JP2009246624A - Layered balun transformer, and high frequency switch module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a layered balun transformer which can be made small in size and low in height and has excellent characteristics, and to provide a high frequency switch module using the layered balun transformer. <P>SOLUTION: In the layered balun transformer, each of first to fourth transmission lines constituting the balun transformer is configured by electrically and spirally connecting a plurality of conductor patterns formed on surfaces of a plurality of dielectric layers, and inductors constituted of the first to fourth transmission lines are arranged so as to be overlapped when viewed in a layering direction. The layered balun transformer includes a dielectric layer forming a part of conductor patterns constituting the first transmission line and a part of the conductor patterns constituting the third transmission line, and another dielectric layer forming a part of the conductor patterns constituting the second transmission line and a part of conductor patterns constituting the fourth transmission line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated balun transformer that is used in mobile communication devices such as a mobile phone and a mobile terminal, connects a balanced circuit and an unbalanced circuit, and can also be used for impedance conversion, and a high-frequency switch using the same Regarding modules.

  For example, as shown in FIG. 2, the balun transformer, which is a balanced-unbalanced conversion element, includes a first transmission line 11 and a second transmission line 12 that are unbalanced transmission lines. Four transmission lines are provided with two balanced terminals. Such a balun transformer is used by connecting an unbalanced transmission line to an unbalanced terminal and connecting two signal lines of the balanced transmission line to two balanced terminals. Then, the unbalanced signal input from the unbalanced terminal connected to the first transmission line is converted, and a balanced signal is output from the two balanced terminals of the third and fourth transmission lines by the phase difference. Conversely, the balanced signal from the balanced terminal is converted into an unbalanced signal and output from the unbalanced terminal. For example, in Patent Document 1, two spiral inductors are juxtaposed in a dielectric layer as shown in the laminated diagram of FIG. 9, and a balanced line and an unbalanced line are configured for each dielectric layer. A laminated balun transformer is disclosed. Further, in Patent Document 2, spiral inductors are formed in a plurality of dielectric layers, and the plurality of inductors are formed as balanced transmission lines and unbalanced transmission lines, and the plurality of inductors are overlapped when viewed from the top of the laminate. A structure is disclosed.

  These balun transformers are used alone, but are often built in high-frequency switch modules. Due to the recent miniaturization and thinning of mobile phones and portable terminals, a plurality of balun transformers may be mounted in high-frequency switch modules, and there is a demand for further reduction in balun transformer size and height. In addition, due to the miniaturization and high integration of the high frequency switch module, there is a demand for a narrow pitch in the terminals of the high frequency switch module, and the balun transformer needs to be connected to the terminals with the narrow pitch.

JP 2002-299127 A JP-A-9-260145

  In the conventional example of Patent Document 1, each transmission line has a spiral structure wound many times. As a result, the area occupied by the transmission line in each layer increases, and as a result, there is a problem that the demand for miniaturization of the balun transformer cannot be met. In addition, when a plurality of balun transformers of this conventional example are arranged side by side in a high-frequency switch module, each balun transformer cannot cope with downsizing, so that there is a problem that each balanced output terminal cannot be arranged at a narrow pitch. .

  In the conventional example of Patent Document 2, the balun transformer can be reduced in size as compared with the conventional example of Patent Document 1, but each transmission line has a spiral structure wound many times, so that the transmission line in each layer. Occupies a large area, and there is a problem that it is impossible to meet the demand for downsizing the balun transformer. Further, when a plurality of balun transformers are mounted in the high-frequency switch module, each balun transformer cannot cope with downsizing, so that there is a problem that the respective balanced output terminals cannot be arranged at a narrow pitch.

  In order to reduce the mounting area, each line is divided into a plurality of layers as shown in FIG. 9 as a third conventional example, and the number of turns of the lines formed per layer is one turn or less. There is a way to do it. However, in this method, since the number of turns per layer is reduced, the electromagnetic coupling between the balanced side line and the unbalanced side line becomes weak, and the insertion loss tends to deteriorate.

  In the third conventional example, in order to strengthen the electromagnetic coupling between the balanced line and the unbalanced line, the number of turns in the laminate is increased by increasing the number of layers constituting the transmission line, There is a method to increase the area of the inductor to be made. In the former method, since the number of layers in the stack increases, the stack becomes thick, and there is a problem that it is not possible to meet the demand for a low profile. In the latter method, the area occupied by the transmission line is increased, and as a result, there is a problem that it is impossible to meet the demand for downsizing the balun transformer.

  Also, when a balun transformer is built in the high frequency switch module, the connection between the balanced side terminal of the balun transformer and the balanced terminal on the mounting surface of the high frequency switch module connected to the balanced side terminal is not balanced output phase difference or balanced It is necessary to shorten the output amplitude difference as much as possible. Therefore, when multiple balun transformers are mounted on a high-frequency switch module, the increase in the area occupied by the balun transformer is not only a problem for miniaturization of the high-frequency switch module, but also the narrow pitch of the mounting terminals of the high-frequency switch module There was a risk of disruption.

  It is an object of the present invention to provide a laminated balun transformer having a small size and a low profile and having good characteristics, and a high-frequency switch module using the same.

  The laminated balun transformer according to the present invention includes a first transmission line and a second transmission line electrically connected to the first transmission line on a laminated body in which a plurality of dielectric layers on which a conductor pattern is formed are laminated. A transmission line; a third transmission line that is electromagnetically coupled to the first transmission line; and a fourth transmission line that is electromagnetically coupled to the second transmission line. Connected to a balanced terminal, the other end is connected to one end of the second transmission line, the other end of the second transmission line is an open end, one end of the third transmission line is grounded, and the other end is A laminated balun transformer connected to a first balanced terminal, having one end grounded and the other end connected to a second balanced terminal, wherein the first to fourth transmission lines are connected to the first balanced terminal. Electrically connect the conductor patterns formed on the surfaces of the plurality of dielectric layers in a spiral manner The inductors configured by the first to fourth transmission lines are arranged so as to overlap each other when viewed from the stacking direction, and a part of the conductor pattern that configures the first transmission line. A dielectric layer formed with a part of the conductor pattern constituting the third transmission line, and a part of the conductor pattern constituting the second transmission line and the fourth transmission line. And having another dielectric layer formed with a part of the conductor pattern to be formed.

  According to such a configuration, the number of windings of the transmission line in each layer can be reduced to 1 or less, so that the mounting area of the multilayer balun transformer can be reduced. Further, a part of the first and third transmission lines is formed on the same dielectric layer, and a part of the second and fourth transmission lines is formed on a dielectric layer different from the same dielectric layer. Therefore, the number of layers of the laminated body can be reduced, and the height of the laminated balun transformer can be reduced. In addition, the space occupied by the inductor formed by the first transmission line and the space occupied by the inductor formed by the third transmission line, and the space occupied by the inductor formed by the second transmission line and the fourth transmission line are formed. Since the space occupied by the inductor is partially overlapped, the coupling between the first transmission line and the third transmission line, and the second transmission line and the fourth transmission line is strengthened, and the insertion loss is reduced. It becomes possible.

  Further, in the multilayer balun transformer, each of the first to fourth transmission lines has a substantially rectangular outer shape having the same longitudinal direction when viewed from the lamination direction, and the balanced terminal is substantially rectangular. It is preferable that it is derived | led-out to the short side side. According to such a configuration, even when a plurality of balun transformers are arranged, the balanced terminals of the respective balun transformers can be brought close to each other, and the pitch of the balanced terminals can be reduced.

  The high-frequency switch module of the present invention is arranged between an antenna terminal, a reception terminal that outputs a reception signal, a transmission terminal that receives a transmission signal, and the antenna terminal, the reception terminal, and the transmission terminal. A high frequency circuit comprising a transmission / reception path and a switch circuit for switching a connection between a transmission path or a reception path, a multilayer substrate formed by stacking and integrating a conductor pattern on a plurality of dielectric layers, and a surface of the multilayer substrate A high-frequency switch module configured by mounted elements, wherein at least one of the reception terminal and the transmission terminal is configured by a balanced terminal connected to the multilayer balun transformer configured in the multilayer substrate It is characterized by being. According to such a configuration, in a high-frequency module including a balun transformer, it is possible to realize a high-frequency switch module that has a small mounting area, can easily form mounting terminals at a narrow pitch, and has a low profile and low insertion loss. is there.

  Another high-frequency switch module of the present invention includes an antenna terminal, a first reception terminal from which a reception signal of the first communication system is output, and a second frequency band that is different from the first communication system in a use frequency band. A second receiving terminal from which a received signal of the communication system is output; a first transmitting terminal to which the transmitted signal of the first communication system is input; and a first receiving terminal to which the transmitted signal of the second communication system is input. A switch that is arranged between two transmission terminals, the antenna terminal, the first and second reception terminals, and the first and second transmission terminals, and switches a connection between the transmission / reception path and the transmission path or the reception path. A high frequency circuit including a circuit and a common path shared by the first and second communication systems is divided into a path of the first communication system and a path of the second communication system. A multi-band high-frequency switch module comprising a laminated substrate in which conductive patterns are formed on a layer and laminated and integrated, and an element mounted on the surface of the laminated substrate, wherein the first and second transmission terminals At least one of the terminal group consisting of the terminal group and the terminal group consisting of the first and second receiving terminals is composed of a balanced terminal to which the multilayer balun transformer configured in the multilayer substrate is connected, A terminal group composed of balanced terminals is arranged at a peripheral portion of the main surface of the multilayer substrate, and each terminal of the terminal group composed of the balanced terminals does not go through a DC power supply terminal and other high-frequency signal terminals. It is characterized by being adjacent to each other. According to such a configuration, in a multiband high-frequency switch module using a plurality of different frequency bands, even when a plurality of balun transformers are connected corresponding to a plurality of communication systems having different frequency bands, the mounting area is small, and the low profile is low. Thus, it is possible to realize a high-frequency switch module with a small insertion loss. The above configuration that can be formed with a balanced terminal as a mounting terminal at a narrow pitch is a preferable configuration for reducing the occupied space of the entire balun transformer by adjoining a plurality of balun transformers.

  According to the present invention, it is possible to provide a laminated balun transformer and a high-frequency switch module with a small insertion loss even if the size is small and low or the size is reduced.

  Examples of the present invention will be described in detail below, but the present invention is not limited thereto. FIG. 1 is an exploded perspective view showing an embodiment of a laminated balun transformer according to the present invention. The laminated balun transformer is configured as a laminated body in which a plurality of dielectric layers on which conductor patterns are formed are laminated. This laminate is made of a ceramic dielectric material that can be fired at a low temperature, and a desired conductor pattern is formed by printing a conductor on a green sheet having a thickness of 10 μm to 200 μm, and a plurality of green having the conductor pattern It can be manufactured by laminating and integrating sheets, and further firing them integrally.

  An equivalent circuit diagram of the balun transformer is shown in FIG. The laminated balun transformer according to the present invention includes a first transmission line l1, a second transmission line l2 electrically connected to the first transmission line l1, and a first transmission line l1 that is electromagnetically coupled to the first transmission line l1. 3 transmission lines l3 and a fourth transmission line l4 electromagnetically coupled to the second transmission line l2. One end of the first transmission line l1 is connected to the unbalanced terminal P1, the other end is connected to one end of the second transmission line l2, and the other end of the second transmission line l2 is an open end (OPEN). Yes. One end of the third transmission line 13 is grounded, the other end is connected to the first balanced terminal P2, and one end of the fourth transmission line 14 is grounded, and the other end is connected to the second balanced terminal P3. Yes.

  The internal structure of the laminate will be described in the order of lamination. First, a shield ground electrode e1 for electromagnetically shielding the balun transformer from the outside is formed on the first green sheet. Thereby, the electromagnetic influence when other circuits and mounted components are arranged in a layer higher than the first layer can be reduced.

  On the second layer green sheet, a conductor pattern l1a constituting a part of the first transmission line l1 and a conductor pattern l3c constituting a part of the third transmission line l3 are formed. One end of the conductor pattern l1a is provided with a connection portion for connection to the unbalanced terminal P1 of the multilayer body, and the other end is connected to the third layer conductor pattern l1b through a through hole. One end of the conductor pattern l3c is grounded through a through hole, and the other end is connected to the third layer conductor pattern l3b through a through hole.

  Next, a conductor pattern l1b constituting a part of the first transmission line l1 and a conductor pattern l3b constituting a part of the third transmission line l3 are formed on the third layer green sheet.

  In the fourth layer green sheet, a conductor pattern l1c constituting a part of the first transmission line l1 and a conductor pattern l3a constituting a part of the third transmission line are formed. One end of the conductor pattern l3a is connected to one balanced terminal P2 on the bottom surface of the multilayer body through a through hole.

  A conductor pattern l1d constituting a part of the first transmission line l1 is formed on the fifth layer green sheet. In the fifth layer, which is the layer closest to the second transmission line, only the conductor pattern of the first transmission line is formed except for the through hole, and the conductor pattern of the third transmission line is formed. Absent. One end of the conductor pattern l1d is connected to the seventh-layer conductor pattern l2a through a through hole.

  A ground electrode e2 is formed on the sixth layer green sheet. As a result, electromagnetic interference between the conductor patterns l1 and l3 formed in the upper layer above e2 and the conductor patterns l2 and l4 formed in the lower layer can be reduced.

  On the seventh layer green sheet, a conductor pattern l2a constituting a part of the second transmission line l2 is formed. In the seventh layer, which is the layer closest to the first transmission line, only the conductor pattern of the second transmission line is formed except for the through hole, and the conductor pattern of the fourth transmission line is formed. Absent.

  The eighth-layer green sheet is formed with a conductor pattern l2b that forms part of the second transmission line l2 and a conductor pattern l4a that forms part of the fourth transmission line l4. One end of the conductor pattern l4a is connected to the other balanced terminal P3 on the bottom surface of the multilayer body through a through hole.

  In the ninth layer green sheet, a conductor pattern l2c constituting a part of the second transmission line l2 and a conductor pattern l4b constituting the fourth transmission line l4 are formed.

  The tenth layer green sheet is formed with a conductor pattern l2d constituting a part of the second transmission line l2 and a conductor pattern l4c constituting a fourth transmission line l4.

  Capacitor electrodes c1 and c2 constituting capacitors for balance adjustment of balanced output are formed on the 11th layer green sheet.

  A ground electrode e3 is formed on the twelfth layer green sheet.

  The green sheets of the first layer to the twelfth layer are sequentially laminated to form a laminate. The conductor pattern formed in each layer has a portion bent at 90 °, but all have less than one turn. Conductor patterns l1a, l1b, l1c and l1d formed on the surfaces of the plurality of dielectric layers are electrically connected in a spiral manner to form a first transmission line l1. Similarly, the conductor patterns l2a, l2b, l2c, and l2d formed on the surfaces of the plurality of dielectric layers are electrically connected in a spiral manner to form the second transmission line l2. In addition, the conductor patterns l3a, l3b and l3c formed on the surfaces of the plurality of dielectric layers are electrically connected in a spiral to form a third transmission line l3, and the conductor patterns l4a, l4b and l4c are electrically connected. A fourth transmission line 14 is formed in a spiral connection. In the configuration of FIG. 1, each transmission line has a spiral of about one turn, but the number of turns is not particularly limited and may be one or more turns.

  In the above green sheet, for example, regarding the arrangement of the conductor patterns for the second to fifth green sheets, the conductor pattern constituting a part of the first transmission line l1 and a part of the third transmission line l3 Are formed alternately on the upper and lower layers in the upper and lower layers, and when viewed from the stacking direction, the conductor pattern constituting the first transmission line l1 and the conductor pattern constituting the third transmission line l3 are formed. They are arranged so as to overlap each other. By arranging in this way, an electromagnetic coupling is formed between the inductor constituted by the first transmission line l1 and the inductor constituted by the third transmission line l3.

  Similarly, regarding the arrangement of the conductor patterns for the seventh to tenth green sheets, the conductor pattern constituting a part of the second transmission line l2 and the conductor constituting a part of the fourth transmission line l4. Patterns are alternately formed on the upper and lower layers, and when viewed from the stacking direction, the conductor pattern constituting the second transmission line l2 and the conductor pattern constituting the fourth transmission line l4 overlap each other. The result is the arrangement and composition. By arranging in this way, an electromagnetic coupling is formed between the inductor constituted by the second transmission line l2 and the inductor constituted by the fourth transmission line l4.

  Further, when viewed from the stacking direction, the conductor pattern constituting the first transmission line l1 and the conductor pattern constituting the third transmission line l3, the conductor pattern constituting the second transmission line l2, and the fourth transmission line. The conductor patterns constituting l4 are also arranged so as to overlap each other. Therefore, the inductors configured by the first to fourth transmission lines are arranged so as to overlap each other when viewed from the stacking direction, and the configuration area of the balun transformer is reduced.

  The second to fourth green sheets are each formed with a part of the conductor pattern constituting the first transmission line l1 and a part of the conductor pattern constituting the third transmission line l3. Has been. Similarly, each of the eighth to tenth green sheets has a part of the conductor pattern constituting the second transmission line l2 and a part of the conductor pattern constituting the fourth transmission line l4. Is formed. By including such a dielectric layer in the laminate, the dielectric layer is configured by an inductor constituted by the first transmission line l1, an inductor constituted by the third transmission line l3, and a second transmission line l2. Since the inductor constituted by the fourth transmission line 14 can be partially spatially shared, the balun transformer can be reduced in height. Moreover, in each inductor combination, the inductors are closely formed so as to be spatially shared, thereby improving the mutual inductance in each inductor combination and reducing the insertion loss of the multilayer balun transformer. It becomes possible. The dielectric layer on which a part of the conductor pattern composing the first transmission line l1 and a part of the conductor pattern composing the third transmission line l3 may be a single layer, but the height is reduced. In order to improve mutual inductance, two or more layers are preferable. The same applies to the dielectric layer in which a part of the conductor pattern constituting the second transmission line l2 and a part of the conductor pattern constituting the fourth transmission line l4 are formed. .

  Each of the first to fourth transmission lines configured by electrically connecting the conductor patterns formed on the surfaces of the plurality of dielectric layers in a spiral shape is substantially rectangular with the same longitudinal direction when viewed from the stacking direction. It has an external shape. The term “substantially rectangular” means that even a portion deviating from the rectangle is allowed due to a connection portion to a terminal or a conductor pattern for connecting a through hole. The part which comprises the helical coil part should just be a rectangle. The balanced terminals P2 and P3 are led out to the short side of the substantially rectangular shape. This longitudinal direction also coincides with the longitudinal direction of the rectangular laminated balun transformer. By arranging the balanced terminals P2 and P3 on the short side of the rectangular transmission line and the rectangular balun transformer as in this embodiment, the balanced terminals can be arranged even when a plurality of balun transformers are arranged in the high frequency switch module. It becomes possible to arrange with a narrow pitch.

  Next, characteristics of the multilayer balun transformer according to the present invention will be shown. FIG. 5 and FIG. 6 show the results of impedance and insertion loss evaluation assuming the 2.4 GHz band communication of the wireless LAN using the conventional structure shown in FIG. 10 and the structure of FIG. 1 according to the present invention, respectively. In the conventional structure shown in FIG. 10, the conductor patterns l1a and l1b constituting the first transmission line l1 and the conductor patterns l3a and l3b constituting the third transmission line l3 are formed in different layers. Similarly, the conductor patterns l2a and l2b constituting the second transmission line l2 and the conductor patterns l4a and l4b constituting the fourth transmission line l4 are formed in different layers. In FIG. 5, P1 means an unbalanced terminal, P2 and P3 mean balanced terminals, and shows an impedance Smith chart and a return loss at each terminal. FIG. 6 shows the insertion loss of the balun transformer. In FIGS. 5 and 6, the thin line is the result when the conventional structure shown in FIG. 10 is used, and the thick line is the result when the present invention is used. In the Smith chart, the closer the impedance is to the center of the circle, the better the impedance matching, the greater the return loss, and the smaller the insertion loss as a result. From the Smith chart of FIG. 5, it can be seen that the impedance of the conventional structure shown in FIG. 10 is close to the outer periphery and impedance matching is not achieved. Therefore, the return loss is about 1 dB in the vicinity of 2.4 GHz, and the insertion loss shown in FIG. 6 is also inferior to about 10 dB. On the other hand, in the structure according to the present invention, the impedance passes through the center of the Smith chart and is matched, and the return loss is 25 dB or more at 2.4 GHz. As a result, the insertion loss is also 1 dB or less.

  In the embodiment shown in FIG. 2, one end of the third and fourth transmission lines is short-circuited to the ground, but it may be connected to the ground via a capacitor C3 as shown in FIG. By doing so, the balanced terminal of the balun transformer is insulated from the ground, and a DC cut capacitor that cuts off a direct current when connected to an RF-IC or the like becomes unnecessary.

  In addition, when a laminated balun transformer is used in a communication device, a component such as an LNA may be connected to a balanced terminal of the balun. In order to stably operate components such as the LNA, it may be required that a predetermined DC voltage is applied as a bias voltage to the balanced terminal of the multilayer balun transformer. A circuit for enabling application of such a bias voltage is shown in FIG. By applying a predetermined DC voltage to the voltage terminal indicated by VC in the figure, it becomes possible to apply a bias voltage to the balanced terminal.

  The multilayer balun transformer according to the present invention may be constituted by itself or may be integrated with another circuit element and a multilayer substrate like a multilayer module. By using the multilayer balun transformer according to the present invention, it is possible to realize space saving by downsizing and low profile inside the multilayer substrate. Therefore, it is easy to combine the balun transformer with other parts. The multilayer balun transformer according to the present invention can be widely applied to a multilayer module including a balun transformer regardless of the configuration of a high-frequency circuit. As a preferred embodiment for the combination, there is a high-frequency switch module used for a wireless LAN or the like. As an example, FIG. 7 shows a block diagram of a dual-band high-frequency switch module to which the laminated balun transformer according to the present invention is applied. The high-frequency circuit configured in the high-frequency switch module includes an antenna terminal ANT, a first reception terminal Rx1 from which a reception signal of the first communication system is output, and a second frequency band different from that of the first communication system. The second reception terminal Rx2 from which the reception signal of the communication system of No. 1 is output, the first transmission terminal Tx1 to which the transmission signal of the first communication system is input, and the transmission signal of the second communication system are input. A second transmission terminal Tx2 is provided. Further, the high-frequency circuit includes a transmission / reception path and a transmission path in a path between the antenna terminal ANT, the first and second reception terminals (Rx1, Rx2), and the first and second transmission terminals (Tx1, Tx2). A switch circuit SW that switches connection with a path or a reception path, and a branching circuit Dip1 that branches a common path shared by the first and second communication systems into a path of the first communication system and a path of the second communication system And Dip2. In the configuration shown in FIG. 7, the balun transformers B1 and B2 are connected to the terminals of the terminal group including the first receiving terminal Rx1 and the second receiving terminal Rx2, respectively, and the terminals are balanced terminals Rx1 + and Rx1 +, respectively. It is composed of Rx1-, Rx2 +, and Rx2-.

  In the high frequency switch module shown in FIG. 7, at the time of transmission, a high frequency signal input from the Tx1 terminal or Tx2 terminal flows to the antenna terminal ANT via the branching circuit Dip1 and the switch circuit SW. At the time of reception, a signal input from the antenna terminal ANT flows to the branching circuit Dip2 via the switch circuit SW. In the duplexer Dip2, the received signal of the first communication system is distributed to the filter F1. The filter F1 passes a signal corresponding to the frequency band of the first communication system and blocks the unnecessary frequency band. The received signal that has passed through the filter F1 is output to the balanced output terminals Rx1 + and Rx1- through the balun transformer B1. The received signal of the second communication system is distributed from the duplexer Dip2 to the filter F2. In the filter F2, an unnecessary frequency band is blocked by passing a signal corresponding to the frequency band of the second communication system. The received signal that has passed through the filter F2 is output to the balanced output terminals Rx2 + and Rx2- through the balun transformer B2. Note that the balun transformer according to the present invention may be used for the transmission terminals Tx1 and Tx2.

  The high-frequency switch module includes a multilayer substrate formed by integrally stacking conductor patterns on a plurality of dielectric layers, and an element mounted on the surface of the multilayer substrate. As the balun transformers B1 and B2 in FIG. 7 described above, the multilayer balun transformer according to the present invention is configured and used in a multilayer substrate. Further, the branching circuit, the filter, and the balun transformer in the high frequency switch module are configured by a conductor pattern formed inside the multilayer substrate. The switch circuit includes a component mounted outside the multilayer substrate or a conductive pattern formed inside the multilayer substrate and the component mounted outside the multilayer substrate. This switch circuit may use a PIN diode, or may use a GaAs switch or the like.

  FIG. 8 shows the terminal electrode arrangement on the main surface on the mounting side of the multilayer substrate constituting the high-frequency switch module. Only balanced terminals Rx1 +, Rx1-, Rx2 +, and Rx2- are labeled, but a terminal group constituted by these balanced terminals is disposed along the peripheral edge of the main surface of the multilayer substrate. In addition to the balanced terminals Rx1 +, Rx1-, Rx2 +, and Rx2- that are reception terminals, a DC power supply terminal (control circuit output terminal for controlling a switch circuit, an amplifier circuit, etc.) is provided on the peripheral portion of the main surface of the multilayer substrate. Other than the balanced terminals Rx1 +, Rx1-, Rx2 + and Rx2- such as antenna terminals and transmission terminals, ground terminals, dummy terminals not connected to circuit elements, etc. It is formed along the side. As shown in FIG. 8, the balanced terminals Rx1 +, Rx1-, Rx2 +, and Rx2- are adjacent to each other without passing through the DC power supply terminal and other high-frequency signal terminals. The balanced terminals Rx1 +, Rx1-, Rx2 +, and Rx2- may be adjacent to each other via a ground terminal or a dummy terminal in order to ensure isolation between them, but from the viewpoint of miniaturization of the high-frequency switch module Are preferably adjacent to each other without interposing other terminals. By using the laminated balun transformer according to the present invention that is downsized, the balanced terminals can be easily arranged at a narrow pitch. In particular, when each of the first to fourth transmission lines has a substantially rectangular outer shape that is the same in the longitudinal direction when viewed from the stacking direction, a configuration is adopted in which the balanced terminal is led out to the short side of the substantially rectangular shape. Then, the pitch of the balanced terminal arrangement can be further reduced. A plurality of balun transformers should be arranged in a compact arrangement if the length in the direction along the short side of the region occupied by the conductor pattern of the multilayer balun transformer is made smaller than the pitch of the balanced terminals formed on the main surface. Can do.

  The high-frequency switch module shown in FIG. 7 has a configuration in which the common terminal of the switch circuit SW is connected to the antenna terminal ANT and the switching terminal is connected to the transmission-side branching circuit Dip1 and the reception-side branching circuit Dip2. The arrangement of the wave circuit may be reversed. That is, the transmission / reception path connected to the demultiplexing circuit is connected to the antenna terminal ANT, and the switch circuit for switching transmission / reception to the first communication system path side and the second communication system path side of the demultiplexing circuit is connected. It can also be adopted. The switch circuit may be an SPDT type switch circuit as shown in FIG. 7, or may be an SP3T type switch circuit having a switching terminal. Further, the filter can be omitted or added as appropriate according to the required characteristics. Further, the arrangement of the filters may be changed as appropriate.

  The configuration shown in FIG. 7 is an example of a dual-band high-frequency switch module. However, the present invention can be widely applied to multi-band high-frequency switch modules including triple-and high-frequency switch modules that use many communication systems. On the other hand, it goes without saying that the high-frequency module using the laminated balun transformer of the present invention can be applied not only to a multi-band high-frequency switch module but also to a single-band high-frequency switch module. In this case, the antenna terminal, the reception terminal to which the reception signal is output, the transmission terminal to which the transmission signal is input, and the antenna terminal, the reception terminal, and the transmission terminal are disposed between the transmission / reception path and the transmission terminal. A switch circuit for switching the connection with the path or the reception path may be provided. The dual-band high-frequency switch shown in FIG. 7 is that the high-frequency circuit is composed of a laminated substrate in which conductor patterns are formed on a plurality of dielectric layers and laminated and integrated, and an element mounted on the surface of the laminated substrate. Similar to the module example. A laminated balun transformer according to the present invention configured in a laminated substrate is connected to at least one of the receiving terminal and the transmitting terminal to constitute a balanced terminal.

It is a disassembled perspective view of the laminated body which shows one Embodiment of the laminated balun transformer which concerns on this invention. It is an equivalent circuit of one embodiment of the balun transformer according to the present invention. 6 is an equivalent circuit of another embodiment of the balun transformer according to the present invention. 6 is an equivalent circuit of another embodiment of the balun transformer according to the present invention. It is a figure which shows the impedance characteristic of a lamination type balun transformer. It is a figure which shows the insertion loss of a lamination type balun transformer. It is a block diagram which shows an example of the high frequency switch module which concerns on this invention. It is a figure which shows terminal arrangement | positioning formed in the main surface of the high frequency switch module which concerns on this invention. It is a figure which shows the conventional balun transformer. It is a disassembled perspective view of the laminated body of the conventional laminated balun transformer.

Explanation of symbols

P1: Unbalanced terminal
P2, P3: balanced terminals l1-l4: transmission line C3: capacitors l1a, l1b, l1c, l1d: conductor patterns l2a, l2b, l2c, l2d: conductor patterns l3a, l3b, l3c: conductor patterns l4a, l4b, l4c: conductors Patterns c1, c2: Capacitor electrodes e1, e2, e3, GND: Ground electrodes ANT: Antenna terminals Tx1, Tx2: Transmission terminals Rx1, Rx2: Reception terminals VC: Voltage terminals Rx1 +, Rx1-: Balanced reception terminals Rx2 +, Rx2-: Balanced reception terminal Dip1, Dip2: demultiplexing circuit F1, F2: filter B1, B2: balun transformer SW: switch circuit

Claims (4)

A first transmission line, a second transmission line electrically connected to the first transmission line, and the first transmission are stacked on a laminate in which a plurality of dielectric layers each having a conductor pattern are stacked. A third transmission line electromagnetically coupled to the line, and a fourth transmission line electromagnetically coupled to the second transmission line,
One end of the first transmission line is connected to an unbalanced terminal, the other end is connected to one end of the second transmission line, and the other end of the second transmission line is an open end,
The third transmission line has one end grounded and the other end connected to the first balanced terminal,
The fourth transmission line is a laminated balun transformer having one end grounded and the other end connected to the second balanced terminal,
Each of the first to fourth transmission lines is formed by electrically connecting conductor patterns formed on the surfaces of the plurality of dielectric layers in a spiral manner.
Each inductor composed of the first to fourth transmission lines is arranged so as to overlap when viewed from the lamination direction,
A dielectric layer formed with a part of the conductor pattern constituting the first transmission line and a part of the conductor pattern constituting the third transmission line;
A laminate having another dielectric layer in which a part of a conductor pattern constituting the second transmission line and a part of a conductor pattern constituting the fourth transmission line are formed. Type balun transformer.   Each of the first to fourth transmission lines has a substantially rectangular outer shape having the same longitudinal direction when viewed from the stacking direction, and the balanced terminal is led out to the short side of the substantially rectangular shape. The laminated balun transformer according to claim 1. An antenna terminal;
A receiving terminal for outputting a received signal;
A transmission terminal to which a transmission signal is input; and
A high-frequency circuit that is disposed between the antenna terminal and the reception terminal and the transmission terminal and includes a switch circuit that switches connection between a transmission / reception path and a transmission path or a reception path,
A high-frequency switch module configured by a laminated substrate formed by integrating conductor layers by forming conductor patterns on a plurality of dielectric layers, and an element mounted on the surface of the laminated substrate,
At least one of the reception terminal and the transmission terminal is configured by a balanced terminal to which the multilayer balun transformer according to claim 1 or 2 configured in the multilayer substrate is connected. Switch module. An antenna terminal;
A first reception terminal from which a reception signal of the first communication system is output; a second reception terminal from which a reception signal of a second communication system having a different frequency band from that of the first communication system is output;
A first transmission terminal to which a transmission signal of the first communication system is input; a second transmission terminal to which a transmission signal of the second communication system is input;
A switch circuit disposed between the antenna terminal, the first and second reception terminals, and the first and second transmission terminals, and switches between a transmission / reception path and a transmission path or a reception path, and first and first A high-frequency circuit including a demultiplexing circuit that branches a common path shared by the two communication systems into a path of the first communication system and a path of the second communication system;
A multi-band high-frequency switch module comprising a multi-layer substrate in which conductor patterns are formed and integrated in a plurality of dielectric layers, and an element mounted on the surface of the multi-layer substrate,
3. The device according to claim 1, wherein at least one of a terminal group including the first and second transmission terminals and a terminal group including the first and second reception terminals is configured in the multilayer substrate. A laminated balun transformer is connected and consists of balanced terminals.
The terminal group composed of the balanced terminals is arranged at the peripheral edge of the main surface of the multilayer substrate, and each terminal of the terminal group composed of the balanced terminals is connected via a DC power supply terminal and other high-frequency signal terminals. A high-frequency switch module characterized by being adjacent to each other.

Images