JP2002064401A - High-frequency switch module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency switch module which is reduced in insertion loss and improved in receiving sensitivity in receiving. SOLUTION: A high-frequency switch module has a structure in which a first switching element is disposed between a transmission circuit and an antenna, a transmission line is disposed between the antenna and a receiving circuit, the end of the transmission line on the receiving circuit side is grounded through the intermediary of a second switching element, and a filter circuit is arranged between the antenna and the connecting point between the first switching element and the transmission line. The high-frequency switch module switches the signal path of high-frequency signals from one to another by the use of the first and second switching element, and the characteristic impedance of the transmission line is set at 30 to 45 Ω.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency composite component used in a high-frequency band such as a quasi-microwave band, and more particularly to a high-frequency switch module in which at least one antenna handles a transmitting / receiving system.

[0002]

2. Description of the Related Art In recent years, the spread of mobile phones has been remarkable, and the functions and services of mobile phones have been improved. Such mobile phone wireless communication systems include:
There are PDC, PCS, GSM1800, EGSM and the like.
Initial mobile phones began with single-band mobile phones that shared one antenna for one transmitting and receiving system. Such a high-frequency switch is disclosed, for example, in Japanese Patent Application Laid-Open No. 2-108301. This high-frequency switch has a diode disposed between the transmission circuit and the antenna, and a λ / 4 phase line disposed between the antenna and the reception circuit.
The receiving circuit side of the / 4 phase line is grounded via a diode, thereby constituting a λ / 4 switch circuit for switching a signal path by a bias current flowing through each diode. Further, a high-frequency switch has been developed in which such a λ / 4 type switch circuit is integrated with a laminated body using a low-temperature sintered dielectric ceramic material to form a multilayer substrate (see, for example, JP-A-6-197040).

[0003] Thereafter, the number of subscribers of the mobile telephone service has increased rapidly, and the frequency band allocated to each system has not been able to cover all the cases. Thus, a dual-band mobile phone or the like that makes it possible to use a plurality of systems to substantially increase the available frequency has come to the market. This dual-band mobile phone handles two or more transmission / reception systems, while an ordinary mobile phone handles only one transmission / reception system. For example, in a dual-band mobile phone, GSM1800 (transmission TX.
5 MHz, RX RX. 1805 to 1880 MHz), EGSM (TX TX: 880 to 915 MHz) as a second transmission / reception system
z, RX RX. 925-960 MHz). In such a mobile phone, a high-frequency switch including a branching circuit and a switch circuit is used as a signal path corresponding to each frequency and a switch for switching a plurality of frequencies (for example, Japanese Patent Laid-Open No.
No.-225089). This allows the user of the mobile phone to select and use a convenient transmission / reception system.
Such a high-frequency switch is hereinafter referred to as a high-frequency switch module.

[0004]

The components used in the high-frequency circuit in which the high-frequency switch module is used include:
Generally, the value of the characteristic impedance is set to 50Ω. As the size and weight of the mobile phone have been reduced, high-frequency switch modules have also been strongly required to be reduced in size and height. As is well known, the characteristic impedance of a transmission line varies depending on the distance from the ground plane, the relative permittivity of a dielectric material forming the transmission line, and the width of the transmission line. In order to form the transmission line on a multilayer substrate and set its characteristic impedance to approximately 50Ω, it is easy to appropriately adjust and set the width of the transmission line. More specifically, the width of the transmission line is reduced as the size and height of the high-frequency switch module are reduced. As a result, there is a problem that the resistance of the transmission line increases, the insertion loss on the receiving side increases, and the receiving sensitivity decreases. Accordingly, an object of the present invention is to provide a high-frequency switch module that does not deteriorate the insertion loss on the receiving side even if the high-frequency switch module is reduced in size and height.

[0005]

SUMMARY OF THE INVENTION The present invention provides a first switching element disposed between a transmitting circuit and an antenna, a transmission line disposed between the antenna and a receiving circuit, and a receiving line of the transmission line. The circuit side is grounded via a second switching element, a filter circuit is arranged between a connection point between the first switching element and the transmission line and an antenna, and the first and second switching elements A high-frequency switch module for switching a signal path of a high-frequency signal, wherein a characteristic impedance of the transmission line is 30Ω to
This is a high-frequency switch module of 45Ω. In the present invention, it is preferable that an impedance when the filter circuit is viewed from the connection point is substantially equal to a characteristic impedance of the transmission line. Further, it is preferable that the transmission line is a strip line or a microstrip line formed on a multilayer substrate formed by laminating a plurality of dielectric layers. Preferably, the filter circuit includes a strip line or a microstrip line formed on the multilayer substrate and a capacitor. More preferably, the switching element is at least one selected from a diode and a transistor, and is mounted on the outer surface of the multilayer substrate.

(Function) In order to reduce the size of the high-frequency switch module, the present inventors have tried to solve the problem of deterioration of insertion loss on the receiving side by reducing the resistance of the transmission line disposed between the antenna and the receiving circuit. Focusing on loss and conducting various studies,
In order to configure the transmission line with low resistance loss, Ag or Cu
The idea was to configure the transmission line using low-resistance conductors such as those described above, and to increase the width of the transmission line so as to increase the skin area of the transmission line.

[0010] In a limited space of a multi-layer substrate, making the width of the transmission line large leads to a decrease in its characteristic impedance. As described above, in a high-frequency circuit, the value of the characteristic impedance is generally set to 50Ω. However, the present inventors have changed the idea and changed the pattern width of the transmission line in the main path of the reception path to a functional value. Specifically, the pattern width of the transmission line connected to the main path is made relatively large, so that the characteristic impedance of the transmission line is deliberately lowered, thereby increasing the resistance of the transmission line without increasing the resistance of the transmission line. It has been found that the received signal can be efficiently transmitted from the antenna to the receiving terminal without deterioration of the insertion loss.

If the characteristic impedance of the transmission line exceeds 45Ω, the insertion loss at the time of reception is not so different from the conventional one. If the characteristic impedance is less than 30Ω, the effect of reducing the insertion loss is large, but the pattern width is too wide. However, the demand for miniaturization cannot be met.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-frequency switch module using a transmission line according to the present invention will be described with reference to the drawings. FIG. 1 shows an equivalent circuit when applied to a single band, and FIG. 2 shows an equivalent circuit when applied to a dual band.

FIG. 1 shows a circuit of a high-frequency switch module used in a single-band portable telephone according to an embodiment of the present invention. This switch circuit uses two diodes DP1 and DP2 as switching elements, and
With two transmission lines LP1 and LP2 and a diode DP1
Has an anode connected to the antenna terminal ANT side, a cathode connected to the transmission circuit TX side, and a transmission line LP1 connected to the ground connected to the cathode side. Then, a transmission line LP2 is connected between the antenna side and the receiving circuit RX, a diode DP2 having a cathode connected to the receiving circuit RX side is connected, and a capacitor CP6 is connected between the anode of the diode DP2 and the ground. Connected, between which an inductor is connected and connected to the control circuit VC2. The transmission line LP2 is a strip line or a microstrip line formed on a multilayer substrate formed by laminating a plurality of dielectric layers,
By making the width wider, its characteristic impedance is reduced to 3
0 to 45Ω.

Further, a filter circuit is arranged between the antenna and the connection point between the diode DP1 and the transmission line LP2. In the present embodiment, the filter circuit is a low-pass filter including the transmission line LF11 and the capacitors CF11 and CF12 so as to suppress harmonic components from the transmission circuit TX. Here, the configuration is such that the impedance of the filter circuit as viewed from the connection point is substantially equal to the characteristic impedance of the transmission line. As a result, the loss due to the mismatch between the filter circuit and the switch circuit can be reduced, and the antenna terminal ANT and the receiving system RX can be connected with low resistance.

[0015] Usually, a lot-shaped or wire-shaped antenna is mounted outside the high-frequency switch module and connected to the antenna terminal ANT of the high-frequency switch module. A high-frequency switch module that further incorporates and incorporates is also conceivable. Although the present invention exemplifies a case where an antenna is externally mounted as an embodiment, the present invention can also be applied to a composite module including an antenna.

FIG. 2 shows another embodiment of the high-frequency switch module. In this embodiment, a first transmitting / receiving system (EGSM900) and a second transmitting / receiving system (GSM1
800) is a high-frequency switch module that handles
A first switch circuit for switching between a transmission signal and a reception signal of a transmission / reception system (EGSM900), a first low-pass filter circuit connected to a transmission line of the first switch circuit,
A second switch circuit for switching between a transmission signal and a reception signal of the second transmission / reception system (GSM1800), a second low-pass filter circuit connected to the transmission line of the second switch circuit, the first transmission / reception system and the second It is composed of a demultiplexing circuit composed of two filter circuits for demultiplexing a transmission / reception system.

The branch circuit portion connected to the antenna terminal ANT mainly includes two notch filter circuits. That is, the transmission line LF1 and the capacitor CF1 form one notch circuit, and the transmission line LF2 and the capacitor C1.
F2 constitutes another notch filter circuit.
The capacitor CF3 connected to the ground is connected to one notch filter circuit. This capacitor CF3 is connected for the purpose of improving the low-pass filter characteristics of the demultiplexing characteristics. Another notch filter circuit includes a transmission line LF3 connected to the ground.
And the capacitor CF4 are connected in series. The transmission line LF3 and the capacitor CF4 are connected for the purpose of improving the high-pass filter characteristics of the demultiplexing characteristics. This demultiplexing circuit may use, for example, a band-pass filter circuit, a low-pass filter circuit, a high-pass filter circuit, or the like, other than the notch filter circuit, and may be configured by appropriately combining these.

Next, the first switch circuit will be described. The first switch circuit is the switch circuit on the upper side in FIG. 2 and switches between transmission TX and reception RX of the EGSM900 system. This switch circuit SW includes two diodes DG1 and DG2 and two transmission lines LG1 and LG.
The transmission line LG has a diode DG1, an anode connected to the antenna terminal ANT side, a cathode connected to the transmission TX side, and a ground connected to the cathode side.
1 is connected. A transmission line LG2 is connected between the antenna side and the reception RX, a diode DG2 having a cathode connected to the reception side is connected, and a capacitor C is connected between the anode of the diode DG2 and the ground.
G6 is connected, while the inductor LG is connected,
Connected to control circuit VC1. In the present invention, the line impedance of the transmission line LG2 is set to 30 to 45Ω to reduce the insertion loss at the time of reception. The low-pass filter circuit inserted on the transmission TX circuit side includes a transmission line LG.
3 and capacitors CG3, CG4, CG7, the diode DG1 of the switch circuit SW and the transmission line L
It is inserted between G1.

Next, the second switch circuit will be described. The second switch circuit is a switch circuit on the lower side in FIG. 2 and switches between the transmission TX and the reception RX of the GSM1800 system. This switch circuit SW includes two diodes DP1 and DP2 and two transmission lines LP1 and LP2.
The transmission line LP has a diode DP1, an anode connected to the antenna terminal ANT side, a cathode connected to the transmission TX side, and a ground connected to the cathode side.
1 is connected. A transmission line LP2 is connected between the antenna and the reception RX, a diode DP2 having a cathode connected to the reception RX is connected, and a capacitor CP6 is connected between the anode of the diode DP2 and the ground. , Between which the inductor is connected,
Connected to control circuit VC2. In the present invention, the line impedance of the transmission line LP2 is set to 30 to 45Ω to reduce the insertion loss at the time of reception.

The operation of the control circuit will be described. EG
To enable SM900 transmission, the voltage terminal V
A predetermined voltage is applied to C1. Similarly, the voltage terminal VC2
When a predetermined voltage is applied to GSM1800, transmission of the GSM1800 system becomes effective. At the time of reception, either of the voltage terminals VC1, VC
No voltage is applied to 2. The low-pass filter circuit inserted on the transmission TX circuit side includes a transmission line LP3,
It is composed of capacitors CP3, CP4 and CP7 and is inserted between the diode DP1 of the switch circuit SW and the transmission line LP1.

In the embodiment shown in FIG.
LP2 and RX (RX / EGSM900, RX / GS
M1800), a band pass filter using a surface acoustic wave element (SAW) represented by SG and SP is connected. By using the SAW filter, the size can be reduced, the filter can be electrically high in Q (the sharpness of the resonance circuit), and the size and the selectivity of the received signal can be improved. In FIG. 2, the function of the capacitor CGP is to lower the impedance between the connection point N1 of the transmission lines LG1 and LP1 and the ground at high frequencies.
The function of the resistor R in FIG. 2 is to control the value of the current flowing through the diode. In this embodiment, the EGSM900 system and G
Each control circuit VC1, VC1 of SM1800 series
2, the number of components can be reduced. In FIG. 2, a DC (direct current) cut capacitor is not required between the transmission line and the SAW filter. S
This is because the AW filter can cut off DC (direct current) due to its structure. As described above, the present invention has been described with respect to a single band and a dual band high frequency switch module.
Applicable to multiple bands of triple band or more.

FIG. 3 is a perspective view of a high-frequency switch module using a band pass filter using a surface acoustic wave element (SAW) represented by SG and SP. FIG. 3 shows an embodiment in which a circuit is formed only by through holes without using side electrodes, and the electrodes are concentrated on the bottom of the high-frequency switch module. Side electrodes may be used or may be used in combination. The use of the side electrodes not only increases the degree of freedom in pattern design but also improves the solder strength by forming fillets, but the pitch of the external electrodes of the high-frequency switch module is reduced from 1.27 mm to 0.65 mm. As the trend toward pitch miniaturization of modules and improvement in package density progresses, the weight of the high-frequency switch module decreases and the necessity of improving solder strength decreases, but solder bridges (bridges) occur between electrodes during soldering. This is because the risk of short-circuiting with the component mounted on the upper surface of the laminate is increasing. SAW filters (SG, SP), PIN diodes (DG1, DG2, DP1, DP2), capacitors (C
G1, CGP) and the resistor R were all formed as printed circuits on the laminate ML. As a large configuration, two SAW filters are arranged in front of FIG. 3, and a duplexer is arranged on the left side of FIG. 3, and through a dielectric layer on which a ground pattern is formed,
Under that, a switch circuit, a low-pass filter, and a dielectric layer on which a ground pattern is formed are sandwiched,
Dielectric layer with capacitor pattern printed, and
The ground pattern was arranged at the bottom. In the mounting shown in FIG. 3, since the SAW filters (SG, SP) are arranged by providing a step in the stacked bodies ML1 and ML2, the height can be reduced and the size can be further reduced. Stacks ML1, ML2
Is an integral structure.

According to the present invention, as shown in FIG. 3, the high-frequency switch module can be miniaturized by arranging chip components on the laminated structure and the laminated body. The antenna terminal ANT, which is a common terminal of the plurality of transmission / reception systems, the transmission system terminal TX, and the reception system terminal RX of each transmission / reception system are terminals for high-frequency signals, and are called high-frequency terminals. The high-frequency terminals are formed on the back surface or the back surface and the side surface of the laminated body as illustrated in FIGS. 3 and 4, and are arranged so that the high-frequency terminals are not adjacent to each other. The symbol of each high-frequency terminal corresponds to the equivalent circuit in FIG. A ground terminal GND or a switch circuit control terminal (VC1, VC2) is arranged between the high-frequency terminals. It is preferable that at least one ground terminal GND is arranged between the high-frequency terminals. As described above, by keeping the high-frequency terminals from being adjacent to each other and by arranging the ground terminals between the high-frequency terminals, interference between the high-frequency terminals can be suppressed and the loss can be reduced.

It is preferable that the transmission system terminal and the reception system terminal are arranged so close to each other that the transmission system terminals and the reception system terminals are not adjacent to each other. In addition, it is preferable that the transmission system terminal and the reception system terminal are respectively arranged in different regions with respect to the center line of the laminate. In addition, this transmission system terminal,
It is preferable that the receiving system terminals are arranged in line symmetry.
With this configuration, in a device that handles a plurality of transmission / reception systems on which the high-frequency switch module is mounted,
It is easy to connect to the transmission system circuit and the reception system circuit.

It is preferable that the common terminal and the transmission terminal and the reception terminal of each transmission / reception system are formed in different regions when the laminate is divided into two parts by a plane perpendicular to the mounting surface. Since the high-frequency switch module is disposed between the antenna and the transmission / reception circuit, this terminal arrangement allows the antenna and the high-frequency switch module and the transmission / reception circuit and the high-frequency switch module to be connected with the shortest line, and an extra loss Can be prevented.

In the present invention, it is preferable to arrange a metal case so as to surround the chip components arranged on the laminate. This is because not only the shielding effect, but also the vacuum suction is easy for the user of the high-frequency switch module in the case of the metal when soldering with the chip mounter. If a shielding effect is not required and it is only for forming a flat surface for supplying the chip mounter, mold the high-frequency switch module with a heat-resistant resin that can withstand the heat during reflow soldering, or coat the surface with a metal coating Is also good. This metal case is preferably mounted with the terminal electrodes on the side surfaces of the laminate exposed. Further, the metal case can be fixed to the upper surface of the laminate by soldering. Further, with the metal case, the high-frequency switch module of the present invention can be mounted using a mounter device. When a SAW filter is used as a bandpass filter of a receiving system, a SA that is already packaged and commercially available is used.
A W filter may be used, but if the entire high-frequency switch module is packaged using a bare-chip or flip-chip SAW filter, the size and performance can be further reduced.

The internal structure of the laminate will be described.
FIGS. 5 and 6 show print patterns of each layer. This embodiment is an example in which electrodes of each layer are printed on a dielectric sheet having a thickness of 0.05 mm (dimension after integrated firing) and connected by through holes. The through holes in FIGS. 5 and 6 are lands marked with x. A hole is formed in the X portion to form a through hole. FIG. 5 shows the laminate from the uppermost layer (1) to the eighth layer (8) every 0.05 mm in thickness, and FIG. 6 shows the further lower layer from the ninth layer (9). 18th layer (18)
Up to Symbols such as DG1, CG1, and DG2 attached to the pattern correspond to the equivalent circuit in FIG.

For this laminate, a green sheet made of a ceramic dielectric material that can be fired at a low temperature is prepared, and a conductive paste such as Ag, Pd, or Cu is printed on the green sheet to form a desired electrode pattern. Then, they are laminated as appropriate and fired integrally. Hereinafter, the configuration of each layer after firing will be described in order from the lowest layer. First, on the lowermost eighteenth layer (FIG. 6 (18)), a ground electrode GND is formed on almost the entire surface (for the GND electrode, a pattern is painted out for easy understanding). This ensures a stable ground. In particular, in this embodiment, a plurality of through holes (in the case of FIG. 6 (18), six through holes on each side) communicate with the back surface, and can be used as a wide and elongated GND shown in FIG. 4 for connection to an external circuit. A stable ground effect is obtained. On the seventeenth layer (FIG. 6 (17)), capacitor electrodes (CG6, CGL, CP6, CPL) are formed. These capacitors are used in a control circuit that controls the opening and closing of the diode of the switch circuit.
The GND electrode is also formed on almost the entire surface of the sixteenth layer (FIG. 6 (16)). The 15th layer (FIG. 6 (15)) is bordered by the dashed line, and the GSM1800 series is on the near side and EGS is on the opposite side.
M900 system was arranged. As a result, the connection can be minimized, and the electrical characteristics can be improved. The fifteenth layer (FIG. 6 (1
From 5)) to the eleventh layer (FIG. 6 (11)), the coils LG and LP of the control circuit inductances LG and LP were formed in the right half of the layer. The fifteenth layer (FIG. 6 (1
In the left half of 5)), the capacitor patterns (CG3, CG4, CP3, CP4) of the low-pass filter are arranged.
In the fourteenth layer (FIG. 6 (14)), a part of the pattern of the above-described inductances LG and LP is arranged in the right half, and capacitors CG7 and CP7 of the low-pass filter are arranged in the left half. In the thirteenth layer (FIG. 6 (13)), a part of the pattern of the above-described inductances LG and LP is arranged on the right half, and the transmission lines LG1, LG2, LP1, and LP2 of the switch circuit are arranged on the left. In the twelfth layer (FIG. 6 (12)), on the right half, a part of the pattern of the above-described inductances LG and LP, and on the left side, the transmission lines of the above-described switch circuit, LG1, LG2, and LP.
2 and LP3, and transmission lines LG1 and LP1 of the switch circuit were also arranged. Layer 11 (FIG. 6
(11)) has the above-mentioned inductance LG in the right half,
A part of the pattern of the LP, the transmission line of the switch circuit described above, a part of the pattern of the LG1, LG2, LP2, and LP3 on the left side, and the transmission lines LG1 and LP1 of the switch circuit.
A part of the pattern was arranged. The tenth layer (FIG. 6 (1
0)), a part of the pattern of the transmission lines LG2 and LG3 of the EGSM900-based switch circuit is arranged. In this embodiment, the line width of the transmission line LG2 is different from other lines, and the line width is increased to reduce the line resistance. And the line impedance is reduced. Further, since the switch circuit and the low-pass filter are arranged on the same plane, the matching between the two is further improved. The ninth layer (Fig. 6
In (9)), patterns for SAW filters SG and SP, which are low-pass filters of the receiving system, are arranged on the right side of the vertical line shown in the center. The pattern of the branching circuit was arranged on the left side of the vertical line shown in the center.

Each layer shown in FIG. 5, unlike each layer shown in FIG. 6, has a shape lacking the right side. The broken line in FIG. 5 indicates a portion corresponding to each layer in FIG. 6 below. By such a combination of shapes, the laminated body ML having a step as shown in FIG.
1, ML2 are obtained, and the SAW filters SG, S
A compact high-frequency switch module equipped with P was obtained. The stacked body ML1 corresponds to FIG. 5, and the stacked body ML2 corresponds to FIG. An example of a method for forming the step will be described. First, the electrode patterns shown in FIGS. 5 and 6 are printed on green sheets having the same dimensions. In the case of the pattern of FIG. 5, only the left portion is printed, and there is no print pattern on the right portion. Next, each green sheet is laminated. After laminating the 18th layer (FIG. 6 (18)) and laminating the ninth layer (FIG. 6 (9)), the green sheet is reduced to a thickness of about 80 μm. A PET (polyethylene terephthalate) sheet or the like (referred to as a release sheet) which is sufficiently thin (about 20 μm) and which can be released from the green sheet is inserted into the portion indicated by the broken line in FIG. )) To the first layer (FIG. 5)
(1)) to complete the laminate. Then, FIG.
When a cut is made from the vertical line portion to the top of the release sheet with a carbide blade, and the release sheet and the green sheet laminate thereon are removed, the step portion shown in FIG. 3 can be easily formed. Hereinafter, the arrangement of each layer corresponding to the multilayer body ML1 will be described with reference to FIG. The eighth and seventh layers (FIGS. 5 (8) and (7)) include capacitors CF1, CF2 and C of the branching circuit.
Print the pattern of F4. The sixth layer (FIG. 5 (6)) is a dummy layer. Dummy layers are upper and lower layers (fifth and seventh layers).
A layer provided with a through-hole for electrically connecting the electrode pattern formed on the layer) and having no other electrode pattern printed thereon. In the laminate, the antenna terminal ANT and the transmission lines LF1, LF2, and LF3 are provided to keep the distance therebetween. Note that the antenna terminal ANT is not a dummy layer.
The layer thickness of the layer on which the transmission lines LF1, LF2, and LF3 are pattern-printed may be changed. When a dummy layer is used, all the layers can be formed by one sheet of, for example, 50 μm, which has an effect of improving productivity. The fifth layer and the fourth layer (FIGS. 5 (5) and (4)) have transmission lines LF1 to LF3 constituting filters of the branching circuit. The third layer (FIG. 5)
(3)) is a transmission line L constituting a filter of the demultiplexing circuit.
F1 and LF2 were arranged. This allows the antenna to be arranged furthest away from the ground pattern GND (FIGS. 6 (16) and (18)) and maximizes the distance between the two, so that a sufficiently large inductance can be obtained. The first layer includes diodes DG1, DG2, and DP, which are components mounted on the multilayer body ML1.
1, DP2, capacitors CG1, CGP, and a resistor R. The second layer (FIG. 5 (2)) shows a pattern for connecting those mounted components to another pattern in the laminate.

As described above, an embodiment of the high-frequency switch module using a SAW filter as a bandpass filter of a receiving system and providing a step in the laminated body and miniaturizing the laminated body has been described. The present invention is not limited to this, and a SAW filter may be mounted on the laminate by providing a cavity (recess), or a SAW filter may be mounted on a flat laminate.

(Embodiment) In order to reduce the insertion loss at the time of reception by setting the characteristic impedance of the transmission line connected to the reception system to 30 to 45Ω, in this embodiment, the pattern width of the line LG2 is set to ( As shown in 10) to (13),
0.16mm and other transmission lines to 0.07mm,
The line impedance of LG2 was set to 40Ω. As a comparative example, the pattern width of the transmission line LG2 was set to 0.07 mm similarly to the other transmission lines, and the line impedance was set to 50Ω. As a result, the insertion loss at the time of reception was reduced to 0.9 dB from the comparative example of 1.2 dB. The resistance was reduced, the conductor loss was reduced, and the insertion loss was reduced. Further, when the line width of the transmission line is set to 0.08 mm or more and 0.30 mm or less and the line impedance is set to 30Ω to 45Ω, the insertion loss at the time of reception can be reduced.

[0032]

According to the present invention, it is possible to provide a high-frequency switch module in which insertion loss during reception is reduced and reception sensitivity is improved. According to the present invention, this high-frequency switch module can be made compact and one-chip, preferably by using a laminated structure. This is effective for miniaturization of devices such as dual-band mobile phones.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of one embodiment according to the present invention.

FIG. 2 is an equivalent circuit diagram of another embodiment according to the present invention.

FIG. 3 is a perspective view showing a high-frequency switch module according to the present invention.

FIG. 4 is an electrode layout diagram of the bottom of the high-frequency switch module according to the present invention.

FIG. 5 is a diagram showing a pattern of each layer of the laminate of the equivalent circuit shown in FIG. 2;

FIG. 6 is a diagram showing a continuation of the pattern of each layer of the laminate of FIG. 5;

[Explanation of symbols]

 LF2, LF3 transmission line LP2, LP3 transmission line TX transmission system terminal RX reception system terminal ANT antenna terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J012 BA03 BA04 5J024 AA01 CA09 DA01 DA28 EA01 EA07 5K011 BA03 DA22 DA25 FA01 JA01 KA05

Claims (5)

[Claims] A first circuit disposed between the transmitting circuit and the antenna;
A switching element, a transmission line disposed between the antenna and the receiving circuit, and
, A filter circuit is arranged between the antenna and a connection point between the first switching element and the transmission line, and a signal path of a high-frequency signal by the first and second switching elements. , Wherein the characteristic impedance of the transmission line is 30Ω to 45Ω. 2. The high-frequency switch module according to claim 1, wherein an impedance when the filter circuit is viewed from the connection point is substantially equal to a characteristic impedance of the transmission line. 3. The high-frequency switch module according to claim 1, wherein the transmission line is a stripline or a microstripline formed on a multilayer substrate formed by laminating a plurality of dielectric layers. . 4. The high-frequency switch module according to claim 3, wherein the filter circuit includes a strip line or a microstrip line formed on the multilayer substrate and a capacitor. 5. The high-frequency switch module according to claim 3, wherein the switching element is at least one selected from a diode and a transistor, and is mounted on an outer surface of the multilayer substrate.