JPH10276116A - Composite switch circuit parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized composite switch circuit parts with satisfactory characteristics by constituting transmission lines and a low path filter circuit of conductive patterns formed in the stack body of a dielectric layer and arranging electrodes constituting a capacitor for the low pass filer circuit at an upper side of a mounting face compared to the transmission lines in the stack body. SOLUTION: The first transmission line and the second transmission line are arranged between the first ground electrode 31 and the second ground electrode 32. The switch circuit is arranged on the mounting side of the composite switch circuit parts. The low pass filter circuit is constituted on the upper side of the switch circuit. The low pass filter circuit parts are arranged on the upper side of the switch circuit part. Thus, the second ground electrode 32 facing the conductive patterns 42 and 43 constituting the capacity has a drawer part connected to the ground of a substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch circuit, and more particularly to a high-frequency circuit such as a digital cellular phone.
The present invention relates to a diode switch applied to a high-frequency switch circuit for switching a signal transmission path.

[0002]

2. Description of the Related Art For example, a switch circuit of a digital cellular phone or the like is used to switch a transmission path between an antenna and a reception circuit and a transmission path between a transmission circuit and an antenna.

Further, this switch circuit is used for switching a transmission path between a reception circuit and a first antenna and a transmission path between a reception circuit and a second antenna in a telephone or the like employing a reception diversity system. Is also used. Similarly, in the case of a base station for a mobile phone adopting the transmission diversity system, the base station is used to switch the transmission path between the transmission circuit and the first antenna and the transmission path between the transmission circuit and the second antenna. Is done.

Further, this switch circuit switches between an internal circuit such as a mobile phone having a terminal for external connection to a vehicle-mounted booster or the like and a path to the terminal, and a plurality of channels such as a base station for a mobile phone. Also used for switching.

A conventional switch circuit is disclosed in Japanese Unexamined Patent Publication No.
There is one disclosed in 197040. FIG. 9 shows a circuit diagram of this conventional example. This switch circuit is connected to the antenna ANT, the transmission circuit TX, and the reception circuit RX.
An anode of a first diode D101 is connected to the transmission circuit TX via a first capacitor C101.
Is connected to the antenna ANT via the third capacitor C103.

The antenna ANT has a third capacitor C
103, a second transmission line SL2, a fourth capacitor C1
04 is connected to the receiving circuit RX via the series circuit. The anode of the first diode D1 is grounded via a series circuit of the first transmission line SL1 and the second capacitor C102. Further, a control circuit T1 is connected between the first transmission line SL1 and the second capacitor C102 via a resistor R101. An anode of the second diode D102 is connected between the second transmission line SL2 and the fourth capacitor C104, and a cathode of the second diode D102 is grounded.

The transmission line and the capacitor are formed in a laminate, and a diode, a capacitor,
It has a structure to mount a resistor.

[0008]

SUMMARY OF THE INVENTION
When connecting and using filter components, the switch circuit and the filter circuit are separate components and are combined. For this reason, there is a problem that a mounting area is large and an impedance matching circuit must be added.

On the other hand, Japanese Patent Application Laid-Open No. H8-97743 proposes a component in which a switch circuit and a filter circuit are combined. FIG. 10 shows an equivalent circuit diagram of this conventional example.

In the case of this conventional example, a portion surrounded by a broken line is a low-pass filter circuit, but a five-stage low-pass filter circuit is used. An important characteristic of a low-pass filter is attenuation of 2f, 3f (f is a pass frequency).
In order to obtain the attenuation amounts of 2f and 3f, a five-stage low-pass filter circuit configuration is provided. For this reason, there is a limit to miniaturization.

An object of the present invention is to solve the above problems and to provide a small-sized composite switch circuit component having good characteristics.

[0012]

According to the present invention, there is provided a first diode having an anode connected to a transmitting circuit and a cathode connected to an antenna, and a first transmission connected to an anode of the first diode. A switch circuit including a line, a second transmission line connected between the antenna and a receiving circuit, and a second diode having an anode connected to the receiving circuit side and a cathode connected to the ground side; A composite switch circuit component having a low-pass filter circuit connected to the anode side of a first diode, wherein the transmission line and the low-pass filter circuit are configured by a conductive pattern formed in a laminate of dielectric layers; An electrode constituting a capacitor for the low-pass filter circuit is disposed above a transmission surface in the laminate with respect to a mounting surface. A composite switch circuit component according to claim Rukoto.

Further, according to the present invention, the transmission line formed in the laminate is sandwiched between ground electrode layers arranged vertically.
The capacitor for the low-pass filter circuit is formed by an upper earth electrode layer sandwiching the transmission line and an electrode facing the earth electrode layer.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a switch circuit and a low-pass filter circuit are formed as a single component, and furthermore, are formed in a laminated structure, thereby forming a small composite switch circuit component. Moreover, in the present invention, in the laminated structure,
The switch circuit section is disposed below the mounting surface of the composite switch circuit component, and the low-pass filter circuit section is disposed above the mounting surface.

In the present invention, the transmission line for the switch circuit is sandwiched between the ground electrodes from above and below, and the conductive pattern of the capacitor for the low-pass filter circuit is formed further above the ground electrode on the upper side. With this structure, a composite switch circuit component that is small and has good characteristics can be obtained.

Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 is a perspective view of an embodiment according to the present invention. FIG. 2 is an exploded perspective view of the embodiment, and FIG. 3 is an equivalent circuit diagram thereof. This embodiment is composed of a laminate 2 of dielectric layers and a semiconductor element 1 having two built-in diodes. In the equivalent circuit diagram, the inside of the outer broken line is the portion of this embodiment, and the capacitors C11,
C12, C13, C14 and resistors R1, R2 are connected as external components on a circuit board or the like. Further, the external component can be configured in the laminate or on the laminate.

The internal structure of the laminate 2 is as shown in FIG. On the lower dielectric layer 21, a first ground electrode 31 is formed, and a predetermined lead electrode is formed. Then, it is connected to an external electrode.

On the dielectric layer 21, a dielectric layer 22 on which a capacitor electrode 41 forming a capacitor C1 is formed facing the first ground electrode 31 is laminated. The capacitor electrode 41 has a lead electrode formed thereon.
Then, it is connected to an external electrode.

On this, two dielectric layers 23 and 24 constituting a transmission line are laminated. The transmission line L1 in the equivalent circuit diagram is configured by connecting the line electrode 11 of the dielectric layer 23 and the line electrode 12 of the dielectric layer 24. The connection between the two line electrodes is performed via a through-hole electrode 51. Then, a lead electrode facing the side surface of each dielectric layer is formed and connected to an external electrode.

The transmission line L2 in the equivalent circuit diagram is
The line electrode 13 of the dielectric layer 23 is connected to the line electrode 14 of the dielectric layer 24. The connection between the two line electrodes is performed via a through-hole electrode 52. Then, a lead electrode facing the side surface of each dielectric layer is formed and connected to an external electrode.

A second earth electrode 32 is formed on the dielectric layer 25 thereon, and a predetermined lead electrode is formed. Then, it is connected to an external electrode.

On the dielectric layer 26 thereover, capacitor electrodes 42 and 43 forming capacitors C2 and C3 are formed so as to face the second ground electrode 32. The capacitor electrode 42 has a lead electrode formed and is connected to an external electrode.

On the dielectric layer 27 thereon, a capacitor electrode 44 for forming a capacitor C4 is formed facing the capacitor electrode 42. This capacitor electrode 4
4 is formed with a through-hole electrode 53 and connected to the capacitor electrode 43 in the lower layer.

The coil electrode 15 constituting L3 is formed on the dielectric layer 28 thereon. One end of the coil electrode 15 is connected to an external electrode, and the other is a through-hole electrode 54, which is connected to a lower-layer through-hole electrode 53.

On the upper surface of the uppermost dielectric layer 29, a pattern electrode is formed. One pattern electrode 16 is connected to a lower layer through-hole electrode 54 via a through-hole electrode 55. Also, the pattern electrode 17
Is a mark. In addition, a pattern electrode connected to an external electrode is formed.

This laminated body is formed into a sheet by a doctor blade using a dielectric material, and an Ag electrode is screen-printed on the sheet to form a pattern electrode, which is laminated, pressed, and integrally fired. It was done. And
After firing, a terminal electrode on the side surface and a pattern electrode on the upper surface were formed. The terminals of the semiconductor element 1 having two built-in diodes are the pattern electrodes 1 respectively.
6 and.

FIG. 5 shows the insertion loss characteristics of this embodiment.
As shown in FIG. 5, according to this embodiment, 2f, 3
A composite switch circuit component that suppresses harmonics such as f can be obtained.

In this embodiment, a first transmission line and a second transmission line are arranged between a first ground electrode 31 and a second ground electrode 32. The switch circuit is arranged on the mounting surface side of the composite switch circuit component. A low-pass filter circuit is formed above the switch circuit.

Since this low-pass filter circuit portion is disposed above the switch circuit portion, the conductive patterns 42 constituting the capacitance of the capacitors C2 and C3 inserted between the grounds of the low-pass filter circuit portion. , 43 facing the second ground electrode 32
Have a drawer that connects to the ground on the actual board. In the case of this embodiment, the external electrodes correspond thereto. This external electrode functions as a line electrode, and can be regarded as a circuit in which the inductors L are connected in series to the capacitors C2 and C3. FIG. 4 shows an equivalent circuit. Thereby, attenuation poles can be created at 2f, 3f, etc. by parallel resonance of the capacitor C4 and the inductor L3, or series resonance of the capacitor C2 and the inductor L4, and series resonance of the capacitor C3 and the inductor L5.
It is effective in reducing harmonics.

Each of the transmission lines L1 and L2 is formed in a spiral shape, and is formed in two layers. By adopting this spiral shape and further providing an overlapping portion, the line length could be shortened.

FIG. 6 is an exploded perspective view of a laminate according to another embodiment of the present invention, and FIG. 7 is an equivalent circuit diagram thereof. This figure 6
In FIG. 2, the same parts as those in FIG. This embodiment has substantially the same structure as the above-described embodiment, and a capacitor C5 connected between one end of the first transmission line L1 and the ground is connected. This is because the first dielectric layer 22 formed on the lower dielectric layer 21 and the second dielectric layer 22
And a capacitor forming electrode pattern 45 formed so as to face the ground electrode 31 of FIG. Other structures are the same.

According to this embodiment, the same characteristics as those of the above embodiment could be obtained. The capacitor C5 may be connected as shown in FIG. Each of the capacitor C5 of FIG. 7 and the capacitor C6 of FIG. 8 has an effect of shortening the line length of the first transmission line L1.

According to the present invention, a switch circuit having a built-in low-pass filter circuit can be integrally formed in a small size. Moreover, it has excellent characteristics of low loss and high harmonic suppression effect. In the present invention, the description has been given as the switch circuit of the transmitting circuit, the antenna, and the receiving circuit. is there.

[0034]

According to the present invention, it is possible to construct a small-sized composite switch circuit having excellent characteristics, which is a switch circuit incorporating a low-pass filter circuit. In addition, a transmission line and a low-pass filter circuit are formed in a laminate of dielectric layers, so that a small composite switch circuit component can be configured.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of the laminate of the embodiment shown in FIG.

FIG. 3 is an equivalent circuit diagram of the embodiment according to the present invention shown in FIG. 1;

FIG. 4 is a part of an equivalent circuit of the embodiment according to the present invention.

FIG. 5 is a graph showing insertion loss characteristics of an example according to the present invention.

FIG. 6 is an exploded perspective view of a laminate according to another embodiment of the present invention.

FIG. 7 is an equivalent circuit diagram of another embodiment according to the present invention.

FIG. 8 is an equivalent circuit diagram of another embodiment according to the present invention.

FIG. 9 is an equivalent circuit diagram of a conventional switch circuit.

FIG. 10 is an equivalent circuit diagram of another conventional switch circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Stacked body 21, 22, 23, 24, 25, 26, 27, 28, 2
9 Dielectric layer 31 First ground electrode 11, 12, 13, 14, 15 Line electrode 51, 52, 53, 54, 55 Through hole electrode 32 Second ground electrode 41, 42, 43, 44, 45 For capacitor electrode

Claims (2)

[Claims] A first diode having an anode connected to the transmission circuit side and a cathode connected to the antenna side, a first transmission line connected to the anode of the first diode, the antenna and the reception circuit; A switch circuit including a second diode having an anode connected to the receiving circuit side and a cathode connected to the ground side; and a second transmission line connected to the receiving circuit side, and a second diode connected to the anode side of the first diode. A composite switch circuit component having a low-pass filter circuit connected thereto, wherein the transmission line and the low-pass filter circuit are formed by conductive patterns formed in a laminate of dielectric layers, and a capacitor for the low-pass filter circuit is provided. A composite electrode, wherein the constituent electrodes are arranged above the transmission line in the laminate with respect to the mounting surface. Switch circuit components. 2. The transmission line formed in the laminate,
2. The capacitor for the low-pass filter circuit, which is sandwiched between earth electrode layers arranged vertically, wherein the capacitor for the low-pass filter circuit is formed by an upper earth electrode layer sandwiching the transmission line and an electrode opposed thereto. A composite switch circuit component as described.