KR20030073658A - Dielectric filter - Google Patents

Abstract

PURPOSE: A dielectric filter is provided to allow the cross coupling of the first-fourth holes to be independently controlled from the cross couplings of the first-third holes and second-fourth holes. CONSTITUTION: A dielectric filter(100) comprises a dielectric filter(110) having a near rectangular parallelepiped shape, and four side surfaces and a bottom surface plated with a conductor; a plurality of resonance holes(111,112,113,114) penetrating through the top and bottom surfaces of the dielectric block, wherein each of the resonance holes has an inner wall plated with a conductor; a first conductive pattern(121) extended into a near strip line shape from the first and second resonance holes, and bent into the gap formed between the second and third resonance holes; and a second conductive pattern(122) extended into a near strip line shape from the third and fourth resonance holes, and bent into the gap formed between the second and third resonance holes.

Description

Dielectric filter

The present invention relates to a dielectric filter. More specifically, in the case of a 4-pole dielectric filter having a cross coupling, the cross coupling of 1-4 holes is 1-3 holes, 2 A dielectric filter that can be adjusted independently of a -4 hole cross coupling.

In general, in the mobile communication field, a duplexer including a band pass filter for a transmitter and a receiver is disposed next to an antenna terminal of a terminal, which filters a transmission / reception signal of a frequency. Among the duplexers, there is a mono block dielectric filter using a ceramic dielectric, which implements a coupling circuit for coupling a resonator and an external circuit by forming external patterns or holes, thereby eliminating the need for additional components and mass production. As it is possible to achieve low price, many researches and developments are underway.

FIG. 1A shows a conventional dielectric filter 100 'and FIG. 1B shows an equivalent circuit thereof. Referring to this, a conventional technology is described below.

As shown in the drawing, the conventional dielectric filter 100 'includes a substantially rectangular parallelepiped dielectric block 110', and includes a plurality of resonance holes 111 'and 112' from the top surface to the bottom surface of the dielectric block 110 ', 113 'and 114' are formed in approximately one line. Here, the inner walls of the plurality of resonant holes 111 ′, 112 ′, 113 ′, and 114 ′ are plated with a conductor to function as internal electrodes. In addition, parallel to the resonance holes 111 ′, 112 ′, 113 ′, and 114 ′, a conductive pattern 21 ′ having a strip line shape is formed to be long.

Meanwhile, all four side surfaces and the bottom surface of the dielectric block 110 'except for the top surface are plated with a conductor to function as an external electrode.

Accordingly, each of the resonant holes 111 ′, 112 ′, 113 ′, and 114 ′ has a conductor (internal electrode) plated on an inner wall and a conductor (external electrode) plated on four sides and a bottom surface of the dielectric block 110. Thereby forming a loading capacitance and forming cross capacitance between adjacent resonance holes 111 ′, 112 ′, 113 ′ and 114 ′. In addition, the strip line conductive pattern 21 ′ forms a cross coupling capacitance between adjacent resonance holes 111 ′, 112 ′, 113 ′, and 114 ′. That is, a cross coupling capacitance is formed between 1-3 holes 111'-113 ', 2-4 holes 112'-114', and 1-4 holes 111'-114 '.

The operating principle of the dielectric filter 100 'will be described with reference to the equivalent circuit of FIG. 1B.

In the figure, C01 and C40 are input / output end coupling capacitances formed between the internal electrodes of the resonance holes 111 'and 114' and the input and output electrodes 130 'and 140', and C12 to C34 are the resonance holes 111. Coupling capacitance between '112', 113 'and 114', and C1 to C4 are the internal electrodes of the respective resonant holes 111 ', 112', 113 'and 114' and the outside of the dielectric block 110 '. It is the loading capacitance formed between the electrodes. In addition, C15 to C45 are coupling capacitances between the conductive patterns 121 'in the form of strip lines and the respective resonance holes 111', 112 ', 113' and 114 ', and C50 is the conductive patterns 121' and the dielectric. It is the coupling capacitance formed between the external electrodes of the block 110 '. In addition, 1-3 is the resonance state by the cross coupling of the resonance holes 111 'and 113', and 2-4 is the resonance state by the cross coupling of the resonance holes 112 'and 114', and 1-4. Shows a resonance state by cross coupling of the resonance holes 111 'and 114'.

In the equivalent circuit, when a predetermined electrical signal is applied to the input electrode 130 ′, electric fields are formed in the four resonant holes 111 ′, 112 ′, 113 ′, and 114 ′ to operate each resonator. At this time, the coupling capacitances C12, C23, and C34 of the resonance period are increased by the conductive pattern 121 'formed in the upper surface of the dielectric block 110'. As a result, the impedance value is maximized at the resonance point due to the coupling capacitance (and inductance), and the attenuation occurs at the resonance point at the maximum.

The resonance point is changed by changing the coupling capacitance value. That is, since the coupling capacitance value can be changed by changing the length and width of the conductive pattern 121 ', the attenuation point can be adjusted by adjusting the length and width of the conductive pattern as a result. Done.

As described above, the dielectric filter 100 'does not have coupling capacitance between each of the resonant holes 111', 112 ', 113', and 114 ', but each of the resonant holes 111', 112 ', There is also a cross coupling capacitance between 113 'and 114'. That is, cross coupling of 1-3 holes 111'-113 ', 2-4 holes 112'-114', and 1-4 holes 111'-114 'also exists, whereby On the same principle, there are also attenuation points.

However, as can be seen in the equivalent circuit, 1-4 holes cross coupling, 1-3 holes, 2-4 holes cross coupling are subordinate to one conductive pattern, so if C15 and C45 are adjusted, 1-4 holes , 1-3 holes and 2-4 holes cross coupling is simultaneously affected and changed. That is, since the 1-4 hole cross coupling cannot be adjusted independently of the 1-3 hole and 2-4 hole couplings, there is a problem in that the attenuation point, particularly the attenuation point associated with the cross coupling, cannot be freely moved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In the case of a 4-pole dielectric filter having a cross coupling, the cross coupling of 1-4 holes is independent of the 1-3 holes and 2-4 holes cross coupling. It is to provide a dielectric filter that can be adjusted by.

Fig. 1A is a perspective view showing a conventional dielectric filter, and Fig. 1B is an equivalent circuit diagram thereof.

Fig. 2A is a perspective view showing a dielectric filter according to the present invention, and Fig. 2B is an equivalent circuit diagram thereof.

3 is a perspective view showing another dielectric filter according to the present invention.

4 is a perspective view showing another dielectric filter according to the present invention.

5 is a perspective view showing another dielectric filter according to the present invention.

Description of the main symbols in the drawings

100,200,300,400; Dielectric filter according to the present invention

110; Dielectric blocks 111, 112, 113, 114; Resonance hole

121; First conductive pattern 122; Second challenge pattern

130; Input electrode 140; Output electrode

In order to achieve the above object, the dielectric filter according to the present invention has a substantially rectangular parallelepiped dielectric block having four sides and a bottom surface plated with a conductor; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; A first conductive pattern extending in a strip line shape on one side of the first and second resonance holes, and bent between the second and third resonance holes; The second and fourth resonant holes on the other side of the strip extending in the form of a substantially parallel line, characterized in that made of a second conductive pattern formed by bending between the second and third resonant holes.

Here, the first conductive pattern and the second conductive pattern bent between the second resonance hole and the third resonance hole may be spaced apart by a predetermined distance in the horizontal direction.

In addition, the first conductive pattern and the second conductive pattern bent between the second resonance hole and the third resonance hole may be spaced apart by a predetermined distance in the vertical direction.

In addition, to achieve the above object, another dielectric filter according to the present invention includes a dielectric block having four sides and a bottom surface plated with a conductor, except for an upper surface, in a substantially rectangular parallelepiped form; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; One side of the four vacuum holes extending in a substantially strip line shape, characterized in that it comprises a conductive pattern formed by bending a predetermined length toward the first vacuum hole and the fourth vacuum hole.

Another dielectric filter according to the present invention for achieving the above object is a substantially rectangular parallelepiped dielectric block plated on the four sides and the lower surface except the upper surface; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; A first conductive pattern extending in a strip line shape on one side of the four vacuum holes; And a second conductive pattern extending in the form of a strip line on the other side of the second and third resonance holes.

According to the dielectric filter according to the present invention as described above, the secondary coupling can be adjusted by adjusting the length and width of the conductive pattern to adjust the primary coupling as in the related art, and by appropriately adjusting the distance between the two conductive patterns. Can be adjusted independently. That is, it is possible to independently adjust the cross coupling of 1-3 holes, 2-4 holes and 1-4 holes.

In addition, the conductive patterns bent toward the first and fourth resonance holes may control the primary coupling and the secondary coupling by appropriately adjusting the widths of the bent conductive patterns.

In addition, the two conductive patterns having different lengths on one side and the other side of the resonance hole may readjust the primary coupling by appropriately adjusting the length of the shorter conductive pattern.

(Example)

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that those skilled in the art may easily implement the present invention.

Fig. 2A is a perspective view showing the dielectric filter 100 according to the present invention, and Fig. 2B is an equivalent circuit diagram thereof.

As shown in the figure, the dielectric block 110 is formed of a substantially rectangular parallelepiped, in which four sides and a bottom surface of the dielectric block 110 are plated with a conductor, and four holes are formed in a line through the top and bottom surfaces of the dielectric block 110. The inner wall of each of the holes is provided with a plurality of resonant holes 111, 112, 113, and 114 in which a conductor is plated (inner electrode).

In addition, one side of the first and fourth resonant holes 111 and 114 of the resonant holes 111, 112, 113, and 114 as the upper surface of the dielectric block 110 is formed with the input electrode 130 and the output electrode 140 spaced apart from each other by a predetermined distance.

Meanwhile, one side of the first and second resonance holes 111 and 112 of the resonance holes 111, 112, 113, and 114 extends in a substantially strip line shape, and is bent between the second resonance hole 112 and the third resonance hole 113 to form a first conductive pattern ( 121) is formed. In addition, the second and third resonance holes 122 and 114 extend in a substantially strip line shape at the same time, and are bent between the second resonance hole 112 and the third resonance hole 113 to form a second conductive pattern 122. have.

Here, the first conductive pattern 121 and the second conductive pattern 122 are spaced apart by a predetermined distance in the horizontal direction, and the separation distance L between the first conductive pattern 121 and the second conductive pattern 122. By adjusting, the cross coupling between the 1-4 holes 111-114 is adjusted.

Referring to the operation of the dielectric filter 100 as described above using the equivalent circuit of Figure 2b.

In the figure, C01 and C40 are input / output end coupling capacitances formed between the internal electrodes of the resonant holes 111 and 114 and the input and output electrodes 130 and 140, and C12 to C34 are coupling capacitances between the resonant holes 111, 112, 113 and 114, and C1. ˜C4 is a loading capacitance formed between the inner electrode of each of the resonance holes 111, 112, 113, and 114 and the outer electrode of the dielectric block 110. In addition, C15 is the first resonance hole 111 and the first conductive pattern 121, C25 is the second resonance hole 112 and the first conductive pattern 121, C26 is the second resonance hole 112 and the second conductive pattern ( 122), C35 is the third resonant hole 113 and the first conductive pattern 121, C36 is the third resonant hole 113 and the second conductive pattern 122, C46 is the fourth resonant hole 114 and the second conductive pattern Reference numeral 122 and C50 denote coupling capacitance between the first conductive pattern 121 and the external electrode, and C60 denotes the coupling capacitance between the second conductive pattern 122 and the external electrode. In addition, C is a coupling capacitance between the first conductive pattern 121 and the second conductive pattern 122.

In addition, 1-3 is cross coupling of the resonant holes 111-113, 2-4 is cross coupling of the resonant holes 112-114, and 1-4 is cross coupling of the resonant holes 111-114. Ring.

In the equivalent circuit, when a predetermined electrical signal is applied to the input electrode 130, electric fields are formed in the four resonant holes 111, 112, 113, and 114, and the resonator operates. In this case, the coupling capacitances C12, C23, and C34 of the resonance period are increased by the first conductive pattern 121 and the second conductive pattern 122 in the form of strip lines formed on the upper surface of the dielectric block 110, while the coupling Inductance is reduced. As a result, the impedance of the resonance point becomes maximum due to the coupling capacitance and the inductance, and the attenuation occurs to the resonance point to the maximum.

The resonance point is changed by changing the above-mentioned coupling capacitance and coupling inductance or both.

That is, it is possible to change the coupling capacitance and the coupling inductance value by changing the distance between the first conductive pattern 121 and the second conductive pattern 122 and the widths facing each other. By adjusting the distance and width of the pattern, the attenuation point can be adjusted.

Of course, the dielectric filter does not only have coupling capacitance between the resonance holes 111, 112, 113, and 114 as described above, but also cross coupling capacitance between the resonance holes 111, 112, 113, and 114. That is, cross coupling of 1-3 holes 111-113, 2-4 holes 112-114, and 1-4 holes 111-114 also exists, whereby attenuation viscosity in accordance with the principle described above. Each exists.

However, as described above, since the first conductive pattern 121 and the second conductive pattern 122 are connected to C differently from each other, C15, C46, and C can be adjusted separately, and thus, 1-3 holes ( 111-113, the 2-4 holes 112-114 and the 1-4 holes 111-114 cross coupling become independently adjustable. Finally, by adjusting the cross coupling of the 1-4 holes 111-114 independently of the 1-3 holes 111-113 and the 2-4 holes 112-114 coupling, The associated attenuation point can be freely moved.

3 is a perspective view showing another dielectric filter 200 according to the present invention. Since the dielectric filter 200 of FIG. 3 is similar to the dielectric filter 100 of FIG. 2, only the differences will be described. The same is true of the other embodiments described below.

As illustrated, the first conductive pattern 121 and the second conductive pattern 122 on the upper surface of the dielectric block 210 are formed to be spaced apart by a predetermined distance (L) in the vertical direction. Therefore, by appropriately adjusting the vertical distance between the first conductive pattern 121 and the second conductive pattern 122, it is possible to independently adjust the cross coupling of the 1-4 holes 211-214.

4 is a perspective view showing another dielectric filter 300 according to the present invention. As shown, the conductive pattern 321 extends in a substantially strip line shape at one side of the four resonant holes 311, 312, 313, and 314, and is bent by a predetermined length toward the first and fourth resonant holes 311 and 314. Formed. Therefore, by appropriately adjusting the width of the conductive pattern 321 bent toward the first resonance hole 311 and the fourth resonance hole 314, the primary couplings (1-2, 2-3, 3-4) and The secondary couplings 1-3, 2-4, and 1-4 can be adjusted to predetermined values.

5 is a perspective view showing another dielectric filter 400 according to the present invention. As shown in the drawing, the first conductive pattern 421 extends substantially in the form of a strip line at one side of the four resonant holes 411, 412, 413, and 414 as in the prior art, and has a different strip line shape at the other side of the second and third resonant holes 412, 414. The second conductive pattern 422 is formed. With this structure, by adjusting the length and width of the second conductive pattern 422 appropriately, the primary couplings 1-2, 2-3, 3-4 can be readjusted.

As described above, although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto, and various modified embodiments may be possible without departing from the scope and spirit of the present invention.

Therefore, according to the dielectric filter according to the present invention, the secondary coupling is independently controlled by adjusting the length and width of the conductive pattern to adjust the primary coupling as in the related art, and by appropriately adjusting the distance between the two conductive patterns. It can be effective. That is, there is an effect that can be independently controlled 1-3, 2-4 and 1-4 cross coupling.

In addition, the conductive patterns bent toward the first and fourth resonance holes have an effect of controlling the primary coupling and the secondary coupling by appropriately adjusting the widths of the bent conductive patterns.

In addition, the two conductive patterns having different lengths on one side and the other side of the resonance hole have an effect of re-adjusting the primary coupling by appropriately adjusting the length of the shorter conductive pattern.

Claims (5)

A dielectric block in a substantially rectangular parallelepiped shape in which four sides and a bottom surface except the top surface are plated with a conductor; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; A first conductive pattern extending in a strip line shape on one side of the first and second resonance holes, and bent between the second and third resonance holes; And a second conductive pattern extending to the other side of the third and fourth resonant holes in a substantially strip line shape and bent between the second and third resonant holes. The dielectric filter of claim 1, wherein the first conductive pattern and the second conductive pattern bent between the second resonance hole and the third resonance hole are spaced apart by a predetermined distance in a horizontal direction. The dielectric filter of claim 1, wherein the first conductive pattern and the second conductive pattern bent between the second resonance hole and the third resonance hole are spaced apart by a predetermined distance in a vertical direction. A dielectric block in a substantially rectangular parallelepiped shape in which four sides and a bottom surface except the top surface are plated with a conductor; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; A dielectric filter extending on one side of the four vacuum holes in a substantially strip line shape, the conductive pattern being bent by a predetermined length toward the first vacuum hole and the fourth vacuum hole. A dielectric block having a substantially rectangular parallelepiped, in which four sides and a bottom surface except for the top surface are plated with a conductor; Four resonance holes are formed in a row through the upper and lower surfaces of the dielectric block, and a plurality of resonant holes are plated with a conductor in an inner wall of the hole; A first conductive pattern extending in a strip line shape on one side of the four vacuum holes; And a second conductive pattern extending in the form of a strip line on the other side of the second and third resonance holes.