JPH11239009A - Band widening structure of irreversible circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen the band without making elements large-sized by forming a resonance circuit on a circuit board where the irreversible circuit element and other circuit elements are mounted and grounding the ground terminal of the irreversible element through the resonance circuit. SOLUTION: The irreversible circuit element 40 is used and has two input/ output terminals 5 and two ground terminals 3 from its flank to the bottom surface. On the circuit board 31 where the irreversible circuit element 40 is mounted, a pattern electrode 32 to which the input/output terminals 5 are connected and a pattern electrode 33 to which the ground terminals 3 are connected are formed. To the pattern electrode 33 to which the earth terminals 3, a strip line inductor 34 is connected. A stack chip inductor 36 is connected between the strip line inductor 34 and ground electrodes 35. Consequently, the irreversible circuit equivalent to an equivalent circuit can be obtained and the band of the irreversible circuit element can be widened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to VHF, UHF,
The present invention relates to a non-reciprocal circuit device such as a lumped-constant circulator and an isolator used in an SHF band or the like, and to a structure for widening the band of the non-reciprocal circuit device.

[0002]

2. Description of the Related Art Generally, non-reciprocal circuit devices such as lumped-constant isolators and circulators have a function of hardly attenuating in a signal transmission direction and increasing in a reverse direction. For example, it is used in a transmission / reception circuit of a mobile communication device such as a mobile phone and a car phone.

FIG. 8 is an exploded perspective view of a conventional lumped constant type isolator. In this conventional example, there is a resin case 1 at the bottom. In the resin case 1, three conductor plates are formed integrally with the resin portion. This one conductor plate is a ground electrode plate 2, which is widely disposed on the bottom of the resin case 1, and a ground terminal 3 connected to the ground electrode plate 2 is led out to a back surface serving as a mounting surface of the resin case 1. The other two conductive plates are used for input / output terminals, and are U-shaped conductive plates in which the inner circuit connection terminal 4 and the outer input / output terminal 5 are connected. The inner circuit connection terminal 4 has a projection 6 formed on the surface on which the ground plate electrode 2 is arranged.
Is placed on top. The ground terminal 3 and the input / output terminal 5 are formed to face each other.

On the resin case 1, a metal case 7
Is placed. The lower metal case 7 has a cutout 8 corresponding to the projection 6 of the resin case 1, and is soldered to the ground electrode plate 2 of the resin case 1.

On the lower metal case 7, a plate-like capacitor 9 having electrodes formed on the upper and lower surfaces of a dielectric plate, a chip resistor 10, and a center conductor 12 on a ferrite core 11 are insulated from each other by 120 degrees. And the center conductor portion, which is arranged rotationally symmetrically at an interval of. Of the three center conductors 12, the tip portions 13a and 13b of the two center conductors 12 are connected to the plate-shaped capacitor 9 and the inner circuit connection terminal 4 on the resin case 1, respectively, and the tip ends of the other one of the center conductors Part 13
c is connected to the plate capacitor 9 and the chip resistor 10. The lower part of the ferrite core 11 of the center conductor is 3
Common part of the two center conductors, which is connected to the lower part 7 of the metal case and grounded. The plate capacitor 9 is also connected to the lower metal case 7 on the side opposite to the surface to which the tip of the center conductor is connected, and is also grounded. And
The terminal electrode of the chip resistor 10 is connected to the lower metal case 7 and grounded.

Next, a resin mold 20 is formed on the center conductor.
Put on. The resin mold 20 has a through hole 21 having a size substantially equal to the outer diameter of the ferrite core 11 at the center,
At the lower part, three claw portions 22 are formed so as to contact the outer peripheral portion of the ferrite core 11. The claw portion 22 is located at the center conductor on the side surface of the ferrite core, and positions the ferrite core. This resin mold 20
Has a size such that the outer shape is accommodated inside the resin case 1 and the metal case lower part 7, and a protrusion 23 for positioning the magnet 24 is formed on the upper surface. Then, the protrusion 23
The magnet 24 is arranged at a position where the magnet 24 is positioned. Then, the metal case upper part 25 is covered, and the metal case upper part 25 and the metal case lower part 7 are soldered to form a lumped constant type isolator.

[0007]

One application in which a conventional non-reciprocal circuit device is used is a cellular phone. The size of the mobile phone has been remarkably reduced, and the size of the non-reciprocal circuit device used for the mobile phone has also been reduced. Recently, a non-reciprocal circuit element having a size of 7 mm square has been used. On the other hand, there is a tendency that the operating frequency range of mobile phones is widened.

FIG. 5 shows an equivalent circuit of a conventional lumped constant type non-reciprocal circuit device. L1, L2, L composed of a center conductor
3 and C1, C2 and C3 formed by plate capacitors, one end of which is grounded and the other end is an input / output terminal. In this example, since an isolator is shown, one input / output terminal is connected to a dummy resistor R formed by a chip resistor and grounded. This conventional lumped-constant type nonreciprocal circuit element has a single-peak characteristic, and the circuit needs to be changed in order to widen the band.

An equivalent circuit shown in FIG. 6 is known as a circuit configuration for widening the bandwidth of a conventional nonreciprocal circuit device. In this example, the series resonance circuits 51, 5
2, 53 are connected. Thereby, a bimodal characteristic can be obtained, and the band can be widened. Further, in the example shown in FIG. 6, a series resonance circuit is required at each input / output terminal, whereas an equivalent circuit shown in FIG. 7 is also known. In the configuration shown in FIG. 7, the series resonance circuit 54 is connected between each ground connection terminal and the ground, which are conventionally grounded, and there is an advantage that only one series resonance circuit is required. As this conventional example, there is one disclosed in FIGS. 10 and 11 of JP-A-9-270607. This conventional example has a structure in which a resonance circuit is configured by a laminated substrate in which three substrates are laminated, and is arranged on a lower surface of a magnetic yoke. According to this, a problem has been pointed out that the increase in size and weight is inevitable due to the increase in the height of the parts, and it is not possible to cope with downsizing and weight reduction.

Conventionally, the lumped-constant type nonreciprocal circuit element has been broadened by utilizing these structures. However, in each case, a series resonance circuit is added as the nonreciprocal circuit element, and the element is compact. It was a factor that hindered the conversion.

In view of the above, the present invention provides a broadband structure of a non-reciprocal circuit device capable of achieving a wide band without increasing the size of the device.

[0012]

Means for Solving the Problems A first invention of the present invention is:
A resonance circuit is formed on a circuit board on which the non-reciprocal circuit element and other circuit elements are mounted, and a ground terminal of the non-reciprocal circuit element is connected to ground via the resonance circuit. Thus, the non-reciprocal circuit device can achieve a wider band.

A second invention of the present invention is characterized in that the non-reciprocal circuit device is a lumped constant non-reciprocal circuit device having a single peak characteristic.

According to a third aspect of the present invention, the resonance circuit includes:
It is a series resonance circuit composed of a stripline inductor and a multilayer chip capacitor.

According to a fourth aspect of the present invention, the circuit board is a multilayer wiring board, and the resonance circuit is an LC resonance circuit formed by a multilayer structure of the multilayer wiring board. .

According to a fifth aspect of the present invention, the non-reciprocal circuit device is a small lumped constant type non-reciprocal circuit device having a size of 7 mm square or less.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention aims at widening the bandwidth of a non-reciprocal circuit device, and in order to widen the band, a non-reciprocal circuit device having a single peak characteristic has a bimodal characteristic.
In order to widen the band, a resonance circuit is connected to the ground terminal of the non-reciprocal circuit element and grounded,
The resonance circuit is formed on a circuit board on which a non-reciprocal circuit element and other circuit elements are mounted. That is,
As the non-reciprocal circuit device, there is no need to particularly improve the conventional device, and the non-reciprocal circuit device is compatible with the mounting substrate.

According to the present invention, as the non-reciprocal circuit device,
The same non-reciprocal circuit element can be used for a wide band and a narrow band (ordinary band) without any special design change, and there are significant design and manufacturing advantages. on the other hand,
As a circuit board, each circuit element is mounted and wired, and adding a resonance circuit does not result in a large load. Therefore, according to the present invention, it is possible to achieve a wide band of the nonreciprocal circuit device with a very simple structure.

FIG. 1 is an exploded perspective view of an embodiment according to the present invention.
Shown in This embodiment uses the non-reciprocal circuit device 40 described in the related art, and has two input / output terminals 5 and two ground terminals 3 from the side surface to the bottom surface. Then, the circuit board 31 on which the non-reciprocal circuit element 40 is mounted
Has a pattern electrode 32 to which the input / output terminal 5 is connected.
And a pattern electrode 33 to which the ground terminal 3 is connected is formed. The strip electrode 34 is connected to the pattern electrode 33 to which the ground terminal 3 is connected. A multilayer chip inductor 36 is connected between the stripline inductor 34 and the ground electrode 35. As a result, a non-reciprocal circuit equivalent to the equivalent circuit shown in FIG. 7 can be obtained, and a wider band of the non-reciprocal circuit device can be achieved. FIG. 2 shows the insertion loss characteristics of this embodiment and the conventional example. It is apparent that the band of the present invention is broadened.

FIG. 3 is an exploded perspective view of another embodiment according to the present invention. This embodiment also uses the non-reciprocal circuit device 40 described in the related art. And the non-reciprocal circuit element 4
The pattern electrode 32 to which the input / output terminal 5 is connected and the pattern electrode 37 to which the ground terminal 3 is connected are formed on the circuit board 31 on which 0 is mounted. This circuit board is a multilayer wiring board, and a perspective view showing an internal structure thereof is shown in FIG. In the inside, first, a pattern electrode 38 facing the pattern electrode 37 and constituting a capacitor is formed at a predetermined interval. A through hole 39 is formed in the pattern electrode 38, and is connected to an inductor line 42 formed further below. The inductor line 42 has a land 41 connected to the through hole 39, and the other end is connected to the ground line 43. As a result, a non-reciprocal circuit equivalent to the equivalent circuit shown in FIG. 7 can be obtained, and a wider band of the non-reciprocal circuit device can be achieved.

In such a circuit board, a multilayer wiring board is widely used, and it is easy to configure the above-described resonance circuit inside the multilayer wiring board. Also,
In the above two embodiments, the shape of the pattern electrode can be appropriately designed, and the configuration of the resonance circuit can be appropriately changed. The present invention can be implemented as long as the circuit board is configured to form a resonance circuit connected to the ground terminal of the non-reciprocal circuit element (terminal connected to the ground in the conventional structure) and to connect the resonance circuit to the ground. . Of course, other circuit elements are also mounted on this circuit board, and are used, for example, as circuit boards for mobile phones.

It is clear that the non-reciprocal circuit device according to the present invention is not limited to those described in the above embodiments.
The non-reciprocal circuit device according to the present invention does not need to particularly consider a wide band, and a normal product can be used. The nonreciprocal circuit device according to the present invention may have a single-peak characteristic. In the above embodiment, the isolator has been described. However, a similar effect can be obtained with a circulator. To make it a circulator, the terminal connected to the resistor may be made the same as the other input / output terminals.

The non-reciprocal circuit device according to the present invention comprises a magnetic material, three central conductors arranged closely to the magnetic material, a capacitor component connected to each central conductor, and a DC magnetic field applied to the magnetic material. It is preferable to have a configuration having a permanent magnet to be applied.

According to the present invention, it is possible to achieve a wide band of the nonreciprocal circuit device. In addition, the non-reciprocal circuit element may have the same structure as the conventional structure, and does not increase in size or increase in weight. Therefore, the miniaturization of the non-reciprocal circuit device is not hindered. The present invention is particularly effective in a small non-reciprocal circuit device, and particularly effective in a non-reciprocal circuit device having a size of 7 mm square or less. Further, it does not hinder the reduction in thickness, and is particularly effective in a thin non-reciprocal circuit device, and is particularly effective in a non-reciprocal circuit device having a height of 2.5 mm or less. Further, it is particularly effective for a non-reciprocal circuit device having a height of 2.0 mm or less.

As the wiring board of the present invention, various substrates such as a printed board, a flexible board, and a multilayer wiring board can be used. In recent years, a multi-layer substrate has been widely used, and a multi-layer substrate can be configured in exactly the same space as in the related art. Further, the thickness of the multilayer substrate does not need to be particularly large.

[0026]

According to the present invention, it is not necessary to newly design and construct a non-reciprocal circuit device, and it is possible to use a non-reciprocal circuit device having the same configuration as that of the related art and construct a resonance circuit on the wiring board. This enables the nonreciprocal circuit device to have a wider band. An extremely simple configuration enables a wide band, and is extremely useful in communication equipment using a non-reciprocal circuit device such as a mobile phone.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment according to the present invention.

FIG. 2 shows insertion loss characteristics of one embodiment according to the present invention and a conventional example.

FIG. 3 is an exploded perspective view of another embodiment according to the present invention.

FIG. 4 is an internal structural view of a circuit board according to another embodiment of the present invention.

FIG. 5 is an equivalent circuit diagram of a conventional non-reciprocal circuit device.

FIG. 6 is an equivalent circuit diagram of an example of a broadband circuit of a non-reciprocal circuit device.

FIG. 7 is an equivalent circuit diagram of another example of the broadband circuit of the non-reciprocal circuit device.

FIG. 8 is an exploded perspective view of a conventional non-reciprocal circuit device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 Circuit board 32, 33, 37, 38 Pattern electrode 34 Stripline inductor 35, 43 Ground pattern 36 Multilayer chip capacitor 39 Through hole 42 Inductor line

Claims (5)

[Claims] 1. A resonance circuit is formed on a circuit board on which a non-reciprocal circuit element and other circuit elements are mounted, and a ground terminal of the non-reciprocal circuit element is connected to ground via the resonance circuit. A broadband structure of a non-reciprocal circuit device. 2. The non-reciprocal circuit device according to claim 1, wherein the non-reciprocal circuit device is a lumped constant type non-reciprocal circuit device having a single peak characteristic.
A broadband structure of the non-reciprocal circuit device according to the above. 3. The non-reciprocal circuit device according to claim 1, wherein the resonance circuit is a series resonance circuit including a strip line inductor and a multilayer chip capacitor. 4. The non-reciprocal circuit device according to claim 1, wherein the circuit board is a multilayer wiring board, and the resonance circuit is an LC resonance circuit formed by a multilayer structure of the multilayer wiring board. Broadband structure. 5. The broadband structure of a non-reciprocal circuit device according to claim 1, wherein the non-reciprocal circuit device is a small lumped constant type non-reciprocal circuit device of 7 mm square or less.