JPH0456401A - Dielectric filter and resonator - Google Patents

Abstract

PURPOSE:To realize a small sized and inexpensive dielectric filter and resonator by inserting a chip capacitor in a slit of a base, connecting the capacitor to an electrode pattern and connecting a center conductor of a dielectric coaxial resonator to one electrode of the chip capacitor or the electrode pattern. CONSTITUTION:Plural slits S1-S6 and electrode patterns 8-10 interconnecting adjacent slits of them are formed to a 'Teflon(R)' glass substrate, chip capacitors C1-C11 are inserted to each slit S respectively and each chip capacitor is connected to the respective electrode pattern to form a series circuit of the capacitors. Adjacent dielectric coaxial resonators are capacitive-coupled by connecting each center conductors of the plural dielectric coaxial resonators R1-R8 to one electrode of the chip capacitors or the electrode patterns respectively and a polarized, e.g. band pass filter is formed and miniaturization and low- cost are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (AI Industrial Field of Application) The present invention relates to a dielectric filter in which a plurality of dielectric coaxial resonators are coupled via a substrate, and a duplexer using the same.

(b) Conventional technology A multistage dielectric filter using dielectric coaxial resonators consists of a plurality of dielectric coaxial resonators, a coupling substrate that couples the center conductors of these resonators, and a case that houses them. It is composed of etc.

In addition, an antenna duplexer using such a dielectric filter has a filter on the TX side (transmitting side) and a filter on the RX side (receiving side).
filters are housed in one case.

FIG. 5 shows the configuration of a conventional antenna duplexer as an exploded perspective view. In the figure, R1-R5 are dielectric coaxial resonators on the RX side, and R6-R8 are dielectric coaxial resonators on the TX side. Further, 4 is a coupling board that connects each center conductor of five dielectric coaxial resonators R1 to R5 to couple each resonator, and 5 is a coupling board that connects each center conductor of three dielectric coaxial resonators R6 to R8. This is a second coupling substrate that connects each resonator by direct reading. A plurality of electrode patterns are formed on the first bonding substrate 4, and a predetermined coupling capacitance is formed between each electrode. Electrode patterns for connecting a plurality of chip capacitors and a plurality of coils are formed on the second bonding substrate 5, and capacitors C8 to CLi$ and coils L i , l, 4 are connected to these, and resonance vessel R6
Each center conductor of ~R8 is connected to a capacitor 09~CLI. In addition, the first bonding substrate 4 is
and the second bonded substrate 5 are connected. Furthermore, an RX terminal, an A NT terminal, and a TX terminal are inserted into the second bonding board 5. These internal components are housed within the case 2 and cover 3.

(C) Problem to be Solved by the Invention However, in the example shown in FIG. 5, in the case where a dielectric ceramic substrate is used as the coupling substrate 4 like the RX side filter, as the number of resonator stages increases, the size increases. A dielectric ceramic substrate is required, which not only increases material and manufacturing costs, but also tends to cause defects such as cracks and chips.

In addition, in the example shown in Fig. 5, it is also used as the coupling board for the TX# filter, but a board for fixing signal input/output terminals such as the RX terminal and the ANT terminal is required separately from the coupling board 4. , the case to store them had to be large as well.

An object of the present invention is to provide a small and inexpensive dielectric filter and duplexer that eliminates the need for a large dielectric ceramic substrate, reduces costs, and eliminates wasted space within the case.

(d) Means for Solving the Problems A dielectric filter according to claim 1 of the present invention includes forming a plurality of slits and an electrode pattern connecting these adjacent slits on a substrate, and installing a chip capacitor in the slit. and each chip capacitor is connected to the electrode pattern, and the center conductor of a plurality of dielectric coaxial resonators is connected to one electrode of the chip capacitor or the electrode pattern, respectively.

Further, the duplexer according to claim 2 is provided with a plurality of sets of dielectric filters according to claim 1 in the case, and the duplexer according to claim 3 is provided with a plurality of chip capacitor mounting electrodes on the surface of the substrate, Attach one electrode of a chip capacitor to each of these electrodes, connect a coil between the adjacent chip capacitor mounting electrodes, and connect the center conductors of the plurality of dielectric coaxial resonators to the other electrode of the chip capacitor. The present invention is characterized in that a plurality of connected dielectric filters are provided inside the case.

Furthermore, in the duplexer according to claim 4, a plurality of slits and an electrode pattern connecting these adjacent slits are formed on the substrate, a chip capacitor is inserted into the slit, and each chip capacitor is connected to the electrode pattern. In addition, a dielectric filter in which the center conductors of a plurality of dielectric coaxial resonators are respectively connected to one electrode or the electrode pattern of the chip capacitor, and a plurality of chip capacitor mounting electrodes are provided on the surface of the substrate, and each of these Attach one electrode of the chip capacitor to the electrode, connect the thin coil between the adjacent electrodes for mounting the chip capacitor, and connect the center conductors of the plural dielectric coaxial resonators to the other electrode of the chip capacitor. At least one dielectric filter connected to each other is provided.

(e) Effect: In the dielectric filter according to claim 1 of the present invention, a plurality of slits and an electrode pattern connecting these adjacent slits are formed on the sowing substrate, and a chip capacitor is inserted into each slit. Each chip capacitor is connected to an electrode pattern, thereby forming a so-called series circuit of a plurality of capacitors. The center conductors of the plurality of dielectric coaxial resonators are each connected to one electrode of the chip capacitor or the electrode pattern. As a result, adjacent dielectric coaxial resonators are capacitively coupled and polarized to form, for example, a bandpass filter.

Since the chip capacitor capacitively couples adjacent dielectric coaxial resonators in this way, there is no need to use a dielectric ceramic substrate with a high dielectric constant as a coupling substrate, resulting in excellent material and manufacturing costs. It becomes possible to use a normal substrate with a low dielectric constant. In addition, since through-holes are formed in the coupling board and signal input/output terminals can be easily attached, there is no need for a board for fixing the signal input/output terminals as in the past, making it possible to create a compact and inexpensive dielectric filter. can be configured.

Moreover, in the duplexer according to claim 2, since a plurality of sets of the dielectric filters according to claim 1 are provided in the case, a small and inexpensive duplexer is constructed.

In the duplexer according to claim 3, a plurality of chip capacitor mounting electrodes are provided on the surface of the substrate, one electrode of the chip capacitor is mounted to each of these electrodes, a coil is connected between each electrode, and a plurality of chip capacitor mounting electrodes are provided on the surface of the substrate. The center conductor of the dielectric coaxial resonator is the other chip capacitor! Each of the nine poles is connected to the pole. Therefore, the plurality of dielectric coaxial resonators together with the chip capacitor and coil act as, for example, a band rejection filter. By providing a plurality of sets of dielectric filters configured in this manner within the case, a small and inexpensive duplexer is constructed.

In the duplexer according to claim 4, a plurality of slits and an electrode pattern connecting these adjacent slits are formed on the substrate, a chip capacitor is inserted into each slit, each chip capacitor is connected to the electrode pattern, and a plurality of slits are formed on the substrate. The center conductor of the dielectric coaxial resonator is connected to one electrode of the chip capacitor or an electrode pattern on the substrate. As a result, each stage of the plurality of dielectric coaxial resonators is capacitively coupled, and the plurality of dielectric coaxial resonators act as, for example, a band-pass filter with polar ratios. Further, a plurality of other chip capacitor mounting electrodes are provided on the surface of the same or different board from the above board, one electrode of the chip capacitor is mounted to each of these electrodes, and a coil is connected between each electrode,
Furthermore, center conductors of a plurality of other dielectric coaxial resonators are respectively connected to the other electrode of the chip capacitor. Therefore, the plurality of dielectric coaxial resonators together with the chip capacitor and coil function as, for example, a band stop filter. In this way, a small and inexpensive 11÷→multiplexer using a normal board is constructed.

(f) Embodiment The structure of an antenna duplexer which is an embodiment of the present invention is shown in FIGS. 1 to 3. FIG. 1 is an exploded perspective view thereof. In the same time, R1 to R8 are dielectric coaxial resonators, and lead terminals 11 to 18 are inserted into each center conductor forming through hole. In addition, in the figure, 1 is a low dielectric constant bonding substrate such as so-called Teflon glass, and 6 is denoted by 31 to S6.
An electrode pattern (transmission line) 8 and a chip capacitor connection electrode 9 are formed to connect each slit and these adjacent slits. C1-c6 and C7 are chip capacitors, respectively, and 01-C6 are inserted into the slits 81-s6, respectively, and the picture electrodes of each chip capacitor are respectively connected to the electrode patterns 8 at both ends of the slits. Further, one electrode of the chip capacitor c7 is connected to the electrode 9. The bonding substrate 1 is further provided with four chip capacitor mounting electrodes 10 and six coil mounting holes 20, and one electrode of the chip capacitors 08 to C11 is connected to the electrodes 10, respectively. Coils L3 and L4 are inserted into respective holes indicated by 2o. Further, one terminal of each of the coils L1 and L2 is inserted into the hole 20.20, and the other terminal is connected to the electrode on the upper surface side of the chip capacitor C8. The bonding substrate l also has RX
An X terminal, a N T terminal, and a TX terminal are respectively inserted.The coupling board to which each component is attached as described above and the dielectric coaxial resonators R1 to R8 are housed in the case 2, and the cover 3 is attached to the case 2. one antenna duplexer is constructed.

FIG. 2(A) is a plan view of the combined substrate viewed from the electrode pattern forming surface side, and FIG. 2(CB) is a plan view showing the state of connection between the combined substrate and the dielectric coaxial resonator. As shown in FIG. 2(A), chip capacitors 01 to C6 are connected in series by electrode patterns 8, and one electrode of chip capacitor c7 is connected between capacitors C3 and C4. As shown in the same figure (B), the dielectric coaxial resonator R]~R5
Output terminals 11 to 15 of the center conductor are connected to predetermined electrodes of each chip capacitor.

Further, as shown in FIG. 2(A), four electrode patterns indicated by 10 are formed on the bonding substrate 1, and chip capacitors 08 to CX1 are connected to each of them, and the upper surface of the chip capacitor C8 and the electrode on the substrate are connected to each other. Coils L1 to L4 respectively
are connected to the top electrodes of the chip capacitors 09 to C1l, and the lead terminals 16 to 16 of the center conductor of the dielectric coaxial resonator are connected to the top electrodes of the chip capacitors 09 to C1l.
18 are connected to each other. By arranging the two bonding substrates parallel to the open surface of each resonator in this way,
The distance iD between the open surface of the resonator and the inner surface of the case is narrowed, and the overall size is reduced.

The antenna duplexer shown in FIGS. 1 and 2 can be assembled using the following procedure.

■Signal input terminal RX in three holes of bonding board 1.

Install ANT and TX vertically.

■Apply cream solder on each electrode of the bonding board and perform reflow soldering for half a day.

■The combined board on which each component is mounted is stored in the case 2. At this time, the three protrusions 21 formed on the case 2 are engaged with the three holes of the bonding board 19 and soldered. Further, the ground electrode 22 formed on the back side of the bonding board 1 and the protrusion 23 on the case 2 side are soldered.

(2) A dielectric coaxial resonator is housed in the case 2, and the lead terminals 11 to 18 of each center conductor are soldered to each electrode.

(2) Cover the case 2 with the cover 3, solder the case and the cover, and solder the dielectric coaxial resonators R1 to R8 at the holes formed in the case 2 and the cover 3.

(2) The inductance of the coil is adjusted through the adjustment hole provided in the cover 3, and the resonant frequency and filter characteristics are adjusted by cutting the open side or short-circuited end of each dielectric coaxial resonator.

FIG. 3 is a circuit diagram of the antenna duplexer shown above.

In the figure, a bandpass filter is configured by R1-R5 and capacitors C2" and C7. Capacitor C7 is a polarizing capacitor for forming an attenuation pole in the transmission frequency band.

L1, C8, and L2 act as low-pass filters, and resonators R6 to R8, capacitors 09 to C11, and coils L3+L4 constitute band-stop filters.

In the embodiments described above, the RX side filter is a bandpass filter, and the TX side filter is a lowpass filter and a band rejection filter, but the TX side may also be a bandpass filter similar to the RX side.

Furthermore, a duplexer can be configured by housing a plurality of dielectric filters similar to the RX side filter in the above embodiment in the same case.

Furthermore, a rectangular chip capacitor was used as the coupling capacitance between the resonators and was embedded in the slit of the coupling substrate. For example, as shown in FIG. It may be buried in the ground.

fg) Results of the Invention According to the present invention, there is no need to use a dielectric ceramic substrate with a high dielectric constant, and an ordinary low dielectric constant substrate can be used as a bonding substrate. There are no defects such as cracks or chips over time, and material costs are reduced. In addition, since the signal input/output terminals can be attached directly to the board, there is no need for a board for fixing the signal input/output terminals, reducing the number of parts and improving work efficiency during manufacturing. The space is also narrower and the overall size is smaller.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of an antenna duplexer that is an embodiment of the present invention, and Figures 2 (A) and (B) are plan views of a coupling board used in the antenna duplexer and an assembled state of the antenna duplexer. FIG. FIG. 3 is an equivalent circuit diagram of the antenna duplexer. FIG. 4 is a partial perspective view showing a structure in which a chip capacitor is attached to a bonding substrate according to another embodiment. FIG. 5 is an exploded perspective view of a conventional antenna duplexer. 1-Combination board, 2-Case, 3-Cam-8, 9, 10-Electrode pattern, 11-18-Output terminal of center conductor, R1-R8-Dielectric coaxial resonator 01-CIL-Chip capacitor, L1 ~L4-coil.

Claims (4)

[Claims] (1) Form multiple slits and electrode patterns connecting these adjacent slits on the substrate, insert chip capacitors into the slits, connect each chip capacitor to the electrode pattern, and connect multiple dielectric coaxial A dielectric filter characterized in that a center conductor of a resonator is connected to one electrode of the chip capacitor or the electrode pattern. (2) A duplexer comprising a plurality of sets of dielectric filters according to claim 1 provided in a case. (3) Provide a plurality of chip capacitor mounting electrodes on the surface of the board, attach one electrode of the chip capacitor to each of these electrodes, connect a coil between the adjacent chip capacitor mounting electrodes, and connect a plurality of dielectric A duplexer characterized in that a plurality of sets of dielectric filters each having a center conductor of a body coaxial resonator connected to the other electrode of the chip capacitor are provided in a case. (4) Form a plurality of slits and an electrode pattern connecting these adjacent slits on the substrate, insert a chip capacitor into the slit, connect each chip capacitor to the electrode pattern, and connect a plurality of dielectric coaxial A dielectric filter in which the center conductor of the resonator is connected to one electrode of the chip capacitor or the electrode pattern, and a plurality of chip capacitor mounting electrodes are provided on the surface of the substrate, and one electrode of the chip capacitor is connected to each of these electrodes. and at least one dielectric filter in which a coil is connected between adjacent chip capacitor mounting electrodes, and the center conductors of the plurality of dielectric coaxial resonators are respectively connected to the other electrode of the chip capacitor. The above-mentioned shared equipment is provided.