JP2001332902A - High-frequency component and mobile communications equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency component, which can be miniaturized and lighten in weight by having a filtering function in a high-frequency switch, and a mobile communications equipment using the same. SOLUTION: A high-frequency component 10 is provided with first-third ports P1-P3, first and second diodes D1 and D2, inductors L1 and L2, a λ/4 transmission line SL, capacitors C1-C3 and resistor R. Between the first port P1 and the second port P2, the first diode D1 is interposed, and a serial circuit composed of the inductor L1 and the capacitor C1 is parallel interposed to the first diode D1. Between the first port P1 and the third port P3, a parallel circuit consisting of the λ/4 transmission line SL and the capacitor C2 is connected. Besides, the λ/4 transmission line SL on the side of the third port P3 is grounded via the second diode D2 and the capacitor C3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency component and a mobile communication device using the same, and more particularly to a high-frequency component used for switching a signal transmission path and a mobile communication device using the same.

[0002]

2. Description of the Related Art A high-frequency switch used in a mobile communication device typified by a cellular phone or the like plays a role of switching a transmission path between an antenna and a reception circuit and a transmission path between an antenna and a transmission circuit.

FIG. 9 is a block diagram showing an RF unit of a general portable telephone. The RF unit 50 of the mobile phone includes an antenna ANT, a high-frequency switch SW, a transmitting unit Tx, and a receiving unit Rx. The receiving unit Rx includes a low-pass filter LPF, a surface acoustic wave filter SAW, and a low-noise amplifier L
The transmission unit Tx includes a low-pass filter LPF, a directional coupler CPL, a high-output amplifier PA, and a mixer MIX. Also, the transmitting unit T
A synthesizer SYN that generates a local oscillation signal is connected to one input of the mixer MIX of x and the mixer MIX of the reception unit Rx.

It is expected that mobile communication devices typified by portable telephones equipped with the RF unit 50 will continue to be further reduced in size and weight while enhancing their functions. Further downsizing of the RF unit 50,
Weight reduction is an essential element.

[0005]

However, according to the above-mentioned conventional RF section, since the discrete components are mounted on the printed circuit board, it is difficult to further reduce the size and weight, and as a result, this RF section is difficult. There is a problem that it is difficult to reduce the size and weight of the mobile communication device on which the unit is mounted.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a high-frequency switch and a high-frequency component which can be reduced in size and weight by providing a high-frequency switch with a filter function. It is an object of the present invention to provide a mobile communication device.

[0007]

In order to solve the above-mentioned problems, a high-frequency component according to the present invention includes first to third ports, and a high-frequency component connected between the first port and the second port. One diode, an inductor connected between the second port and ground, a λ / 4 transmission line (λ: wavelength of a high-frequency signal) connected between the first port and the third port, A capacitor connected in parallel to the / 4 transmission line and a second diode connected between the third port and ground.

Further, the high-frequency component of the present invention includes a laminated body formed by laminating a plurality of dielectric layers, wherein at least the λ / 4 transmission line is incorporated in the laminated body, and at least the first
And a second diode.

[0009] A mobile communication device according to the present invention is characterized by using the above-described high-frequency component.

According to the high frequency component of the present invention, since there is a λ / 4 transmission line connected between the first port and the third port, and a capacitor connected in parallel to the λ / 4 transmission line, A parallel resonance circuit can be constituted by the λ / 4 transmission line and the capacitor.

According to the mobile communication device of the present invention, since a high-frequency component that can be reduced in size and weight is used for the RF unit, the size and weight of the mobile communication device can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a first embodiment according to the high frequency component of the present invention. The high-frequency component 10 includes first to first
Third ports P1 to P3, first and second diodes D1,
D2, inductors L1 and L2, λ / 4 transmission line SL, capacitors C1 to C3, and resistor R.

A first diode D1 is connected between the first port P1 and the second port P2.
Is connected in parallel with a series circuit including an inductor L1 and a capacitor C1. Also, the second diode D1
The port P2 side, that is, the anode is grounded via the inductor L2, and the ground side of the inductor L2 is connected to the control terminal Vc.

Further, a first port P1 and a third port P3
Is connected to a λ / 4 transmission line SL, and a capacitor C2 is connected to the λ / 4 transmission line SL in parallel. Also,
The third port P3 side of the λ / 4 transmission line SL is grounded via a second diode D2 and a capacitor C3, and a connection point between the second diode D2 and the capacitor C3 is grounded via a resistor R.

With the above configuration, a parallel resonance circuit including the λ / 4 transmission line SL and the capacitor C2 is formed between the first port P1 and the third port P3 of the high-frequency component 10, and the parallel resonance circuit is formed. The circuit acts as a low pass filter. As a result, the high-frequency component 10 has a function of a high-frequency switch and a function of a low-pass filter.

That is, in the RF section of the portable telephone shown in FIG. 9, the high-frequency switch SW and the low-pass filter LPF of the receiving section Rx are integrated.

FIG. 2 is a partially exploded perspective view showing a specific configuration of the high frequency component shown in FIG. High frequency components 10
Includes a laminated body 11, and although not shown, the laminated body 11 includes therein an inductor L1, a λ / 4 transmission line SL, and a capacitor C2 (see FIG. 1).

On the surface of the multilayer body 11, diodes D1 and D2, inductor L2, capacitors C1 and C3, and a resistor R are respectively mounted. Further, external terminals T1 to T8 are provided from the side surface to the lower surface of the multilayer body 11.

The diodes D1, D2, inductor L2, capacitors C1, C3 mounted on the laminate 11
And the protruding portion 12 on the opposite short side while covering the resistance R.
The metal cap 12 is put on the stacked body 11 so that the bases 1 and 122 are in contact with the external terminals T4 and T8.

At this time, the external terminal T1 is connected to the first port P1,
The external terminal T3 is the third port P3, the external terminal T5 is the second port P2, the external terminal T6 is the control terminal Vc, the external terminal T
2, T4, T7, T8 are ground terminals.

FIGS. 3 (a) to 3 (f), 4 (a) and 4 (b) are top views of dielectric layers constituting a laminate of the high-frequency component of FIG. FIG. 4C is a bottom view of FIG. The laminated body 11 includes first to first ceramics mainly composed of barium oxide, aluminum oxide, and silica.
Eighth dielectric layers 11a to 11h are sequentially laminated from the top,
It is formed by firing at a firing temperature of 000 ° C. or less.

Then, on the upper surface of the first dielectric layer 11a, diodes D1 and D mounted on the surface of the multilayer body 11 are provided.
2, inductor L2, capacitors C1 and C3 and resistor R
Is formed. Strip line electrodes ST1 to ST3 are formed on the upper surfaces of the second, third and seventh dielectric layers 11b, 11c and 11g, respectively.

Further, the fourth and fifth dielectric layers 11d, 11d,
On the upper surface of 11e, capacitor electrodes Cp1 and Cp2 are respectively formed. In addition, the sixth and eighth dielectric layers 11
Ground electrodes Gp1 and Gp2 are formed on the upper surfaces of f and 11h, respectively.

Further, the lower surface of the eighth dielectric layer (FIG. 4)
At (11hu) in (c), external terminals T1 to T8 are formed. The first to sixth dielectric layers 11a to 11f have stripline electrodes ST1 to STf at predetermined positions.
3, capacitor electrodes Cp1, Cp2, ground electrode Gp
1, a via hole electrode Vh for connecting the Gp2 and the land La is provided.

At this time, the inductor L1 (see FIG. 1) is formed by the strip line electrodes ST1 and ST2, and the λ / 4 transmission line SL (see FIG. 1) is formed by the strip line electrode ST3. Further, a capacitor C2 (see FIG. 1) is formed by the capacitor electrodes Cp1 and Cp2, respectively.

FIG. 5 is a graph showing attenuation characteristics between the first port and the third port of the high-frequency component provided with the circuit of FIG.
In FIG. 5, the solid line indicates the high-frequency component 10 of the first embodiment.
(FIG. 1), the broken line shows the case of the conventional high-frequency switch.

From this figure, it can be seen that the high-frequency component 1 of the first embodiment
0 (solid line), the λ / 4 transmission line SL and the capacitor C2
It can be understood that the attenuation pole due to the parallel resonance circuit composed of the following occurs near 2.6 GHz, and the attenuation in the high frequency region is large.

FIG. 6 is a circuit diagram of a high-frequency component according to a second embodiment of the present invention. The high frequency component 20 is different from the high frequency component 10 of the first embodiment in that a surface acoustic wave filter SAW is provided between the λ / 4 transmission line SL and the third port P3.

That is, in the RF section of the portable telephone shown in FIG. 9, the high-frequency switch SW is integrated with the low-pass filter LPF and the surface acoustic wave filter SAW of the receiving section Rx.

FIG. 7 is a partially exploded perspective view showing a specific configuration of the high frequency component shown in FIG. High frequency component 20
Includes a laminated body 21. Although not shown, the laminated body 21 includes an inductor L1, a λ / 4 transmission line SL, and a capacitor C2 (see FIG. 6).

On the surface of the laminate 21, diodes D1 and D2, inductor L2, capacitors C1 and C3,
The resistance R and the surface acoustic wave filter SAW are respectively mounted. Further, external terminals T1 to T8 are provided from the side surface to the lower surface of the laminate 21.

The diodes D1 and D2, the inductor L2, and the capacitors C1 and C2 mounted on the laminate 21
3, a metal cap 12 is placed on the laminate 21 so as to cover the resistor R and the surface acoustic wave filter SAW, and to make the opposite short side projections 121 and 122 abut against the external terminals T4 and T8.

At this time, the external terminal T1 is connected to the first port P1,
The external terminal T3 is the third port P3, the external terminal T5 is the second port P2, the external terminal T6 is the control terminal Vc, the external terminal T
2, T4, T7, T8 are ground terminals. Further, the laminate 21 has the same internal configuration as the laminate 11 of the high-frequency component 10 (see FIG. 2) shown in FIGS.

According to the high frequency component of the above-described embodiment, the λ / 4 transmission line is connected between the first port and the third port, and the capacitor is connected in parallel to the λ / 4 transmission line. Therefore, a parallel resonance circuit can be constituted by the λ / 4 transmission line and the capacitor. Therefore, since the parallel resonance circuit functions as a low-pass filter, it is possible to provide a high-frequency component that has a function of a high-frequency switch and a function of a low-pass filter and that can be reduced in size and weight.

Further, since the high-frequency component is constituted by a laminate formed by laminating a plurality of dielectric layers, each connection can be provided inside the laminate. Therefore, the size of the high-frequency component can be reduced, and the size of the mobile communication device on which the high-frequency component is mounted can be reduced.

Further, since loss due to wiring for connection can be improved, the loss of the high-frequency component as a whole can be improved, and the performance of a mobile communication device equipped with this high-frequency component can be improved. Can also be realized at the same time.

Further, since the λ / 4 transmission line constituting the high-frequency component is built in the laminate, the λ / 4 transmission line is reduced due to the wavelength shortening effect.
The length of the / 4 transmission line can be reduced. Therefore, the insertion loss of these λ / 4 transmission lines can be improved, and downsizing and low loss of high-frequency components can be realized. As a result, miniaturization and high performance of the mobile communication device equipped with the high-frequency component can be realized at the same time.

FIG. 8 is a diagram showing attenuation characteristics between the first port and the third port of the high-frequency component having the circuit of FIG.
In FIG. 8, the solid line indicates the high-frequency component 20 of the second embodiment.
(FIG. 6), the broken line shows the case where the conventional high-frequency switch and the surface acoustic wave filter are combined.

From this figure, it can be seen that the high-frequency component 2 of the second embodiment
Even at 0 (solid line), it is understood that the vicinity of 3.6 GHz is attenuated by the parallel resonance circuit including the λ / 4 transmission line SL and the capacitor C2, and the attenuation in the high frequency region is increased.

In the above-described high-frequency components of the first and second embodiments, the case where the high-frequency components are formed of a laminate has been described. However, the same applies when the discrete components are mounted on a circuit board. The effect of is obtained.

[0041]

According to the high frequency component of the first aspect, a λ / 4 transmission line connected between the first port and the third port,
And a capacitor connected in parallel to the λ / 4 transmission line, a parallel resonance circuit can be formed by the λ / 4 transmission line and the capacitor.

Therefore, since the parallel resonance circuit functions as a low-pass filter, it is possible to provide a high-frequency component having the function of a high-frequency switch and the function of a low-pass filter, which can be reduced in size and weight. In addition, the attenuation in the high frequency region increases, and a high frequency component having excellent attenuation characteristics in the high frequency region can be provided.

According to the high frequency component of the second aspect, since the high frequency component is constituted by a laminate formed by laminating a plurality of dielectric layers, each connection can be provided inside the laminate. Therefore, the size of the high-frequency component can be reduced.

Further, since the loss due to the wiring for connection can be reduced, the loss of the whole high-frequency component can be reduced.

Further, since the λ / 4 transmission line constituting the high-frequency component is built in the laminate, the wavelength shortening effect is provided.
The length of the λ / 4 transmission line can be reduced. Therefore, the insertion loss of these λ / 4 transmission lines can be improved, and downsizing and low loss of high-frequency components can be realized.

According to the third aspect of the present invention, since high-frequency components capable of miniaturization and high performance are mounted, the miniaturization and high performance of the mobile communication device can be realized.

Further, since high-frequency components having excellent high-frequency attenuation characteristics are mounted, the performance of the mobile communication device can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a first embodiment according to a high-frequency component of the present invention.

FIG. 2 is a partially exploded perspective view showing a specific configuration of the high-frequency component shown in FIG.

3A to 3F are top views of (a) a first dielectric layer to (f) a sixth dielectric layer which constitute a laminate of the high-frequency component in FIG. 2;

FIG. 4 is a top view of (a) a seventh dielectric layer to (d) a tenth dielectric layer, and (e) a lower surface of the tenth dielectric layer, which constitutes a laminate of the high-frequency component of FIG. FIG.

FIG. 5 is a diagram illustrating attenuation characteristics of the high-frequency component of FIG. 1;

FIG. 6 is a circuit diagram of a second embodiment according to the high-frequency component of the present invention.

FIG. 7 is a partially exploded perspective view showing a specific configuration of the high-frequency component shown in FIG.

FIG. 8 is a diagram illustrating attenuation characteristics of the high-frequency component of FIG. 6;

FIG. 9 shows RF of a general portable telephone (mobile communication device).
It is a block diagram showing a part.

[Explanation of symbols]

 10, 20 High-frequency component 11, 21 Stack C1-C3 Capacitor D1, D2 Diode L1, L2 Inductor P1-P3 First-third port SL λ / 4 transmission line

Claims (3)

[Claims] A first diode connected between the first port and the second port; an inductor connected between the second port and a ground; A λ / 4 transmission line (λ: wavelength of a high-frequency signal) connected between the first port and the third port,
A high frequency component comprising: a capacitor connected in parallel to a / 4 transmission line; and a second diode connected between the third port and ground. 2. A laminated body comprising a plurality of dielectric layers laminated, wherein at least the λ / 4 transmission line is built in the laminated body, and at least the first and second diodes are mounted. The high-frequency component according to claim 1, wherein 3. A mobile communication device using the high-frequency component according to claim 1 or 2.