JP2009027319A - High-frequency circuit, high-frequency component, and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration which is adaptable with a simple circuit configuration even if frequency bands are close to each other for a MIMO high-frequency circuit which can accommodate at least two different communication systems, high-frequency components using the high-frequency circuit, and a communication device using the high-frequency components. <P>SOLUTION: First and second receiving terminals for a first communication system can be connected to separate antenna terminals, and first and second receiving terminals for a second communication system can also be connected to separate antenna terminals. A receiving terminal pair consisting of the first receiving terminal for the first communication system and the first receiving terminal for the second communication system or the like can be connected to one and the same antenna terminal out of the plurality of antenna terminals via a branch circuit. A variable notch filter is inserted between the one and the same antenna terminal and the branch circuit, while a bandpass filter circuit is inserted between each receiving terminal and the branch circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus that performs wireless transmission between electronic and electrical devices, and relates to a high-frequency circuit that can support at least two different communication systems, a high-frequency component having such a high-frequency circuit, and a communication apparatus using the same.

  At present, data communication using a wireless LAN represented by the IEEE 802.11 standard is widely used. For example, personal computers (PCs), PC peripherals such as printers, hard disks, broadband routers, fax machines, refrigerators, standard televisions (SDTVs), high-definition televisions (HDTVs), electronic devices such as cameras, videos, mobile phones, etc. It is adopted as a signal transmission means that replaces wired communication in airplanes, and wireless data transmission is performed between each electronic appliance.

  As a wireless LAN standard, IEEE802.11a supports high-speed data communication of up to 54 Mbps using an OFDM (Orthogonal Frequency Division Multiples) modulation method, and the frequency band is 5 GHz. Is done. IEEE802.11b is a DSSS (Direct Sequence Spread Spectrum) system that supports high-speed communication at 5.5 Mbps and 11 Mbps, and can be freely used without a radio license. The 4 GHz ISM (Industrial Scientific and Medical) band is utilized. IEEE802.11g supports a high-speed data communication of a maximum of 54 Mbps using the OFDM modulation method, and uses the 2.4 GHz band as in the case of IEEE802.11b.

  A high-frequency circuit used in such a multiband communication apparatus using a wireless LAN is one that can be transmitted and received by two communication systems (IEEE802.11a and IEEE802.11b and / or IEEE802.11g) having different communication frequency bands. A high-frequency switch for switching the connection between the antenna, the transmission side circuit, and the reception side circuit. With such a high frequency switch, the transmission side circuit and the reception side circuit of the two communication systems are switched.

  In recent years, WiMAX (IEEE802.16-2004, IEEE802.16e-2005, etc.) has been proposed as a high-speed wireless communication standard that covers a communication distance of about several kilometers, and is expected as a technology that supplements the so-called last one mile of optical communication, for example. ing. WiMAX uses three frequency bands of 2.5 GHz band, 3.5 GHz band, and 5.8 GHz band as frequency bands. When the wireless LAN and WiMAX are shared to increase the functionality of the communication device, it is important to separate and handle the transmission / reception signals of these communication systems. As a high-frequency component that performs transmission / reception of systems having different frequencies, for example, Patent Document 1 discloses two dual-band antennas that can transmit and receive in two communication systems (IEEE802.11a and IEEE802.11b) having different communication frequency bands, and transmission. A high-frequency switch having four ports for switching the connection between the side circuit and the reception-side circuit, a demultiplexing circuit disposed between one port of the high-frequency switch and the transmission-side circuit, and another port of the high-frequency switch. A high frequency circuit including a demultiplexing circuit disposed between the receiving side circuit and the diversity receiving circuit is disclosed.

  Patent Document 2 discloses a high-frequency circuit used for a composite radio device using substantially the same frequency band. That is, in Patent Document 2, as a circuit shared by wireless LAN and Bluetooth, a bandpass filter is provided between the antenna and the antenna changeover switch, and a power amplifier shared by the wireless LAN and Bluetooth is switched on the transmission side that is switched by the antenna changeover switch. In order to separate wireless LAN transmission and Bluetooth, a distributor is connected to the power amplifier, and a low noise amplifier shared by wireless LAN reception and Bluetooth reception is provided on the receiving side that can be switched with the antenna switch, and the low noise amplifier The circuit which connected the divider | distributor which separates reception of wireless LAN and reception of Bluetooth is disclosed.

International Publication No. 2006/003959 Pamphlet JP 2002-208874 A

  Of the wireless LAN and WiMAX use bands, the 2.4 GHz band of the wireless LAN and the 2.5 GHz band of the WiMAX are very close, so it is difficult to share the wireless LAN and WiMAX using these bands. . Patent Document 1 provides high-frequency components for a dual-band communication device that can be transmitted and received by two communication systems having different communication frequency bands. However, the wireless LAN 2.4 GHz band and WiMAX 2.5 GHz band are used. It was not possible to cope with the case where the frequency band was close. On the other hand, the high-frequency circuit disclosed in Patent Document 2 is not intended for a case where a wireless LAN and Bluetooth operate simultaneously. Therefore, when the wireless LAN and WiMAX signals are shared, it cannot be applied immediately.

  In particular, in a MIMO (Multiple-Input, Multiple-Output) wireless communication system that has been attracting attention in recent years, the circuit configuration such as the number of receiving terminals increases with respect to one communication system. Therefore, in addition to the difficulty in isolation between communication systems, the circuit configuration is also complicated. Therefore, it is even more difficult to apply the MIMO scheme to a wireless LAN and WiMAX. Become. Hereinafter, the MIMO is used as a concept including SIMO (Single-Input, Multiple-Output) and MISO (Multiple-Input, Single-Output).

  In view of the above-mentioned problems, the present invention has a simple circuit configuration even when the frequency band is close in a MIMO type high-frequency circuit, a high-frequency component, and a communication device using the same, which are compatible with at least two different communication systems. It aims to provide an adaptable configuration.

  The high-frequency circuit of the present invention includes a plurality of antenna terminals, at least a first transmission terminal for the first communication system, first and second reception terminals, and at least a first transmission terminal for the second communication system. And the first and second receiving terminals for the first communication system can be connected to the separate antenna terminals, respectively, and the second communication system The first and second receiving terminals can be connected to the separate antenna terminals, respectively, and the first receiving terminal for the first communication system and the first receiving for the second communication system Receiving at least one of a receiving terminal pair constituted by terminals and a receiving terminal pair constituted by a second receiving terminal for the first communication system and a second receiving terminal for the second communication system end The pair can be connected to the same one of the plurality of antenna terminals via a branch circuit, and a variable notch filter is provided between the same one antenna terminal and the branch circuit, and the branch A band-pass filter circuit is provided between each receiving terminal constituting the receiving terminal pair connected to the circuit and the branch circuit. In this configuration, the circuit configuration is simplified by connecting the reception terminal for the first system and the reception terminal for the second system to the same one antenna terminal. Further, the notch can be switched between the frequency band of the first system and the frequency band of the second system by the variable notch filter. Therefore, the frequency band of the first communication system and the frequency band of the second communication system are close to each other by the above-described configuration in which the variable notch filter having steep blocking characteristics, the branch circuit connected thereto, and the bandpass filter circuit are provided. Even if it is a case, the received signal of another communication system can be excluded and the received signal of a desired communication system can be taken out to a receiving terminal.

Further, in the high-frequency circuit, first and second switch circuits for switching between a transmission path and a reception path, first, second, and third antenna terminals as the plurality of antenna terminals,
A first branch circuit as the branch circuit; and a first variable notch filter as the variable notch filter; a first transmission terminal for the first communication system and a first transmission terminal for the first communication system; The reception terminal can be connected to the first antenna terminal via the first switch circuit, and the first transmission terminal for the second communication system and the first transmission terminal for the second communication system. The receiving terminal can be connected to the second antenna terminal via the second switch circuit, and the second receiving terminal for the first communication system and the second receiving terminal for the second communication system. A receiving terminal pair constituted by receiving terminals can be connected to the third antenna terminal via a first variable notch filter connected to a common terminal side of the first branch circuit and the first branch circuit. That it is Masui. According to this configuration, when the frequency band of the first communication system and the frequency band of the second communication system are close to each other, the high-frequency circuit for 1T2R (one transmission and two reception) type MIMO communication is configured with a simple configuration. Can be obtained.

  In the high-frequency circuit, a first notch filter is provided between the first receiving terminal for the first communication system and the first switch circuit, and the first notch for the second communication system is provided. A second notch filter is provided between the first receiving terminal for the first communication system and the second receiving circuit. Preferably, a band-pass filter circuit is provided between each of the notch filters and the first reception terminal for the second communication system. Similar to the path in which the first system receiving terminal and the second system receiving terminal are connected to the same antenna terminal, the other structure uses the notch filter having a steep blocking characteristic. According to the present invention, even when the frequency band of the first communication system and the frequency band of the second communication system are close to each other, the reception signal of the desired communication system is excluded by eliminating the reception signal of the other communication system. Can be taken out to the receiving terminal.

  Further, in the high-frequency circuit, the connection between the third antenna terminal and the first variable notch filter and the third antenna terminal and the termination are provided between the first variable notch filter and the third antenna terminal. It is preferable to have a third switch circuit capable of switching the connection with the resistor. With this configuration, transmission / reception isolation can be improved.

  Further, in the high-frequency circuit, fourth and fifth switch circuits for switching between a transmission path and a reception path, fourth and fifth antenna terminals as the plurality of antenna terminals, and second and third as the branch circuits A branch circuit and second and third variable notch filters as the variable notch filter are provided, and a first transmission terminal for the first communication system is connected to the fourth antenna terminal via the fourth switch circuit. The first transmission terminal for the second communication system can be connected to the fifth antenna terminal via the fifth switch circuit, and the first transmission terminal for the first communication system can be connected to the first transmission terminal for the first communication system. A receiving terminal pair including a first receiving terminal and a first receiving terminal for the second communication system is connected to the common terminal side of the second branch circuit and the second branch circuit. The second variable notch filter and the fourth switch terminal connected to the second variable notch filter can be connected to the fourth antenna terminal, and the second variable notch filter can be connected to the fourth communication terminal for the first communication system. A reception terminal pair configured by a second reception terminal and a second reception terminal for the second communication system is connected to the third branch circuit and the common terminal side of the third branch circuit. It is also preferable to be able to connect to the fifth antenna terminal via the third variable notch filter and the fifth switch circuit connected to the third variable notch filter. In such a configuration, the circuit can be further simplified by using a plurality of variable notch filters.

  Furthermore, in the high frequency circuit, it is preferable that a low noise amplifier circuit is disposed between the variable notch filter and the branch circuit. In the case of a communication system with high signal strength, amplification is not always necessary, but by arranging a low noise amplifier circuit, sufficient signal strength can be ensured and good reception sensitivity can be obtained. Furthermore, by arranging a low noise amplifier circuit between the variable notch filter and the branch circuit, an increase in the number of low noise amplifier circuits can be suppressed, and the circuit is simplified.

  The high-frequency component of the present invention is a high-frequency component having any one of the high-frequency circuits, wherein the high-frequency circuit is formed by stacking and integrating electrode patterns on a plurality of layers, and the stacked body. It is characterized by comprising elements mounted on the surface. By integrating the high-frequency circuit into the laminate, the high-frequency component can be reduced in size. By reducing the size of the high-frequency component, it contributes to the reduction of insertion loss due to wiring resistance.

  The communication apparatus of the present invention is characterized by using the high-frequency component. Employing the high-frequency component contributes to the miniaturization of communication devices, particularly portable communication devices and personal computers that are required to be lightweight and miniaturized.

  According to the present invention, a MIMO type high-frequency circuit, a high-frequency component, and a communication device using the same that can support at least two different communication systems can be adapted with a simple circuit even when the frequency bands of the communication system are close to each other. It is possible to provide a possible configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is a high-frequency circuit applicable to wireless communication using at least a first communication system and a second communication system. Specifically, in the high-frequency circuit according to the present invention, the first and second receiving terminals for the first communication system can be connected to different antenna terminals, respectively, and the first for the second communication system is connected. The second receiving terminal is configured to be connectable to a separate antenna terminal. The high-frequency circuit has a configuration applicable to MIMO wireless communication. Further, in such a high-frequency circuit, a reception terminal pair constituted by a first reception terminal for the first communication system and a first reception terminal for the second communication system, and for the first communication system At least one receiving terminal pair among the receiving terminal pair constituted by the second receiving terminal and the second receiving terminal for the second communication system is the same among the plurality of antenna terminals via a branch circuit. It can be connected to two antenna terminals. Further, a variable notch filter is provided between the same one antenna terminal and the branch circuit, and a band is provided between each of the reception terminals constituting the reception terminal pair connected to the branch circuit and the branch circuit. A pass filter circuit is provided. Hereinafter, specific embodiments having such a configuration will be described in detail. A communication apparatus for performing wireless communication, wherein the first communication system is a 2.4 GHz band wireless LAN, and the second communication system is a 2.5 GHz band WiMAX whose frequency band is higher than that of the first communication system. A high-frequency circuit of a front end module used in the above will be described as an example. Note that the communication system is not particularly limited. For example, a 3.5 GHz band WiMAX, a 5 GHz band wireless LAN, a 5.5 GHz band WiMAX, or the like may be used in combination.

(First embodiment)
The high-frequency circuit of the circuit block shown in FIG. 1 includes a first antenna terminal Ant1, a second antenna terminal Ant2, a third antenna terminal Ant3 as a plurality of antenna terminals, and a first transmission for the first communication system. Terminal Tx1-1, first reception terminal Rx1-1 and second reception terminal Rx1-2, first transmission terminal Tx2-1, first reception terminal Rx2-1 and second reception terminal Rx1-2 for the second communication system 2 reception terminals Rx2-2, a first switch circuit SPDT1 and a second switch circuit SPDT2 for switching between a transmission path and a reception path, a first branch circuit SPL1, and a first variable notch filter TNF1. The first transmission terminal Tx1-1 for the first communication system and the first reception terminal Rx1-1 for the first communication system are connected to the first antenna terminal Ant1 via the first switch circuit SPDT1. It is configured to be possible. The first antenna terminal Ant1 is connected to a common terminal of the single-pole double-throw switch circuit SPDT1, and the transmission side terminal of the switch circuit SPDT1 is connected to the first transmission terminal Tx1-1 for the first communication system. The receiving path is connected to the receiving terminal and the receiving path to the first receiving terminal Rx1-1. On the other hand, the first transmission terminal Tx2-1 for the second communication system and the first reception terminal Rx2-1 for the second communication system are connected to the second antenna terminal Ant2 via the second switch circuit SPDT2. It is configured to be connectable to. The second antenna terminal Ant2 is connected to a common terminal of the single-pole double-throw switch circuit SPDT2, and the transmission side terminal of the switch circuit SPDT2 is connected to the first transmission terminal Tx2-1 for the second communication system. The receiving path is connected to the receiving terminal, and the receiving path to the first receiving terminal Rx2-1 is connected. Further, the reception terminal pair constituted by the second reception terminal Rx1-2 for the first communication system and the second reception terminal Rx2-2 for the second communication system is connected to the first branch circuit SPL1 and the second branch circuit SPL1. The first branch circuit SPL1 is configured to be connectable to the third antenna terminal Ant3 via the first variable notch filter TNF1 connected to the common terminal side.

  First, a circuit connected to the third antenna terminal Ant3 will be described more specifically. A common terminal of a single-pole double-throw switch circuit SPDT3 is connected to the third antenna terminal Ant3 via a high-pass filter circuit HPF3. The high-pass filter circuit HPF3 passes signals in the first system frequency band and the second frequency band, and blocks unnecessary signals on the lower frequency side. For example, in order to block the signal of the cellular phone on the lower frequency side than the 2.4 GHz band wireless LAN which is the first communication system, it is configured to attenuate 2.17 GHz or less. Although it is possible to use a bandpass filter circuit instead of the highpass filter circuit, since the insertion loss of the highpass filter circuit is smaller than that of the bandpass filter circuit, the reception sensitivity is higher than that of the bandpass filter circuit. Since it contributes to improvement, it is preferable. When receiving the first communication system or the second communication system, the switch circuit SPDT3 uses the second reception terminal Rx1-2 for the first communication system and the second reception for the second communication system as a signal path. Switching to the path leading to the receiving terminal pair constituted by the terminal Rx2-2, and switching to the path grounded via the 50Ω termination resistor R during transmission of the first communication system or the second communication system. With this configuration, transmission / reception isolation can be improved. However, the configuration relating to the high-pass filter circuit and the switch circuit may be appropriately changed or omitted depending on the communication system used and the required characteristics.

  A first variable notch filter TNF1 is provided in the signal path connected to the switch circuit SPDT3. The first variable notch filter TNF1 is set to a notch (attenuation pole) set to 2.4 GHz which is a frequency band of the first communication system and 2.5 GHz which is a frequency band of the second communication system. The notch (attenuation pole) can be switched. When receiving the 2.4 GHz band signal of the first communication system, the notch is switched to the 2.5 GHz band which is the frequency band of the second communication system. On the other hand, when receiving the 2.5 GHz band signal of the second communication system, the notch is switched to the 2.4 GHz band which is the frequency band of the first communication system. Necessary when receiving a 2.4 GHz band wireless LAN and a 2.5 GHz band WiMAX signal using the same single antenna terminal by using a variable notch filter with steep rejection characteristics. It is possible to pass a signal of another communication system and prevent a signal of another communication system from passing.

  The variable notch filter TNF1 is used to block signals of some communication systems out of two or more communication systems to be used. This point is different from the conventional usage mode for simply reducing unnecessary harmonics. Furthermore, when a low-noise amplifier circuit is arranged on the receiving side path, a variable notch filter is provided at the front stage of the low-noise amplifier circuit, so that signals with different frequency bands enter the low-noise amplifier circuit and interfere with each other. Can be prevented from occurring.

  As the variable notch filter, for example, the one having the configuration shown in FIG. 3 may be used. The variable notch filter circuit has an inductance element L1, capacitance elements C1, C11, a resistor R1, a PIN diode D1, and a voltage terminal VC for applying a voltage to the PIN diode D1 between terminals P1 and P2. The terminal P1 is connected to the third switch circuit SPDT3, and the terminal P2 is connected to the input side of the low noise amplifier circuit LNA3. Instead of the PIN diode, a variable capacitance diode or FET (field effect transistor) can be used. The use of FETs has the advantage that the drive current can be reduced and the switching speed can be increased, and the use of PIN diodes and variable capacitance diodes has the advantage that low-priced and small package products can be used. In the configuration of FIG. 3, one end of the capacitance element C1 is connected to the node of the path between the terminals P1 and P2, and one end of the inductance element L1 is connected in series to the other end of the capacitance element C1. One end of a parallel circuit of a PIN diode D1 and a capacitance element C11 is further connected in series to the other end of the inductance element L1, and the other end of the parallel circuit of the PIN diode D1 and the capacitance element C11 is grounded. One end of the resistor R1 is connected to a node between the other end of the inductance element L1 and one end of the parallel circuit of the PIN diode D1 and the capacitance element C11, and the other end of the resistor R1 is connected to the voltage terminal VC. The attenuation pole of the notch filter circuit can be adjusted by ON / OFF control of the PIN diode D1, which is a switch circuit, using a bias voltage from the voltage terminal VC. The PIN diode D1 is turned on when a positive bias voltage is applied from the voltage terminal VC, and functions as a minute inductor. When a bias voltage of 0 is applied from the voltage terminal VC, it is turned off and functions as a small capacitor. That is, in FIG. 3, the resonance frequency of the LC resonance is changed by ON / OFF control of the PIN diode D1, and the center frequency of the attenuation pole is switched between 2.4 GHz and 2.5 GHz.

  A first branch circuit SPL1 is connected to the receiving terminal pair side of the first variable notch filter TNF1 via a low noise amplifier circuit LNA3. Note that the low noise amplifier circuit can be provided on the receiving terminal side of the branch circuit SPL1, but by providing the low noise amplifier circuit on the antenna terminal side of the first branch circuit SPL1, the first communication system and the second communication system can be provided. The low noise amplifier circuit can be shared and the circuit can be simplified. That is, it is preferable that a low noise amplifier circuit is disposed between the first variable notch filter TNF1 and the first branch circuit SPL1. When the low noise amplifier circuit is provided in another circuit connected to the subsequent stage of the high frequency circuit shown in FIG. 1, the low noise amplifier circuit shown in FIG. 1 can be omitted.

  The signal that has passed through the first variable notch filter TNF1 provided between the same antenna terminal Ant3 and the first branch circuit SPL1 is distributed to the two signal paths by the first branch circuit SPL1. . As the first branch circuit, in addition to the splitter, a switch such as SPDT, a coupler, or the like may be used. Band-pass filter circuits BPF5 and BPF6 are provided between the second reception terminal Rx1-2 of the first communication system, the second reception terminal Rx2-2 of the second communication system, and the first branch circuit SPL1, respectively. ing. The pass band of the bandpass filter circuit BPF5 connected to the second receiving terminal Rx1-2 of the first communication system is set to the 2.4 GHz band of the wireless LAN of the first communication system, and WiMAX 2 Blocks 5 GHz band signals and other unnecessary signals. The pass band of the bandpass filter circuit BPF6 connected to the second reception terminal Rx2-2 of the second communication system is set to the 2.5 GHz band of WiMAX which is the second communication system. 2.4 GHz band signals and other unnecessary signals are blocked. With this configuration, when the notch of the first variable notch filter TNF1 is set to the 2.4 GHz band of the wireless LAN that is the first communication system, WiMAX 2 is connected to the second reception terminal Rx2-2 of the second communication system. .5 GHz band signal is output. On the other hand, when the notch of the first variable notch filter TNF1 is set in the 2.5 GHz band of WiMAX, which is the second communication system, 2.4 GHz of the wireless LAN is connected to the second reception terminal Rx2-1 of the first communication system. A band signal is output. With this configuration, even when the bands of the first communication system and the second communication system are close to each other, it is possible to share the reception path connected to the same one antenna terminal. Therefore, the number of parts is reduced and a simple circuit is realized.

  For example, a splitter circuit as shown in FIG. 4 may be used as the branch circuit SPL1. The splitter circuit includes inductor elements SL1 and SL2, a resistance element SR, and a capacitor element SC. The inductor element SL1 is connected between the terminals P3 and P4, and the inductor element SL2 is connected between the terminals P3 and P5. The terminal P3 is connected to the output side of the low noise amplifier circuit LNA3, the terminal P4 is connected to the input side of the bandpass filter circuit BPF5, and the terminal P5 is connected to the input side of the bandpass filter circuit BPF6. Capacitor element SC is connected to terminal P3, and resistance element SR is connected between terminals P4 and P5. The signal input to the terminal P3 is almost equally distributed and output from the terminals P4 and P5. That is, a signal having about half the strength of the signal input to the terminal P3 is output from the terminals P4 and P5. The branch circuit SPL1 may use a coupler circuit instead of the splitter circuit. An example of the coupler circuit is shown in FIG. In this coupler circuit, a main line CL1 and a sub line CL2 coupled to the main line are provided between a terminal P3 and a terminal P4, one end of the sub line is connected to the terminal P5, and the other end of the sub line is a resistor. It is connected to the ground electrode through CR. When the coupler circuit is used, it is possible to change the distribution ratio of the signal strength to the second terminal Rx1-2 of the first communication system and the signal strength to the second terminal Rx2-2 of the second communication system. For example, the signal strength to the second terminal Rx1-2 of the first communication system: the signal strength to the second terminal Rx2-2 of the second communication system can be distributed as 10: 1. The ratio of the signal strength to the second terminal Rx1-2 and the signal strength to the second terminal Rx2-2 of the second communication system can be set as appropriate, and more efficient signal reception is possible.

  The configurations of the bandpass filter circuits BPF5 and BPF6 are not particularly limited. For example, a configuration as shown in FIG. 7 may be used. The bandpass filter shown here is composed of two resonant lines lb1 and lb2 which are arranged between terminals P8 and P9 and coupled to each other, and capacitance elements cb1 to cb5. By appropriately adjusting the coupling between the resonance lines lb1 and lb2 and the capacitance elements cb1 to cb5, a bandpass filter having a pass band and a stop band at a desired frequency is formed.

  Next, the signal path connected to the first antenna terminal Ant1 in the configuration shown in FIG. 1 will be further described. Such a signal path corresponds to a 2.4 GHz band wireless LAN transmission / reception path. A common terminal of a single-pole double-throw switch circuit SPDT1 is connected to the first antenna terminal Ant1 via a high-pass filter circuit HPF1. The high-pass filter circuit HPF1 passes signals in the frequency band of the first system and blocks unnecessary signals on the lower frequency side. For example, in order to block the signal of the cellular phone on the lower frequency side than the 2.4 GHz band wireless LAN which is the first communication system, it is configured to attenuate 2.17 GHz or less. The switch circuit SPDT1 switches connection between a transmission path that reaches the first transmission terminal Tx1-1 for the first communication system and a reception path that reaches the first reception terminal Rx1-1. In the example shown in FIG. 1, a single-pole double-throw switch circuit (SPDT) using a field effect transistor is used as the switch circuit, but a diode switch circuit may be used. A first amplifier circuit PA1 that amplifies a transmission signal of the first communication system is connected to a transmission side terminal of the switch circuit SPDT1 via a detection circuit DET1. A band-pass filter circuit BPF1 is provided on the input terminal side of the first amplifier circuit PA1, and a low-pass filter circuit LPF1 is provided on the output terminal side.

  The first notch filter NoF1 is provided between the first receiving terminal Rx1-1 for the first communication system and the first switch circuit SPDT1, and the first notch filter NoF1 and the first communication system are used. The first receiving terminal Rx1-1 and the band-pass filter circuit BPF2 are provided. Further, a low noise amplifier circuit LNA1 is provided between the first notch filter NoF1 and the band pass filter circuit BPF2. By setting the notch (attenuation pole) of the first notch filter NoF1 to the 2.5 GHz band which is the frequency band of the second communication system, the received signal in the second frequency band is blocked. Further, by setting the pass band of the bandpass filter circuit BPF2 to the 2.4 GHz band that is the frequency band of the first communication system, unnecessary signals other than the signals of the first communication system can be removed. The configuration between the first antenna terminal Ant1 and the first switch circuit SPDT1, the first switch circuit SPDT1, the first transmission terminal Tx1-1 and the first reception terminal Rx1 for the first communication system. The configuration between -1 can be changed according to the required function and characteristics.

  Next, the signal path connected to the second antenna terminal Ant2 in the configuration shown in FIG. 1 will be further described. Such a signal path corresponds to a 2.5 GHz band WiMAX transmission / reception path. A common terminal of a single-pole double-throw switch circuit SPDT2 is connected to the second antenna terminal Ant2 via a high-pass filter circuit HPF2. The high-pass filter circuit HPF2 passes signals in the frequency band of the second system and blocks unnecessary signals on the lower frequency side. For example, it is configured to attenuate 2.17 GHz or less in order to block at least a cellular phone signal on the lower frequency side than the 2.5 GHz band WiMAX which is the second communication system. The switch circuit SPDT2 switches the connection between the transmission path reaching the first transmission terminal Tx2-1 for the second communication system and the reception path reaching the first reception terminal Rx2-1. A second amplification circuit PA2 for amplifying a transmission signal of the second communication system is connected to the transmission side terminal of the switch circuit SPDT2 via the detection circuit DET2. A band-pass filter circuit BPF3 is provided on the input terminal side of the second amplifier circuit PA2, and a low-pass filter circuit LPF2 is provided on the output terminal side.

  A second notch filter NoF2 is provided between the first reception terminal Rx2-1 for the second communication system and the second switch circuit SPDT2, and the second notch filter NoF2 and the second communication system are used. And a band-pass filter circuit BPF4 is provided between the first receiving terminal Rx2-1 and the first receiving terminal Rx2-1. Further, a low noise amplifier circuit LNA2 is provided between the second notch filter NoF2 and the band pass filter circuit BPF4. By setting the notch (attenuation pole) of the second notch filter NoF2 to the 2.4 GHz band that is the frequency band of the first communication system, the received signal in the first frequency band is blocked. Further, by setting the pass band of the bandpass filter circuit BPF4 to the 2.5 GHz band that is the frequency band of the second communication system, unnecessary signals other than the signals of the second communication system can be removed. The configuration between the second antenna terminal Ant2 and the second switch circuit SPDT2, the first transmission terminal Tx2-1 and the first reception terminal Rx2 for the second switch circuit SPDT2 and the second communication system. The configuration between -1 can be changed according to the required function and characteristics.

  For example, the first and second notch filters NoF1 and NoF2 may be configured as shown in FIG. In the notch filter of FIG. 6A, one end of an inductance element L2 is connected to a node of a path between terminals P6 and P7. One end of a capacitance element C2 is connected in series to the other end of the inductance element L2, and the other end of the capacitance element C2 is grounded. The notch filter may be configured by setting the resonance frequency of the series resonance circuit including the inductance element L2 and the capacitance element C2 to the first frequency band or the second frequency band. You may use the notch filter of FIG.4 (b). The notch filter of FIG. 4B is obtained by connecting a parallel resonant circuit composed of an inductance element L3 and a capacitor element C3 to the path between terminals P6 and P7. The notch filter may be configured by setting the resonance frequency of the parallel resonance circuit including the inductance element L3 and the capacitance element C3 to the first frequency band or the second frequency band.

  With the configuration according to FIG. 1 described above, the present invention can also be applied to a case where two communication systems in close proximity to each other are used, such as a 2.4 GHz band wireless LAN and a 2.5 GHz band WiMAX. 1T2R type high frequency circuit for MIMO can be provided. In addition, we provide high-frequency circuits suitable for front-end modules of communication devices that employ WiMAX using the 2.5 GHz band, 3.5 GHz band, and 5.5 GHz band, and front-end modules of communication devices that combine WiMAX and wireless LAN. can do.

  The circuit elements provided in the signal path connected to the first antenna terminal Ant1 and the signal path connected to the second antenna terminal Ant2 will be described. Bandpass filter circuits BPF1 and BPF3 provided on the input terminal side of the amplifier circuits PA1 and PA2 remove unnecessary noise outside the band included in the transmission signal input from the transmission terminal. On the other hand, the low-pass filter circuits LPF1 and LPF2 provided on the output terminal side of the amplifier circuits PA1 and PA2 attenuate the harmonic signals generated from the amplifier circuits. In order to prevent interference with the mobile phone system, it is necessary to suppress signals in the reception frequency band of the mobile phone system that are generated from each amplifier circuit. For example, the reception frequency of a mobile terminal of WCDMA (Wide Band CDMA) system is 2.11 to 2.17 GHz, which is close to the 2.4 GHz band of wireless LAN and the 2.5 GHz band of WiMAX. Therefore, a band pass filter circuit may be used instead of the low pass filter circuit.

  As the detection circuits DET1 and DET2, for example, a coupler circuit in which a main line and a sub-line are coupled to each other, one end of the sub-line is grounded via a resistor, the other end is connected to a matching transmission line, and a resistor is connected. A configuration in which the Schottky diode and the voltage smoothing circuit including the resistance element and the capacitance element are connected to the detection output terminal may be used. From this detection output terminal, a DC voltage corresponding to the output power of the amplifier circuits PA1 and PA2 is output. The detection circuit may be integrated in the amplifier circuit. In this case, it is not necessary to provide the detection circuit at the position shown in FIG.

  Between the low-noise amplifier circuits LNA1 and SPDT2 provided between the switch circuit SPDT1 and the first reception terminal Rx1-1 of the first communication system and the first reception terminal Rx2-1 of the second communication system The low noise amplifier circuit LNA2 provided in the amplifies the received signal of each communication system.

(Second Embodiment)
The high frequency circuit of the circuit block shown in FIG. 2 includes, as a plurality of antenna terminals, a fourth antenna terminal Ant4 and a fifth antenna terminal Ant5, a first transmission terminal Tx1-1 for the first communication system, and a first antenna terminal. Reception terminal Rx1-1 and second reception terminal Rx1-2, and first transmission terminal Tx2-1 and first reception terminal Rx2-1 and second reception terminal Rx2-2 for the second communication system. The fourth switch circuit SPDT4 and the fifth switch circuit SPDT5 for switching between the transmission path and the reception path, the second branch circuit SPL2, the third branch circuit SPL3, the second variable notch filter TNF2, and the third Variable notch filter TNF3. The first transmission terminal Tx1-1 for the first communication system is connectable to the fourth antenna terminal Ant4 via the single-pole double-throw fourth switch circuit SPDT4, and the second transmission system Tx1-1 is connected to the fourth antenna terminal Ant4. One transmission terminal Tx2-1 is configured to be connectable to a fifth antenna terminal Ant5 via a single-pole double-throw fifth switch circuit SPDT5. The reception terminal pair constituted by the first reception terminal Rx1-1 for the first communication system and the first reception terminal Rx2-1 for the second communication system is the second branch circuit SPL2, the second The second variable notch filter TNF2 connected to the common terminal side of the branch circuit SPL2 and the fourth switch circuit SPDT4 connected to the second variable notch filter TNF2 can be connected to the fourth antenna terminal Ant4. Has been. On the other hand, the reception terminal pair configured by the second reception terminal Rx1-2 for the first communication system and the second reception terminal Rx2-2 for the second communication system is the third branch circuit SPL3, Can be connected to the fifth antenna terminal Ant5 via the third variable notch filter TNF3 connected to the common terminal side of the third branch circuit SPL3 and the fifth switch circuit SPDT5 connected to the third variable notch filter TNF3 It is configured.

  First, a circuit connected to the fourth antenna terminal Ant4 will be described more specifically. The shared terminal of the single-pole double-throw switch circuit SPDT4 is connected to the fourth antenna terminal Ant4 via a high-pass filter circuit HPF4. Since the configuration and function of the high-pass filter circuit are the same as those in the first embodiment, description thereof is omitted. The switch circuit SPDT4 has a signal path that reaches the reception terminal pair configured by the first reception terminal Rx1-1 for the first communication system and the first reception terminal Rx2-1 for the second communication system. The route is switched to the transmission side route to the first transmission terminal Tx1-1 for the first communication system. A second variable notch filter TNF2 is provided on the reception side path connected to the switch circuit SPDT4. The second variable notch filter TNF2 is set to a notch (attenuation pole) set to 2.4 GHz which is a frequency band of the first communication system and 2.5 GHz which is a frequency band of the second communication system. The notch (attenuation pole) can be switched. When receiving the 2.4 GHz band signal of the first communication system, the notch is switched to the 2.5 GHz band which is the frequency band of the second communication system. On the other hand, when receiving the 2.5 GHz band signal of the second communication system, the notch is switched to the 2.4 GHz band which is the frequency band of the first communication system. Necessary when receiving a 2.4 GHz band wireless LAN and a 2.5 GHz band WiMAX signal using the same single antenna terminal by using a variable notch filter with steep blocking characteristics. It is possible to pass a signal of another communication system and prevent a signal of another communication system from passing. Note that the configuration and function of the variable notch filter are the same as those in the first embodiment, and thus description thereof is omitted.

  A second branch circuit SPL2 is connected to the reception terminal pair side of the second variable notch filter TNF2 via a low noise amplifier circuit LNA4. Note that the low noise amplifier circuit can be provided on the receiving terminal side of the branch circuit SPL2, but by providing it on the antenna terminal side of the second branch circuit SPL2, the first communication system and the second communication system can be provided. The low noise amplifier circuit can be shared and the circuit can be simplified. That is, it is preferable that a low noise amplifier circuit is disposed between the second variable notch filter TNF2 and the second branch circuit SPL2. When the low noise amplifier circuit is provided in another circuit connected to the subsequent stage of the high frequency circuit shown in FIG. 2, the low noise amplifier circuit shown in FIG. 2 can be omitted.

  The signal that has passed through the second variable notch filter TNF2 provided between Ant4 that is the same antenna terminal and the second branch circuit SPL2 is distributed to two signal paths by the second branch circuit SPL2. . Band pass filter circuits BPF8 and BPF10 are provided between the first receiving terminal Rx1-1 of the first communication system, the first receiving terminal Rx2-1 of the second communication system, and the second branch circuit SPL2, respectively. ing. Since the configuration and function of the second branch circuit SPL2 and the bandpass filter circuits BPF8 and BPF10 connected to the branch circuit are the same as those in the first embodiment, the description thereof is omitted. With this configuration, when the notch of the second variable notch filter TNF2 is set to the 2.4 GHz band of the wireless LAN that is the first communication system, WiMAX 2 is connected to the first reception terminal Rx2-1 of the second communication system. .5 GHz band signal is output. On the other hand, when the notch of the second variable notch filter TNF2 is set to the 2.5 GHz band of WiMAX, which is the second communication system, 2.4 GHz of the wireless LAN is connected to the first reception terminal Rx1-1 of the first communication system. A band signal is output. With this configuration, even when the bands of the first communication system and the second communication system are close to each other, it is possible to share the reception path connected to the same one antenna terminal. Therefore, the number of parts is reduced and a simple circuit is realized.

  On the other hand, a third amplifier circuit PA3 for amplifying the transmission signal of the first communication system is connected to the transmission side terminal of the switch circuit SPDT4 via the detection circuit DET3. A band-pass filter circuit BPF7 is provided on the input terminal side of the third amplifier circuit PA3, and a low-pass filter circuit LPF3 is provided on the output terminal side. Since these circuits on the transmission side are the same as those in the first embodiment, description thereof will be omitted.

  In addition, since the circuit connected to the fifth antenna terminal Ant5 is configured in the same manner as the circuit connected to the fourth antenna terminal, description of overlapping parts will be omitted as appropriate. A common terminal of a single-pole double-throw switch circuit SPDT5 is connected to the fifth antenna terminal Ant5 via a high-pass filter circuit HPF5. The switch circuit SPDT5 has a signal path that reaches the receiving terminal pair configured by the second receiving terminal Rx1-2 for the first communication system and the second receiving terminal Rx2-2 for the second communication system. The route is switched to the transmission side route that reaches the first transmission terminal Tx2-1 for the second communication system. A third variable notch filter TNF3 is provided on the reception side path connected to the switch circuit SPDT5. The third variable notch filter TNF3 is set to a notch (attenuation pole) set to 2.4 GHz which is a frequency band of the first communication system and 2.5 GHz which is a frequency band of the second communication system. The notch (attenuation pole) can be switched. When receiving the 2.4 GHz band signal of the first communication system, the notch is switched to the 2.5 GHz band which is the frequency band of the second communication system. On the other hand, when receiving the 2.5 GHz band signal of the second communication system, the notch is switched to the 2.4 GHz band which is the frequency band of the first communication system.

  A third branch circuit SPL3 is connected to the reception terminal pair side of the third variable notch filter TNF3 via a low noise amplifier circuit LNA5. The low-noise amplifier circuit can be provided on the receiving terminal side of the branch circuit SPL3. However, the low-noise amplifier circuit is provided on the antenna terminal side of the third branch circuit SPL3. The low noise amplifier circuit can be shared and the circuit can be simplified. That is, it is preferable that a low noise amplifier circuit is disposed between the third variable notch filter TNF3 and the third branch circuit SPL3.

  The signal that has passed through the third variable notch filter TNF3 provided between the same antenna terminal Ant5 and the third branch circuit SPL3 is distributed to two signal paths by the third branch circuit SPL3. . Band-pass filter circuits BPF11 and BPF12 are provided between the second reception terminal Rx1-2 of the first communication system, the second reception terminal Rx2-2 of the second communication system, and the third branch circuit SPL3, respectively. ing. With this configuration, when the notch of the third variable notch filter TNF3 is set in the 2.4 GHz band of the wireless LAN that is the first communication system, WiMAX 2 is connected to the second reception terminal Rx2-2 of the second communication system. .5 GHz band signal is output. On the other hand, when the notch of the third variable notch filter TNF3 is set to the 2.5 GHz band of WiMAX which is the second communication system, the wireless LAN 2.4 GHz is connected to the second reception terminal Rx1-2 of the first communication system. A band signal is output.

  On the other hand, a transmission side terminal of the switch circuit SPDT5 is connected to a fourth amplification circuit PA4 that amplifies a transmission signal of the second communication system via a detection circuit DET4. A band-pass filter circuit BPF9 is provided on the input terminal side of the fourth amplifier circuit PA4, and a low-pass filter circuit LPF4 is provided on the output terminal side.

  The configuration shown in FIG. 2 differs from the first embodiment shown in FIG. 1 in that two variable notch filters are used. Two antenna terminals are used according to the configuration, and the second receiving terminal Rx1-2 for the first communication system and the second receiving terminal for the second communication system that can be connected to the same one antenna terminal Ant5. In addition to the reception terminal pair configured by Rx2-2, the reception configured by the first reception terminal Rx1-1 for the first communication system and the first reception terminal Rx2-1 for the second communication system. The terminal pair is also configured to be connectable to the same one antenna terminal Ant4 via a branch circuit. Such a configuration simplifies the high-frequency circuit.

  The configuration of the high-frequency circuit according to the present invention is not limited to the first and second embodiments. For example, a high frequency circuit may be configured by adding circuit elements such as an antenna terminal, a transmission terminal, and a reception terminal. It is also possible to increase the number of transmitting antenna terminals to separate the transmission side path and the reception side path. Further, an SP3T type switch circuit can be used instead of the SPDT type switch circuit, so that the high frequency circuit can be shared with other communication systems. In any case, a receiving terminal pair composed of a receiving terminal for the first communication system and a receiving terminal for the second communication system can be connected to the same one antenna terminal via a branch circuit, A configuration in which a variable notch filter is provided between the same antenna terminal and the branch circuit, and a band-pass filter circuit is provided between each of the reception terminals constituting the reception terminal pair connected to the branch circuit and the branch circuit As long as it has. When the frequency band of the first communication system and the frequency band of the second communication system are close to each other, the high-frequency circuit according to the present invention has, for example, the upper limit of the first communication system frequency and the lower limit of the second communication system frequency. It is suitable when the frequency interval is 0.2 GHz or less.

Next, an example in which a high-frequency component having a high-frequency circuit according to the present invention is configured as a multilayer component (component using a ceramic multilayer substrate) will be described. FIG. 8 is a perspective view of a high-frequency component according to an embodiment of the present invention in which a multilayer component is configured using a ceramic multilayer substrate. The ceramic laminated substrate is made of a ceramic dielectric material LTCC (Low Temperature Co-fired Ceramics), which can be sintered at a low temperature of 1000 ° C. or less, for example, on a green sheet having a thickness of 10 μm to 200 μm, and low resistivity Ag or Cu It can be manufactured by printing a conductive paste such as a predetermined electrode pattern, appropriately stacking a plurality of green sheets, and sintering. As the dielectric material, for example, Al, Si, Sr as a main component, Ti, Bi, Cu, Mn, Na, K as a subcomponent, Al, Si, Sr as a main component, Ca, Pb, A material containing Na and K as a multicomponent, a material containing Al, Mg, Si, and Gd, and a material containing Al, Si, Zr, and Mg are used, and a material having a dielectric constant of about 5 to 15 is used. In addition to the ceramic dielectric material, it is also possible to use a resin multilayer substrate or a multilayer substrate made of a composite material obtained by mixing a resin and ceramic dielectric powder. Further, the ceramic substrate is made of HTCC (high temperature co-fired ceramic) technology, the dielectric material is mainly Al ₂ O ₃ , and the transmission line is a metal conductor that can be sintered at a high temperature such as tungsten or molybdenum. You may comprise as.

  In each layer of this ceramic multilayer substrate, pattern electrodes for inductance elements, capacitance elements, wiring lines, and ground electrodes are appropriately configured, and via hole electrodes are formed between layers to form a desired circuit. The Mainly, a circuit portion that can be configured by an LC circuit is configured. Here, the band-pass filter circuit, the low-pass filter circuit, and the high-pass filter circuit are mainly configured inside the ceramic multilayer substrate. Moreover, a chip element mounted on the upper surface of the ceramic multilayer substrate may be used as a part of the elements of each circuit. For example, the capacitance element, the inductance element, the resistor, and the diode constituting the variable notch filter may all be mounted on the multilayer substrate as chip components.

  The ceramic multilayer substrate is mounted with semiconductor elements for the switch circuit SPDT, the amplifier circuit PA, and the low noise amplifier circuit LNA. And it connects to a ceramic laminated substrate with a wire bonder, LGA, BGA, etc., and the high frequency circuit of this invention can be comprised as a small high frequency component. Of course, the component mounted on the ceramic multilayer substrate and the built-in element of the ceramic multilayer substrate are connected to form a predetermined circuit, and a high frequency circuit is configured. In addition to the semiconductor elements described above, elements such as a chip capacitor, a chip resistor, and a chip inductor are appropriately mounted on the ceramic multilayer substrate. These mounting elements can be appropriately selected from the relationship with the elements incorporated in the ceramic laminated substrate.

  Further, by using the above-described high-frequency components, it is possible to configure a communication device that can handle at least two adjacent different frequency bands, which contributes to cost reduction and size reduction of the communication device. Further, the high-frequency component can be widely applied to portable devices, personal computers, and the like having a wireless communication function.

It is a circuit block of one embodiment of the high frequency circuit of the present invention. It is a circuit block of other embodiments of the high frequency circuit of the present invention. It is a figure which shows an example of a structure of a variable notch filter. It is a figure which shows an example of a structure of a splitter circuit. It is a figure which shows an example of a structure of a coupler circuit. It is a figure which shows an example of a structure of a notch filter. It is a figure which shows an example of a structure of a band pass filter circuit. It is a perspective view of the high frequency component of one Example based on this invention comprised using the ceramic laminated substrate.

Explanation of symbols

SPL1-3: Branch circuit TNF1-3: Variable notch filter NoF1, 2: Notch filter Ant1-5: Antenna terminal SPDT1-5: Switch circuit DET1-4: Detection circuit BPF1-12: Band pass filter circuit HPF1-5: High pass Filter circuit LPF1-4: Low-pass filter circuit PA1-4: Amplifier circuit LNA1-5: Low noise amplifier circuit Rx1-1, Rx1-2: Reception terminal of first communication system Tx1-1: Transmission of first communication system Terminals Rx2-1, Rx2-2: Reception terminals of the second communication system Tx2-1: Transmission terminals of the second communication system P1-4: Terminals C1-3, C11, SC: Capacitance elements L1-3, SL1 2, CL1-2: Inductance elements R, R1, SR, CR: Resistance

Claims (8)

Multiple antenna terminals,
At least a first transmission terminal and first and second reception terminals for a first communication system;
Having at least a first transmission terminal and first and second reception terminals for a second communication system;
The first and second receiving terminals for the first communication system can be connected to separate antenna terminals, respectively.
The first and second receiving terminals for the second communication system can be connected to separate antenna terminals, respectively.
A receiving terminal pair comprising a first receiving terminal for the first communication system and a first receiving terminal for the second communication system; and a second receiving terminal for the first communication system; At least one receiving terminal pair among the receiving terminal pairs constituted by the second receiving terminals for the second communication system can be connected to the same one of the plurality of antenna terminals via a branch circuit. And
A variable notch filter is provided between the same one antenna terminal and the branch circuit,
A high-frequency circuit in which a band-pass filter circuit is provided between each of the receiving terminals constituting the receiving terminal pair connected to the branch circuit and the branch circuit. First and second switch circuits for switching between a transmission path and a reception path;
First, second and third antenna terminals as the plurality of antenna terminals;
A first branch circuit as the branch circuit;
And a first variable notch filter as the variable notch filter,
A first transmission terminal for the first communication system and a first reception terminal for the first communication system can be connected to the first antenna terminal via the first switch circuit;
A first transmission terminal for the second communication system and a first reception terminal for the second communication system can be connected to the second antenna terminal via the second switch circuit;
A reception terminal pair configured by a second reception terminal for the first communication system and a second reception terminal for the second communication system is formed of the first branch circuit and the first branch circuit. 2. The high-frequency circuit according to claim 1, wherein the high-frequency circuit can be connected to the third antenna terminal through a first variable notch filter connected to a common terminal side. A first notch filter is provided between the first receiving terminal for the first communication system and the first switch circuit;
A second notch filter is provided between the first receiving terminal for the second communication system and the second switch circuit;
A band is provided between the first notch filter and the first receiving terminal for the first communication system, and between the second notch filter and the first receiving terminal for the second communication system. The high-frequency circuit according to claim 2, further comprising a pass filter circuit.   Switching between the connection between the third antenna terminal and the first variable notch filter and the connection between the third antenna terminal and a termination resistor between the first variable notch filter and the third antenna terminal. The high-frequency circuit according to claim 2, further comprising a third switch circuit that can be configured. Fourth and fifth switch circuits for switching between the transmission path and the reception path;
Fourth and fifth antenna terminals as the plurality of antenna terminals,
Second and third branch circuits as the branch circuit,
And second and third variable notch filters as the variable notch filter,
A first transmission terminal for the first communication system is connectable to the fourth antenna terminal via the fourth switch circuit;
A first transmission terminal for the second communication system is connectable to the fifth antenna terminal via the fifth switch circuit;
The reception terminal pair configured by the first reception terminal for the first communication system and the first reception terminal for the second communication system is the second branch circuit and the second branch circuit. It can be connected to the fourth antenna terminal via the second variable notch filter connected to the common terminal side and the fourth switch circuit connected to the second variable notch filter,
The reception terminal pair configured by the second reception terminal for the first communication system and the second reception terminal for the second communication system is configured by the third branch circuit and the third branch circuit. The third variable notch filter connected to the common terminal side and the fifth switch circuit connected to the third variable notch filter can be connected to the fifth antenna terminal. The high-frequency circuit according to claim 1.   6. The high frequency circuit according to claim 1, wherein a low noise amplifier circuit is disposed between the variable notch filter and the branch circuit. A high-frequency component having the high-frequency circuit according to claim 1,
The high frequency circuit includes a laminated body in which electrode patterns are formed in a plurality of layers and laminated and integrated, and an element mounted on a surface of the laminated body.   A communication apparatus using the high-frequency component according to claim 7.

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