JPH051124Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial applications] Used in interstage matching circuits of microwave amplifiers, to prevent damage caused by reflected waves from loads, and in antenna circuits that separate transmitted and received waves. Regarding high power circulators.

[Conventional technology]

In the radar band of 1 to 2 _GHZ , the use of solid-state transmitters is progressing due to the remarkable improvement in the output power of microwave transistors in recent years. These solid-state transmitters combine the output power of multiple microwave transistors and have already obtained an output of several kilowatts or more, but with these high-power microwave transistor amplifiers, there is no risk of damage to the transistors due to reflected power from the output circuit. To prevent this, an isolator with a non-reflection termination connected to the circulator has become an indispensable component. Furthermore, circulators for high power amplifiers are required to have improved power durability and to be smaller in size, so high power lumped constant type circulators are desired.

The basic configuration of a lumped constant type circulator is as shown in FIG.
A center conductor 3 is provided by knitting ferrites 1-1 and 1-2 into a mesh, and a ground conductor 4- is provided on the outer surface of the two ferrites 1-1 and 1-2.
1 and 4-2 are closely arranged, and this ground conductor 4-
Magnets 5-1 and 5-2 that magnetize the ferrites 1-1 and 1-2 are installed outside of the ferrites 1-4-2.
Also, one end of each of the three conductors 2-1 to 2-3 has a connecting terminal a connected to a connector (not shown).
~c, and ground terminals d~f connected to the ground conductor 4-2 are provided at the other end. Furthermore, connection terminal a~
Parallel capacitors 6-1 to 6-3 are connected between the ground conductor 4-c and the ground conductor 4-2, respectively.

FIG. 5 shows details of the mesh-like central conductor 4, and the three conductors 2-1 to 2-3 each have a U-shape with two branch conductors branching from the connection terminals a to c. and are grounded to the ground conductor 4-2 through ground terminals d to f while maintaining an insulating relationship. Note that the three conductors 2-1 to 2-3 are cross-insulated so that the stray capacitances seen from the three connection terminals a to c are distributed completely symmetrically. Furthermore, in order to maintain this insulation property, the branch conductors of each conductor 2-1 to 2-3 are covered with dielectric material (for example, Teflon adhesive tape).
Each center conductor is constructed by wrapping it with

[Problem that the invention attempts to solve]

FIG. 6 is a side view of a conventional lumped constant circulator taken along Y-Y' in FIG. 5, as viewed in the direction of the arrow. As shown in FIG. 6, the ground terminal e of one conductor 2-2 of the center conductor 3 is bent in order to connect to the ground conductor 4-2.
In this case, the conductor 2-2 is connected from the ground terminal e to the other conductor 2-2.
The shortest position of the intersection with -1 to 2-3 (the part surrounded by broken line B in Figure 5) is above the other conductor 2-1, so bend the ground terminal e and connect it to the ground conductor. Adjacent conductor 2 when grounding to 4-2
-1. Therefore, in such a structure, the spatial distance is shortened in the area surrounded by the broken line B in FIG. 5, and electric lines of force are concentrated, which may cause dielectric breakdown.
Note that the spatial distance here refers to the connection terminal a, b, or c side conductor when the conductor 12-1, 12-2, or 12-3 is branched into two and is networked, and each is in a vertical relationship. This is the distance between the ground conductors 4-2, and includes the portion sandwiched between the ferrites and the space separated from the region of the ferrite 1. Furthermore, as can be seen from FIGS. 5 and 6, when the conductor 2-1 on the grounding terminal e side of the conventional structure is located above the conductor 2-2 on the connecting terminal a side,
The electric lines of force generated from the high voltage conductor 2-2 are
Electric lines of force concentrate not only on the conductor 2-1 on the ground terminal e side located on the upper side, but also on the ground conductor 4-2 on the lower side. Moreover, even in the space outside the area of ferrite 1, the distance between the ground conductor 4-2 and the connection terminal a is narrowed by the thickness of the conductor 2-1 on the connection terminal e side,
It becomes weaker in terms of power resistance.

In other words, Fig. 7 shows an equivalent circuit diagram of the center conductor, and the parallel capacitor C, the inductance L due to the center conductor of the ferrite-loaded part, and the terminal impedance of the output side load (not shown) of the circulator are equivalent to the input side. Converted terminating resistance Z _O
are connected in parallel. At the operating frequency, the parallel capacitor C and the inductance L are in a parallel resonant state, and the input impedance is matched and equal to the terminating resistor _ZO . In this case, the parallel capacitor C and inductance L are in a parallel resonant state, the impedances are matched, and the terminating resistance
Z is equal to _O. Now, if the input power is P(w) and the voltage across the inductance L is V(v), then P=V ² /Z ₀ and V=√ _p ·(v). For example, Z _p =50Ω, P
= 8KW, a voltage of V = 632V will be applied to connection terminal a. Figure 8 shows the voltage distribution of the center conductor, from connection terminal a to ground terminal d.
The voltage decreases linearly at . Therefore, a high voltage is applied especially to the area surrounded by the broken line B in Figure 5, and even slight differences in distance or spatial arrangement can cause concentration of the electric field, leading to discharge. In other words, a lumped constant circulator with a center conductor having a mesh-like structure has the disadvantage that it does not have sufficient power resistance.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks and provide a lumped constant type circulator with high power resistance.

[Means for solving problems]

The configuration of the present invention for achieving the above object will be explained using FIG. 1 corresponding to an embodiment. The lumped constant circulator of the present invention has an improved structure of the center conductor, and other parts are the same as the conventional lumped constant circulator.

As shown in FIG. 1, a central conductor 11 constituting the lumped constant circulator of the present invention has connection terminals a to c at one end and ground terminals d to f at the other end.
Three U-shaped conductors 1 with branched book conductors
It is constructed by knitting 2-1 to 12-3 in a mesh pattern. In addition, the other two conductors 12-1 and 1 at the shortest distance from one of the three conductors 12-1 to 12-3, for example, the ground terminal e of the conductor 12-2,
At the intersection with 2-3, one conductor 12-2
The three conductors are woven into a mesh so that all the conductors satisfy the relationship such that the conductor is located below the other two conductors 12-1 and 12-3.

[Effect]

FIG. 2 is a side view of the case where the center conductor 11 shown in FIG. 1 is installed in the conventional lumped constant type circulator shown in FIG. 4, taken along line X-X' in FIG. be. In Figure 2, conductor 1
When the grounding terminal e of the conductor 12-2 is bent and grounded to the grounding conductor 4-2, at the intersection at the shortest position from the grounding terminal e of the conductor 12-2 to the other conductors 12-1 and 12-3, Conductor 12-2 is connected to other conductor 12-1,
12-3, the other conductor 12-1,
Since the conductor 12-2 is not grounded across the conductor 12-3, the spatial distance between the ground terminal e and the connection terminal a is not shortened, and dielectric breakdown due to concentration of electric lines of force can be prevented. Therefore, as in the configuration of the present application, the conductor 12-1 on the grounding terminal e side is connected to the conductor 1 on the connecting terminal a side.
If placed below 2-2, the electric lines of force will reach the conductor 12.
It concentrates only on -1 and does not concentrate on ground conductor 4-5. Furthermore, the ground conductor 4 outside the ferrite area
The distance between -2 and the connection terminal a is increased by the thickness of the conductor 12-1 on the ground terminal e side compared to the conventional structure, and the power resistance is improved.

This also applies to other intersections (portions surrounded by broken lines A in FIG. 1), so that a lumped constant circulator with high power resistance can be constructed.

〔Example〕

The present invention will be described in detail below based on embodiments shown in the drawings. FIG. 1 shows the central conductor arranged in a mesh form constituting the lumped constant circulator of the present invention, and the lumped constant circulator is constructed with the same structure as the conventional one except for this central conductor.

In Figure 1, the connection terminal a provided at one end
Three U-shaped conductors 1 with two branch conductors branching from ~c and having ground terminals d~f at the other end and wrapped with a dielectric material (e.g. Teflon adhesive tape)
2-1 and 12-3 at the intersection point located at the shortest position from each ground terminal d to f (broken line A in Figure 1).
The center conductor is constructed by knitting the center conductor in a mesh pattern so that the portion surrounded by the center conductor is all located below the connection terminals a to c.

In other words, one of the three conductors 12-1 to 12-3, for example, the other two conductors 12-1 and 12 located at the optimal distance from the ground terminal e of the conductor 12-2.
-3, the three conductors are meshed so that all conductors satisfy the relationship such that one conductor 12-2 is located lower than the other two conductors 12-1 and 12-3. The central conductor is constructed by knitting it into a shape.

When knitting the three conductors 12-1 to 12-3 in a mesh shape, the positional relationship of each conductor 12-1 to 12-3 is determined by the grounding of the two branch conductors of each conductor 12-1 to 12-3. The relationships below/below/below/above and below/above/above/above are satisfied from terminals d to f to the intersections with branch lines of other conductors, and in any case, each conductor is connected to other conductors from its ground terminal. The shortest point of intersection with the other conductor is below the other conductor.

Furthermore, this mesh-like center conductor is connected to each connecting terminal a of the center conductor in the same manner as shown in FIG.
- c are connected to a connector (not shown), and each ground terminal d - f is bent and connected to the ground conductor 4 - 2 to form a lumped constant type circulator.

FIG. 2 is a side view of the lumped constant circulator incorporating the center conductor shown in FIG. 1, taken along line X-X' and viewed in the direction of the arrow. In FIG. 2, it can be seen that the connection terminal a and the ground terminal e do not straddle each other but are connected in parallel to the connector or the ground conductor 4-2.

Figure 3 is a diagram showing the power test results of the lumped constant circulator of the present invention and the conventional lumped constant circulator. Ten circulators of the present invention and ten conventional circulators were selected at a frequency of 1000 MHz and a pulse width of 1000 MHz.
Measurements were taken under the test conditions of 1 μs and Duty 0.001 by applying a matching load and gradually increasing the voltage. Third
As is clear from the figure, the discharge starting power is 12 to 13 (KW peak) in the circulator of the present invention, compared to 8 to 9 (KW peak) in the conventional circulator.
It can be seen that the circulator of the present invention has a higher withstand voltage.

By the way, in the present invention, three conductors 12-1 to 12
-3 in a mesh pattern, the positional relationship of each conductor is below/below/below/above and below/above/with respect to the intersection between the ground terminal of two branch conductors of each conductor and the branch conductor of another conductor. The above/above relationship is satisfied, but if the intersections of each branch conductor with other branch conductors at the shortest position from the ground terminal are all below the connection terminal, it is possible to create a mesh by other combinations. The center conductor may be configured in the shape of

[Effect of idea]

As described above, according to the configuration of the present invention, a mesh-like center conductor is formed in which the intersections with the branch conductors of other conductors located at the shortest position from the ground terminal of each conductor are all below the connecting terminal. By using this to construct a lumped constant type circulator, it is possible to provide a lumped constant type circulator with improved power resistance.

[Brief explanation of the drawing]

Figure 1 is a top view showing the center conductor of the lumped constant circulator of the present invention, and Figure 2 is a view of the direction of the arrow when the lumped constant circulator of the present invention is cut along line X-X' in Figure 1. Side view, 3rd
The figure is a comparison of the withstand voltage of the lumped constant circulator of the present invention and the conventional lumped constant circulator. Figure 4 is an exploded perspective view of the conventional lumped constant circulator. Figure 5 is the conventional lumped constant circulator. 6 is a top view showing the center conductor of , FIG. 6 is a side view of the conventional lumped constant circulator shown in FIG. 4 taken along Y-Y' in FIG. The equivalent circuit diagram of the conductor, FIG. 8, is a voltage distribution diagram of the center conductor. 1-1, 1-2...ferrite, 4-1, 4-
2... Earth conductor, 5-1, 5-2... Magnet, 6-
1, 6-2... Capacitor, 11... Center conductor,
12-1, 12-2...Conductor, a-c...Connection terminal, d-f...Grounding terminal.

Claims (1)

[Scope of utility model registration request] The branch side of each of the three conductors, which are installed between two opposing disk-shaped ferrites and the opposing surfaces of the ferrites and each branched into a plurality of parts, is a connecting terminal, and the other end is a grounding terminal. The central conductor is arranged in a mesh pattern with an interval of 120 degrees from each other, is in close contact with the outer surface of the two ferrite sheets, and is connected to the connecting terminal via a capacitor, and is connected to the grounding terminal. is a lumped constant type circulator consisting of a directly connected ground conductor and a magnet that magnetizes the two ferrite sheets, and the other two conductors are located at the shortest distance from the ground terminal of one of the three conductors. The three conductors are woven into a mesh so that all the conductors satisfy a relationship such that one conductor is located lower than the other two conductors at the intersection with the main conductor. A lumped constant type circulator.