JPH0457121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a Y-type circuit made of microstrips that is suitable for microwave integrated circuits (hereinafter referred to as MICs) based on microstrip lines and has excellent magnetic shielding effects. This relates to a branch type circulator.

Conventionally, there have been microstrip circulators shown in FIGS. 1a and 2b and 2a and 2b as microstrip circulators incorporated into a circuit composed of a plurality of microwave circuits. FIG. 1a is a plan view showing an example of a conventional microstrip circulator, and FIG. 1b is a sectional view taken along the line AA shown in FIG. 1a. In FIG. 1, 1 is a housing, 2 is a fixing plate formed by gold-plating a ferromagnetic metal such as Kovar, and 3 is a MIC board having a Y-branched circulator pattern attached to the fixing plate 2. ,
4 is a circular conductor part of the pattern on the MIC board 3;
Reference numeral 5 denotes a matching circuit section protruding from the circular conductor section 4 in a Y-branched manner at intervals of 120 degrees, 6 a transmission line connected to the matching circuit section 5, and 7 generating a magnetic field to be applied to the circular conductor section 4. Magnet, 8 is the top lid, 9a and 9
b is an iron plate for magnetic shunting and magnetic shielding, and 10 is a screw for fixing the fixing plate.

Fig. 2a is a plan view showing another example of the conventional microstrip circulator, and Fig. 2b is a plan view showing another example of the conventional microstrip circulator.
It is an AA cross-sectional view shown in figure a, and 1 to 10 are the first
The structure is similar to that shown in the figure, and reference numeral 11 denotes a dielectric holding plate with a dielectric constant close to 1 that holds the magnet 7.

The conventional microstrip circulator is
Since the structure is as described above, in the case of FIG. 1, the magnetic field generated by the magnet 7 does not form a closed loop, and the two iron plates 9a and 9
Since magnetic field leakage occurs between B and B, there is a drawback that it is easily influenced by peripheral circuits. Also, in the case of Fig. 2, the magnetic field does not form a closed loop as in Fig. 1, and magnet leakage occurs between the iron plate 9 for magnetization and magnetic shielding and the fixed plate 2 made of magnetic Kovar.
Also, the circular conductor portion 4 is susceptible to the influence of peripheral circuits.
Since the dielectric holding plate 11 is placed directly on top, there is a drawback in that it affects the electric field emitted from the circular conductor portion 4 and may cause deterioration of characteristics.

This invention was made to eliminate these drawbacks, and a fixing plate 2 is provided on the upper surface of the fixing plate 2.
A Y-shaped yoke made of a material with the same magnetic permeability as is provided, and a magnet 7 is attached to the inner surface of the Y-shaped yoke so that the magnetic field generated from the magnet 7 forms a closed loop, resulting in a microstructure with an excellent magnetic shielding effect. It provides a strip circulator.

An embodiment of the present invention shown in FIGS. 3a and 3b will be described below.

3a is a plan view of the circulator of the present invention, FIG. 3b is a side view of FIG. 3a, and FIG. 3c is a diagram showing a Y-shaped yoke.
0 is the same as in FIG. Reference numeral 12 denotes a Y-shaped yoke made of a magnetic material having the same magnetic permeability as the fixed plate.
The Y-shaped yoke 12 has fixing protrusions 13 at three ends, and these protrusions 13
The Y-branch transmission line 6 on the MIC board 7 is fixed so as to be in direct contact with the fixing plate 2 at a portion between the three lines. The magnet 7 has a diameter similar to that of the circular conductor section 4, and is fixed to the inner surface of the Y-shaped yoke 12 facing the circular conductor section 4. are spaced at a predetermined interval.

With such a structure, in the circulator of the present invention, the magnetic field generated by the magnet 7 continuously passes through the fixed plate 2 made of ferromagnetic metal and the Y-shaped yoke 12, forming a closed loop. Therefore, the magnetic shielding effect is excellent. Further, since there is a space at a predetermined distance between the magnet 7 and the MIC board 3, the influence on the electric field emitted from the circular conductor portion 4 is small, preventing deterioration of characteristics, and moreover, the Y-branch transmission line Since the Y-shaped yoke 12 is notched in the section 6, the peripheral circuit and the line can be connected by bonding with a gold ribbon or the like while the Y-shaped yoke 12 is attached to the carrier 2.

As described above, the microstrip circulator according to the present invention has the advantage that it is easy to connect lines with peripheral circuits and is not easily influenced by peripheral circuits because of its excellent magnetic shielding effect.

[Brief explanation of drawings]

Fig. 1a is a plan view showing an example of a conventional microstrip circulator, and Fig. 1b is a plan view of an example of a conventional microstrip circulator.
Figure 2a is a plan view showing another example of a conventional microstrip circulator, Figure 2b is a cross-sectional view taken along line A-A in Figure 2a, Figure 3a is 3 is a plan view showing an embodiment of the microstrip circulator of the present invention, FIG. 3b is a side view of FIG. 3a, and FIG. 3c is a view showing a Y-shaped yoke. In the figure, 1 is the housing, 2 is the fixing plate, 3 is the MIC board,
4 is a circular conductor part, 5 is a matching circuit part, 6 is a transmission line, 7 is a magnet, 8 is a top cover, 9 is an iron plate for magnetizing and magnetic shielding, 10 is a screw, 11 is made of a dielectric with a relative dielectric constant close to 1 The holding plate, 12 is a Y-shaped yoke, and 13 is a protrusion. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

Claims (1)

[Claims] 1 In a Y-branch type circulator composed of microstrips, a ferromagnetic metal fixed plate,
A microwave which is fixed on the fixed plate and has a Y-branch type circulator pattern consisting of a circular conductor part, a matching circuit part protruding from the circular conductor part in a Y-branch shape, and a transmission line connected to the matching circuit part. It is formed of an integrated circuit board and a ferromagnetic metal having the same magnetic permeability as the fixed plate, and the three Y-branched tips have a Y-branched shape of the Y-branched circulator pattern on the microwave integrated circuit. A Y-shape having fixing protrusions fixed respectively on the fixing plate between the three protruding transmission lines, and arranged to cover the top surface of the circular conductor part of the Y-branch circulator pattern. A microstrip circulator comprising: a yoke; and a magnet fixed to the inner surface of the Y-shaped yoke opposite to the Y-branched circulator pattern on the microwave integrated circuit.