SU1103353A1 - R.f. pulse shaper - Google Patents

Abstract

FORMING RADIO IMPULSES, containing a short pulse generator connected in series. Vr ffi ".r ... IP -: .-. TC1-0; 5Si delay line and gating unit, the control input of which is connected to the output of the fixed delay unit, as well as the master clock generator, different JQM, that, in order to control the duration of radio pulses, between the output clock master clock generator and the control input of the generator of short pulses and also between the output of the master clock generator and the input of the fixed delay block, respectively, a frequency divider by N and a frequency divider by N + 1 are entered, and output b the gate locator is connected to the input of the inputted continuous signal recovery unit, the output of which is the output of a 9-body radio pulse. (L with

Description

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Soo 1 The claim relates to radio engineering and can be used to generate long duration radio pulses with a given modulation law using a delay line in measuring devices, navigation and radar systems. A radio pulse former with a predetermined modulation law is known, comprising a series-connected short pulse generator and a delay line, the output of which is the output of the radio pulse former. A short radio pulse arrives from the output of the generator of short pulses at the input of the delay line, as a result of which a signal corresponding to the pulse response of the delay line appears at the output of the radio pulse generator. The shape of the output signal is determined by the characteristics of the delay line, which can be implemented in various ways. The most promising are delay lines based on surface acoustic waves, since they are characterized by ease of implementation in advance of the specified characteristics 1. However, the known driver of radio pulses cannot generate radio pulses with sufficiently steep fronts, since the impulse response is characterized by extended fronts, which is caused by limited bandwidth of any delay line. The closest to the proposed is a radio pulse shaper, containing a series-connected short pulse generator, a delay line and a gating unit, whose control input is connected to the output of a fixed delay unit, as well as a master clock generator, one output of which is connected to the control input of a fixed delay unit and the other through an adjustable delay unit with a control input of the short pulse generator 2. However, this known driver of radio pulses does not provides adjustment of the duration of the radio pulses. The purpose of the invention is to provide control over the duration of the radio pulses. . The goal is achieved by the fact that a radio pulse shaper, containing a series-connected short pulse generator, a delay line and a gating unit, the control input of which is connected to the output of the fixed delay unit, and the master clock generator, between the master clock generator output and the control the input of the generator of short pulses, as well as between the output of the master clock generator and the input of the block of a fixed delay are entered respectively divides Plot a frequency to N and a frequency divider to N + 1, and the output of the gating unit is connected to the input of the inputted unit to restore the continuous signal, the output of which is the output of the radio pulse generator. FIG. Figure 1 shows the structural electrical circuit of the proposed radio pulse shaper; in fig. 2 - time diagrams of his work. The radio pulse shaper contains a generator 1 short pulses, a delay line 2, a gating unit 3, a master clock 4, a fixed delay unit 5, a frequency divider by N 6, a frequency divider by N + 1 7, I W 1 D1 P d 14 V,. G1 1 D 1 CIV- i. 4J 1 Ul i l I -I i block 8 recovery of a continuous signal. Shaper radio pulses works as follows. The master clock generator 4 generates a series of video pulses (Fig. 2a), the following period of which is determined in accordance with the Kotelnikov theorem, i.e., where the width of the signal spectrum generated at the output of the delay line 2. These pulses enter the frequency divider at N 6, at the output of which only Ne pulses appear (Fig. 26). These pulses control the operation of generator 1, and at times corresponding to their appearance, short radio pulses of large amplitude are produced at the output of generator 1. As a result, at the output of the delay line 2, after the time t0, short responses of radio pulses to its input appear (Fig. 2c), the shape of which determines the shape of the output radio pulse of the radio pulse former. The shape of the response is determined by the design and characteristics of the delay line 2. It is most advisable to implement such a delay line based on surface acoustic waves, since then it is possible to simply ensure the formation of radio pulses with any given modulation law: FM, FM, AM. In order to simplify the graphic material in FIG. Figure 2c shows the output responses having the form of a radio pulse with a constant filling frequency. The frequency divider by N + 17 has a conversion factor equal to N-fl, therefore the follow-up period of the pulses at its output is (N + l) (Fig. 2 g). Therefore, the first pulse at the output of the frequency divider by N-f 1 7 is shifted relative to the pulse of the frequency divider by N 6 by d.1, then the second pulses at their outputs are shifted relative to each other by 2at, the third ones - by time Zl1, etc. (see Fig. 26 and 2d). The pulses from the output of the frequency divider to N-f 1 are delayed in block 5 of a fixed delay by an amount t.

(Fig. 2d). Short video pulses from the output of the fixed-delay unit 5 control the operation of the gating unit 3 in such a way that during their operation at the output of the gating unit 3 there appear samples from the output response of the delay line 2 (Fig. 2e). Since the sampling period corresponds to the Kotelnikov theorem, the shape of the radio pulse at the output of the continuous signal recovery unit 8 (Fig. 2 g) is similar to the shape of each response at the output of the delay line 2 (Fig. 26), but differs N times as large in scale and duration. Block

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the restoration of the continuous signal can be implemented as a low-pass filter or as an interpolation circuit.

In the proposed radio pulse shaper, radio pulses are formed with a given modulation law, a time scale, and accordingly, the duration of which can be easily adjusted by changing the conversion factor of the N frequency dividers. An increase in the conversion factor N leads to an increase in the duration of the output radio pulses.

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Claims (1)

A RADIO PULSE SHAPER comprising a serially connected short pulse generator, a delay line and a gating unit, the control input of which is connected to the output of the fixed delay unit, as well as a master clock, characterized in that, in order to control the duration of the radio pulses, between the output of the master clock and the control input of the short pulse generator, as well as between the output of the master clock and the input of the block is fixed To this end, a frequency divider by N and a frequency divider by N + 1 are respectively introduced, and the output of the gating block is connected to the input of the introduced continuous signal recovery block, the output of which is the output of the radio pulse shaper. § Figure 1