KR20010001955A - Dielectric filter - Google Patents

Abstract

PURPOSE: A dielectric filter is provided to prevent a damage of a substrate capacitor without an air gap by installing a sub-substrate between the flat substrate capacitor and a PCB(Printed Circuit Board) and to improve the durability by preventing a lengthwise drop of the capacitor with the sub- substrate. CONSTITUTION: A dielectric filter(10) comprises a resonator(20), a substrate capacitor(30), a PCB(40) and a combining member(50). The combining member(50) is formed by a sub substrate with epoxy or Teflon to block a generation of a parasitic capacitor and to prevent a damage of the substrate capacitor(30). To combine the sub substrate(50) between the substrate capacitor(30) and the PCB(40), an electrode(52b) connected with electrodes(32,42) is integrally formed in both ends of the sub substrate(50). The electrodes(32,42,52b) are connected by soldering or a conductive resin.

Description

Dielectric filter

The present invention relates to a dielectric filter using a dielectric resonator. More particularly, the present invention relates to a substrate filter and a printed circuit board (hereinafter, referred to as a PCB) that form an input / output terminal of a dielectric filter. The present invention relates to a dielectric filter for preventing damage to a substrate capacitor in advance, and efficiently preventing parasitic capacitors easily generated between the substrate capacitor and the PCB.

Generally, dielectric filter using coaxial dielectric resonator is mainly used in mobile communication equipment such as car phone or mobile phone used in high frequency range (300 MHz ~ several GHz). The dielectric filter used in such mobile communication equipment is small and Light weight is desirable, and also impact resistance is required, and a bandwidth of about 20-30 MHz is required.

Such a dielectric filter is a coupling capacitor which is formed on a PCB while a dielectric block having a resonator hole is mounted on a PCB, and a capacitor electrically connected and connected to the dielectric block forms an input and an output terminal of the dielectric filter. The characteristics of the dielectric filter are determined.

In addition, a plurality of dielectric resonators may be used according to filter characteristics, and up to seven dielectric resonators may be used in one signal terminal (receiving terminal or transmitting terminal), and the capacitor is mainly a flat plate capacitor (hereinafter, referred to as 'substrate'). Capacitors are usually used as the input and output stage capacitors of dielectric filters, and the reason for using such flat capacitors is to form an electrode on the upper and lower surfaces of a thin plate of dielectric. For miniaturization of parts.

In this case, in general, the use of a duplexer that combines transmission and reception in a wireless communication device is common, which is a filter in which a transmitting end and a receiving end are implemented in one filter, and as a transmitting, receiving end, and matching circuit (Matching). Circuit).

In the conventional dielectric filter related to the above technique, as shown in FIGS. 1 and 2, the dielectric resonator 120 having the resonator hole 122 penetrating through the PCB 110 and having electrodes formed on the surface thereof. Is mounted, the circuit board 112 for input and output formed on the PCB 110 is a plate-type substrate capacitor 130 is formed on the PCB 110 having the upper electrode 132 is electrically connected as the resonator hole 122 and the connecting rod 124 ) Is connected to the lower electrode 134 via the metal plate 140.

In this case, the reason why the metal plate 140 is connected between the substrate capacitor 130 and the PCB 110 is to form an air gap G between the PCB 110 and the capacitor 130. The air gap G forms a gap between the capacitor 130 and the PCB 110, and when there is a signal processing or ground pattern 150 formed on the PCB 110, the dielectric substrate of the capacitor 130. This is to prevent parasitic capacitors from occurring and deterioration of the filter characteristics.

In particular, in the above-described conventional duplexer 100a, as shown in FIG. 3, the height difference between the substrate capacitors CT1 (CT2) 130 provided in the transmitting end TX and the receiving end RX, respectively, is offset. In order to do so, the metal plate 140 is connected between the capacitor RC of the receiving end RX and the PCB 110.

However, in the conventional dielectric filter and duplexer as described above, as shown in Figs. 1 to 3, the soldering operation for connecting the extremely small metal plate 140 between the plate capacitor 130 and the PCB 110. This becomes extremely difficult, and therefore, a poor soldering occurs easily, and the detachment phenomenon of the capacitor 130 due to the poor soldering occurs easily, which affects the filter characteristics, thereby deteriorating component reliability.

In addition, due to the air gap G formed by the metal plate 140, a space is generated between the flat capacitor 130 and the PCB 110, which is caused by an external shock applied to the filter component. There was a problem that the upper capacitor portion is easily broken.

In addition, an error gap G is formed as the metal plate 140 to prevent the occurrence of parasitic capacitors as described above, but it is impossible to remove the parasitic capacitors completely, which may affect the filter characteristics. Increasing the width of the air gap G in order to reduce the capacity of the capacitor has a number of problems, such as the breakage of the above-mentioned capacitor easily occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a sub-sub substrate having a low dielectric constant between a flat substrate capacitor and a PCB, thereby preventing breakage of the substrate capacitor without forming an air gap. It is possible to provide a dielectric filter which can be prevented and prevents the deflection in the longitudinal direction of the capacitor as the sub substrate even when using a plurality of resonators, thereby making the filter structure more robust and improving component durability. have.

Another object of the present invention is to provide a sub-substrate with a low dielectric constant, thereby blocking between the substrate capacitor and the PCB signal processing or grounding pattern, thereby effectively preventing the generation of parasitic capacitors, thereby improving the characteristics of the filter. It is to provide a dielectric filter.

1 is a plan view showing a conventional dielectric filter

2 is a front view showing a mounting structure of a substrate capacitor in a conventional dielectric filter;

3 is an overall configuration diagram showing a substrate capacitor mounting structure in a conventional duplexer

4 is an exploded perspective view illustrating a dielectric filter for mounting a substrate capacitor using a sub substrate according to the present invention.

5 is a front view showing the dielectric filter of the present invention;

6 is a front view illustrating a substrate capacitor of a duplexer according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10 ... dielectric filter 20 ... resonator

30 .... Substrate Capacitors 32,42,44,52 .... pattern

40 ... filter printed circuit board 50 .... connection member

54 .... through hole 60 .... duplexer

As a technical means for achieving the above object, the present invention, a plurality of resonators having a resonance hole formed therein,

A substrate capacitor electrically connected and connected to the resonator and forming an input and an output end of a filter;

A PCB mounted with the resonator and the substrate capacitor connected to each other;

By providing a dielectric filter comprising a connection member having a low dielectric constant connected between the capacitor and the PCB to prevent breakage of the substrate capacitor and generation of parasitic capacitor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is an exploded perspective view illustrating a dielectric filter for mounting a substrate capacitor using a sub-substrate according to the present invention, FIG. 5 is a front view illustrating the dielectric filter of the present invention, and FIG. 6 is a diagram of a duplexer according to an embodiment of the present invention. As a front view of the substrate capacitor, the dielectric filter 10 of the present invention is configured as the resonator 20, the substrate capacitor 30, the PCB 40, and the connecting member 50. As shown in FIG.

The dielectric filter 10 mainly used in communication devices such as a mobile phone is mainly used in a high frequency region (300 MHz to several GHz), and the capacitor 30 used in the input and output terminals of the dielectric filter 10 may include a PCB 40. The dielectric filter 10 using the connection member 50 to prevent the damage of the capacitor 30 and minimize the influence of the parasitic capacitor generated therebetween is as follows.

First, although not shown in detail in the drawing, the dielectric filter 10 generally conveys the resonator 20 having electrodes formed on the dielectric block, and the resonator hole 22 penetrates integrally inside the resonator 20. Is formed.

In this case, the number of the resonator 20 is different according to the filter characteristics, in the present invention relates to the dielectric filter 10 is provided with the lowest three resonators 20, as shown in Figures 4 and 5 When the appropriate number of resonators 20 are connected to the filter component PCB 40, one end of the electrode rod 24 is connected to the internal resonator hole 22 of the resonator 20, and the The other end of the electrode rod 24 is connected to the substrate capacitor 30 mounted on the PCB 40 to one side.

In this case, as described above, the substrate capacitor 30 forms an input and an output end of the filter, and is installed to implement a coupling capacitor that affects the characteristics of the dielectric filter. In recent years, in accordance with the trend toward miniaturization of filter components, electrodes 32 are formed on both sides of end portions of plate-shaped dielectric blocks to realize capacitors. The other end of 24 is electrically connected to the electrode 32 of the substrate capacitor 30.

In addition, since the use of the electrode 24 is inconvenient in the manufacturing process, the use of the resonator in which the input and output electrode terminals are formed using the electrode gap formed on the surface of the resonator 20 is common. It does not relate to the gist of the present invention.

In addition, as shown in FIG. 5, the substrate capacitor 30 should be mounted on the PCB 40, wherein the lower electrode 32 of the substrate capacitor 30 is formed on the PCB 40. Connection of the resonator electrode 24, the substrate capacitor 30, and the electrodes 32, 42 of the PCB 40, as described above, is performed by soldering or conductive Resin is used.

In this case, as shown in FIGS. 4 and 5, one side and the other side of the electrodes 32 and 42 of the substrate capacitor 30 and the PCB 40 respectively constitute the input and output ends of the filter 10. The substrate capacitor 30 is operated as an input and an output capacitor.

Subsequently, as described above, the PCB 40 is provided with a pattern 44 for signal processing or ground, so that the substrate capacitor 30 needs to be spaced apart from the PCB 40. This is because the pattern 44 of the PCB 40 causes the parasitic capacitor to deteriorate the filter characteristics by the substrate capacitor 30 as the dielectric block.

Therefore, in the present invention, the connection member 50 is used during the PCB 40 mounting operation of the substrate capacitor 30, which will be described in more detail as follows.

First, as shown in FIGS. 4 and 5, the connection member 50 blocks the generation of the above-mentioned parasitic capacitors, and the substrate capacitor 30 is separated from the PCB 40 by the substrate capacitor 30. 30) Materials with extremely low dielectric constants are used to prevent breakage, usually formed from thin substrates using epoxy or Teflon.

At this time, in order to connect the sub-substrate 50 between the input / output terminal substrate capacitor 30 and the PCB 40, the electrode portions 32 and 42 of the substrate capacitor 30 and the PCB 40 are connected. The electrodes 52 connected to each other are integrally formed above and below both ends, and as described above, the respective electrode portions 32, 42, 52 are connected by soldering or conductive resin.

Therefore, while the substrate capacitor 30 is stably mounted on the PCB 40, generation of parasitic capacitors between the substrate capacitor 30 and the PCB 40 is effectively blocked, and at the same time, the substrate capacitor 30 is externally impacted. It is prevented from being easily damaged by, as shown in Figure 2, when using the conventional metal plate 140 is 0.3-0.4 mm spaced (G), but in the case of the present invention, as shown in Figure 5, Extremely fine intervals of 0.03-0.04 mm are formed so that even when an external shock is applied to the substrate capacitor 30, it is not easily broken.

On the other hand, the through holes 54 are integrally penetrated through the electrode portions 52a and 52b of the sub-substrate 50. As shown in FIG. 4, the through holes 54a and 54b are formed as shown in FIG. This is to prevent unnecessary capacitors from being generated by both electrodes of the sub-substrate, which is the dielectric block, and molten lead or conductive resin is applied in the through-hole 54 when the sub-substrate 50 is connected to the through-hole 54 ) Is conducted.

Subsequently, the through hole 54 is formed with one or two different numbers according to input and output capacitors implemented on one side and the other side of the sub-substrate 50, which facilitates assembly of the filter characteristics and manufacturing. To do that.

Meanwhile, as shown in FIG. 6, the sub-substrate 50 is installed in the duplexer 60, which is an embodiment of the present invention, and the transmitting terminal TX of the duplexer 60 performs an upper pass function. It is configured as a lower capacitor CT2 that performs a low pass function with CT1, and on the contrary, the receiving end RX uses one capacitor 30, and each capacitor is similarly a substrate capacitor.

Therefore, as shown in FIG. 6, in the duplexer 60, it is necessary to adjust the installation height by different numbers of capacitors (CT1) (CT2) 30 installed at the transmitting and receiving ends. Accordingly, the sub-substrate 30 is connected between the receiving end capacitor 30 and the PCB 40.

That is, as described above, when the sub substrate is used for the duplexer 60, it is possible to prevent the occurrence of parasitic capacitors, and in particular, to prevent the substrate capacitor 30 of the duplexer receiving end from being extremely easily damaged by external impact. To do so.

As described above, according to the dielectric filter of the present invention, a sub-sub substrate having a low dielectric constant is provided between the planar substrate capacitor and the PCB, thereby preventing breakage of the substrate capacitor without forming an air gap, and using a plurality of resonators. Even in this case, the deflection in the longitudinal direction of the capacitor is prevented as the sub-substrate, so that the filter structure is more firm and the component durability is improved.

In addition, by installing a sub-substrate having a low dielectric constant to cut off between the plate-type capacitor and the signal processing or grounding pattern of the PCB, the generation of parasitic capacitors is effectively blocked, thereby improving the characteristics of the filter.

Claims (13)

A plurality of resonators 20 having a resonance hole 22 formed therein, A substrate capacitor 30 electrically connected to the resonator 20 and forming an input and an output end of the filter; A PCB 40 mounted in a state in which the resonator 20 and the capacitor 30 are connected to each other; And a connecting member (50) having a low dielectric constant connected between the capacitor (30) and the PCB (40) to prevent breakage of the capacitor (30) and generation of parasitic capacitors. The dielectric filter as claimed in claim 1, wherein the connection member (50) is composed of a plate-shaped sub substrate. 3. The dielectric filter of claim 2, wherein the sub substrate 50 is made of epoxy. 3. The dielectric filter of claim 2, wherein the sub substrate 50 is made of Teflon. The electrodes 52a and 52b of the second substrate 50 are formed at both ends of the sub-substrate 50 and electrically connected to the electrodes 32 and 42 formed on the capacitor 30 and the PCB 40, respectively. Dielectric filter characterized by 6. The dielectric filter according to claim 5, wherein the capacitor 30, the electrodes 32 and 42 of the PCB 40, and the electrodes 52 of the sub-substrate 50 are soldered and connected. 6. The dielectric filter according to claim 5, wherein the capacitor 30, the electrodes 32 and 42 of the PCB 40, and the electrodes 52 of the sub-substrate 50 are connected with a conductive resin. 6. The dielectric filter as claimed in claim 5, wherein a through hole (54) is formed in the electrode (52) of the sub-substrate (50) to integrally penetrate the substrate and the electrode to prevent the generation of capacitors. 9. The dielectric filter according to claim 8, wherein both through holes 54a and 54b of the sub-substrate electrode 52 have different numbers depending on input and output. The dielectric filter according to claim 1, wherein at least three resonators are installed. The dielectric filter as claimed in claim 1, wherein the resonator (20) consists of a duplexer (60) having a transmitting and receiving end. 12. The dielectric filter of claim 1 or 11, wherein the connection member 50 is installed at a receiving end Rx of the duplexer 60. The method of claim 12, wherein the connecting member 50 is installed so as to match the height between each substrate capacitor (CT1) (CT2) and 30 of the transmitting end (Tx) and the receiving end (Rx) of the duplexer (60). Dielectric filter