JP3307116B2 - Antenna duplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna duplexer used for portable telephones and the like.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional antenna duplexer, in which first to fourth coaxial resonators 2 to 5 are arranged on an upper surface of a substrate 1. Of these, the first and third coaxial resonators 2 and 4 form an output filter, and the second and fourth coaxial resonators 3 and 5 form an input filter. That is, the electrical connection is made as shown in FIG. 3, the capacitor 6 is connected between the coaxial resonators 3-5, and the coil 7 is connected between the coaxial resonators 2-4. In FIGS. 3 and 4, reference numerals 8 and 9 denote coupling capacitors, and reference numerals 10, 11 and 12 denote capacitors for forming a low-pass filter together with the coils 7 and 13. Further, 14 and 15 are notch filter capacitors. In the above-mentioned configuration, in the conventional one, as shown in FIG. 4, the coaxial resonator 2-5 for forming the input / output filter is alternately provided with the terminals of the coaxial resonator 2-5, thereby increasing the isolation of the input / output filter. .

[0003]

The problem with the above arrangement is that the filter characteristics of the input filter are degraded. That is, in the conventional device, the coaxial resonator 2-
Since the terminals 5 are alternately drawn, the coaxial resonator 4 for the output filter is interposed between the coaxial resonators 3-5 for the input filter. As a result, as shown in FIG. The distance between the terminals 3a and 5a of the terminals 3 and 5 becomes long. This means that the length of the conductive pattern 16 for connecting the terminals 3a and 5a becomes longer, which increases the inductance components connected to both sides of the capacitor 6 shown in FIG. That is, the characteristics of the input filter deteriorate. Accordingly, an object of the present invention is to prevent the filter characteristics of the input filter from deteriorating.

[0004]

In order to achieve this object, the present invention comprises first to fourth coaxial resonators arranged side by side on a substrate, wherein the first to fourth coaxial resonators are arranged. An output filter is formed by the first and fourth coaxial resonators on both sides, and an input filter is formed by the inner second and third coaxial resonators, and the output filter is formed.
Terminals of the first and fourth coaxial resonators in the same direction.
And the second and third filters forming the input filter.
Connect the terminal of the shaft resonator in the opposite direction to the terminal of the output filter.
It is made to protrude .

[0005]

According to the above construction, the second filter for the input filter can be used.
Since the third coaxial resonator is arranged on the inner side, the distance between the connection terminals is short, and thus the inductance component generated in the connection pattern is small, and as a result, the filter characteristics as an input filter deteriorate. Can be prevented.

[0006]

1 to 3 show one embodiment of the present invention, and the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals. That is, in this embodiment, as shown in FIGS. 1 to 3, an output filter is formed by the coaxial resonators 2 and 4 on both sides mounted on the upper surface of the substrate 1, and an input filter is formed by the inner coaxial resonators 3 and 5. To form. Therefore, the connection terminals 3a and 5a of the input filter coaxial resonators 3 and 5 project leftward in FIG. 1, and a capacitor 6 as a capacitance component is connected between them. or,
Connection terminals 2a of coaxial resonators 2 and 4 for output filters,
Reference numeral 4a protrudes rightward in FIG. 1, between which a coil 7 as an inductance component is connected. 1 and 2, reference numeral 1a denotes an output terminal of the input filter, 1b denotes an input terminal of the output filter, and 1c denotes an antenna terminal. According to the above configuration, the terminals 3a and 5a and the terminals 2a and 4a of the input filter and the output filter protrude in the opposite direction on the substrate 1, so that sufficient isolation between the input and output filters is obtained as in the conventional example. Can be. Further, since the coaxial resonators 3 and 5 as input filters are arranged side by side on the inside, the distance between the terminals 3a and 5a is short, and thus the inductance component generated by the connection pattern 16 therebetween is small. As a result, deterioration of the filter characteristics as a filter can be prevented.

In the above configuration, the distance between the terminals 2a and 4a of the coaxial resonators 2 and 4 for the output filter becomes longer, and accordingly, the connection pattern 16 becomes longer and the inductance component becomes larger. But
In the first place, the connection is made by using the coil 7 which is an inductance component, and conversely, this leads to a reduction in size.

[0008]

As described above, according to the present invention, of the first to fourth coaxial resonators arranged side by side on the substrate, the first and fourth coaxial resonators on both sides constitute an output filter. An input filter is formed by the inner second and third coaxial resonators and first and fourth coaxial resonators forming the output filter.
Protrude the terminals of the shaft resonator in the same direction, and
Terminals of the second and third coaxial resonators forming
It is projected in the direction opposite to the terminal of the output filter .

According to the above configuration, since the second and third coaxial resonators for the input filter are arranged inside, the distance between the connection terminals is reduced, and therefore the connection pattern is reduced. Is small, and as a result, deterioration of filter characteristics as an input filter can be prevented.

[Brief description of the drawings]

FIG. 1 is a top view of one embodiment of the present invention.

FIG. 2 is a perspective view thereof.

FIG. 3 is a circuit diagram thereof.

FIG. 4 is a perspective view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Coaxial resonator 3 Coaxial resonator 4 Coaxial resonator 5 Coaxial resonator 6 Capacitor 7 Coil

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kimio Aizawa Tanabe-cho, Suzuki-gun, Kyoto 55-42, Osumi-koza, Hamamatsu 12 Matsushita Nitto Electric Co., Ltd. (58) Field surveyed (Int.Cl. ⁷ , DB name) H01P 1/20-1/219 H01P ^7/ 00-7/10

Claims (2)

(57) [Claims] A first coaxial resonator disposed on the substrate and a first to a fourth coaxial resonator disposed on the substrate;
Of the coaxial resonator, the first sides, the fourth form the output filter in coaxial resonators, a second inner, to form the input filter in the third coaxial resonator, said output filter
The terminals of the formed first and fourth coaxial resonators are
A second, projecting in the direction, forming the input filter;
The terminal of the third coaxial resonator is opposite to the terminal of the output filter.
An antenna duplexer protruding in the opposite direction . 2. The first and fourth coaxial resonators are connected via an inductance component mounted on a substrate, and the second and third coaxial resonators are connected via a capacitance component mounted on a substrate. The antenna duplexer according to claim 1.