KR101416998B1 - Band pass filter of Stepped Impedance Resonator type - Google Patents

Abstract

A SIR-type band-pass filter according to an embodiment of the present invention relates to a band-pass filter including a patterned resonance portion on a substrate and includes a first multi-stage line structure having a plurality of turn- A resonance part; And a second resonator part having the line structure and at least a part formed inside the resonance area of the first resonator part.

According to the SIR type band-pass filter according to the embodiment, the minimized size and high-order filter characteristics can be realized at the same time. Also, the number and size of the resonance regions can be variously applied by the multilayer substrate structure, the multi-stage line structure, and the slot structures of various types, and thus the filter characteristics can be accurately implemented.

SIR, LTCC, resonator, bandpass filter, microstrip line

Description

[0001] The present invention relates to an SIR type band pass filter,

The embodiment relates to an SIR type bandpass filter used in a communication module.

BACKGROUND ART Communication devices such as a cellular phone, a PDA (Personal Digital Assistant), and an RFID (Radio Frequency Identification) device are equipped with communication modules in which various electronic devices are integrated on a substrate. Such a communication module is provided with a filter for eliminating a signal of a noise component, separating transmission / reception signals, or matching the input / output impedance of a circuit.

In addition, techniques such as SIP (System In Package) technology for reducing the number of components and mounting area by patterning passive components on LTCC (Low Temperature Co-fired Ceramic) substrates have been widely used in accordance with integration trend of communication modules.

Particularly, because of advantages such as ease of LTCC process and size reduction, SIR (Stepped Impedance Resonator) is used as a bandpass filter, SIR is arranged symmetrically in parallel with strip lines, and difference in impedance Thereby generating a resonance at a specific frequency, thereby functioning as a band-pass filter.

The SIR-type band-pass filter determines the passband frequency according to factors such as the difference in impedance depending on the size and shape of the strip line, and the separation distance of each strip line.

1 is a diagram illustrating various forms of an SIR type band-pass filter.

The filter shown in Fig. 1 (a) has a horizontal structure with a small number of resonance regions and a long width in the longitudinal direction because the resonance width is narrow. In the filter of the horizontal structure, the lengths (L1 and L3) of the resonance region and the resonance region distance (L2) are main design variables, and the characteristic impedance, the resonance frequency and the wavelength can be adjusted by these parameters.

For example, in order to resonate the 2.4 GHz band signal, the total length Lt of the filter should be about 12.5 cm corresponding to the wavelength of 2.4 GHz, which is disadvantageous for downsizing.

It can be seen that the filter shown in Fig. 1 (b) has a vertical structure in which the region causing resonance is expanded and reduced in the longitudinal direction. In this case, the frequency band is determined by the design variables of the width (W), the length (L) and the spacing (S) of the resonance region and the frequency of the attenuation pole Can be adjusted.

Therefore, while the filter in (b) is reduced in the longitudinal direction, the entire region must be enlarged on the secondary plane, and therefore, there is a limitation in minimizing the size of the filter.

The filter shown in FIG. 1 (c) is an example of implementing a high-dimensional filter by increasing the number and size of resonance regions and increasing the number of multi-stepped lines by arranging the filters of FIG. Here, "dimension" means the order of the transfer function S parameter used to define the characteristics of the filter.

However, as described above, the higher the size of the filter, the larger the size of the filter. In the multi-stage structure of the above-described filters, there is a limit to increase the degree of the filter.

The embodiment provides an SIR-type band-pass filter having a minimized size and high-order filter characteristics.

The embodiment provides an SIR-type bandpass filter capable of precisely adjusting the position and resonance frequency band of the attenuation pole on the S-parameter.

A SIR-type band-pass filter according to an embodiment of the present invention relates to a band-pass filter including a patterned resonance portion on a substrate and includes a first multi-stage line structure having a plurality of turn- A resonance part; And a second resonator part having the line structure and at least a part formed inside the resonance area of the first resonator part.

The SIR-type band-pass filter according to the embodiment includes a first resonance part having a multi-stepped multi-stage line structure and forming a resonance area of a closed loop or an open loop structure, and a first resonance part having the line structure inside the resonance area of the first resonance part A first substrate formed in a form of a metal thin film having a second resonant portion formed at least partially; A second substrate having the same structure as the first substrate; And a third substrate positioned between the first substrate and the second substrate and having a slot formed in an area corresponding to at least one of the first resonator and the second resonator.

According to the SIR type band-pass filter according to the embodiment, the minimized size and high-order filter characteristics can be realized at the same time.

According to the embodiment, the number and size of the resonance region can be variously applied by the multilayer substrate structure, the multi-stage line structure, and the slot structure of various types, and thus the filter characteristic can be accurately realized.

According to the embodiment, the design freedom of the SIR type band-pass filter can be secured.

The SIR band-pass filter according to the embodiment will be described in detail with reference to the accompanying drawings.

Fig. 2 is a top view schematically showing the structure of an SIR band-pass filter (hereinafter referred to as "filter according to the first embodiment ") 100 according to the first embodiment.

The first resonator part 110 and the second resonator part 120 are formed on the substrate A (A) and the second resonator part 120. The filter 100 according to the first embodiment includes a first resonator part 110 and a second resonator part 120, May be implemented in a pattern form in which a part of the metal thin film on the substrate is removed, for example, in the form of a stripline.

The first resonator unit 110 has a multi-stage multi-stage line structure and forms a resonance region.

Similar to the first resonator 110, the second resonator 120 has a multi-stage multi-stage line structure and is formed inside the resonance region of the first resonator 110.

It is a matter of course that the second resonance part 120 is formed inside the resonance area of the first resonance part 110, so that a resonance area of a closed loop or an open loop structure can be formed.

The first resonator 110 includes a first conductor 112, a second conductor 114, a third conductor 116, and a fourth conductor 118, The portion 120 includes a fifth conductor 122, a sixth conductor 124, and a seventh conductor 126.

The structure of the first conductor 112 to the seventh conductor 126 to be described below is one embodiment and the first resonator part 110 and the second resonator part 120 are formed in a multi- Structure, and loop structure, and the structure in which the resonance regions are overlapped with each other can be variously modified.

Hereinafter, the first resonator unit 110 will be described.

The first conductor 112 and the second conductor 114 are disposed to face each other with a predetermined distance from each other and the third conductor 116 is disposed between the first conductor 112 and the second conductor 114).

The ends of the first conductor 112 and the second conductor 114 connected by the third conductor 116 are opposite to each other and the third conductor 116 is linear.

Thus, the first conductor 112, the second conductor 114, and the third conductor 116 form a closed loop region with one side open, and the closed loop region includes the first conductor 112 and the second conductor 116, Corresponds to the resonance region of the conductor 114.

The fourth conductor 118 extends from the third conductor 116 and is extended toward the outside of the resonance region.

The first conductor 112 to the fourth conductor 114 are basically formed in the form of a stripline while the first conductor 112 and the second conductor 114 are connected to the third conductor 116, And is close to a rectangular shape having a larger width than the fourth conductor 118.

The first conductor 112 and the second conductor 114 have the same size and shape for resonance.

Hereinafter, the second resonator unit 120 will be described.

The fifth conductor 122 and the sixth conductor 124 are formed inside the resonance region of the first resonator unit 110 and are disposed to face each other with a predetermined distance therebetween.

The seventh conductor 126 connects the ends of the fifth conductor 122 and the sixth conductor 124.

The seventh conductor 126 connects the fifth conductor 122 and the sixth conductor 124 to each other at one end of the fifth conductor 122 and the sixth conductor 124, 124).

The fifth conductor 122 and the sixth conductor 124 are close to a rectangular shape having a larger width than the seventh conductor 128. In addition, the fifth conductor 122 and the sixth conductor 124 have the same size and shape for resonance.

The filter 100 according to the first embodiment having such a resonance structure takes into consideration factors such as a resonance (pass) frequency band, a filter characteristic, a filter size, and the like, and its structure can be summarized as follows.

Firstly, the structure according to the number of regions where each conductor generates a resonance phenomenon, second, the structure according to the width and length of each conductor, the structure according to the spacing of each conductor, and the structure according to the shape of each conductor. , Fifth, the tilting (multi-stage) structure of each conductor.

For example, when the filter is implemented as a resistor R, an inductor L and a capacitor C, one filter may be completed by forming a RLC unit and then forming a series-parallel circuit, The larger the number of RLCs, the higher the dimension of the filter. That is, the higher the order of the transfer function S parameter which is an index of the filter characteristic, the more the number of RLCs having a multi-stage structure becomes.

In a similar principle, when a high-order number of filters is manufactured in the SIR type, a resonance region and a multi-stage structure of a conductor are formed in large numbers, and the filter order can be increased as the size of the resonance region is larger.

For example, when the number of resonance regions is determined by the number of slots, the possible slots on the filter according to the first embodiment can be calculated as follows.

First, a slot between the first conductor 112 and the second conductor 114, a slot formed by each side of the looped seventh conductor 126, and third, a slot formed by the seventh conductor 126 Fifth and sixth conductors 122 and 126 and a slot between the fifth and sixth conductors 122 and 126 and a slot between the fifth and sixth conductors 122 and 126, A slot formed by the sixth conductor 124 with the first conductor 112 and the third conductor 116 and a slot formed by the sixth conductor 124 with the second conductor 114 and the third conductor 116, This can be.

Therefore, according to the filter 100 according to the first embodiment, a high-dimensional filter can be realized by forming a large number of slots to be formed, forming a large number of bending structures, and the like.

In addition, a high-dimensional filter can be implemented, and the type, bandwidth, and attenuation pole position of the resonance band can be adjusted, and the size and insertion loss of the filter can be minimized.

Next, the SIR type band-pass filter according to the second embodiment will be described.

3 is a perspective view schematically showing the structure of an SIR type band-pass filter (hereinafter referred to as "filter according to the second embodiment") according to the second embodiment.

The filter according to the second embodiment is differentiated from the first embodiment in that it is formed on the substrate of a multilayer structure, and the effect of the filter 100 according to the first embodiment can be further maximized.

3, the filter according to the second embodiment includes a first substrate 100 of the uppermost layer, a second substrate 100 of the lowermost layer, and a third substrate 200 of an intermediate layer. The first substrate 100 And the second substrate 100 are substrates having the same structure and formed with the filter structure according to the first embodiment. Therefore, the same reference numerals are used for the first substrate 100, the second substrate 200, and the filter 100 according to the first embodiment.

That is, the first substrate 100 and the second substrate 100 correspond to the filter 100 according to the first embodiment and can be seen as independent filters, and they can be connected by the third substrate 200 A new filter function can be implemented as a whole.

Since the structures of the first substrate 100 and the second substrate 100 are the same as those of the first embodiment, repetitive description will be omitted.

The third substrate 200 includes a metal thin film layer, and slots 210, 220, and 230 in which a portion of the metal thin film is removed are formed.

When the first substrate 100 and the second substrate 100 are stacked in a vertical structure, second resonance occurs at the ends of the first resonator 110 and the second resonator 120 of each substrate 100 .

Therefore, the third substrate 200 is formed in a region corresponding to the first resonator 110 and the second resonator 120 of the first substrate 100 and the second substrate 100, Three slots 210, 220, and 230 are provided.

The first slot 210 and the third slot 230 are formed at positions corresponding to the ends of the first conductor 112 and the second conductor 114 respectively, 5 conductors 122 and the ends of the sixth conductors 124. As shown in FIG.

Since the fifth conductor 122 and the sixth conductor 124 are disposed adjacent to each other, the second slots 220 may be isolated from each other, or the second slots 220 may be divided into two, The first conductor 122 and the sixth conductor 124 may be insulated from each other.

Through this structure, the filter according to the second embodiment can maximize the effect of the first embodiment. Even if only the number of resonance parts is shown, the number of resonance parts according to the first embodiment is two, It can be seen that the number of resonance parts according to the example is four.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications other than those described above are possible. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram illustrating various forms of an SIR type band-pass filter. Fig.

Fig. 2 is a top view schematically showing the structure of an SIR type band-pass filter according to the first embodiment; Fig.

3 is a perspective view schematically showing the structure of an SIR type band-pass filter according to the second embodiment.

Claims (11)

delete A first substrate formed in the form of a metal thin film having a first resonance portion having a multi-step bent multi-stage line structure and forming a resonance region and a second resonance portion having the line structure and at least a part formed inside the resonance region of the first resonance portion; A second substrate having the same structure as the first substrate; And And a third substrate disposed between the first substrate and the second substrate and having a slot formed in an area corresponding to at least one of the first resonator and the second resonator. 3. The apparatus of claim 2, An SIR bandpass filter formed by removing a metal thin film. The resonator according to claim 2, wherein the first resonator and the second resonator An SIR type bandpass filter implemented in strip line form. The resonator according to claim 2, wherein the first resonator A first conductor and a second conductor disposed opposite to each other; And And a third conductor connecting mutually opposite ends of the first conductor and the second conductor. 6. The method of claim 5, And a fourth conductor extending from the third conductor so as to face the outside of the region between the first conductor and the second conductor. 6. The method of claim 5, wherein the first and second conductors An SIR type bandpass filter having the same size and shape as each other. 6. The method of claim 5, wherein the third conductor Wherein the first conductor and the second conductor are connected in a linear form. 3. The resonator according to claim 2, wherein the second resonator A fifth conductor and a sixth conductor arranged to face each other; And And a seventh conductor connecting mutually opposite ends of the fifth conductor and the sixth conductor. 10. The method of claim 9, wherein the fifth and sixth conductors An SIR type bandpass filter having the same size and shape as each other. 10. The device of claim 9, wherein the seventh conductor In connecting the mutually opposing ends of the fifth conductor and the sixth conductor, And the other end of the fifth conductor and the sixth conductor is connected in a loop shape to surround the other end of the fifth conductor and the sixth conductor.

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