JPH02220501A - Filter branching device - Google Patents

Abstract

PURPOSE:To decrease a change in a characteristic by providing plural hand pass filters and leading out respective input/output terminals onto a board having a prescribed dielectric constant via a connection pin. CONSTITUTION:A low pass filter 14 and a band pass filter 20 are arranged between an antenna terminal 11 and a reception signal output terminal 12 in a case 10 and a band pass filter 15 is arranged so as to be located symmetrically to the band pass filter 20. The input and output terminals of the filters 15, 20 are led out via a connection pin 40 and the connection pin 40 is formed to interconnect printed circuit boards 30-33 each having a prescribed dielectric constant. Each printed circuit board (30-33) is formed by forming a prescribed pattern of conductive layer on a board and circuit components are connected to adjacent other circuit components via an input and output capacitor. Then the input and output terminal of the filters 15, 20 is able to be arranged on the side face, and a stable characteristic is obtained through the provision of the printed circuit boards 30-33.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a filter duplexer, more specifically, a first bandpass filter consisting of a dielectric resonator, which transmits a transmission signal from a transmission signal input terminal, and The present invention relates to a filter duplexer that guides a received signal from the antenna terminal to an antenna terminal via a low-pass filter and guides a received signal from the antenna terminal to a received signal output terminal via the low-pass filter and a second bandpass filter.

[Conventional technology]

This type of filter duplexer is used, for example, as a shared antenna duplexer built into a car telephone, and one with a structure shown in FIG. 6 is known. The filter duplexer shown in Fig. 6 has an antenna terminal 11 on one side of a case 10 made of die-cast aluminum, a received signal output terminal 12 on one end of the opposite side, and a transmission signal input on the other end. Terminal 1
3 are installed respectively. The antenna terminal 11, the received signal output terminal 12, and the transmitted signal input terminal 13 are respectively connected to a transmitting/receiving antenna, a receiving circuit, and a transmitting circuit (not shown).

Inside the case 10, a first bandpass filter 15 and a low-pass filter 14 are arranged between the transmission signal input terminal 13 and the antenna terminal 11, and a low-pass filter 14 is arranged between the antenna terminal 11 and the reception signal output terminal 12. A low-pass filter 14 and a second bandpass filter 20 are arranged to share the filter 14. The double-band filters 15, 20 are constituted by dielectric resonators. First band filter 15 and low pass filter 14 . The second bandpass filter 20 is connected via lead wires 16 and 21, respectively.

Incidentally, a band rejection filter is connected to the reception signal output terminal 12 and the transmission signal input terminal 13 in a shunt manner, respectively, but illustration thereof is omitted here.

As mentioned above, the double-band filter 15.20 is constituted by a dielectric resonator. In that case, the dielectric filter is arranged with its so-called open side facing upward, without a conductive layer, and the input/output terminals at both ends are connected to the other terminals via input/output capacitors 17.18 to 22.23 consisting of parallel plate capacitors. connected to circuit components. The circuit connections of these output capacitors 17.18 to 22.23 are made by soldering.

[Problem to be solved by the invention]

In conventional filter duplexers, due to wiring etc.
Since each bandpass filter 15, 20 made of a dielectric filter is arranged with its open side facing upward, there is a disadvantage that the height of the filter duplexer becomes high.

Furthermore, since the input/output coupling of the dielectric filters constituting the bandpass filters 15 and 20 is done by input/output capacitors consisting of parallel plate capacitors, the length of the wiring becomes long, and the wiring inductance may vary depending on the wiring condition such as movement of the wiring. There is also the problem that the characteristics change, such as the generation of so-called double waves.

The present invention has been made in consideration of the above circumstances, and it is possible to reduce the height and to reduce the change in characteristics, especially in the case of two
It is an object of the present invention to provide a filter duplexer that can avoid generation of harmonics.

(Means for Solving the Problems) In order to achieve the above object, the filter duplexer of the present invention has the following features:
The first bandpass filter and the second bandpass filter are arranged so that the input/output terminals are on the sides, and the input/output terminals of each bandpass filter are led out via connection pins, and the connection pins are connected to predetermined locations. It is characterized in that it is connected to other adjacent circuit components via an input/output capacitor formed by a printed circuit board formed by forming a conductive layer with a predetermined pattern on a substrate having a dielectric constant.

[For production]

By arranging the first bandpass filter and the second bandpass filter so that the input and output terminals are on the sides, the height of the filter duplexer can be reduced, and the input and output capacitors of each bandpass filter can also be used as input and output capacitors. By disposing a printed circuit board in which a conductive layer of a predetermined pattern is formed on a substrate having a predetermined dielectric constant, stable input/output capacitance can be constructed almost unaffected by wiring.

〔Example〕

FIG. 1 and FIG. 2 are a perspective view and a block diagram, respectively, showing one embodiment of the present invention. Here, the same reference numerals as in FIG. 6 indicate parts that are the same or correspond to each other.

The antenna terminal 11, the received signal output terminal 12, and the transmitted signal input terminal 13 in the filter duplexer shown in FIG. 1 are arranged on different sides of the case 10, respectively. Inside the case 10, there is an antenna terminal 11 and a received signal output terminal 1.
a low-pass filter 14 and a second
A bandpass filter 20 is arranged, and the transmission signal input terminal 13
The first bandpass filter 15 is arranged close to and symmetrically with the second bandpass filter 20 .

Further, a band-elimination filter 19 is placed close to the transmission signal input terminal 13, and a band-elimination filter 24 is placed close to the reception signal output terminal 12. Each of these filters 14, 15, 19, 20, and 24 is arranged so that its input and output ends are located on the sides, that is, in a horizontal arrangement. Printed circuit boards 30 and 31, which will be described later, are arranged at the input and output ends of the bandpass filter 15, and similarly, printed circuit boards 32 and 33 are arranged at the input and output ends of the bandpass filter 20.

Both output ends of the bandpass filter 15.20 and input ends of the band-stop filter 19.24 are each configured as a pin insertion hole, and electrical connection can be made by inserting a connecting pin 40 (see Fig. 3). be exposed.

As shown in FIG. 3, the connecting pin 40 consists of a hole insertion part 41 and a connecting lug part 42. The hole insertion portion 41 is inserted into the pin insertion hole.

The printed circuit boards 30 and 33 constitute a three-terminal type input/output capacitor, and as shown in FIG. Three conductive layers 51, 52.5 in a predetermined pattern forming three terminals in a facing manner.
3 was formed. Similarly, printed circuit board 31.
As shown in FIG. 5, 32 constitutes a two-terminal input/output capacitor, and two conductive layers 54 and 55 forming the two-terminal input/output capacitor are formed on one surface of a substrate 50. . In this way, conductive layers 51 to 51 are formed on one surface of the substrate 50.
By forming 51, a capacitor with the conductive layer as an electrode is constructed between the conductive layers facing each other, and this acts as an input/output capacitor or a coupling capacitor for each filter as shown in FIG. . The capacitance of each capacitor can be adjusted quite arbitrarily by adjusting the dielectric constant of the substrate 50, the opposing lengths of the opposing conductive layers, and the spacing between the opposing conductive layers.

The components shown in FIG. 1 are electrically connected as shown in FIG. 2. That is, the transmission signal input terminal 13, the bandpass filter 15, and the bandstop filter 19 are each capacitor-coupled to each other by a three-terminal printed circuit board 30, and similarly, two terminals are connected between the bandpass filter 15 and the low-pass filter 14. A low-pass filter 14 and a bandpass filter 20 are capacitor-coupled by a type printed circuit board 31.
The bandpass filter 20 , the received signal output terminal 12 , and the band rejection filter 24 are capacitor-coupled to each other by a three-terminal printed circuit board 33 .

The filter duplexer configured as described above can be made low in height by arranging each filter so that the input and output ends are on the sides, and furthermore, the height of each filter can be reduced. By arranging a printed circuit board with a conductive layer of a predetermined pattern on a substrate with a predetermined dielectric constant as an input/output capacitor or a coupling capacitor, stable input/output capacitance can be constructed with almost no influence from wiring. can do.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a high-performance filter duplexer that is low in height, is not easily affected by wiring, and can particularly avoid generation of double waves.

[Brief explanation of the drawing]

1 is a perspective view showing an embodiment of the present invention; FIG. 2 is a block diagram showing the electrical configuration of the filter duplexer shown in FIG. 1;
Figure 3 is a perspective view of the connection pins in the filter duplexer shown in Figure 1, Figures 4 and 5 are perspective views of the printed circuit board in the filter duplexer shown in Figure 1, and Figure 6 is a conventional filter. It is a perspective view of a duplexer. 10...Case, 11...Antenna terminal, 12...
・Reception signal output terminal, 13...Transmission signal input terminal, 1
4...Low pass filter, 15.20...Band filter, 19.24...Band elimination filter, 30.33...
・3 terminal type printed circuit board, 31.32...2 terminal type printed circuit board, 40...connection pin. Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A transmission signal from a transmission signal input terminal is guided to an antenna terminal via a first bandpass filter consisting of a dielectric resonator and a low-pass filter, and a reception input signal from this antenna terminal is guided to the antenna terminal. In a filter duplexer configured to guide a received signal to an output terminal via a low-pass filter and a second bandpass filter consisting of a dielectric resonator, the first bandpass filter and the second bandpass filter are input and output, respectively. Arrange the ends so that they are on the sides, and lead out the input and output ends of each bandpass filter via the connection pins.
The connecting pin is connected to other adjacent circuit components via an input/output capacitor formed by a printed circuit board formed by forming a conductive layer in a predetermined pattern on a substrate having a predetermined dielectric constant. Filter splitter.