected to the outputs of the corresponding triggers, the S-inputs of which are connected to the HIHHOH "Installation, and -sho1) | - with the inputs of the element OR so that the R-input of the first and subsequent triggers are connected to the second and the next inputs of the element OR.

FIG. Figure 1 shows a structural electrical diagram of the selector of impulses by duration; in fig. 2c-n is a temporary chart of his work.

The duration selector contains a multi-selector 1, the outputs of the cascades of which are connected to the first inputs of the AND 2, 3, 4, 4HCjro elements per unit of which the number of inputs of the multi-selector selector is YA8, triggers 5, 6, 7 and the element OR 8. The output of each cascade of the multidirectional selector corresponds to the selection thresholds T r2 t5 t4 The outputs of all elements AND 2, 3 and 4 and the output of the cascade with threshold t are connected to the inputs of the element OR 8, the output of which forms an immersion stream literacy. In addition, the outputs of switches 3, 4 and the output of the cascade with threshold G1 are connected to the first inputs of the corresponding triggers 5, 6 and 7. A signal "Installation, installation of triggers to the initial state" is given to the S-inputs of the triggers.

The first inputs, 1, 2, 3, and 4 connectors with the corresponding outputs of the multi-range selector. The second inputs of 2, 3, and 4 elements are connected to the outputs of the corresponding t) iggers 5, 6, or 7.

The selector works as follows.

The flow of pulses (Fig. 2, and the input of the multi-selector selector sia enters. The selector cascades of impulses appear only if its duration t exceeds their selection threshold of PII. , the second inputs of these elements are resolved., and the unit level notional from the output of flip-flops 5, 6, and 7. When the selector receives an input pulse t, whose duration lies within ti t, .T: I, at the output of the cascade with a threshold g selector also appears impulse (I eat. Fig. 2, b), k The element 2 that goes through the element 2 (Fig. 2, g) passes to the output of the element OR 8 (Fig. 2, ..i) .When the pulse duration increases to ve, the pulse is also generated at the output of the cascade with a threshold tg (Fig 2, c), which passes through the element IZ (Fig. 2, i) and sets the trigger 5 to the position prohibiting the operation of the element II. The change in potential at the output of the trigger 5 is shown in Fig. 2, e.

Similarly, the operation of the transponder 6 npis notation of the device of pulses with a duration of G4 (2, g, L: s and trigger 7 when pulses of duration

(Fig. 2 d. To,). In all cases, with the arrival of imiuls, the duration of which precedes the duration of the previous pulses by the value of Lt, where Dt ta - - Ci gz - ta T4-c3, the device selection threshold also increases by D.

Thus, a pulse of pulses is formed at the output of the device, in which each successive imp: 1cc has a duration equal to or greater than the duration of the previous impulse at the input. The impulse ts to the output of the element OR 8 does not pass, since t j G4. If the notes of pulses with a duration of-14. was recognized as useful, the pulse t 5 should be attributed to interference, and its filtering by the device improves the noise immunity of the system as a whole.

The device returns to its initial state by means of a pulse "Installation, supplied by the i-3-input of the flip-flops 5, 6 and 7 (Fig. 2, n).

The use of automatic selection threshold switching in a multi-limit selector allows increasing the noise immunity of their devices and immobile telemetry systems in the case when the duration of useful pulses is predetermined exactly what is known and can be measured randomly due to a change in pulse duration in the transmitter and pulse broadening in the receiver.

The effectiveness of the selector is the better, the greater the duration of the useful signals and the shorter the average duration of interference pulses.

The effectiveness of the selector also depends on the law of the distribution of the duration of non-triggered imps;

Formula 1 3breg

The selector pnnulsov but the duration of a-b. St. N ° 434586, characterized in that, in order to increase the noise immunity, elements AND, triggers and

: -.- lement OR, all inputs of which, except for the hp of the next, are connected via the ele fi ces of the AND, and the latter is directly connected to the corresponding outputs of the cascades of the selector, the second inputs of the element that are connected to the outputs

corresponding to the SCH triggers, the S-inputs of which are connected to the “Installation,” and the R inputs of the OR element so that the R inputs of the first and subsequent triggers are connected to the second and subsequent inputs of the OR element.

Information sources,

taken into account during the examination 1. USSR author's certificate 434568, cl. H 03 K 5/18, 03/19/73.

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Claims (1)

Claim Pulse selector by duration according to ed. St. No. 434586, characterized in that, in order to increase the noise immunity, AND elements, triggers and OR elements are introduced into it, all of whose inputs, except the last, are connected through the And elements, and the latter are directly connected to the corresponding outputs of the selector cascades, the second inputs of the AND elements are connected to the outputs of the corresponding triggers, the S-inputs of which are connected to the "Installation" bus, and the R-inputs are with the inputs of the OR element so that the R-inputs of the first and subsequent triggers are connected to the second and subsequent inputs of the OR element. 21 stops of information taken into account during the examination 1. USSR copyright certificate No. 434568, cl. H 03 K 5/18, 03.19.73. Fig j Jk t2 .. a G 7 2 3 * I ya 5 n-p P | - | P § π Π π i s ...... g .. ΓΊ d and I® ----— ^5EB | ”| Jzz gg p Π _____________ Z.t 3 and D Π t TO 1 l Π π _ t Μ Π □ Jzl π Η π * figure 2