SU737853A1 - Voltage divider - Google Patents

Description

in such a way that the running times of electromagnetic waves along the long lines between the input and output points of the long line of the low-resistance arm are the same, and an active resistor is connected parallel to the long line of the high-resistance arm, which is an active divider with the output line of the measured signal equal to dividing the divider into active lines.

The length of the low-resistance arm line is made in the form of two coaxial cylinders connected to the coaxial long lines of the high-resistance arm

FIG. 1 shows a voltage divider circuit of FIG. 2 — an equivalent circuit for longer times; in fig. 3 - coaxial voltage divider.

The voltage divider contains a transmitting long line 1, which is simultaneously a high-resistance divider arm, a LONG10 10 low-resistance arm line, which with its ends is inserted into the breaks of the conductor of a long high-resistance arm line so that the travel times of the electromagnetic waves between the input and output sites are the same, the output line 3 the measured signal, which is usually used as a coaxial cable, matched at the opposite end, and resistance 4.

The signal is transmitted through line 1 and is the branch point of line 2 is divided between these lines in accordance with their characteristic impedances, which the Shch1 signal is turned off sequentially. In the place of input of LI.NII 2 to line 1, the signals transmitted via these lines are merged, if the signals are sent to This place at the same time, no reflected signal arises, traveling along line 2 in the direction opposite to the original signal.

For signals that are longer than the travel time of an electromagnetic wave between the input and output points of line 2, the voltage divider, which initially divided the signal voltage by wave, the resistances of lines 1 and 2, begins to affect the signal as a capacitive divider, in which the high-voltage arm and the low-voltage arm is the capacitance of the sections of the long lines 1. and 2 between the input and output points. Moreover, the condition of equality of the travel time of electromagnet waves on lines 1.and 2 between the places of input and output of line 2 is equivalent to the condition of equality of the division factors of the voltage divider on the long lines in the range of short times and the capacitive divider, i.e. This equality of division factors leads to the absence of a transient process.

in the range of long times. The resulting capacitive voltage divider has an increased input capacitance, since it can be performed on a sufficiently long section of line 1, which improves its quality, but it does not load the signal transmission line.

The useful signal is usually removed by using a long line 3 (coaxial cable), which is matched at the opposite end and, therefore, for the voltage divider, line 3 is active resistance equal to the characteristic impedance of line 3. To reduce the distortion of signal transmission, it is reasonable to parallel the long line of the high-voltage arm to include active resistance 4 so that the division factor of the resulting divider by active resistances is equal to the division ratio of the voltage divider on long lines, i.e. to create a compensated active-capacitive divider (figure 2).

If line 1 is a coaxial cable, then line 2 is also convenient to be coaxial, i.e. made of two coaxial cylinders (figure 3). At the same time, for better matching, line 2 is connected to line 1 by flanges, the distance between which decreases as it approaches the axis (they form a radial Long line with a characteristic impedance equal to the characteristic impedance of line 2).

Thus, the proposed voltage divider is characterized by a wide operating frequency band, since it significantly reduces the influence of spurious parameters. The limiting frequency band is determined by the transverse dimensions of the voltage divider versus the electromagnetic wavelength and the carefulness of matching the individual elements. As a result, the scope of application of a voltage divider increases and there is no need to use a number of voltage dividers with narrower bands of operating parts.

Claims (2)

Invention Formula  I, Voltage divider containing a long line as a high-resistance arm and a long line with a characteristic impedance less than that of a high-resistance scientific institute of a high-resistance arm, as a low-impedance shoulder, derived from a discontinuity in a conductor of a long high-resistance line. This is due to the fact that, in order to expand the working frequency band, the length of the low-resistance arm line is introduced into another gap in the conductor of the long high-resistance arm line in such a way that the travel times of electromagnetic waves along long lines between the input and output points of a long line of a low-resistance arm are the same, and parallel to the long line of a high-resistance arm an active resistor is connected, which is an active divider with a output line of the measured signal, with a division factor equal to the division factor of the delLitel on long lines x.i 2. The divider pop. 1, is distinguished by the Dt and also by the fact that the length of the shoulder of the shoulder is made in the form of two coaxial cylinders connected to the coaxial and invisible line of the upper arm of the upper arm. - k Sources of information taken into account expertise 1.V 7robyov GA, Mes c. Shaping nanosecond pulses technology. M., 1963, p. 134-141. 2, Fectcher R.C., Rev. Sci Tnstruraent v. 20, 12, p. 861-869, 1949.