KR102428338B1 - Front end module - Google Patents

Abstract

A front-end module according to an embodiment of the present invention includes an antenna terminal; and a first filter connected to the antenna terminal, and a second filter supporting wireless communication of a standard different from the standard supported by the first filter in a frequency band different from the frequency band of the first filter; including, wherein each of the first filter and the second filter includes an LC filter, a portion of an operation time period of the first filter overlaps a portion of an operation time period of the second filter, and the first filter includes an antenna terminal and a plurality of series portions connected in series between the and the first terminal, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the first terminal and the ground, wherein the second filter comprises: the antenna terminal and the second a plurality of series portions connected in series between terminals, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the second terminal and a ground, wherein at least one of the plurality of shunt portions of the first filter comprises: A capacitor and an inductor may include a capacitor and an inductor connected in series with each other to form an attenuation band, and at least one of the plurality of shunt units of the second filter may include a capacitor and an inductor that are connected in series with each other to form an attenuation band.

Description

Front-end module {FRONT END MODULE}

The present invention relates to a front end module.

5G communication is expected to efficiently connect more devices with more large-capacity data and faster data transmission speed compared to existing LTE (Long Term Evolution) communication.

5G communication is developing in the direction of using the frequency band of 24250 MHz to 52600 MHz corresponding to the millimeter wave (mmWave) band and the frequency band of 450 MHz to 6000 MHz corresponding to the sub-6 GHz band.

Each of the n77 bands (3300MHz~4200MHz), n78 bands (3300MHz~3800MHz) and n79 bands (4400MH~5000MHz) was defined as one of the operating bands of sub-6GHz, n77 bands (3300MHz~4200MHz), n78 bands (3300MHz~3800MHz) and n79 bands (4400MH~5000MHz) are scheduled to be used as main bands according to the advantage of having a wide bandwidth.

In the sub-6GHz band, a 4*4 MIMO (Multi-Input/Multi-Output) system is basically applied to improve frequency efficiency. MIMO is a technology that can expand the bandwidth in proportion to the number of antennas. When four antennas are used, the frequency efficiency is 4 times higher than that of a single antenna. However, according to the trend of slimming and miniaturization of mobile devices, there is a limit to the space in which the antenna is mounted, and there are physical restrictions in implementing additionally four antennas in the terminal under the condition that antennas used in the existing system exist.

An object of the present invention is to provide a front-end module capable of reducing the number of antennas mounted on a mobile device.

A front-end module according to an embodiment of the present invention includes an antenna terminal; and a first filter connected to the antenna terminal, and a second filter supporting wireless communication of a standard different from the standard supported by the first filter in a frequency band different from the frequency band of the first filter; including, wherein each of the first filter and the second filter includes an LC filter, a portion of an operation time period of the first filter overlaps a portion of an operation time period of the second filter, and the first filter includes an antenna terminal and a plurality of series portions connected in series between the and the first terminal, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the first terminal and the ground, wherein the second filter comprises: the antenna terminal and the second a plurality of series portions connected in series between terminals, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the second terminal and a ground, wherein at least one of the plurality of shunt portions of the first filter comprises: A capacitor and an inductor may include a capacitor and an inductor connected in series with each other to form an attenuation band, and at least one of the plurality of shunt units of the second filter may include a capacitor and an inductor that are connected in series with each other to form an attenuation band.

According to an embodiment of the present invention, by reducing the number of antennas employed in the mobile device, the isolation characteristic of the antenna can be improved.

1 is a block diagram of a mobile device equipped with a front-end module according to an embodiment of the present invention.
2 is a block diagram of a front-end module according to an embodiment of the present invention.
3 is a circuit diagram of a duplexer according to an embodiment of the present invention.
4 shows a frequency response according to an embodiment of the present invention.
5 to 7 are block diagrams of a front-end module according to various embodiments of the present invention.
8 is a block diagram illustrating an example of an amplifier connected to a filter according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] Reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein with respect to one embodiment may be embodied in other embodiments without departing from the spirit and scope of the invention. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the detailed description set forth below is not intended to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all scope equivalents to those claimed. Like reference numerals in the drawings refer to the same or similar functions throughout the various aspects.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to enable those of ordinary skill in the art to easily practice the present invention.

1 is a block diagram of a mobile device equipped with a front-end module according to an embodiment of the present invention.

Referring to FIG. 1 , a mobile device 1 according to an embodiment of the present invention includes a plurality of antennas ANT1 to ANT6 and a plurality of front-end modules connected to different antennas among the plurality of antennas ANT1 to ANT6, respectively. (FEM1 to FEM6) may be included.

The mobile device 1 performs wireless communication of various standards, such as cellular (LTE/WCDMA/GSM) communication, 2.4 GHz and 5 GHz Wifi communication, and Bluetooth communication. The plurality of antennas ANT1 to ANT6 and the plurality of front-end modules FEM1 to FEM6 included in the mobile device 1 support wireless communication of various standards.

However, when the plurality of antennas ANT1 to ANT6 are implemented in a limited space of the mobile device 1 , RF signals input and output from the plurality of antennas ANT1 to ANT6 are mutually interfered with each other, which causes deterioration of antenna performance. there is a problem.

Therefore, it is necessary to reduce the number of antennas mounted in the mobile device 1 by supporting a plurality of standard wireless communication by a front-end module connected to any one antenna.

2 is a block diagram of a front-end module according to an embodiment of the present invention.

The front-end module according to an embodiment of the present invention includes a first antenna terminal T_ANTa, a first terminal T1, a second terminal T2, and a first filter F1 and a second filter F2. and a duplexer (DPX).

The first filter F1 is disposed between the first antenna terminal T_ANTa and the first terminal T1 . One end of the first filter F1 is connected to the first antenna terminal T_ANTa, and the other end of the first filter F1 is connected to the first terminal T1.

The second filter F2 is disposed between the first antenna terminal T_ANTa and the second terminal T2 . One end of the second filter F2 is connected to the first antenna terminal T_ANTa, and the other end of the second filter F2 is connected to the second terminal T2. The second filter F2 may support wireless communication of a standard different from the standard supported by the first filter F1 in a frequency band different from that of the first filter F1.

The first filter F1 supports cellular communication in a preset first frequency band among the Sub-6 GHz band. For example, the first filter F1 may support cellular communication in a 3.3 GHz to 4.2 GHz band (n77 band) corresponding to the first frequency band. According to an embodiment, the first filter F1 may support cellular communication in a 3.3 GHz to 3.8 GHz band (n78 band).

The first filter F1 operates as a band pass filter. For example, the first filter F1 may include a band pass filter having a pass band of a band of 3.3 GHz to 4.2 GHz, and having a lower limit frequency of 3.3 GHz and an upper limit frequency of 4.2 GHz. According to an embodiment, the first filter F1 may include a band pass filter having a pass band of a band of 3.3 GHz to 3.8 GHz and a lower limit frequency of 3.3 GHz and an upper limit frequency of 3.8 GHz.

The second filter F2 supports Wi-Fi communication in the 5 GHz band. For example, the second filter F2 may support Wi-Fi communication in a band of 5.15 GHz to 5.950 GHz.

The second filter F2 operates as a band pass filter. As an example, the second filter F2 may include a band pass filter having a passband of a band of 5.15 GHz to 5.950 GHz and having a lower limit frequency of 5.15 GHz and an upper limit frequency of 5.950 GHz.

According to an embodiment of the present invention, a first filter (F1) supporting cellular communication in a sub-6 GHz band and a second filter (F2) supporting Wi-Fi communication in a 5 GHz band are configured as one duplexer (DPX) In addition, by connecting the duplexer DPX with one first antenna ANTa, the number of antennas provided in the mobile device can be remarkably reduced. A part of the operation time period of the first filter F1 included in one duplexer DPX may overlap a part of the operation time period of the second filter F2 . For example, the operation time period of the first filter F1 may coincide with the operation time period of the second filter F2, and the first antenna ANTa may simultaneously perform cellular communication and Wi-Fi communication with an external device. .

According to an embodiment of the present invention, by reducing the number of antennas provided in the mobile device, RF signals output from different antennas are prevented from interfering with each other, thereby improving the communication performance of the mobile device. Furthermore, by integrating filters supporting different standards into one front-end module, the total area of the front-end module can be reduced.

Meanwhile, referring to FIG. 2 , the first filter F1 supporting cellular communication in the sub-6 GHz band and the second filter F2 supporting Wi-Fi communication in the 5 GHz band share one antenna, so that different Compared to the case where the filters are connected to different antennas, it is necessary to have higher attenuation characteristics.

For example, when the first filter F1 supporting cellular communication in the sub-6 GHz band and the second filter F2 supporting Wi-Fi communication in the 5 GHz band are connected to separate antennas, the first filter F1 and each of the second filters F2, assuming that an attenuation characteristic of 25 dB is required, when the first filter F1 and the second filter F2 are connected to one antenna, the antenna isolation degree by 10 dB Since additional characteristics are required, each of the first filter F1 and the second filter F2 needs to have a total attenuation characteristic of 35 dB or more.

Although the BAW filter has excellent attenuation characteristics, it is difficult to form a wide passband, so it is difficult to apply to 5G communication requiring wideband frequency characteristics. Therefore, in order to satisfy the broadband frequency characteristic, it is necessary to configure the filters as an LC filter implemented by a combination of a capacitor and an inductor.

3 is a circuit diagram of a duplexer according to an embodiment of the present invention.

Referring to FIG. 3 , the duplexer DPX may include a first filter F1 , a second filter F2 , and an impedance matching unit IMU.

Each of the first filter F1 and the second filter F2 may include an LC filter implemented as a combination of a capacitor and an inductor. Each of the first filter F1 and the second filter F2 may have an attenuation characteristic of 35 dB or more, including the LC filter.

The first filter F1 includes a plurality of series units SE1 to SE3 disposed in series between the first antenna terminal T_ANTa and the first terminal T1 , and the first antenna terminal T_ANTa and the first terminal T1 . ) and a plurality of shunt units SH1 to SH3 disposed between different nodes and the ground.

For example, the plurality of series units SE1 to SE3 includes a first series unit SE1 , a second series unit SE2 sequentially disposed between the first antenna terminal T_ANTa and the first terminal T1 , and a third series unit SE3, and the plurality of shunt units SH1 to SH3 includes a first shunt unit disposed between the ground and a node between the first series unit SE1 and the second series unit SE2. SH1), the second shunt unit SH2 disposed between the node between the second series unit SE2 and the third series unit SE3 and the ground, and between the third series unit SE3 and the first terminal T1 It may include a third shunt unit SH3 disposed between the node of , and the ground.

The first series unit SE1 may include a capacitor C and an inductor L that are connected in parallel to each other, and a capacitor C and a capacitor C that are connected in series with the inductor L that are connected in parallel with each other. have.

The second series part SE2 may include a capacitor C, and the third series part SE3 includes a capacitor C and an inductor L connected in parallel to each other, and a capacitor C connected in parallel to each other. and an inductor (L) connected in series with the inductor (L).

Each of the first shunt unit SH1 , the second shunt unit SH2 , and the third shunt unit SH3 may include a capacitor C and an inductor L connected in series.

The capacitor C and the inductor L provided in each of the first series unit SE1 and the third series unit SE3 and connected in parallel to each other may form an attenuation region by parallel resonance. The first series unit SE1 may form an attenuation band at 5.90 GHz to 6.0 GHz, specifically, about 5.95 GHz, and the third series unit SE3 may form an attenuation band at 2.25 GHz to 2.35 GHz, specifically, about 2.3 GHz. An attenuation zone can be formed.

According to an embodiment of the present invention, the first filter F1 is connected to a high frequency band (WiFi 5GHz high) of the Wi-Fi 5GHz band according to the attenuation band formed at about 5.95GHz by the first series unit SE1. The attenuation characteristic can be improved, and according to the attenuation band formed at about 2.3 GHz by the third series unit SE3, the attenuation characteristic with the low frequency band (LTE HB low) of the LTE high band (HB) can be improved. can

The capacitor C and the inductor L provided in each of the first shunt unit SH1 , the second shunt unit SH2 , and the third shunt unit SH3 may form an attenuation region by series resonance. The first shunt unit SH1 may form an attenuation band at 1.95 GHz to 2.05 GHz, specifically, about 2 GHz, and the second shunt unit SH2 may form an attenuation band at 2.64 GHz to 2.74 GHz, about 2.69 GHz. In this case, the third shunt unit SH3 may form an attenuation band at 5.10 GHz to 5.20 GHz, about 5.15 GHz.

According to an embodiment of the present invention, the first filter F1 improves the attenuation characteristics with the 1.7GHz to 2.0GHz band (LTE MB) according to the attenuation band formed in the approximately 2GHz band by the first shunt unit SH1. Depending on the attenuation band formed at about 2.69 GHz by the second shunt unit SH2, the attenuation characteristic with the high frequency band (LTE HB high) among the 2.3 GHz to 2.7 GHz bands (LTE HB) can be improved. Also, according to the attenuation band formed at about 5.15 GHz by the third shunt unit SH3, the attenuation characteristic with the low frequency band (WiFi 5 GHz low) among the WiFi 5 GHz bands may be improved.

The second filter F2 includes a plurality of series portions SE4 to SE7 disposed in series between the first antenna terminal T_ANTa and the second terminal T2 , and the first antenna terminal T_ANTa and the second terminal T2 . ) and a plurality of shunt units SH4 to SH6 disposed between different nodes and the ground.

For example, the plurality of series units SE4 to SE7 may include a fourth series unit SE4, a fifth series unit SE5, and a fourth series unit SE4 sequentially disposed between the first antenna terminal T_ANTa and the second terminal T2. a 6-series unit SE6 and a 7th-series unit SE7, wherein the plurality of shunt units SH4 to SH6 are disposed between a node between the fourth series unit SE4 and the fifth series unit SE5 and the ground The fourth shunt unit SH4 disposed in ) and a sixth shunt unit SH6 disposed between a node between the seventh series unit SE7 and the ground.

The fourth series unit SE4 may include a capacitor C and an inductor L that are connected in parallel with each other, and a capacitor C and a capacitor C that are connected in series with the inductor L that are connected in parallel with each other. have. The fifth series part SE5 may include an inductor L, and each of the sixth series part SE6 and the seventh series part SE7 may include a capacitor C. As shown in FIG.

The fourth shunt unit SH4 may include a capacitor C, and each of the fifth shunt unit SH5 and the sixth shunt unit SH6 includes a capacitor C and an inductor L connected in series. may include

According to an embodiment of the present invention, the capacitor C and the inductor L connected in parallel to each other of the fourth series unit SE4 may implement a second harmonic attenuation characteristic in an 11 GHz band.

In addition, the capacitor C and the inductor L provided in each of the fifth shunt unit SH5 and the sixth shunt unit SH6 may form an attenuation region due to series resonance. The fifth shunt unit SH5 may form an attenuation band at 4.15 GHz to 4.25 GHz, specifically, about 4.2 GHz, and the sixth shunt unit SH6 may operate at 3.70 GHz to 3.80 GHz, specifically, about 3.75 GHz. An attenuation zone can be formed.

According to an embodiment of the present invention, the second filter F2 has an attenuation characteristic with the high frequency band n77 high among the n77 bands according to the attenuation band formed in the approximately 4.20 GHz band by the fifth shunt unit SH5. The attenuation characteristics with the intermediate frequency band n77 mid among the n77 bands may be improved according to the attenuation band formed at about 3.75 GHz by the sixth shunt unit SH6.

Meanwhile, in order to implement the first filter F1 and the second filter F2 as one duplexer DPX, the impedance of the pass band of the first filter F1 and the impedance of the pass band of the second filter F2 are used. need to match.

According to an embodiment of the present invention, by providing an impedance matching unit (IMU) between the first antenna terminal (T_ANTa) and the first filter (F1) / the second filter (F2), the first filter (F1) and The impedance of each passband of the second filter F2 may be matched. The impedance matching unit IMU may be disposed between a node connected to each of the first antenna terminal T_ANTa, the first filter F1 , and the second filter F2 and the ground.

The impedance matching unit IMU may include a matching inductor Lmat disposed between the first antenna terminal T_ANTa and the ground. The matching inductor Lmat may match the impedance of each passband of the first filter F1 and the second filter F2 to 50 ohms.

When a phase shifter in which a plurality of elements are arranged in a ð-shape or a T-shape is employed as the impedance matching unit, as the number of elements for impedance matching increases, there is a disadvantage in that signal loss increases. In particular, signal loss tends to be greater when devices are placed on the signal path.

According to an embodiment of the present invention, the matching inductor Lmat for impedance matching is not disposed directly in the signal path, but is disposed between the first antenna terminal T_ANTa and the ground, which can be greatly advantageous in terms of signal loss. have.

4 shows a frequency response according to an embodiment of the present invention.

In FIG. 4 , a first graph graph1 indicates a frequency response of the first filter F1 , and a second graph graph2 indicates a frequency response of the second filter F2 .

Referring to the first graph of FIG. 4 , the frequency response of the first filter F1 has a pass characteristic of about -1.53 dB at about 3.3 GHz and about -1.30 dB at about 4.20 GHz. The first filter F1 has high attenuation characteristics for the 2.300 GHz to 2.690 GHz band allocated to the LTE communication band, and at the same time to have high attenuation characteristics for the 5.15 GHz to 5.950 GHz band allocated to the Wi-Fi communication band. can

Referring to the second graph (graph2) of FIG. 4 , the frequency response of the second filter F2 has a pass characteristic of about −0.97 dB at about 5.15 GHz and about −0.66 dB at about 5.95 GHz. The second filter F2 may have a high attenuation characteristic for the 3.3 GHz to 4.2 GHz band allocated to the Sub-6 GHz band.

According to an embodiment of the present invention, the first filter F1 may have an attenuation characteristic of about -39.05 dB at 5.15 GHz, and the second filter F2 has an attenuation characteristic of about -36.95 dB at 4.2 GHz. Therefore, even when the first filter F1 and the second filter F2 share one antenna, RF signals can be stably transmitted and received without interference.

According to an embodiment of the present invention, filters having high attenuation characteristics are implemented as a duplexer, which is significantly advantageous in terms of signal loss compared to a case in which a separate diplexer is provided in addition to the filters, and the front end due to the simplification of components The area of the module can be reduced, and the manufacturing cost can be reduced.

5 to 7 are block diagrams of a front-end module according to various embodiments of the present invention.

Since the front-end module according to the embodiment of FIGS. 5 to 7 is similar to the front-end module according to the embodiment of FIG. 2 , the overlapping description will be omitted and the differences will be mainly described.

Referring to FIG. 5 , the front-end module according to the embodiment of FIG. 5 may further include a third filter F3 and a switch SW, compared to the front-end module according to the embodiment of FIG. 2 . The third filter F3 is disposed between the switch SW and the third terminal T3. One end of the third filter F3 is connected to the switch SW, and the other end of the third filter F3 is connected to the third terminal T3.

The third filter F3 supports cellular communication in a preset second frequency band among the Sub-6 GHz band. For example, the third filter F3 may support cellular communication in a 4.4 GHz to 5.0 GHz band (n79 band) corresponding to the second frequency band.

The third filter F3 operates as a band pass filter. For example, the third filter F3 may include a band pass filter having a pass band of a band of 4.4 GHz to 5.0 GHz and including a lower limit frequency of 4.4 GHz and an upper limit frequency of 5.0 GHz.

The switch SW is implemented as a 3-terminal switch in the form of a single pole double throw (SPDT). One end of the switch SW may be connected to the first antenna terminal T_ANTa, and the other end of the switch SW may be selectively connected to the duplexer DPX and the third filter F3. The switch SW may selectively connect the duplexer DPX and the third filter F3 to the first antenna terminal T_ANTa.

The 4.4 GHz to 5.0 GHz band corresponding to the pass band of the third filter F3 is a 3.3 GHz to 4.2 GHz band corresponding to the pass band of the first filter F1 and the pass band corresponding to the second filter F2. Since the band gap of 5.15 GHz to 5.95 GHz is extremely narrow, RF signals can be transmitted and received through one first antenna ANTa in a time division manner through the switch SW. Accordingly, the operation time period of the first filter F1 and the second filter F2 and the operation time period of the third filter F3 may be different from each other.

The front-end module according to this embodiment includes cellular communication in the n77 band (3.3 GHz to 4.2 GHz) of the sub-6 GHz band and Wi-Fi communication in the 5 GHz band, as well as cellular communication in the n79 band (4.4 GHz to 5.0 GHz) of the sub-6 GHz band. communication can be performed.

Referring to FIG. 6 , the front-end module according to the embodiment of FIG. 6 may further include a fourth filter F4 compared to the front-end module according to the embodiment of FIG. 2 .

The fourth filter F4 is disposed between the second antenna terminal T_ANTb and the fourth terminal T4 . One end of the fourth filter F4 is connected to the second antenna terminal T_ANTb, and the other end of the fourth filter F4 is connected to the fourth terminal T4.

The fourth filter F4 supports Wi-Fi communication in the 2.4 GHz band. For example, the fourth filter F4 may support Wi-Fi communication in a band of 2.4 GHz to 2.4835 GHz.

The fourth filter F4 operates as a band pass filter. For example, the fourth filter F4 may include a band pass filter having a passband of a band of 2.4 GHz to 2.4835 GHz and having a lower limit frequency of 2.4 GHz and an upper limit frequency of 2.4835 GHz.

The front-end module according to the present embodiment may perform Wi-Fi communication in the 2.4 GHz band in addition to cellular communication in the n77 band (3.3 GHz to 4.2 GHz) and Wi-Fi communication in the 5 GHz band among the sub-6 GHz band.

Referring to FIG. 7 , the front-end module according to the embodiment of FIG. 7 further includes a third filter F3 , a fourth filter F4 and a switch SW compared to the front-end module according to the embodiment of FIG. 2 . may include The third filter F3, the fourth filter F4, and the switch SW of FIG. 7 are the same as the third filter F3 and the switch SW of FIG. 5, and the fourth filter F4 of FIG. , a detailed description will be omitted.

The front-end module according to this embodiment includes cellular communication in the n77 band (3.3 GHz to 4.2 GHz) of the sub-6 GHz band and Wi-Fi communication in the 5 GHz band, as well as cellular communication in the n79 band (4.4 GHz to 5.0 GHz) of the sub-6 GHz band. Communication and Wi-Fi communication in the 2.4 GHz band can be performed.

8 is a block diagram illustrating an example of an amplifier connected to a filter according to an embodiment of the present invention.

In FIG. 8 , the filter F includes the first filter F1 , the second filter F2 , the third filter F3 , and the fourth filter F4 of FIGS. 2 , 5 , 6 , and 7 . It may be understood as a configuration corresponding to any one of them. In addition, the receiving end Rx and the transmitting end Tx may be understood as being included in any one of the first terminals T1 to T4 of FIGS. 2, 5, 6, and 7 . . For example, the first terminal T1 may include a receiving end Rx and a transmitting end Tx.

The amplifier AU may include a switch SW, a low noise amplifier (LNA), and a power amplifier (PA).

Referring to FIG. 8 , the filter F is connected to one end of the low noise amplifier LNA and one end of the power amplifier PA through a switch SW, respectively. The low noise amplifier LNA may be disposed in the reception path Rx_RF of the RF signal, and the power amplifier PA may be disposed in the transmission path Tx_RF of the RF signal. In addition, the other end of the low noise amplifier (LNA) is connected to the receiving end (Rx), and the other end of the power amplifier (PA) is connected to the transmitting end (Tx).

In FIG. 8 , the low noise amplifier LNA is disposed in the receive path Rx_RF and the power amplifier PA is disposed in the transmit path Tx_RF. However, depending on the need for amplification according to the design, the receiving path The low noise amplifier LNA may be removed from (Rx_RF), or the power amplifier PA may be removed from the transmission path Tx_RF.

According to an embodiment of the present invention, by reducing the number of antennas employed in the mobile device, the isolation characteristic of the antenna can be improved.

In the above, the present invention has been described with specific matters such as specific components and limited embodiments and drawings, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , those of ordinary skill in the art to which the present invention pertains can devise various modifications and variations from these descriptions.

Therefore, the spirit of the present invention should not be limited to the above-described embodiments, and not only the claims described below, but also all modifications equivalently or equivalently to the claims described below belong to the scope of the spirit of the present invention. will do it

ANT: antenna
F1: first filter
F2: second filter
F3: 3rd filter
F4: fourth filter
DPX: Duplexer

Claims (16)

antenna terminal; and
a duplexer including a first filter connected to the antenna terminal, and a second filter supporting wireless communication of a standard different from the standard supported by the first filter in a frequency band different from that of the first filter; including,
Each of the first filter and the second filter includes an LC filter, and a portion of an operation time period of the first filter overlaps a portion of an operation time period of the second filter,
The first filter includes a plurality of series portions connected in series between the antenna terminal and the first terminal, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the first terminal and the ground, and ,
The second filter includes a plurality of series portions connected in series between the antenna terminal and the second terminal, and a plurality of shunt portions disposed between different nodes between the antenna terminal and the second terminal and the ground, ,
At least one of the plurality of shunt units of the first filter includes a capacitor and an inductor connected in series with each other to form an attenuation region,
and at least one of the plurality of shunt units of the second filter includes a capacitor and an inductor connected in series with each other to form an attenuation region.
According to claim 1,
The duplexer further comprises an impedance matching unit for matching the impedance of the pass band of the first filter and the impedance of the pass band of the second filter,
The impedance matching unit may include a matching inductor disposed between the antenna terminal and the ground.
According to claim 1,
The first filter supports cellular communication in a band of 3.3 GHz to 4.2 GHz, and the second filter supports Wi-Fi communication in a band of 5.15 GHz to 5.950 GHz.
4. The method of claim 3,
The attenuation band formed by the capacitor and the inductor connected in series with at least one of the plurality of shunt units of the first filter is formed at 5.10 GHz to 5.20 GHz,
An attenuation band formed by a capacitor and an inductor connected in series with at least one of the plurality of shunt units of the second filter is formed in a range of 4.15 GHz to 4.25 GHz.
5. The method of claim 3 or 4,
At least one of the plurality of series units of the first filter includes a capacitor and an inductor connected in parallel to each other to form an attenuation band at 5.90 GHz to 6.0 GHz.
6. The method of claim 5,
At least one of the plurality of series parts of the first filter further comprises a capacitor and an inductor connected in parallel to each other to form an attenuation band at 2.25 GHz to 2.35 GHz,
At least one of the plurality of shunt units of the first filter includes a capacitor and an inductor connected in series with each other to form an attenuation band at 1.95 GHz to 2.05 GHz, and a capacitor and an inductor connected in series with each other to form an attenuation band at 2.64 GHz to 2.74 GHz further comprising a capacitor and an inductor;
At least one of the plurality of shunt units of the second filter further includes a capacitor and an inductor connected in series to each other to form an attenuation band in 3.70 GHz to 3.80 GHz.
According to claim 1,
At least one of the plurality of series parts of the first filter includes a capacitor and an inductor connected in parallel to each other to form an attenuation region,
A frequency difference between an attenuation band formed by at least one of a plurality of shunt units of the first filter and a capacitor and an inductor connected in series with each other and a frequency band of the first filter is at least one of the plurality of series units of the first filter A front-end module smaller than a frequency difference between an attenuation band formed by a capacitor and an inductor connected in parallel with each other and the frequency band of the first filter.
8. The method of claim 1 or 7,
At least one of the plurality of series parts of the second filter includes a capacitor and an inductor connected in parallel to each other to form an attenuation region,
A frequency difference between an attenuation band formed by at least one of a plurality of shunt units of the second filter and a capacitor and an inductor connected in series with each other and a frequency band of the second filter is at least one of the plurality of series units of the second filter A front-end module that is smaller than a frequency difference between an attenuation band formed by a capacitor and an inductor connected in parallel with each other and the frequency band of the second filter.
9. The method of claim 8,
At least one of a plurality of series parts of the second filter including a capacitor and an inductor connected in parallel to each other has a second harmonic attenuation characteristic in the frequency band of the second filter.
According to claim 1,
An attenuation band formed by a capacitor and an inductor connected in series with at least one of the plurality of shunt units of the first filter is formed such that the highest frequency of the frequency band of the first filter is located within.
11. The method of claim 10,
The attenuation band formed by the capacitor and the inductor connected in series with at least one of the plurality of shunt units of the second filter is formed such that the lowest frequency of the frequency band of the second filter is located within.
According to claim 1,
At least one of the plurality of series parts of the first filter includes a capacitor and an inductor connected in parallel to each other to form an attenuation region,
The number of shunt parts including the capacitor and the inductor connected in series among the plurality of shunt parts of the first filter is greater than the number of series parts including the capacitor and the inductor connected in parallel among the plurality of series parts of the first filter Many front-end modules.
13. The method of claim 1 or 12,
At least one of the plurality of series parts of the second filter includes a capacitor and an inductor connected in parallel to each other to form an attenuation region,
Among the plurality of shunt units of the second filter, the number of shunt units including capacitors and inductors connected in series with each other is greater than the number of series units including capacitors and inductors connected in parallel with each other among the plurality of series units of the second filter. Many front-end modules.
According to claim 1,
a third filter having a pass band of 4.4 GHz to 5.0 GHz; and
a switch selectively connecting the duplexer and the third filter to the antenna terminal; A front-end module that further includes .
According to claim 1,
a fourth filter having a pass band of 2.4 GHz to 2.4835 GHz; further comprising,
The fourth filter is a front-end module connected to an antenna terminal to which the duplexer is connected and another antenna terminal.
According to claim 1,
Each of the first filter and the second filter is a front-end module having an attenuation characteristic of 35 dB or more.

Images