SU77465A3 - Balanced high-frequency circuit - Google Patents

Description

The subject of the invention is a balanced high frequency circuit consisting of a capacitor and an inductor placed in different electrostatic shields.

A distinctive feature of the circuit is that, to form a system of a circuit that is symmetrical with respect to the earth, the electrostatic screens isolated from the latter are attached to the anodes of the lamps of a two-stroke amplifier or a generator of ultrashort waves.

The invention is explained in FIG. 1-7.

In high frequency circuits (for example, in generators, measurement circuits), careful balancing of circuits with respect to earth is often required. At very high frequencies, it is practically impossible to obtain such a balancing with the help of conventional inductors and capacitors due to the difficulties associated with the manufacture of various circuit elements. fairly symmetrical about the ground. In the proposed circuit, these difficulties are eliminated.

FIG. 1 and 2 show identical metallic hollow cylinders, denoted by / and 2.

Inside the cylinder / placed variable capacitor. Its clamp 3 is electrically connected to the cylinder, and the clamp 4 is isolated from the cylinder by an insulator 5.

The insulator 5 supporting the capacitor is attached to the end of the cylinder with gaskets 6 and screws 7. The movable plates of the capacitor, which are attached to the clamp 3, are moved by adjusting to the slot through a small hole 6a.

Cylinder 2 is hollow. The wire 8 at one end passes through the hole a of the cylinder / and connects to the clip 4 connected to the fixed plates of the capacitor, and the second end connects to the cylinder 2 at point e. From the cylinder / wire 8 is insulated by means of an insulator into hole a.

The cylinders (i) and (2), isolated from the ground by means of gaskets (M.), are intended to align the container with the ground.

429

The method of using capacitors is as follows.

Both cylinders connected to different terminals of a variable capacitor are themselves the plates of the entire capacitor system. Since geometrically they are quite similar, their capacity with respect to the earth is uniform if they are arranged symmetrically with respect to the latter. However, since the wire 8 is adventitious to only one cylinder, the equilibrium with respect to the earth cannot be perfect.

To correct this, the second wire 9 of the same size as the wire 8, is driven to the cylinder / point c, is parallel to the wire 5 and is passed through the insulated hole inside the cylinder 2 at point d. In the case of earth perpendicular to the axes of the cylinders, both sides the capacitor will be symmetrical with respect to the ground.

FIG. Figure 3 shows the placement of the LI inductors in the cylinder 2. The resonant circuit in this way is perfectly balanced from the ground. One end of the coil LI | П1рИ1КЛ | Ю-чей to the wall of the cylinder, and the other to the wire of 9, that is, the coil of LI lr. Is connected parallel to the condenser. The resonant circuit can be connected to the balanced circuit at the points of e and / or in two other symmetric points: at different points on the cylinders.

FIG. Figures 4 and 5 show how to connect the output of an amplifier to a resonant circuit using an additional inductor Lg, inductively coupled to an LI coil.

The output circuit of these circuits is not balanced with respect to the ground, since the coil L2 forms a capacitance only with respect to one cylinder.

An electrostatic screen S is located between the coils LI and /, 2 (Fig. 5).

To make the output circuit perfectly balanced relative

land, you need to take the scheme shown in fig. 6

Here, the cylinders are divided into two compartments with poi1 and electrostatic screens 5 and 5). The capacitor capacitor is placed in the lower compartment of the first cylinder, and the catheter is passable and the loop inductance is located in the same compartment of the second cylinder.

In the upper compartments on opposite sides of the electrostatic screens separating the interior of the cylinders, there are two identical inductors LZ and L.3, symmetrical with respect to their compartments and therefore forming the same capacitance with respect to the cylinders. The coils LZ and /.3 can be connected at the central point P in series or in parallel.

The wires of the coils La and L: pass through two tubes g and h symmetrically located on the cylinders.

The LZ coil is magnetically coupled to the LI coil. The LS coil is intended primarily to balance the capacitance formed by the LZ coil relative to its shell. Since the coil L cannot be moved without disturbing the balance between the coils L2 and LS and their vessels, the coupling can be controlled by the variable capacitor 4.

If the system is made symmetric with respect to the earth and is adventitious at symmetrical points of any balanced circuit, for example, a balanced generator or measuring circuit, then the system will be balanced with respect to the ground (Fig. 7).

It should be noted that the wires 8 and 9 are located in a plane parallel to the ground, and not one above the other, as shown in FIG. 7

Subject invention

Balanced high-frequency circuit consisting of a capacitor and a self-induction coil placed in different electrostatic shields, characterized in that to form an earth-symmetric system. The screens are insulated and attached to the anodes of a two-stroke lamp or an ultra-short wave generator.

 V9,

FIG. 3

FIG. four

Output

four

M

x

FIG. 5 Exit

Iw

eight

FIG. 6

The output of FIG. 7

Output