JP2773603B2 - Multilayer filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art An electrical equivalent circuit of a conventional multilayer filter has a first capacitor and a first L component directly connected between an input electrode and a ground, and a third capacitor connected between an output electrode and a ground.
And the third L component are directly connected, and the first and third L components are M-coupled.

[0003]

In the above configuration,
Only a single-peak filter characteristic can be obtained, and a sufficient amount of attenuation especially on the high frequency side cannot be obtained, which has been a problem.

[0004] Accordingly, the present invention is applied to a multilayer filter.
The purpose is to increase the Q of the strip line to be formed.

[0005]

To solve this problem, the present invention provides a first capacitor between an input electrode and a ground.
Sensor, the first stripline, and the second capacitor
Column-connected, said first capacitor and a first stripper
The third capacitor and the second L component between the ground and the ground
Are connected in series, and a fourth capacitor is connected between the output electrode and the ground.
And the second strip line and the fifth capacitor are connected in series.
And the fourth capacitor and the second strip line
The sixth capacitor and the fourth L component are directly connected between
In the laminated filter connected in columns, the first and second
Both ends of the strip line are open ends.
A recess is formed on one open end side of the
The first and second strip lines have recesses on the concave side.
From the ground electrode to form the ground
An extended convex portion is provided, and the convex portion and the concave portion are paired.
To form the second and fifth capacitors.
It is.

[0006]

With the above arrangement, the first and second strips are provided.
Concave part provided on each of the lines and convex part of the ground electrode
Frequency pressure by the second and fifth capacitors formed between
Not only the compression effect but also the 1/2 wavelength strip line
The sub-resonance effect is given to the
This can further improve the Q value of the strip line,
It will be high performance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a ceramic sheet, on which a shield electrode 2 is laminated on most of the upper surface by printing. Further, a ceramic sheet 3 is laminated on the upper surface of the shield electrode 2, and first and second strips are formed on the upper surface thereof.
A pline 4 is laminated by printing, and a ceramic sheet 5 is further laminated on an upper surface thereof.

On the upper surface of the ceramic sheet 5, an inter-stage coupling electrode 6, an input / output coupling electrode 7 and a frequency adjusting electrode 8 are provided by printing, respectively, and are thereby laminated on the ceramic sheet 5. It is in a state. A ceramic sheet 9 is laminated on the upper surfaces of the electrodes 6 to 8, a shield electrode 10 is provided on the upper surface by printing, and a ceramic sheet 11 is further 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 side of the laminate, 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 adjustment 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. 3, 4a and 4b denote L components of the first strip line 4 on the left side shown in FIG. 1, and 4c and 4d denote the second strip lines on the right side shown in FIG.
The L component of In 4 is shown. Reference numeral 6a denotes a capacitor capacity formed between the inter-stage coupling electrode 6 and the left and right first and second strip lines 4 . 7a is
1 shows the capacitance of a capacitor formed between the left input / output coupling electrode 7 and the left first strip line 4 in the same manner. FIG. 3B shows the right input / output coupling electrode 7. And the capacitance of the capacitor formed by the second strip line 4 on the right. Further, reference numerals 8a and 8b in FIG. 3 denote frequency adjusting electrodes 8 and first and second left and right electrodes .
Is the capacitance of the capacitor formed between the strip line 4 and the other. Reference numerals 14a and 14b denote L components of the ground electrode 14. Further 15a, 15b the first left and right in FIG. 1
1. Capacitance formed between the concave portion 17 of the second strip line 4 and the convex portion 16a of the ground electrode 16.

[0009] Then, as shown in FIG.
The lip line 4 has a half wavelength with both ends open.
One end is short to ground because of strip line
Compared to the one-quarter wavelength stripline
The Q value can be significantly improved, and the first and second
Across the side second strip line 4, the third Conde
Sensor or the fifth and sixth capacitors are connected.
The frequency compression effect has been sufficiently obtained.
Minimize increase in the length of the pline
It is. Furthermore, the concave portions 4 of the left and right strip lines 4
a formed between the projections 16 a of the ground electrode 16 and the ground electrode 16.
The effect of the sensor capacitors 15a and 15b is the frequency compression effect.
In addition to the above, a sub-
This sub-resonance effect provides a vibration effect.
And the Q value of the strip line can be further improved,
It becomes something.

[0010]

As described above, the present invention provides the first and second switches.
The recess provided on each trip line and the ground
By the second and fifth capacitors formed between the convex portions of the poles
Not only the frequency compression effect but also the half wavelength
The sub-line has a secondary resonance effect.
The resonance effect further increases the Q value of the strip line.
It can be done and has high performance.

[Brief description of the 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 one embodiment of the present invention.

[Explanation of symbols]

2 shield electrode 4 first strip line 4 second strip line 7a first capacitor capacity 7b fourth capacitor capacity 8a third capacitor capacity 8b sixth capacitor capacity 12 ground electrode 14 ground electrode 13A input electrode 13B output Electrode 14a Second L component 14b Fourth L component 15a Second capacitor capacitance 15b Fifth capacitor capacitance 16a Convex portion 17 Concave portion

Continued on the front page. −12 Matsushita Nitto Electric Co., Ltd. (56) References JP-A-5-95202 (JP, A) JP-A-6-268406 (JP, A) JP-A 1-113412 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) H01P 1/20 H01P 1/203 H03H 7/01

Claims (1)

(57) [Claims] 1. A first capacitor and the first strip line and the second capacitor connected in series between the input electrode and the ground, said first capacitor and between the ground first stripline <br/> A third capacitor and a second L component are connected in series between the output electrode and the ground, and a fourth capacitor and a second L component are connected between the output electrode and the ground .
A second capacitor and a fifth capacitor connected in series, and a sixth capacitor and a fourth L component connected in series between the fourth capacitor and the second strip line and ground . The first and second switches
Both ends of the trip line are open ends
A concave portion is formed on one open end side, and these concave portions are formed.
On the concave side of the first and second strip lines,
Extending from the ground electrode for forming
A projected protrusion is provided, and the protrusion and the recess face each other.
That the second and fifth capacitors are configured
A stacked filter characterized by the following .