JPH0722806A - Laminated filter - Google Patents

Abstract

PURPOSE:To increase the extent of attenuation on the high band side and to increase Q with respect to the laminated filter used in a communication machine or the like. CONSTITUTION:For the purpose of achieving these purposes, a capacitor 7a, L components 4a and 4b, and a capacitor 15a are connected between an input electrode 13A and the ground, and a capacitor 8a and an L component 14a are connected in series between the capacitor 7a as well as L components 4a and 4b and the ground, and a capacitor 7b, L components 4c and 4d, and a capacitor 15b are connected between an output electrode 13B and the ground, and a capacitor 8b and an L component 14b are connected in series between the capacitor 7b as well as L components 4c and 4d and the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated filter used in a communication device or the like.

[0002]

2. Description of the Related Art An electrically equivalent circuit in a conventional multilayer filter is such that a first capacitor and a first L component are directly connected between an input electrode and ground, and a third capacitor is connected between an output electrode and ground.
The capacitor and the third L component were directly connected, and the first and third L components were M-coupled.

[0003]

In the above configuration,
This is a problem because a simple unimodal filter characteristic is obtained, and the amount of attenuation is not sufficiently obtained especially on the high frequency side.

Therefore, the present invention has an object, for example, to obtain a large amount of attenuation on the high frequency side and to increase Q.

[0005]

In order to solve this problem, according to the present invention, a first capacitor, a first L component and a second capacitor are connected between an input electrode and ground, and the first capacitor is connected. A third capacitor and a second L component are connected in series between the capacitor and the first L component and the ground, and a fourth capacitor, a third L component and a fifth capacitor are connected between the output electrode and the ground. Is connected, and the sixth capacitor and the fourth L component are connected in series between the fourth capacitor and the third L component and between the ground.

[0006]

With the above configuration, the third capacitor and the second capacitor
Due to the series resonance action of the L component and the series resonance action of the sixth capacitor and the fourth L component, a large amount of attenuation called a notch on the high frequency side can be obtained. In addition, a second capacitor for the first L component, and a third capacitor
The fifth capacitor is connected in series to the L component of the above to resonate, and the values of the second and fifth capacitors connected in series are balanced with the values of the first and third L components, respectively. If so, the Q of the resonance portion can be increased.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a ceramic sheet, and a shield electrode 2 is laminated by printing on most of the upper surface thereof. Further, a ceramic sheet 3 is laminated on the upper surface of the shield electrode 2, a strip line 4 is laminated on the upper surface by printing, and a ceramic sheet 5 is further laminated on the upper surface thereof.

On the upper surface of the ceramic sheet 5, an inter-stage coupling electrode 6, an input coupling electrode 7, an output coupling electrode 7 and a frequency adjusting electrode 8 are provided by printing, respectively, and laminated on the ceramic sheet 5. It is in a state. A ceramic sheet 9 is laminated on the upper surfaces of these electrodes 6 to 8, a shield electrode 10 is laminated on the upper surface by printing, and a ceramic sheet 11 is laminated on the upper surface. The state is shown in FIG.
A long U-shaped ground electrode 12 is provided by printing on one end of this laminated body, and short U-shaped input and output electrodes 13A and 13B and a ground electrode 14 are provided by printing on the other end. ing. That is, the input and output electrodes 13A, 1
3B is electrically connected to the input / output coupling electrode 7, and the ground electrode 14 is connected to the shield electrodes 2 and 10 and the frequency adjusting electrode 8. Further, the ground electrode 12 is electrically connected to the shield electrodes 2 and 10 and the strip line 4. The electric circuit in the above configuration is as shown in FIG. In FIG. 3, 4a and 4b represent L components by the left stripline 4 shown in FIG.
Reference characters c and 4d indicate the L component of the right stripline 4 shown in FIG. Further, 6a indicates a capacitor capacitance formed between the inter-stage coupling electrode 6 and the left and right strip lines 4. Reference numeral 7a denotes a capacitor capacitance formed between the input / output coupling electrode 7 on the left side in FIG. 1 and the strip line 4 on the left side similarly to FIG.
b is a capacitor capacitance formed by the input / output coupling electrode 7 on the right side and the strip line 4 on the right side. Further, 8a and 8b in FIG. 3 are capacitor capacitances formed between the frequency adjustment electrode 8 and the left and right strip lines 4. 14a and 14b are L by the earth electrode 14.
The ingredients are shown. Further, 15a and 15b are capacitor capacitors formed between the concave portions 4a of the left and right strip lines 4 in FIG. 1 and the convex portions 16a of the ground electrode 16.

With the above construction, since the lower end of the ground electrode 14 shown in FIG. 2 is soldered to the ground pattern (not shown) during mounting, the upper and lower ends of the ground electrode 14 become the L component, which is the first component. 3, 6th capacitor capacity 8
a and 8b are connected in series, and a series resonant circuit is formed in each of these portions.

Therefore, the notch A on the high frequency side in the filter characteristic of FIG. 4 is formed. The notch B on the low frequency side is formed by the M coupling of the L components 4a to 4d and the capacitor capacitance 6a.

[0011]

As described above, according to the present invention, the first capacitor, the first L component and the second capacitor are connected between the input electrode and the ground, and the first capacitor and the first L component are connected. The third capacitor and the second L component are connected in series between the output electrode and the ground, and the fourth capacitor and the third L component are connected between the output electrode and the ground.
Component and the fifth capacitor, and the sixth capacitor and the fourth capacitor between the fourth capacitor and the third L component and between the ground
The L component of is connected in series.

With the above arrangement, the so-called notch is large on the high frequency side due to the series resonance action of the third capacitor and the second L component and the series resonance action of the sixth capacitor and the fourth L component. The amount of attenuation can be obtained. Also, for the first L component, the second capacitor,
Further, a fifth capacitor is connected in series to the third L component to resonate, and the values of the second and fifth capacitors connected in series are set to the values of the first and third L components, respectively. If this is balanced, the Q of the resonance portion can be increased.

[Brief description of drawings]

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

FIG. 2 is a perspective view of an embodiment of the present invention.

FIG. 3 is an electrical equivalent circuit diagram of an embodiment of the present invention.

FIG. 4 is a filter characteristic diagram of an embodiment of the present invention.

[Explanation of symbols]

 2 shield electrode 4 strip line 4a L component 4b L component 4c L component 4d L component 6 inter-stage coupling electrode 7 input, output coupling electrode 7a first capacitor capacitance 7b fourth capacitor capacitance 8 frequency adjustment electrode 8a second 3 capacitor capacity 8b 6th capacitor capacity 10 shield electrode 12 earth electrode 14 earth electrode 13A input electrode 13B output electrode 14a second L component 14b fourth L component 15a second capacitor capacity 15b fifth capacitor capacity

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Banno 55-12 Ozumi, Ozumi, Tanabe-cho, Tsuzuki-gun, Kyoto Prefecture Matsu-12 Nitto Electric Co., Ltd. 55-12 Shojihama Matsushita Nitto Electric Co., Ltd.

Claims (2)

[Claims] 1. A first capacitor, a first L component and a second capacitor are connected in series between an input electrode and ground, and a third capacitor is connected between the first capacitor and the first L component and ground.
And a second L component are connected in series, and a fourth capacitor, a third L component and a fifth capacitor are connected in series between the output electrode and the ground, and the fourth capacitor and the third L component are connected. A multilayer filter in which a sixth capacitor and a fourth L component are connected in series between the space and the ground. 2. The multilayer filter according to claim 1, wherein a seventh capacitor is connected between the respective dividing points of the first L component and the third L component.