JP3807615B2 - Multiband antenna switch circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a countermeasure against electrostatic surge in a composite high-frequency component such as a multiband antenna switch circuit or a multiband antenna switch laminated module used in a high frequency band such as a microwave band.
[0002]
[Prior art]
For example, the EGSM (Extended Global System for Mobile Communications) method and the DCS (Digital Cellular System) method popular in Europe, and the PCS (Personal Communication) method popular in the US There are various systems such as PDC (Personal Digital Cellular) system, but with the rapid spread of mobile phones in recent years, the system is used in the frequency bands allocated to each system, especially in major metropolitan areas in developed countries. There are problems such as being unable to cover the party, making it difficult to connect, and disconnecting during a call. Therefore, it has been proposed that the user can use a plurality of systems to increase the number of frequencies that can be substantially used, and further expand the service area and effectively use the communication infrastructure of each system.
[0003]
When the user wants to use a plurality of systems, the user needs to have a portable communication device corresponding to each system, or a small and lightweight portable communication device that can communicate with the plurality of systems. In the latter case, in order to be able to use a plurality of systems with one portable communication device, the portable communication device may be configured using components for each system. However, in the signal transmission system, for example, desired transmission High-frequency switches such as filters that pass transmission signals of frequencies, high-frequency switches that switch transmission / reception circuits, antennas that receive and emit transmission / reception signals, and filters that pass the desired frequency of reception signals that have passed through the high-frequency switch in signal reception systems Circuit components are required for each system. For this reason, the portable communication device becomes expensive and increases in volume and weight, which is not suitable for portable use. Therefore, small and lightweight high-frequency circuit components corresponding to a plurality of systems have become necessary. For example, a dual-band antenna switch module compatible with EGSM and DCS, or a triple-band antenna switch module used in portable communication devices compatible with the three systems EGSM, DCS, and PCS, EGSM, D-AMPS, DCS, There is a quad-band antenna switch module used in a portable communication device compatible with the four PCS systems.
[0004]
As an example, a block diagram of a triple band antenna switch module corresponding to EGSM, DCS, and PCS is shown in FIG. The diplexer Dip demultiplexes the 0.9 GHz band EGSM signal and the 1.8 GHz band DCS / PCS signal, the high frequency switch SW1 switches between transmission and reception of EGSM, and the high frequency switch SW2 switches between transmission and reception of DCS and PCS. The low-pass filters LPF1 and LPF2 reduce the amount of harmonic distortion generated by the power amplifier on the transmission side. The SAW filters SAW1, SAW2, and SAW3 play a role of reducing noise outside the reception band included in the reception signal. In this case, a PIN diode switch using a PIN diode or a GaAs FET switch is used for SW1 and SW2.
[0005]
High-frequency components such as PIN diodes, GaAsFETs, and SAW filters used in the antenna switch module described above are vulnerable to electrostatic surges. In particular, in the case of mobile phones, the above-described high-frequency components are applied when electrostatic surges from the human body are input to the antenna. There was a problem that parts were destroyed. The withstand voltage of the high-frequency component is about 4 kV for a PIN diode, about 100 V to 1 kV for a GaAs FET, and about 50 V for a SAW filter. In particular, the SAW filter is extremely weak against electrostatic surges compared to other high-frequency components. .
In addition, even if the high frequency components are not destroyed, there is a possibility of destroying a circuit connected to a subsequent stage of the antenna switch module such as a power amplifier connected to the transmission terminal and a low noise amplifier connected to the reception terminal. It is important to take measures against electrostatic surges.
[0006]
FIG. 15 shows an equivalent circuit of a dual-band antenna switch module having an electrostatic surge countermeasure circuit as a conventional technique related to electrostatic surge countermeasures. In this equivalent circuit, the electrostatic surge countermeasure circuit is a portion surrounded by a dotted line inside the diplexer, in which an inductance element L3 connected to the ground is inserted into a filter on the low frequency band side (Patent Document 1). . That is, as an electrostatic surge countermeasure, an inductance element is added to a part of the filter constituting the diplexer, but the inventors of the present application have verified the circuit, and the attenuation near 300 MHz is a little less than 5 dB. Only a thing was obtained, and it turned out that it is insufficient for countermeasures against electrostatic surges.
[0007]
[Patent Document 1]
JP 2001-186047 (FIG. 1)
[0008]
In addition, varistors and Zener diodes can be used as anti-static surge components, but in this case, it is necessary to increase the capacitance between the terminals, and deterioration in insertion loss is unavoidable when used in high-frequency signal transmission lines. It could not be used as a countermeasure against electrostatic surges.
[0009]
In view of the above, the present invention solves the above-described problems in the prior art, and provides a multi-band antenna switch circuit that can be matched in a wide band and has little deterioration in insertion loss, and a composite high-frequency component formed on a ceramic multilayer substrate. The purpose is to provide.
[0010]
[Means for Solving the Problems]
The present invention includes a diplexer having first to third ports and including a first inductance element and a first capacitance element, and first to third ports, and the second port of the diplexer. A first switching element, a second inductance element, and a second capacitance element, wherein the first port is switched to either the second port or the third port. A high-frequency switch; a band-pass filter having first and second ports; disposed on a third port side of the high-frequency switch; and at least disposed between the first port of the diplexer and an antenna. A first electrostatic surge protection circuit including a shunt inductor; and a third port of the high-frequency switch and a first port of the bandpass filter. And a second electrostatic surge protection circuit having a high-pass filter having a first port and a second port and comprising a third inductance element and a third capacitance element, A multiband in which a transmission unit of the first communication system is connected to the second port side of the first high-frequency switch, and a reception unit of the first communication system is connected to the second port side of the bandpass filter It is an antenna switch circuit.
[0011]
In the present invention, the first switching element of the high-frequency switch is preferably a PIN diode having a relatively high power durability.
In the present invention, the second electrostatic surge protection circuit and the band pass filter are provided with first to third ports and a second switching element. A second high-frequency switch that switches to either the second or third port may be arranged, and the second switching element may be a field effect transistor.
The diplexer includes a low-pass filter disposed between the first port and the second port, and a high-pass filter disposed between the first port and the third port. It is preferable to configure as described above.
The high-pass filter of the second electrostatic surge protection circuit is connected between an inductance element connected between the first port and the ground, and between the first port and the second port. It is preferable to have a series resonance circuit including another capacitance element, another inductance element connected between the second port and the ground, and another capacitance element, and the other inductance element and the second inductance element. It is more preferable to provide a parallel resonant circuit composed of another inductance element and another capacitance element between the two ports.
[0012]
According to a second invention, in the first invention, the first and second switching elements, the first to third inductance elements, and the first to third capacitance elements are a plurality of sheet layers made of ceramics. Is a composite high-frequency component that is built in or mounted on a ceramic multilayer substrate formed by laminating layers and connected by connecting means formed on the ceramic multilayer substrate.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a multiband antenna switch circuit with an electrostatic surge countermeasure according to the present invention will be described below with reference to the drawings.
Example 1
FIG. 1 shows a multi-band antenna switch circuit according to an embodiment of the present invention, which has a countermeasure against electrostatic surges and is compatible with a plurality of portable radio communication systems. In order to simplify the description below, one of the plurality of portable wireless communication systems f1 is EGSM (transmission frequency Tx880-915 MHz, reception frequency Rx925-960 MHz), and the other f2 is DCS (transmission frequency Tx1710-1785 MHz, reception) The frequency Rx1805 to 1880 MHz) and another f3 will be described as PCS (transmission frequency Tx1850 to 1910 MHz, reception frequency Rx1930 to 1990 MHz).
[0014]
The first stage of the antenna ANT passes a EGSM transmission / reception signal but attenuates and blocks the DCS / PCS transmission / reception signal, and passes the DCS / PCS transmission / reception signal. A second filter circuit (for example, a high-pass filter) 11b that attenuates and blocks the EGSM transmission / reception signal is disposed. The first filter circuit 11a and the second filter circuit 11b function as the diplexer 11 by sharing an antenna. A first electrostatic surge protection circuit 10 having a shunt inductor is disposed between the antenna and the diplexer 11. 2 and 3 illustrate the first electrostatic surge protection circuit 10. 2 is an example in which only an inductance element (shunt inductor 50) that falls to the ground is provided, and an electrostatic surge is released to the ground. FIG. 3 is a capacitance element in series with respect to the transmission path of the high-frequency signal. 65 is arranged. Here, in order for the first electrostatic surge protection circuit to achieve matching in a wide band from 900 MHz band to 1.8 GHz band, the inductance value of the shunt inductor needs to be more than 5 nH. And it is comprised so that the attenuation amount in 300 MHz of the 1st electrostatic surge protection circuit may be 5-10 dB, and it does not substantially attenuate the high frequency signal to 900 MHz band-1.8 GHz band which should be passed through, A switching element such as a PIN diode of the high-frequency switch 12 disposed in the subsequent stage is prevented from being electrostatically damaged.
[0015]
An example of an equivalent circuit of the diplexer 10 is shown in FIGS.
The diplexer of FIG. 6 includes a parallel resonant circuit including a transmission line 70 and a capacitance 75 as an inductance element and a capacitance element between the first port 100a and the second port 100b, and a ground on the second port 100b side. Between the capacitances 77 and 78 connected in series between the first port 100a and the third port 100c, and a low pass filter with a capacitance 76 disposed between A high-pass filter including a series resonance circuit of a transmission line 71 and a capacitance 79 disposed between the ground and the ground is included.
The diplexer shown in FIG. 7 is arranged between the parallel resonant circuit including the transmission line 80 and the capacitance 85 between the first port 100a and the second port 100b and the ground on the second port 100b side. A parallel low-pass filter including a transmission line 81 and a capacitance 87 between the first port 100a and the third port 100c, and on the third port 100c side. A high-pass filter having a transmission line 82 disposed between the ground and a capacitance 88 connected in series with the parallel resonant circuit is provided.
In the diplexer of FIG. 8, the transmission line 90 is connected between the first port 100a and the second port 100b, and the transmission farway 91 and the capacitance are connected between the second port 100b and the ground. 96, a low-pass filter with a series resonance circuit, and capacitances 97 and 98 connected in series between the first port 100a and the second port 100c, and a ground between the capacitances. And a high-pass filter having a series resonance circuit of a transmission line 92 and a capacitance 99 arranged in a line.
The above-described diplexer is a preferred example and does not limit the equivalent circuit and is appropriately configured within the scope of the present invention. However, the second filter circuit 11b is preferably a high-pass filter. The electrostatic surge has a high voltage value of a frequency component of 500 MHz or less. However, if the second filter circuit 11b is a high-pass filter as described above, an attenuation of about 20 dB can be obtained in the band. In the high frequency circuit on the PCS side, the electrostatic surge can be cut off in cooperation with the first electrostatic surge protection circuit 10.
[0016]
The transmission line and capacitance may be composed of chip parts, but the transmission line is composed of distributed constant lines, and a conductive paste mainly composed of Ag or Cu is printed on a ceramic dielectric green sheet that can be fired at low temperature. Then, a desired electrode pattern is formed, and a plurality of green sheets having electrode patterns to be the distributed constant line, capacitance, ground pattern, connection line, etc. are appropriately laminated integrally and sintered to form a ceramic. It is preferable to configure as a multilayer substrate.
[0017]
Connected to the first filter circuit 11a of the diplexer 11 is a first high-frequency switch 12 for switching a signal path of an EGSM transmission signal and a signal path of a reception signal. An example of the first high-frequency switch 12 is shown in FIGS.
The high-frequency switch 12 shown in FIG. 9 mainly includes a transmission line and a diode as an inductance element, a switching element, and a capacitance element, and a transmission line 150 between the first port 102a and the second port 102b, and the transmission line 150 A diode 155 disposed between the ground on the second port 102b side, a DC cut capacitance 157, and a control terminal VC1 formed therebetween. The capacitance 157 is in series with an inductance component when the diode 155 is operated. A resonance circuit is configured so as to be in a short-circuit state when the diode 155 is operated, thereby improving the isolation characteristics. Also, a transmission line between the first port 102a and the third port 102c is connected between the diode 155 and the diode 156 connected in series via the transmission line 150 and the ground on the third port 102c side. 151 is arranged. The diodes 155 and 156 are turned ON / OFF by the control voltage supplied from the control terminal VC1, and the connection between the first port 102a and the second port 102b and between the first port 102a and the third port 102c is established. Switch. Note that a DC-cutting capacitance is appropriately arranged in the first to third ports 102a, 102b, and 102c.
[0018]
The high-frequency switch 12 in FIG. 10 is also a diode switch mainly composed of a transmission line and a diode, and the transmission line 160 and the second of the transmission line 160 are between the first port 102a and the second port 102b. A diode 165 disposed between the grounds on the port 102b side, a DC cut capacitance 167, and a resistor 168 connected in parallel with the capacitance 167 are disposed. A transmission line is connected between the first port 102a and the third port 102c between the diode 165 and the diode 166 connected in series via the transmission line 160 and the ground on the third port 102c side. A control terminal VC2 is arranged between the transmission line 161 and the DC cut capacitance 168. The diodes 165 and 166 are turned ON / OFF by the control voltage supplied from the control terminal VC2, and the connection between the first port 102a and the second port 102b and between the first port 102a and the third port 102c is established. Switch. Note that a DC-cutting capacitance is appropriately arranged in the first to third ports 102a, 102b, and 102c. The high-frequency switch 12 may be configured using a GaAS FET as shown in FIG. 11 and FIG. 12, but in this case, it is necessary to select a GaAS FET having a high withstand voltage.
[0019]
The transmission line and the capacitance may be constituted by chip parts. However, the transmission line is constituted by a distributed constant line together with the diplexer, and a ceramic dielectric green sheet capable of low-temperature firing is mainly composed of Ag or Cu. A paste is printed to form a desired electrode pattern, and a plurality of green sheets having electrode patterns to serve as the distributed constant line, capacitance, ground pattern, connection line, etc. are appropriately laminated integrally and sintered. Therefore, it is preferable to configure as a ceramic multilayer substrate. Diodes and FETs are mounted on a ceramic multilayer substrate. At this time, it is preferable that the diode or FET is in a bare state and the ceramic multilayer substrate is resin-sealed or tube-sealed for miniaturization.
Further, if it is configured as a complex high-frequency component integrated with a diplexer or other high-frequency components, it is possible to further reduce the size, which is preferable. As the ceramic dielectric material capable of low temperature sintering, for example, Al ₂ O ₃ With SiO as the main component ₂ , SrO, CaO, PbO, Na ₂ O and K ₂ Containing at least one of O as a multiple component, Al ₂ O ₃ MgO, SiO ₂ And at least one of GdO as a composite component, Al ₂ O ₃ , SiO ₂ , SrO, Bi ₂ O ₃ TiO ₂ As a main component.
[0020]
A second electrostatic surge protection circuit 13 having a high-pass filter and a band-pass filter 14 are disposed on the rear side of the high-frequency switch 12 and between the EGSM receiver (not shown). . The receiving unit includes a low noise amplifier and has a function of converting a received signal into a signal that can be processed by the signal processing unit. The band pass filter 14 is a SAW filter, an FBAR (Film Bulk Acoustic Resonator), a center frequency variable filter using a switching element, or the like.
4 and 5 show an example of the second electrostatic surge protection circuit 13. In FIG. 4, as an inductance element and a capacitance element, an inductance 51 is connected between the second port 103b and the ground, and a capacitance 60 is inserted between the second port 103b and the second port 103b. A series resonant circuit comprising 52 and a capacitance 61 is connected between the first port 103a and the ground. In this case, a high-pass filter is configured such that the electrostatic surge is released to the ground by appropriately selecting the values of the inductor 51 and the capacitance 60, and the high-frequency signal is transmitted with low loss. Here, the series resonance circuit including the inductance 52 and the capacitance 61 sets the values of L and C so that the resonance frequency is set between 100 MHz and 500 MHz. In this case, the capacitance 61 is preferably 10 pF or more and the inductor 52 is preferably 50 nH or less. As a result, the electrostatic surge in the resonance frequency band, which is a problem in electrostatic breakdown, can be absorbed to the ground, and countermeasures against electrostatic surge can be performed more efficiently. Further, in the EGSM frequency band to be passed, the reflection characteristics V.V. S. W. R was set to be 1.5 or less. As a result, the attenuation amount of the second electrostatic surge protection circuit in the frequency band of 300 MHz or less was set to 30 dB or more, and the insertion loss in the frequency band of the EGSM to be passed could be set to about 0.2 dB.
With this configuration, the electrostatic surge is attenuated in advance by the first electrostatic surge protection circuit and further attenuated by the second electrostatic surge protection circuit. The insertion loss between the antenna and the EGSM reception circuit is slightly deteriorated by the second electrostatic surge protection circuit, but there is substantially no increase in the insertion loss of other signal paths. Since a multiband antenna switch circuit can be configured, it was possible to exhibit excellent electrical characteristics as a multiband antenna switch circuit.
The band pass filter is preferably mounted on the ceramic multilayer substrate together with the diode and FET. For example, it is preferable that the SAW filter be in a bare state and resin-sealed or tube-sealed to the ceramic multilayer substrate because the multiband antenna switch circuit can be miniaturized.
[0021]
FIG. 5 shows another example of the second electrostatic surge protection circuit 13. The roles of the inductances 51 and 52 and the capacitances 60 and 61 are the same as those described above, but the capacitance 60 and the first port 103a are The difference is that a parallel resonant circuit composed of a capacitance 62 and an inductance 53 is inserted therebetween. This parallel resonant circuit has a function of removing high frequency signals in a frequency band of 500 MHz or less, and it is possible to adjust the matching of the entire electrostatic surge circuit by adjusting the values of the inductance 53 and the capacitance 62. It is effective.
[0022]
A low-pass filter 15 is disposed on the downstream side of the high-frequency switch 12 and with an EGSM transmitter (not shown) as necessary. The transmission unit includes a power amplifier, and converts the signal encoded by the signal processing unit into a transmission signal. An isolator (not shown) that transmits a transmission signal only in one direction may be disposed between the transmission unit and the high-frequency switch 12.
FIG. 13 shows an example of the low-pass filter. The low-pass filter of FIG. 13 includes an inductance element between the first port 105a and the second port 105b, a parallel resonance circuit including a transmission line 190 and a capacitance 196 as a capacitance element, and the first port 105a side. And a capacitance 197 disposed between the ground and the second port 105b on the second port 105b side. Such a low-pass filter may be disposed between the diplexer 11 and the high-frequency switch 12.
[0023]
When performing reception by EGSM, a control unit (not shown) connects the first high-frequency switch 12 to the EGSM reception unit, and controls the EGSM reception unit to operate. The incident reception signal is transmitted to the signal processing unit via the first filter circuit. When transmitting by EGSM, the first high-frequency switch 12 is controlled to be connected to the EGSM transmitter so as to operate the EGSM transmitter, and the transmission signal is sent from the antenna ANT via the first filter circuit. Radiate.
[0024]
The second filter circuit 11b of the diplexer 11 is connected to a second high-frequency switch 16 for switching the signal path of the DCS and PCS transmission signal and the signal path of the reception signal. A low-pass filter 17 is appropriately disposed between the transmitter (not shown). Between the DCS and the PCS receiver (not shown), a third high-frequency switch 20 for switching the signal path of the DCS reception signal and the signal path of the PCS reception signal is connected. On the rear stage side of the switch, a band pass filter 18 is arranged between the DCS receiving unit and a band pass filter 19 is arranged between the PCS receiving unit.
The high-frequency switches 16 and 20, the SAW filters 18 and 19, and the low-pass filter 17 used here are configured to be usable in the DCS or PCS frequency band, but the equivalent circuit is substantially the same as described above. Therefore, the description can be omitted.
The first electrostatic surge protection circuit 13 and the high-pass filter 11b of the diplexer 11 make the electrostatic surge input to the high-frequency switch 16 very small. Therefore, the GaAS FET switch shown in FIGS. 11 and 12 is adopted. You can also When a system such as CDMA is handled, a resonator composed of two filter circuits may be arranged in place of the second high frequency switch 16 or the like.
[0025]
(Example 2)
FIG. 14 shows another example of the high-frequency circuit arranged at the subsequent stage of the first high-frequency switch 12.
A difference from the first embodiment is that a fourth high-frequency switch using a GaAS FET shown in FIG. 11 or 12 is arranged between the second electrostatic surge protection circuit 13 and the SAW filter 14. This is an example of a high-frequency circuit in the case of handling another system f4 close to the transmission / reception frequency, for example, D-AMPS.
As the fourth high-frequency switch, the PIN diode disclosed in the first embodiment can be employed. It is preferable to use a GaAS FET switch from the viewpoint of insertion loss and low power consumption, and a PIN diode switch from the viewpoint of cost. Also in this case, when the first and second electrostatic surge protection circuits use GaAS FETs that can substantially block the electrostatic surge input to the fourth high-frequency switch and do not have a large withstand power. However, electrostatic breakdown does not occur.
[0026]
【The invention's effect】
According to the present invention, by using a plurality of electrostatic surge countermeasure circuits, the electrostatic surge from the antenna is released to the ground, and the electrostatic surge is absorbed in a wide range of frequencies, so that the electrostatic breakdown is more completely performed. Measures can be taken. Then, a circuit such as a PIN diode switch or a GaAs FET switch, a reception band-pass filter, a power amplifier connected to the transmission terminal, and a low noise amplifier connected to the reception terminal constituting the multiband antenna switch circuit is protected from electrostatic surges. It is possible to protect, and these subsequent high-frequency electronic components are not destroyed.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of a multiband antenna switch circuit according to an embodiment of the present invention.
FIG. 2 is an equivalent circuit of a first electrostatic surge protection circuit used in the present invention.
FIG. 3 is another equivalent circuit of the first electrostatic surge protection circuit used in the present invention.
FIG. 4 is an equivalent circuit of a second electrostatic surge protection circuit used in the present invention.
FIG. 5 is another equivalent circuit of the second electrostatic surge protection circuit used in the present invention.
FIG. 6 is an equivalent circuit of a diplexer used in the present invention.
FIG. 7 is another equivalent circuit of the diplexer used in the present invention.
FIG. 8 is another equivalent circuit of the diplexer used in the present invention.
FIG. 9 is an equivalent circuit of a high-frequency switch used in the present invention.
FIG. 10 is another equivalent circuit of the high-frequency switch used in the present invention.
FIG. 11 is another equivalent circuit of the high-frequency switch used in the present invention.
FIG. 12 is another equivalent circuit of the high-frequency switch used in the present invention.
FIG. 13 is an equivalent circuit of a low-pass filter used in the present invention.
FIG. 14 is a circuit block diagram of a multiband antenna switch circuit according to another embodiment of the present invention.
FIG. 15 is an equivalent circuit showing an example of a conventional electrostatic surge countermeasure circuit.
FIG. 16 is a circuit block diagram showing an example of a conventional multiband antenna switch circuit.
[Explanation of symbols]
10 First electrostatic surge protection circuit
11 Diplexer
12, 16, 20, 21 High frequency switch
13 Second electrostatic surge protection circuit
14, 18, 19, 22 SAW filter
15, 17 Low-pass filter

Claims (8)

A diplexer having first to third ports and including a first inductance element and a first capacitance element;
The first to third ports are disposed on the second port side of the diplexer and include a first switching element, a second inductance element, and a second capacitance element. A first high-frequency switch that switches the port to one of the second and third ports;
A band-pass filter having first and second ports and disposed on a third port side of the high-frequency switch;
A first electrostatic surge protection circuit comprising at least a shunt inductor disposed between the first port of the diplexer and the antenna;
A first inductance port and a second capacitance port are arranged between the third port of the high-frequency switch and the first port of the bandpass filter, and are constituted by a third inductance element and a third capacitance element. A second electrostatic surge protection circuit having a high pass filter formed,
A transmission unit of the first communication system is connected to the second port side of the first high-frequency switch;
A multiband antenna switch circuit, wherein a receiver of the first communication system is connected to a second port side of the band pass filter. The multiband antenna switch circuit according to claim 1, wherein the first switching element of the high-frequency switch is a PIN diode. Between the second electrostatic surge protection circuit and the band pass filter, there are provided first to third ports, a second switching element is provided, and the first port is used as the second and third ports. 3. The multiband antenna switch circuit according to claim 1, further comprising a second high-frequency switch that switches to any one of the first and second switches, wherein the second switching element is a field effect transistor. 4. Between the second electrostatic surge protection circuit and the band pass filter, there are provided first to third ports, a second switching element is provided, and the first port is used as the second and third ports. 3. The multiband antenna switch circuit according to claim 1, further comprising a second high-frequency switch that switches to any one of the first and second switches, wherein the second switching element is a PIN diode. The diplexer has a low-pass filter disposed between the first port and the second port, and a high-pass filter disposed between the first port and the third port. The multiband antenna switch circuit according to any one of claims 1 to 4, wherein the multiband antenna switch circuit is provided. A high-pass filter of the second electrostatic surge protection circuit is connected between the first port and the second port, an inductance element connected between the first port and the ground. 6. The multi-capacitor according to claim 1, further comprising: a series resonance circuit including another capacitance element, another inductance element connected between the second port and ground, and another capacitance element. Band antenna switch circuit. 8. The high-pass filter according to claim 7, further comprising a parallel resonant circuit including another inductance element and another capacitance element between the other inductance element and the second port. The multiband antenna switch circuit according to any one of claims 1 to 7, wherein the first and second switching elements, the first to third inductance elements, and the first to third capacitance elements are: A composite high-frequency component, wherein the composite high-frequency component is built in or mounted on a ceramic multilayer substrate formed by laminating a plurality of sheet layers made of ceramics and connected by connecting means formed on the ceramic multilayer substrate.

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