JPH07336112A - Concentrated constant type isolator and its adjusting method - Google Patents

Abstract

PURPOSE:To easily correct frequency deviation between the minimum point of insertion loss and the maximum point of loss in an opposite direction of an isolator by employing such constitution that only a capacitor for arranging connected to a resistance part for termination can be capacitance-adjusted. CONSTITUTION:Since a notched part 2 is provided on a double sided printed circuit board 1, a part of the capacitor 16a for arranging connected to a resistor 17 for termination can be directly observed from an upper plane. In such a state, a magnetic field equivalent to the magnetic fields generated in magnets loaded on upper and lower sides is applied from the outside by an electromagnet, etc., and adjustment is performed as measuring isolator characteristic. Such adjustment can be easily attained by a metallic needle or laser beam via the notched part 2 by cutting the capacitor 16a so as to eliminate the frequency deviation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumped constant isolator which is a non-reciprocal circuit device used in a microwave communication device or the like, and a method for manufacturing the isolator.

[0002]

2. Description of the Related Art An example of the structure of a conventional lumped constant isolator is shown in FIG.

In FIG. 8, the central conductor 20 is formed by stacking three strip conductors 11, 12, and 13 at equal angular intervals of 120 ° and insulated from each other via a heat-resistant insulating film 14, so that the whole structure is as a whole. Is formed of a laminated flexible substrate. The double-sided printed circuit board 30 has a through hole 21 for positioning the ferrite disk 15 and a notch 2 for positioning the matching capacitors 16a, 16b, 16c.
2, and a notch (not shown) for positioning the terminating resistor 17 is provided respectively, and the ferrite disc 1
5, the grounding electrode 23 and the input / output electrode 24 are provided on the upper and lower surfaces so that the components of the matching capacitors 16a, 16b, 16c, the terminating resistor 17, and the terminals are electrically connected (the lower surface is not shown). ), They are each through hole 2
The upper and lower surfaces are electrically connected by 5. Similarly, in the double-sided printed circuit board 40, the ground electrode 31 and the input / output electrode 32 are electrically connected to each other in the vertical direction through the through hole 33, and are electrically connected to the respective terminals. According to this example, the central circuit is configured by the above parts. On the other hand, an input terminal (not shown), an output terminal 41, and a ground terminal 42 are integrated in a resin case 50 shown on the lower surface and are led out from the inside of the resin case to the outside. In addition, a magnet through hole 4 for attaching a magnet is provided on the bottom.
4 are provided. Assembling procedure includes resin case 5
The center conductor 20, the ferrite disk 15, the double-sided printed boards 30 and 40, and the matching capacitors 16a and 16
The parts b, 16c, and the terminating resistor 17 are stacked on top of each other while being soldered with cream solder, and soldered by reflow. Thereafter, as shown in FIG. 9, the upper and lower magnets 18 and 19 are housed in a resin case 50, and the upper and lower magnetic yokes 60 and 70 are attached to form a lumped constant isolator.

[0004]

The lumped-constant type isolator is based on the principle that one input / output terminal of the lumped-constant circulator is terminated with a resistor. The capacities of matching capacitors connected in parallel to the respective input / output terminals are all the same. Although this configuration condition is also applied when designing an isolator, in the case of a lumped-constant type isolator, when a terminating resistor is connected to the resistor end, the resistor cannot be ideally terminated, so that there is a slight impedance difference. Due to the mismatch, the optimal isolator configuration conditions are not satisfied, and as shown in FIG. 10, the frequency f between the minimum point F of insertion loss and the maximum point G of reverse loss in the same magnetic field does not match,
It becomes an isolator in a shifted state (shift), and there is a drawback that the bandwidth that satisfies the characteristics of the isolator becomes small. As a method of matching this deviation, there is a method of determining the matching capacitance at each end in advance, but the degree of impedance mismatch also changes depending on the tolerance of the connected resistors, the connection status, etc. It is difficult to keep everything free of frequency shifts.

Therefore, a technical problem of the present invention is to provide a lumped constant isolator capable of easily correcting the frequency deviation between the minimum insertion loss point and the maximum reverse loss point of an isolator to be manufactured, and an adjusting method thereof. To provide.

[0006]

According to the present invention, a lumped constant obtained by applying a magnetic field by a magnet for applying a magnetic field to a central circuit composed of a central conductor, a ferrite, a matching capacitor, and a terminating resistor. Type isolator,
In order to obtain an isolator having desired characteristics, a lumped-constant type isolator characterized in that, of the matching capacitors, only the matching capacitor connected to the terminating resistor portion can be adjusted in capacity is obtained. .

Further, according to the present invention, there is provided a lumped constant isolator characterized in that, in the lumped constant isolator, an adjusting hole for adjusting the capacitance of a matching capacitor connected to the terminating resistor portion is provided. can get.

Further, according to the present invention, in order to obtain an isolator having a desired characteristic by using any one of the lumped constant type isolators described above, the matching capacitor is connected to the termination resistor section. A method for adjusting a lumped-constant type isolator characterized in that the capacity of only a matching capacitor is adjusted.

[0009]

In the present invention, by adjusting the capacitance of only the matching capacitor connected to the resistance end of the lumped constant isolator, it is possible to eliminate the frequency shift between the minimum point of insertion loss and the maximum point of reverse loss, which is effective. The bandwidth can be widened, that is, the characteristics can be improved, and since the adjustment hole for adjusting the capacity is provided, the adjustment can be easily performed, and the productivity can be greatly improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 are views showing a lumped constant isolator according to an embodiment of the present invention, FIGS. 1 and 2 are exploded views, and FIG. 3 is a top view. 1 and 3, the same parts as those of the conventional isolator in FIGS. 8 and 9 are designated by the same reference numerals. 1 and 2, the basic structure and the assembly procedure are the same as those of the conventional one as shown in FIG. 8, but in the embodiment of the present invention, the matching capacitor 1 connected to the termination resistor 17 on the double-sided printed board 1 is used.
This is different from the conventional configuration in that an adjustment hole (notch) 2 for adjusting the capacity of 6a is provided.

Referring to FIG. 3, there is shown a top view of the assembly 10 prior to mounting the magnet and magnetic yoke of FIGS. The capacitance adjusting method is to adjust the capacitance by cutting the matching capacitor 16a from the capacitance adjusting hole 2 so as to eliminate frequency deviation while applying a DC magnetic field to the assembly 10 by applying a DC magnetic field to measure the isolator characteristic. To do. As a cutting method, a needle-shaped metal rod may be used for cutting, or a laser may be used for cutting.

FIGS. 4 and 5 are exploded perspective views showing a lumped constant isolator according to another embodiment of the present invention. FIG. 6 is a side view of the assembly of FIGS. 4 and 5. As shown in FIG. 4, a point different from the conventional example shown in FIG. 8 is that a capacitance adjusting hole 5 of the matching capacitor is provided on the side surface of the resin case 4. FIG. 5 shows the same configuration as the conventional one.

FIG. 6 is a side view of the assembly 7 before mounting the magnet and the magnetic yoke shown in FIGS. 4 and 5. Also in this case, the capacity may be adjusted in the same manner as the embodiment of FIG. Further, the upper and lower magnetic yokes 60, 70 are also provided with capacity adjusting holes corresponding to the capacity adjusting holes 5 of the resin case 4, and the upper and lower magnets 18, 19 and the upper and lower magnetic yokes 60, 70 are mounted. It is also possible to adjust the capacity after doing.

The characteristics of the isolator shown in FIG. 1 are shown in FIG. 7 as an example of the isolator characteristics obtained by the above two embodiments. As can be seen from comparison with FIG. 10, the frequency shift is improved, the frequency f at the minimum point A of the insertion loss and the frequency f at the maximum point B of the reverse loss substantially match, and the isolator characteristic is improved. Further, the same results as in FIG. 6 are obtained for the other examples of FIGS. 4 and 5.

[0016]

As described above, the lumped-constant type isolator according to the present invention adjusts only the matching capacitor connected to the resistance end so that the minimum insertion loss point and the maximum reverse loss point can be obtained. The frequency deviation can be eliminated, the bandwidth that satisfies the isolator can be increased, and an isolator with improved characteristics can be obtained. Further, in the present invention, the capacity can be adjusted more easily by providing the capacitor adjusting hole in the case or the wiring board, and the productive manufacturing can be performed.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a lumped constant isolator according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a lumped constant isolator according to an embodiment of the present invention.

FIG. 3 is a top view of a semi-finished product assembly of an embodiment of a lumped constant isolator according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view of a lumped constant isolator according to another embodiment of the present invention.

FIG. 5 is an exploded perspective view of a lumped constant isolator according to another embodiment of the present invention.

FIG. 6 is a side view of a semi-finished assembly of a lumped constant isolator according to another embodiment of the present invention.

FIG. 5 is a characteristic diagram of a lumped constant isolator according to an embodiment of the present invention.

FIG. 8 is an exploded perspective view of a lumped constant isolator according to a conventional example.

FIG. 9 is an exploded perspective view of a lumped constant isolator according to a conventional example.

FIG. 10 is a characteristic diagram of a lumped constant isolator according to a conventional example.

[Explanation of symbols]

 1,30,40 Double-sided printed circuit board 2,5 Capacitance adjusting hole 4,50 Resin case 7,10 Assembly 15 Ferrite disk 16a, 16b, 16c Matching capacitor 17 Termination resistor 18 Upper magnet 19 Lower magnet 20 Center conductor 21 Through hole 22 Notch 23,31 Ground electrode 24,32 Input / output electrode 25 Through hole 41 Output terminal 42 Ground terminal 44 Magnet through hole 60 Upper magnetic yoke 70 Lower magnetic yoke

Claims (3)

[Claims] 1. A lumped-constant isolator in which a magnetic field is applied by a magnet for applying a magnetic field to a central circuit composed of a central conductor, a ferrite, a matching capacitor, and a terminating resistor, the isolator having desired characteristics. In order to obtain the above, the lumped-constant isolator is configured so that, of the matching capacitors, only the matching capacitor connected to the terminating resistor portion can be adjusted in capacitance. 2. The lumped constant isolator according to claim 1, wherein an adjustment hole for adjusting the capacitance of a matching capacitor connected to the terminating resistor portion is provided. 3. A lumped-constant type isolator according to claim 1, wherein only a matching capacitor connected to the terminating resistor section is used to obtain an isolator having desired characteristics. A method for adjusting a lumped-constant type isolator, which is characterized in that the capacitance is adjusted.