KR100804412B1 - Front-end module for triple-band terminal - Google Patents

Abstract

A front end module of a triple band terminal is provided to improve matching characteristics of an input impedance by providing an impedance matching inductor at input terminals of the second LPF(Low-Pass Filter) and an HPF(High-Pass Filter). The first LPF(410) extracts a signal of the first band from a signal received via a single antenna(400). A capacitor(C2) allows a signal of a high band frequency which has not been extracted by the first LPF(410) to pass therethrough. The second LPF(420) extracts a signal of the second band among signals which have passed through the capacitor(C2). An SAW(Surface Acoustic Wave) filter(440) extracts a signal of the second band from an output signal of the second LPF(420). An HPF(430) extracts a signal of the third band among signals which have passed through the capacitor(C2). An inductor(L3) for matching impedance is formed at a connection point to which the capacitor(C2), the second LPF(420) and the HPF(430) are connected.

Description

Front End Module for Triple Band Terminals {FRONT-END MODULE FOR TRIPLE-BAND TERMINAL}

1 is a view for explaining a frequency band of the triple band,

2 is a view showing an example of a configuration of a conventional front end module,

3 is a view showing the configuration of another example of a conventional front end module,

4 is a circuit diagram showing the configuration of a preferred embodiment of a front end module of the present invention;

5 is a plan view showing the appearance configuration of the front end module of the present invention, and

6 is a view showing a pattern formed on a plurality of dielectric sheets constituting the front end module of the present invention.

The present invention relates to a CDMA (Code Division Multiple Access) signal in the 824 to 894 MHz frequency band, a Global Positioning System (GPS) signal in the 1570 to 1580 MHz frequency band, and a 1850 to 1990 MHz frequency in the United States type Personal Communication Services (PCS). A front end module of a triple band terminal for separating USPCS signals of a band.

In general, a mobile communication terminal can be classified into a CDMA method using a frequency band of 824 to 894 MHz and a USPCS method using a frequency band of 1850 to 1990 MHz as a PCS (Personal Communication Services) method in the United States.

In addition, with the introduction of GPS technology in mobile communication terminals, various next-generation location information services are provided, including location tracking and traffic information. The GPS uses a frequency band of 1570 to 1580 MHz.

Triple band terminal is a terminal capable of receiving and processing the signals of the three frequency bands described above. For example, the signal of the frequency bands of the CDMA, USPCS, and GPS can be received through an antenna and processed separately.

The three frequency bands are, for example, a first band of the CDMA scheme that is the 824 to 894 MHz frequency band, a second band of the GPS that is the 1570 to 1580 MHz frequency band, and a 1850 to 1990 MHz band as shown in FIG. It can be divided into a third band of the frequency band USPCS.

The triple band terminal connects the front end module to the antenna to separate the signals of the first to third bands.

2 is a diagram illustrating an example of a conventional front end module. Referring to FIG. 2, the conventional front end module connects a low pass filter 210, a band pass filter 220, and a high pass filter 230 to a single antenna 200 so that signals of the first to third bands may be connected. The low pass filter 210, the band pass filter 220 and the high pass filter 230 is configured to separate each.

When the low pass filter 210, the band pass filter 220 and the high pass filter 230 are all connected to the antenna 200 as shown in FIG. 2, the low pass filter 210, the band pass filter 220, and The characteristics of the high pass filter 230 should be configured so as not to affect the characteristics of the relative band. In other words, the low pass filter 210 extracting the signal of the first band has an infinite impedance with respect to the signals of the second and third bands and does not affect the band pass filter 220 extracting the signal of the second band. ) Does not affect the signals of the first and third bands having infinite impedance, and the high pass filter 230 extracting the signals of the third band has infinite impedance to the signals of the first and second bands. It should not be affected.

However, when two different frequency bands are far apart from each other, it is impossible to have infinite impedance in both of them.

Therefore, conventionally, as shown in FIG. 3, two low pass filters and two high pass filters are used to separate signals in three frequency bands.

That is, Figure 3 is a view showing the configuration of another example of a conventional front end module. Referring to FIG. 3, a low pass filter 310 and a high pass filter 320 are connected to one antenna 300 to separate signals of the first band and the second and third bands, and the high pass filter. The low pass filter 330 and the high pass filter 330 were connected to the output terminal of the detector 320 to separate signals of the second band and the third band.

However, in the above-described other example, when the signals of the second band and the third band are extracted, the signals of the second band and the third band pass through two filters, that is, the signal of the second band is a high pass filter ( 320 and the low pass filter 330 are extracted, and the third band signal is extracted by passing through the two high pass filters 320 and 340, thereby increasing the insertion loss (Insertion Loss).

In FIG. 3, the low pass filter 310 extracts the signals of the first and second bands, the high pass filter 320 extracts the signals of the third band, and a low pass at the output of the low pass filter 310. The pass filter and the high pass filter may be connected to separate the signals of the first and second bands. However, in order to extract the signals of the first and second bands, two filters must be passed to increase the insertion loss. There was a problem.

It is an object of the present invention to provide a front end module of a triple band terminal capable of extracting the signals of the first to third bands through only one filter.

Another object of the present invention is to provide a front end module of a triple band terminal having an infinite impedance with respect to a signal of another band in addition to the signal of a band to be extracted by each filter.

According to the front end module of the triple band terminal of the present invention having the above object, the first low pass filter is connected to the antenna to extract the signal of the first band.

After connecting a capacitor to the antenna and passing a high frequency signal, a second low pass filter and a high pass filter are used to extract signals of the second band and the third band, respectively, and to the output terminal of the second low pass filter. A Surface Acoustic Wave (SAW) filter is used to precisely extract the signal of the second band.

Therefore, an embodiment of the front end module of the triple band terminal of the present invention may include a first low pass filter that extracts a signal of a first band from a signal received through one antenna, and is not extracted by the first low pass filter. And a second low pass filter for extracting a second band signal from the signals passing through the capacitor, and a second band signal from the output signal of the low pass filter. And a SAW (Surface Acoustic Wave) filter and a high pass filter for extracting a third band signal from the signals passing through the capacitor.

And an inductor for matching impedance to a connection point to which the capacitor, the second low pass filter and the high pass filter are connected.

The first to third band signals are CDMA (Code Division Multiple Access) signals in the 824 to 894 MHz frequency band, Global Positioning System (GPS) signals in the 1570 to 1580 MHz frequency band and 1850 to 1990 MHz frequency band, respectively. It is characterized in that the USPCS (US Personal Communication Services).

The first low pass filter implements a low pass characteristic by allowing an inductor for passing a received signal of the antenna, and signals of a frequency higher than a signal of a first band among signals passing through the inductor to exit to ground. It is characterized by consisting of a series resonator.

The high pass filter includes another capacitor for passing the signal passing through the capacitor, and a signal having a frequency lower than that of the third band signal among the signals passing through the another capacitor exits to ground. It is characterized by consisting of a series resonator for implementing the pass characteristics.

In another embodiment of the front end module of the triple band terminal of the present invention, a laminated dielectric sheet in which a plurality of layers are stacked, a pattern is formed in a plurality of layers stacked vertically on the laminated dielectric sheet, and a received signal of an antenna A first low pass filter for extracting a signal of a first band in a capacitor, a capacitor mounted on an upper surface of the multilayer dielectric sheet, a capacitor for passing signals of a second band and a third band, and a plurality of vertically stacked layers of the multilayer dielectric sheet A pattern is formed on the layer of the second lowpass filter which extracts the second band signal from the signals passing through the capacitor, and the second bandpass filter extracts the second band signal from the signal extracted by the second lowpass filter. A pattern is formed on a surface acoustic wave (SAW) filter and a plurality of layers stacked vertically on the laminated dielectric sheet, and is sealed on an upper surface of the laminated dielectric sheet. With the inductor and in the signal passing through the capacitor characterized by configured by comprising a high pass filter to extract the signal of the third band.

The laminated dielectric sheet is composed of first to ninth layers, and the first low pass filter comprises a pattern of inductor L1 formed in the second and third layers of the laminated dielectric sheet, and the first and second layers of the laminated dielectric sheet. A pattern of the inductor L2 formed in four layers and a capacitor C1 having a capacitance between the seventh layer of the multilayer dielectric sheet and a ground pattern of the eighth layer, the pattern of the inductor L1, the inductor The pattern of L2 and the capacitor C1 are characterized in that they are connected to each other through the via hole.

The laminated dielectric sheet is composed of first to ninth layers, and the second low pass filter comprises a pattern of inductor L4 formed in the fifth and sixth layers of the laminated dielectric sheet, and the laminated dielectric sheet. And a pattern of the capacitor C3 formed in the seventh layer of the capacitor having a capacitance between the ground pattern of the eighth layer, and the patterns of the inductor L4 and the capacitor C3 are connected through the via hole.

The laminated dielectric sheet is composed of first to ninth layers, and the high pass filter is formed on an inductor L5 mounted on an upper surface of the laminated dielectric sheet, and a second layer and a third layer of the laminated dielectric sheet. A pattern of capacitor C4 and a pattern of capacitor C5 formed in the seventh layer and having a capacitance between the ground pattern of the eighth layer, wherein the inductor L5, the pattern of capacitor C4, and the pattern of capacitor C5 are via holes. It is characterized by being connected through.

The laminated dielectric sheet is composed of first to ninth layers, and patterns are formed on second, fourth, and sixth layers of the laminated dielectric sheet to input the second low pass filter and the high pass filter. It further comprises a pattern of the inductor L3 matching the impedance.

The following detailed description is only illustrative, and merely illustrates embodiments of the present invention. In addition, the principles and concepts of the present invention are provided for the purpose of explanation and most useful. Accordingly, various forms that can be implemented by those of ordinary skill in the art, as well as not intended to provide a detailed structure beyond the basic understanding of the present invention through the drawings.

4 is a circuit diagram showing the configuration of a preferred embodiment of a front end module of the present invention. Here, reference numeral 400 denotes an antenna and reference numeral 410 denotes a first low pass filter for extracting a signal of a first band from a signal received through the antenna 400. In the first low pass filter 410, an inductor L1 is connected between the antenna 400 and an output terminal, and an inductor L2 and a capacitor C1 are connected in series with a connection point of the output terminal and the inductor L1. The connected series resonator is connected.

Reference symbol C2 is a capacitor for passing the high-frequency signal in the received signal of the antenna 400. Reference numeral L3 is an inductor connected in series with the capacitor C2 to match impedance. A second low pass filter 420 and a high pass filter 430 are connected to the connection point of the capacitor C2 and the inductor L3.

The second low pass filter 420 has a connection point of the capacitor C2 and the inductor L3 connected to the SAW filter 440 through the inductor L4, and the inductor L4 and the SAW filter 440. The ground capacitor C3 is connected to the connection point of.

The high pass filter 430 has a capacitor C4 connected between the connection point of the capacitor C2 and the inductor L3 and an output terminal, and an inductor L5 and a capacitor (B) between the capacitor C4 and the output terminal. A series resonator C5) is connected in series is connected.

In the front end module of the present invention configured as described above, the first low pass filter 410 filters signals of the first band, that is, CDMA signals having a frequency band of 824 to 894 MHz among the signals received through the antenna 400. Output to the outside.

Among the signals received through the antenna 400, a signal having a higher frequency band than that of the first band, that is, a GPS signal having a frequency band of 1570 to 1580 MHz, which is a second band, and a 1850 to 3rd band, are included. The USPCS signal of the 1990 MHz frequency band is input to the second low pass filter 420 and the high pass filter 430 through the capacitor C2.

In this case, the inductor L3 serves to match the input impedance of the second low pass filter 420 and the high pass filter 430.

Then, the second low pass filter 420 extracts a GPS signal having a frequency band of 1570 to 1580 MHz, which is a signal of a second band, from the input signals, and extracts the second low pass filter 420 from the second low pass filter 420. The band signal is precisely filtered by the SAW filter 440 and output to the outside.

The high pass filter 430 extracts the USPCS signal of the 1850∼1990MHz frequency band, which is the third band, from the input signals and outputs the signal to the outside.

Here, the first low pass filter 410 includes a series resonator. The series resonator built in the first low pass filter 410 has a high attenuation characteristic for a signal of a first band, which is a desired frequency band, and a characteristic for exiting to ground for a signal having a frequency higher than the pass band. As having, the first low pass filter 410 extracts the signal of the first band.

The high pass filter 430 also includes a series resonator. The series resonator built in the high pass filter 430 has a high attenuation characteristic with respect to a signal of a third band which is a desired frequency band, and has a characteristic of exiting to ground for a signal having a frequency lower than the pass band. The high pass filter 430 extracts a signal of a third band.

The signal of the second band is extracted by the second low pass filter 420 and then extracted by the SAW filter 440, so that only the signal of the second band can be precisely separated.

5 is a plan view showing the external configuration of the front end module of the present invention. Referring to FIG. 5, in the front end module of the present invention, a pattern of an inductor and a capacitor is formed on the laminated dielectric sheet 500, and a capacitor C2 having a large capacity is formed on the top layer of the stacked dielectric sheet 500. The inductor L5 and the SAW filter 440 are mounted. Here, the Q value is advantageous to mount the element of the inductor L5 on the uppermost layer of the laminated dielectric sheet 500 without forming the inductor L5 in a pattern on the dielectric sheet.

The multilayer dielectric sheet 500 may include a first low pass filter pattern part 510 in which a pattern of inductors L1 and L2 and a capacitor C1 constituting the first low pass filter 410 is vertically formed; A second low pass filter pattern portion 520 in which a pattern of an inductor L4 and a capacitor C3 constituting the second low pass filter 420 is formed, and a capacitor C4 constituting the high pass filter 430 , C5) and a high pass filter / impedance matching pattern unit 530 in which a pattern of the impedance matching inductor L3 is formed.

6A to 6I illustrate patterns formed on the laminated dielectric sheet 500 constituting the front end module of the present invention. 6A-6I, the laminated dielectric sheet 500 of the present invention is comprised of first through ninth layers 610-690.

Contact patterns 611-1 and 611-2 for mounting the capacitor C2 and contact patterns 613-1 and 613-2 for mounting the inductor L5 on the first layer 610. And an input terminal pattern 615 and an output terminal pattern 617 for connecting an input terminal and an output terminal of the SAW filter 440 mounted on the first layer 610, and a plurality of ground patterns 619-1, 619-2, 619-3) are formed.

The second layer 620 includes an inductor L1 of the first low pass filter 410, one electrode of a capacitor C4 of the high pass filter 430, and an impedance matching inductor L3. Pattern is formed.

A pattern of an inductor L1 of the first low pass filter 410 and the other electrode of the capacitor C4 of the high pass filter 430 is formed in the third layer 630.

In the fourth layer 640, an inductor L2 of the first low pass filter 410 and a pattern of the impedance matching inductor L3 are formed.

A pattern of an inductor L4 of the second low pass filter 420 is formed in the fifth layer 650.

In the sixth layer 660, an inductor L4 of the second low pass filter 420 and a pattern of the impedance matching inductor L3 are formed.

The seventh layer 670 includes a capacitor C1 of the first low pass filter 410, a capacitor C3 of the second low pass filter 420, and a capacitor of the high pass filter 430. A pattern of one terminal of C5) is formed.

The eighth layer 680 has a ground pattern 681 formed thereon, and the capacitor C1 and the second low pass filter 420 of the first low pass filter 410 formed in the seventh layer 670. The capacitor C3 has a predetermined capacitance between the capacitor C3 and the pattern of the capacitor C5 of the high pass filter 430.

The ninth layer 690 is an antenna contact pattern 691 to which the antenna 400 is connected, and a first band output port pattern for outputting a signal of a first band extracted by the first low pass filter 410. 692, a second band output port pattern 693 for outputting a second band signal output from the SAW filter 440, and a third band signal extracted from the high pass filter 430. A third band output port pattern 694 is formed for output.

Circles not described in the first to ninth layers 610 to 690 are via holes, and patterns formed in the first to ninth layers 610 to 690 are electrically connected through the via holes.

In the front end module of the present invention configured as described above, the antenna contact pattern 691 may have a contact pattern 611-1 of the first layer 610 and a pattern of the inductor L1 of the second layer 620 through the via hole. Connected.

The pattern of the inductor L1 of the second layer 620 is connected to the pattern of the inductor L1 of the third layer 630 through the via hole, and the pattern of the inductor L1 of the third layer 630 is The via hole is connected to the pattern of the inductor L2 of the fourth layer 640, and the pattern of the inductor L2 of the fourth layer 640 is connected to the capacitor C1 of the seventh layer 670 through the via hole. It is connected to the pattern of to form a first low pass filter 410.

The contact pattern 611-1 of the first layer 610 is connected to the contact pattern 611-2 through the capacitor C2, and the contact pattern 611-2 is connected to the second layer through the via hole. The pattern of the inductor L3 of the fourth layer 640 and the pattern of the inductor L3 of the fourth layer 640 are connected to the patterns of the capacitor C4 and the inductor L3 of 620. It is sequentially connected to the pattern of L3) to form an impedance matching inductor L3.

In addition, the pattern of the capacitor C4 of the second layer 620 has a capacitance between the pattern of the capacitor C3 of the third layer 630 and the capacitor C3 of the third layer 630. ) Is connected to the contact pattern 613-1 of the first layer 610 through the via hole. The contact pattern 613-1 of the first layer 610 is connected to the contact pattern 613-2 through an inductor L5, and the contact pattern 613-2 is connected to the seventh layer through a via hole. Connected to the pattern of the capacitor C5 of 670 to form a high-pass filter 430 having a capacitance between the pattern of the capacitor C5 of the seventh layer 670 and the ground pattern 681 of the eighth layer. Done.

The pattern of the capacitor C4 of the second layer 620 is connected to the pattern of the inductor L4 of the fifth layer 650 through the via hole, and the pattern of the inductor L4 of the fifth layer 650. Is connected to the pattern of the inductor L4 of the sixth layer 660 through the via hole, and the pattern of the inductor L4 of the sixth layer 660 is connected to the capacitor C3 of the seventh layer 670 through the via hole. And a second low pass filter 420 having a capacitance between the pattern of the capacitor C3 of the seventh layer 670 and the ground pattern 681 of the eighth layer.

As described in detail above, the present invention connects the first low pass filter to the antenna to extract the signal of the first band having the lowest frequency band. The signals of the second band and the third band having a higher frequency than the signals of the first band are extracted using a second low pass filter and a high pass filter after passing through the capacitor.

Therefore, according to the present invention, since the signals of the first to third bands are extracted through only one filter, the insertion loss can be reduced.

In addition, an impedance matching inductor may be provided at an input terminal of the second low pass filter and the high pass filter to match the input impedance, thereby further improving the matching characteristic of the input impedance.

In addition, the present invention can be fabricated in a very small size by forming a pattern on a dielectric sheet composed of a plurality of layers, and by mounting only a SAW filter, one capacitor and an inductor having a large capacitance and inductance on the multilayer dielectric sheet. The size of the triple band terminal can be reduced.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and changes of the present invention without departing from the spirit or field of the invention provided by the claims below It can be easily understood by those skilled in the art.

Claims (10)

A first low pass filter for extracting a signal of a first band from a signal received through one antenna; A capacitor for passing a high frequency signal that is not extracted from the first low pass filter; A second low pass filter for extracting a signal of a second band from the signals passing through the capacitor; A surface acoustic wave (SAW) filter for extracting a second band signal from an output signal of the second low pass filter; And And a high pass filter extracting a third band signal from the signals passing through the capacitor. 2. The system of claim 1, further comprising: a connection point to which the capacitor, the second low pass filter, and the high pass filter are connected; The front end module of the triple band terminal further comprises an inductor for matching impedance. 2. The apparatus of claim 1, wherein the first to third band signals are selected from the group consisting of; Code Division Multiple Access (CDMA) signals in the 824 to 894 MHz frequency band, Global Positioning System (GPS) signals in the 1570 to 1580 MHz frequency band, and US Personal Communication Services (USPCS) in the 1850 to 1990 MHz frequency band, respectively. The front end module of the triple band terminal. 2. The filter of claim 1, wherein the first low pass filter; An inductor for passing the received signal of the antenna; And The front end module of the triple band terminal, characterized in that consisting of a series resonator to implement a low-pass characteristics of the signal passing through the inductor higher frequency than the signal of the first band to the ground. The filter of claim 1, wherein the high pass filter; Another capacitor for passing the signal through the capacitor; And And a series resonator configured to implement a high pass characteristic by causing signals of a lower frequency than signals of the third band to pass to the ground among the signals passing through the another capacitor. A laminated dielectric sheet on which a plurality of layers are laminated; A first low pass filter having a pattern formed on a plurality of layers stacked vertically on the laminated dielectric sheet and extracting a signal of a first band from a received signal of an antenna; A capacitor mounted on an upper surface of the laminated dielectric sheet and configured to pass signals of a second band and a third band; A second low pass filter having a pattern formed on a plurality of layers stacked vertically on the laminated dielectric sheet, and extracting a signal of a second band from signals passing through the capacitor; A surface acoustic wave (SAW) filter for extracting a second band signal from the signal extracted by the second low pass filter; And A pattern is formed on a plurality of layers stacked vertically on the laminated dielectric sheet, and a high pass filter for extracting a third band signal from signals passing through the capacitor together with an inductor mounted on an upper surface of the laminated dielectric sheet. Front end module of the triple band terminal, characterized in that configured to include. The method of claim 6, wherein the laminated dielectric sheet; Consisting of the first to ninth layers, The first low pass filter is; A pattern of the inductor L1 formed in the second and third layers of the laminated dielectric sheet; A pattern of the inductor L2 formed in the fourth layer of the laminated dielectric sheet; And It is formed of a pattern of the capacitor C1 formed in the seventh layer of the laminated dielectric sheet and having a capacitance between the ground pattern of the eighth layer, The front end module of the triple band terminal, characterized in that the pattern of the inductor L1, the pattern of the inductor L2 and the capacitor C1 are connected to each other through a via hole. The method of claim 6, wherein the laminated dielectric sheet; Consisting of the first to ninth layers, The second low pass filter; A pattern of inductor L4 formed in the fifth and sixth layers of the laminated dielectric sheet; And It is formed of a pattern of the capacitor C3 formed in the seventh layer of the laminated dielectric sheet and having a capacitance between the ground pattern of the eighth layer, The front end module of the triple band terminal, characterized in that the inductor L4 and the pattern of the capacitor C3 is connected through the via hole. The method of claim 6, wherein the laminated dielectric sheet; Consisting of the first to ninth layers, The high pass filter is; An inductor L5 mounted on an upper surface of the multilayer dielectric sheet; A pattern of capacitor C4 formed in the second and third layers of the laminated dielectric sheet; And It is formed of a pattern of the capacitor C5 formed in the seventh layer of the laminated dielectric sheet and having a capacitance between the ground pattern of the eighth layer, And the inductor L5, the pattern of the capacitor C4, and the pattern of the capacitor C5 are connected through a via hole. The method of claim 6, wherein the laminated dielectric sheet; Consisting of the first to ninth layers, The pattern is formed on the second, fourth and sixth layers of the laminated dielectric sheet further comprises a pattern of the inductor L3 for matching the input impedance of the second low pass filter and the high pass filter. Front end module for triple band terminals.

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