This application claims the benefit of Korean Patent Application No. 10-2009-0116652, filed on Nov. 30, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a system and method for modifying a hairpin filter, and a hairpin filter.
2. Description of the Related Art
In wireless communication transceivers, filters are typically used to remove undesired signals around wireless communication transceivers. Currently, a large number of studies on filters are being conducted and as a result, filters have a variety of forms.
Among these filters, a hairpin type filter (hereinafter, is referred to as a “hairpin filter”) is most frequently used. Since a hairpin filter is enabled to have a small size in a system where a size of a filter is important, a hairpin filter is preferred over other forms.
Specifically,
As shown in
An aspect of the present invention provides a hairpin filter that may remove an undesired signal near an adjacent frequency band by forming a new transmission zero through a structural transformation of a conventional hairpin filter while maintaining advantages of compactness of the conventional hairpin filter.
Another aspect of the present invention provides a system and method for modifying a hairpin filter that may divide a conventional hairpin filter into a plurality of filters on both sides of the center of the conventional hairpin filter, and may arrange the plurality of filters in a bilaterally symmetrical pattern, so that a transmission zero may be formed on both sides of a pass band.
According to an aspect of the present invention, there is provided a system for modifying a hairpin filter, the system including a structure transformer to divide a hairpin filter into a plurality of filters and to arrange the plurality of filters in a bilaterally symmetrical pattern, and a coupling generator to generate a plurality of coupling lines, each of the plurality of coupling lines being between each of the filters.
The coupling generator may generate the coupling lines between far ends of transmission lines or between center lines, the transmission lines and the center lines being in the filters.
The system may further include a frequency modifier to modify an attenuation frequency by adjusting a parameter value that is associated with the generated coupling lines.
The frequency modifier may modify a first attenuation frequency by adjusting a parameter value that is associated with a length between each of the coupling lines.
The frequency modifier may modify a second attenuation frequency by adjusting another parameter value that is associated with a length between each of the filters.
When a first attenuation frequency and a second attenuation frequency are simultaneously modified, the frequency modifier may adjust the parameter value. Here, the parameter value and the first attenuation frequency may be associated with a length between each of the coupling lines, and the second attenuation frequency may be associated with a length between each of the filters.
According to another aspect of the present invention, there is provided a hairpin filter in which a plurality of filters are arranged in a bilaterally symmetrical pattern, and a plurality of coupling lines are respectively generated between each of the plurality of filters. Here, the plurality of filters may be obtained by dividing the hairpin filter.
According to still another aspect of the present invention, there is provided a method for modifying a hairpin filter, the method including dividing a hairpin filter into a plurality of filters and arranging the plurality of filters in a bilaterally symmetrical pattern, generating a plurality of coupling lines, each of the plurality of coupling lines being between each two of the filters, and modifying an attenuation frequency by adjusting a parameter value, the parameter value being associated with the generated coupling lines.
According to embodiments of the present invention, a process of designing a conventional hairpin filter may be used without any change and thus, it is possible to reduce a time required to design a hairpin filter, and to maintain advantages of compactness.
Additionally, according to embodiments of the present invention, a new transmission zero may be formed through a simple structural transformation of a conventional hairpin filter and thus, it is possible to easily remove an undesired signal in an adjacent frequency band.
These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Exemplary embodiments are described below to explain the present invention by referring to the figures.
The hairpin filter modification system 300 may include a structure transformer 310, a coupling generator 320, and a frequency modifier 330, as shown in
The structure transformer 310 may divide a hairpin filter into a plurality of filters, and may arrange the plurality of filters in a bilaterally symmetrical pattern.
For example, the structure transformer 310 may divide a hairpin filter into two filters, and may arrange the two filters in a bilaterally symmetrical pattern. In other words, the structure transformer 310 may fold the hairpin filter so that the two filters may be symmetrical on both sides of the center of the hairpin filter.
The coupling generator 320 may generate a plurality of coupling lines. Here, each of the plurality of coupling lines may be generated between each of the filters formed in the bilaterally symmetrical pattern.
Additionally, the coupling generator 320 may generate the plurality of coupling lines between far ends of transmission lines or between center lines. Here, the transmission lines and the center lines may be placed in the filters. For example, the coupling generator 320 may form a single or a plurality of coupling characteristics for filters by various schemes of using a coupling between center lines, or using a coupling between far ends of transmission lines, or using both of the two couplings.
As described above, the hairpin filter modified by the hairpin filter modification system 300 may be configured to be foldable so that both sides of the center of the hairpin filter may be symmetrical. Additionally, in the hairpin filter, coupling lines may be generated between each of the filters, to show new coupling characteristics. Accordingly, the hairpin filter may form a band stop characteristic, to easily remove a signal in an undesired band.
The frequency modifier 330 may modify an attenuation frequency by adjusting a parameter value that is associated with the generated coupling lines.
For example, the frequency modifier 330 may modify a first attenuation frequency by adjusting a first parameter value that is associated with a length between each of the coupling lines.
Referring to
Additionally, the frequency modifier 330 may modify the second attenuation frequency by adjusting a second parameter value that is associated with a length between each of the filters arranged in the bilaterally symmetrical pattern. Here, when the first attenuation frequency and the second attenuation frequency are simultaneously modified, the frequency modifier 330 may adjust the first parameter value associated with the length between each of the coupling lines.
Referring to
According to an embodiment of the present invention, it is possible to generate a hairpin filter that may easily remove an undesired signal in an adjacent frequency band by forming a new transmission zero through a simple structural transformation of a conventional hairpin filter while maintaining advantages of compactness of the conventional hairpin filter.
Additionally, according to an embodiment of the present invention, it is possible to generate a hairpin filter that may form a transmission zero on both sides of a passband by dividing a conventional hairpin filter into a plurality of filters on both sides of the center of the conventional hairpin filters and arranging the plurality of filters in a bilaterally symmetrical pattern.
The hairpin filter of
Specifically, the hairpin filter of
Additionally, in the hairpin filter of
Referring to the graph of
As shown in the graph of
As shown in the graph of
As shown in the graph of
As described above, the hairpin filter according to the embodiment of the present invention may modify all of the three attenuation frequencies to desired frequencies. Accordingly, it is possible to simplify a design of a compact hairpin filter having superior attenuation characteristics.
In the hairpin filter according to the other embodiment of the present invention, various schemes of forming coupling characteristics may be provided, for example, a scheme of using only a coupling between center lines, a scheme of using only a coupling between far ends of transmission lines, and a scheme of using both of the two couplings.
The method of modifying a hairpin filter may be performed by the hairpin filter modification system 300 of
In operation 1210, the hairpin filter modification system 300 may divide a hairpin filter into a plurality of filters, and may arrange the plurality of filters in a bilaterally symmetrical pattern.
For example, the structure transformer 310 may divide a hairpin filter into two filters, and may arrange the two filters in a bilaterally symmetrical pattern. In other words, the structure transformer 310 may fold the hairpin filter so that the two filters may be symmetrical on both sides of the center of the hairpin filter.
In operation 1220, the hairpin filter modification system 300 may generate a plurality of coupling lines between each of the filters arranged in the bilaterally symmetrical pattern.
Additionally, the coupling generator 320 may generate the plurality of coupling lines between far ends of transmission lines or between center lines. Here, the transmission lines and the center lines may be placed in the filters. For example, the coupling generator 320 may form a single or a plurality of coupling characteristics for filters by various schemes of using a coupling between center lines, or using a coupling between far ends of transmission lines, or using both of the two couplings.
As described above, the hairpin filter modified by the hairpin filter modification system 300 may be configured to be foldable so that both sides of the center of the hairpin filter may be symmetrical. Additionally, in the hairpin filter, coupling lines may be generated between each of the filters, to show new coupling characteristics. Accordingly, the hairpin filter may form a band stop characteristic, to easily remove a signal in an undesired band.
In operation 1230, the hairpin filter modification system 300 may modify an attenuation frequency by adjusting a parameter value that is associated with the generated coupling lines.
For example, the frequency modifier 330 may modify a first attenuation frequency by adjusting a first parameter value that is associated with a length between each of the coupling lines.
Referring to
Additionally, the frequency modifier 330 may modify the second attenuation frequency by adjusting a second parameter value that is associated with a length between each of the filters arranged in the bilaterally symmetrical pattern. Here, when the first attenuation frequency and the second attenuation frequency are simultaneously modified, the frequency modifier 330 may adjust the first parameter value associated with the length between each of the coupling lines.
Referring to
According to an embodiment of the present invention, it is possible to generate a hairpin filter that may easily remove an undesired signal in an adjacent frequency band by forming a new transmission zero through a simple structural transformation of a conventional hairpin filter while maintaining advantages of compactness of the conventional hairpin filter.
Additionally, according to an embodiment of the present invention, it is possible to generate a hairpin filter that may form a transmission zero on both sides of a passband by dividing a conventional hairpin filter into a plurality of filters on both sides of the center of the conventional hairpin filters and arranging the plurality of filters in a bilaterally symmetrical pattern.
The above-described exemplary embodiments of the present invention may be recorded in non-transitory computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The program instructions recorded on the media may be those specially designed and constructed, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVDs; magneto-optical media such as floptical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter.
Although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Number | Date | Country | Kind |
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10-2009-0116652 | Nov 2009 | KR | national |