JP2009159411A - High frequency circuit, high frequency component and communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple circuit configuration which can be adapted even when a frequency band are close to each other, in a high frequency circuit compatible with at least three different communication systems. <P>SOLUTION: The high frequency circuit comprises: an antenna terminal Ant1; transmission and reception terminals Tx1-1, Tx2-1, Rx1-1 and Rx1-2 for first and second communication systems; a reception terminal Rx3-1 for a third communication system; a switch circuit for switching the connection between a common terminal connected to the antenna terminal and a switching terminal connected to a transmission path or a switching terminal connected to a reception path; a branching circuit for branching the transmission path according to a frequency; a branching circuit for branching the reception path into a common path connected to the reception terminal for the first communication system and the reception terminal for the third communication system and a path connected to the reception terminal for the second communication system according to the frequency; and a branching circuit for branching the common path into a path connected to the reception terminal for the first communication system and a path connected to the reception terminal for the third communication system. <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 three 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, Patent Document 2 discloses a circuit shared between a wireless LAN and Bluetooth (Bluetooth: registered trademark), in which a band pass filter is provided between the antenna and the antenna changeover switch, and the wireless LAN and Bluetooth are switched on the transmission side switched by the antenna changeover switch. A low-noise amplifier that is shared for wireless LAN reception and Bluetooth reception on the receiving side, which is connected to the power amplifier to separate wireless LAN transmission and Bluetooth, and is switched by the antenna selector switch. And a circuit in which a distributor for separating wireless LAN reception and Bluetooth reception is connected to a low-noise amplifier.

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-described problems, the present invention can be applied to a high-frequency circuit, a high-frequency component, and a communication device using the same that are compatible with at least three different communication systems with a simple circuit configuration even when the frequency bands are close to each other. The purpose is to provide a configuration.

The high-frequency circuit of the present invention includes a first antenna terminal, a first transmission terminal and a first reception terminal for the first communication system, a first transmission terminal and a first reception terminal for the second communication system. A receiving terminal;
A first receiving terminal for a third communication system; a common terminal connected to the first antenna terminal; at least a first switching terminal to which a transmission path is connected; or a first terminal to which a receiving path is connected. A first switch circuit that switches a connection to two switching terminals, a path that connects the transmission path to a first transmission terminal for the first communication system, and a second communication system A first branching circuit that branches depending on a frequency to a path connected to the first transmission terminal, the reception path, the first reception terminal for the first communication system, and the third A second branch that branches depending on the frequency into a first common path connected to the first receiving terminal for the communication system and a path connected to the first receiving terminal for the second communication system. A wave circuit and the first common path are connected to the first communication system. And having first and path connected to the reception terminal of the use, and a first branch circuit for branching to a path connected to the first receiving terminal for the third communications system. In this configuration, the circuit from the first antenna terminal to the first common path side of the first branch circuit can be shared as the receiving circuit of the first communication system and the third communication system. The circuit configuration can be simplified.

  In the high-frequency circuit, a first low-noise amplifier circuit is connected between the second branch circuit and the first branch circuit, and the second branch circuit and the second communication system are used. Preferably, a second low noise amplifier circuit is connected between the first receiving terminals. In the case of a communication system with sufficiently large signal strength at the time of reception, a low noise amplifier circuit is not necessarily required, but by arranging a low noise amplifier circuit, sufficient signal strength can be secured and good reception sensitivity can be obtained. Can do. Further, since the first low noise amplifier circuit can be shared as the receiving circuit of the first communication system and the third communication system, the circuit configuration can be simplified.

  In the high-frequency circuit, a first high-frequency amplifier circuit is connected between the first demultiplexing circuit and a first transmission terminal for the first communication system, and the first demultiplexing circuit and the first demultiplexing circuit A second high frequency amplifier circuit is preferably connected between the first transmission terminals for the second communication system. According to this configuration, since the first demultiplexing circuit, the first high frequency amplifier circuit, and the second high frequency amplifier circuit can be designed integrally, the first demultiplexing circuit and the first high frequency amplifier circuit can be designed. It is easy to design a matching circuit between the first branching circuit and the second high-frequency amplifier circuit.

  Further, the high-frequency circuit has a first transmission terminal for the third communication system, the first switch circuit includes a third switching terminal, and the first switching circuit has a first switching terminal. The transmission terminal is preferably connected to the third switching terminal. According to this configuration, since the first antenna can also be used for transmission in the third communication system, the antenna for transmission in the third communication system can be omitted.

  Furthermore, in the high frequency circuit, it is preferable that a third high frequency amplifier circuit is disposed in a path connected to the first transmission terminal for the third communication system. According to this configuration, since the first switch circuit and the third high-frequency amplifier circuit can be designed integrally, it is easy to design a matching circuit between the first switch circuit and the third high-frequency amplifier circuit. become. In addition, since it can be connected to the first switch circuit without going through the first branching circuit, the insertion loss of the transmission path of the third communication system can be reduced.

  In the high-frequency circuit, a second branch circuit is connected to an input side of the first high-frequency amplifier circuit, and the second branch circuit is connected to a first transmission terminal for the first communication system. And a path connected to the first transmission terminal for the third communication system, wherein the first high-frequency amplifier circuit is configured to transmit the first communication system and the third It is also preferable to be shared for transmission of the communication system. According to this configuration, since the first high-frequency amplifier circuit can be shared as the transmission circuit of the first communication system and the third communication system, the circuit configuration can be simplified.

  Furthermore, in the high frequency circuit, it is preferable that a band pass filter circuit is connected to the second branch circuit side of the first branch circuit. With this configuration, since the band-pass filter circuit can be shared as the receiving circuit of the first communication system and the second communication system, the circuit configuration can be simplified. Alternatively, in the high-frequency circuit, between the first branch circuit and the first reception terminal of the first communication system, between the first branch circuit and the first reception terminal of the third communication system. It is also preferable that a band-pass filter circuit is connected between them. According to this configuration, the reception band-pass filter circuit of the first communication system and the reception band-pass filter circuit of the second communication system can be designed to have different characteristics for each reception of each communication system. Therefore, the optimum band pass filter characteristic can be obtained for each reception path.

  In the high-frequency circuit, a second antenna terminal, a second receiving terminal for the first communication system, a second receiving terminal for the second communication system, and the third communication system. A second receiving terminal and a first transmitting terminal, a common terminal connected to the second antenna terminal, a first switching terminal to which another transmitting path is connected, or another receiving path is connected A second switch circuit for switching the connection with the second switching terminal, and the other receiving path for the second receiving terminal for the first communication system and for the third communication system. A third branching circuit that branches depending on the frequency into a second common path connected to the second receiving terminal and a path connected to the second receiving terminal for the second communication system; The second common path to the second reception for the first communication system; A third branch circuit for branching into a path connected to the child and a path connected to the second receiving terminal for the third communication system, and the first branch circuit for the third communication system Is preferably connected to the second switching terminal of the second switch circuit. According to this configuration, it is possible to provide a plurality of reception circuits of the first to third communication systems that can receive simultaneously with a simple configuration, and to obtain a high-frequency circuit for 1T2R (one transmission and two reception) type MIMO communication. Can do. In addition, since the first transmission terminal for the third communication system can be connected to the second antenna terminal, the transmission of the third communication system is connected to the first antenna terminal. It is also possible to control the transmission of the second communication system and the second communication system independently.

  In the high-frequency circuit, a second antenna terminal, a second receiving terminal for the first communication system, a second receiving terminal for the second communication system, and the third communication system. And a second receiving terminal for the first communication system and a second receiving terminal for the third communication system, and a second receiving terminal connected to the second antenna terminal. A third branching circuit that branches according to a frequency into a second common path connected to the receiving terminal and a path connected to the second receiving terminal for the second communication system; and A third path that branches into a path connected to the second receiving terminal for the first communication system and a path connected to the second receiving terminal for the third communication system It is also preferable to have a branch circuit. According to this configuration, it is possible to provide a plurality of reception circuits of the first to third communication systems that can receive simultaneously with a simple configuration, and to obtain a high-frequency circuit for 1T2R (one transmission and two reception) type MIMO communication. Can do.

  Further, in the high-frequency circuit, bandpass filter circuits are connected to the second branch circuit side of the first branch circuit and the third branch circuit side of the third branch circuit, respectively. It is preferable. With this configuration, since the band-pass filter circuit can be shared as the receiving circuit of the first communication system and the second communication system, the circuit configuration can be simplified. Or between the first branch circuit and the first receiving terminal of the first communication system, between the first branch circuit and the first receiving terminal of the third communication system, and the first Band-pass filter circuits between the third branch circuit and the second reception terminal of the first communication system, and between the third branch circuit and the second reception terminal of the third communication system, respectively. It is also preferable that they are connected. According to this configuration, the reception band-pass filter circuit of the first communication system and the reception band-pass filter circuit of the second communication system can be designed to have different characteristics for each reception of each communication system. Therefore, the optimum band pass filter characteristic can be obtained for each reception path.

  Further, in the high-frequency circuit, it is preferable that the third communication system has a larger transmission signal output than the first and second communication systems.

  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, in a high-frequency circuit, a high-frequency component, and a communication device using the same that are compatible with at least three different communication systems, a configuration that can be applied with a simple circuit even when the frequency band of the communication system is close Can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. The present invention is a high-frequency circuit applicable to wireless communication using at least the first to third communication systems. In particular, the high-frequency circuit is suitable when the frequency band of these communication systems is close. Hereinafter, the first communication system is a 2.4 GHz band wireless LAN, the second communication system is a 5 GHz band wireless LAN whose frequency band is higher than that of the first communication system, and the third communication system is a frequency. A specific description will be given by taking as an example a high-frequency circuit of a front-end module used in a communication device that performs wireless communication with a 2.5 GHz band WiMAX band between the first communication system and the second communication system. Note that the communication system is not particularly limited. For example, a 3.5 GHz band WiMAX, a 5.8 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 first transmission terminal Tx1-1 and a first reception terminal Rx1 for a 2.4 GHz band wireless LAN which is the first communication system. -1, a first transmission terminal Tx2-1 and a first reception terminal Rx2-1 for a wireless LAN of 5 GHz band as the second communication system, and a WiMAX of 2.5 GHz band as the third communication system First receiving terminal Rx3-1. Further, a single terminal for switching the connection between the common terminal connected to the first antenna terminal Ant1 and at least the first switching terminal to which the transmission path is connected or the second switching terminal to which the reception path is connected. A pole double throw type first switch circuit SPDT1 is provided. The first branching circuit Dip1 is connected to the first switching terminal of the first switch circuit SPDT1. The first branching circuit Dip1 includes the transmission path, the path connected to the first transmission terminal Tx1-1 for the first communication system, and the first transmission terminal Tx2 for the second communication system. Branches according to the frequency to the path connected to -1. On the other hand, a second branching circuit Dip2 is connected to the second switching terminal of the first switch circuit SPDT1. The second branching circuit Dip2 connects the reception path to the first reception terminal Rx1-1 for the first communication system and the first reception terminal Rx3-1 for the third communication system. The first common path and the path connected to the first receiving terminal Rx2-1 for the second communication system branch according to the frequency. Further, the first common path includes a first common path, a path connected to the first reception terminal Rx1-1 for the first communication system, and a first communication path for the third communication system. A first branch circuit SPL1 that branches to a path connected to the reception terminal Rx3-1 is disposed.

  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 bands of the first to third communication systems 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. When there is no need to block the signal of the mobile phone, it can be configured to attenuate 1 GHz or less as a countermeasure against static electricity. In this case, since the frequency to be attenuated is far from the frequency band of the communication system, the insertion loss of the high-pass filter circuit can be reduced. In addition, when no countermeasure against static electricity is required, a low-pass filter circuit for improving the amount of harmonic generation can be arranged. The switch circuit SPDT1 switches the signal path to a reception path that reaches the reception terminals for the first to third communication systems at the time of reception, and transmits the signal path to the transmission terminals for the first and second communication systems at the time of transmission. Switch to a route. With this configuration, transmission / reception isolation can be improved. The configuration related to the high-pass filter circuit and the switch circuit may be changed or omitted as appropriate according to the communication system used and the required characteristics. In the example shown in FIG. 1, a single-pole double-throw switch circuit (SPDT) using a field effect transistor (FET) is used as a switch circuit for miniaturization, but a diode switch circuit may be used. .

  The transmission path connected to the first switch circuit SPDT1 will be described below. The first branching circuit Dip1 connected to the first switching terminal of the first switch circuit SPDT1 passes the signal of the 2.4 GHz band wireless LAN that is the first communication system and performs the second communication. The system is composed of a low-pass filter unit that blocks a 5 GHz-band wireless LAN signal, and a high-pass filter unit that passes a 5 GHz-band wireless LAN signal and blocks a 2.4 GHz-band wireless LAN signal. In the 2.4 GHz band path between the first branching circuit Dip1 and the first transmission terminal Tx1-1 for the first communication system, the low-pass filter circuit LPF1 is sequentially provided from the first branching circuit Dip1 side. A detector circuit DET1, a first high-frequency amplifier circuit PA1, and a first band-pass filter circuit BPF1 are arranged. Similarly, a low-pass filter circuit is arranged in order from the first demultiplexing circuit Dip1 side on the 5 GHz band path between the first demultiplexing circuit Dip1 and the first transmission terminal Tx2-1 for the second communication system. LPF2, detector circuit DET2, second high-frequency amplifier circuit PA2, and second band-pass filter circuit BPF2 are arranged.

  The bandpass filter circuits BPF1 and BPF2 provided on the input terminal side (transmission terminal side) of the first and second high-frequency amplifier circuits PA1 and PA2 are unnecessary outside the band included in the transmission signal input from the transmission terminal. Remove noise. On the other hand, the low-pass filter circuits LPF1 and LPF2 provided on the output terminal side of the first and second high-frequency amplifier circuits PA1 and PA2 attenuate the harmonic signals generated from the respective high-frequency amplifier circuits. Further, 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 high-frequency amplifier circuit. For example, the reception frequency of a WCDMA (Wide Band CDMA) mobile terminal is 2.11 to 2.17 GHz, which is close to the 2.4 GHz band of a wireless LAN. 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 may be used. In the coupler circuit, one end of the sub line is grounded via a resistor, the other end is connected to a matching transmission line, and further via a voltage smoothing circuit including a Schottky diode, a resistance element, and a capacitance element. Connected to the detection output terminal. From this detection output terminal, a DC voltage corresponding to the output power of the first and second high-frequency amplifier circuits PA1 and PA2 is output. The detection circuit may be connected between the first switch circuit SPDT1 and the first branch circuit Dip1. The detection circuit may be integrated in the high frequency amplifier circuit. In this case, it is not necessary to provide the detection circuit at the position shown in FIG.

  Next, the reception path connected to the first switch circuit SPDT1 will be described. The second demultiplexing circuit Dip2 connected to the second switching terminal of the first switch circuit SPDT1 is a 2.4 GHz band wireless LAN that is the first communication system and the third communication system that are close to each other. A 2.5 GHz band WiMAX signal is allowed to pass, and a low-pass filter unit that blocks a 5 GHz band wireless LAN signal, which is the second communication system, and a 5 GHz band wireless LAN signal are allowed to pass, and a 2.4 GHz band It consists of a wireless LAN and a high-pass filter section that blocks 2.5 GHz band WiMAX signals. The common path connected to the low-pass filter unit of the second demultiplexing circuit Dip2 includes a third bandpass filter circuit, a first low-noise amplifier circuit LNA1, a fourth, in order from the second demultiplexing circuit Dip2 side. A bandpass filter circuit BPF4 is arranged. Further, the fourth band-pass filter circuit BPF4, the first reception terminal Rx1-1 of the 2.4 GHz band wireless LAN which is the first communication system, and the 2.5 GHz band WiMAX of the third communication system. A first branch circuit SPL1 is arranged between the reception terminals Rx3-1.

  For example, a splitter circuit as shown in FIG. 5 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 P1 and P2, and the inductor element SL2 is connected between the terminals P1 and P3. The terminal P1 is on the output side of the first low noise amplifier circuit LNA1, the terminal P2 is on the first reception terminal Rx1-1 of the first communication system, and the terminal P3 is the first reception terminal Rx3 of the third communication system. -1. Capacitor element SC is connected to terminal P1, and resistance element SR is connected between terminals P2 and P3. The signal input to the terminal P1 is substantially equally distributed and output from the terminals P2 and P3. That is, a signal having about half the strength of the signal input to the terminal P1 is output from the terminals P2 and P3. 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 the terminal P1 and the terminal P2, and one end of the sub line is connected to the terminal P3, 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 first terminal Rx1-1 of the first communication system and the signal strength to the first terminal Rx3-1 of the third communication system. For example, the signal intensity to the first terminal Rx1-1 of the first communication system: the signal intensity to the first terminal Rx3-1 of the third communication system can be distributed as 10: 1. The ratio of the signal strength to the first terminal Rx1-1 and the signal strength to the first terminal Rx3-1 of the third communication system can be set as appropriate, and more efficient signal reception is possible. A single-pole double-throw switch circuit can also be used as the branch circuit SPL1. By using these branch circuits, the paths of the first and second communication systems having close frequency bands can be branched. 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, a simple circuit is realized, and this contributes to the miniaturization of the high-frequency circuit and the high-frequency parts that constitute the high-frequency circuit. When the frequency band of the first communication system and the frequency band of the third 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 third communication system frequency. It is suitable when the frequency interval is 0.2 GHz or less.

  A third band-pass filter provided between the low-pass filter unit of the second branching circuit Dip2 and the first low-noise amplifier circuit LNA1 that amplifies the reception signals of the first and third communication systems is Unnecessary waves other than the signals of the first and third communication systems such as the signal of the mobile phone are blocked. Furthermore, the fourth band-pass filter circuit BPF4 provided between the first low-noise amplifier circuit LNA1 and the first branch circuit SPL1 has an unnecessary wave signal and a second band-pass filter BPF3 that cannot be blocked by the third band-pass filter BPF3. 1 to suppress harmonics generated in the low noise amplifier circuit LNA1. In addition, by providing the fourth band-pass filter circuit on the second branching circuit Dip2 side of the first branch circuit SPL1, the first low noise amplifier circuit is received by the first communication system and the third communication system. The third bandpass filter BPF3 and the fourth bandpass filter BPF4 can be shared with the LNA1 to simplify the circuit.

  On the other hand, the fourth band-pass filter circuit can be provided on the reception terminal side of the first branch circuit SPL1. That is, between the first branch circuit SPL1 and the first reception terminal Rx1-1 of the first communication system, and between the first branch circuit SPL1 and the first reception terminal Rx3-1 of the third communication system. Each may be provided with a band-pass filter circuit. In this case, the pass band of the band-pass filter circuit connected to the first receiving terminal Rx1-1 of the first communication system is set to the 2.4 GHz band of the wireless LAN of the first communication system, and WiMAX 2.5 GHz band signals and other unnecessary signals are blocked. Further, the pass band of the bandpass filter connected to the first receiving terminal Rx3-1 of the third communication system is set to the 2.5 GHz band of WiMAX which is the third communication system. Blocks 4 GHz band signals and other unnecessary signals. When the low noise amplifier circuit or the high frequency 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 and / or the high frequency amplifier circuit shown in FIG. 1 can be omitted. . Further, the configuration relating to each filter and detection circuit can be omitted or changed according to the required characteristics. This also applies to the embodiments described later.

  The configuration of the band-pass filter used in the embodiment of the present invention including the band-pass filter circuit is not particularly limited. For example, the configuration shown in FIG. 7 may be used. The bandpass filter shown here is composed of two resonant lines lb1 and lb2 that are arranged between terminals P4 and P5 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.

  On the other hand, the second low noise amplifier circuit LNA2 and the sixth band pass filter circuit BPF6 are arranged in order from the second branch circuit Dip2 side on the path connected to the high pass filter section of the second branch circuit Dip2. Has been. The sixth band-pass filter circuit BPF6 connected between the second low-noise amplifier circuit LNA2 and the first reception terminal of the second communication system cannot be blocked by the high-pass filter of the second branching circuit Dip2. There are no unnecessary wave signals and harmonics generated in the second low noise amplifier circuit LNA2.

(Second Embodiment)
The high-frequency circuit of the circuit block shown in FIG. 2 is obtained by adding a 2.5 GHz band WiMAX first transmission terminal Tx3-1 as a third communication system to the high-frequency circuit shown in FIG. In order to add the transmission terminal Tx3-1, a single-pole three-throw switch circuit SP3T1 is used instead of the first switch circuit SPDT1 of FIG. Switch circuit SP3T1 is connected to the common terminal connected to Ant1, the first switching terminal to which the transmission paths of the first and second communication systems are connected, and the reception paths of the first to third communication systems. The connection between the second switching terminal and the third switching terminal to which the transmission path of the third communication system is connected is switched. WiMAX used as the third communication system has a higher signal strength than the wireless LAN. Therefore, by connecting the transmission path of the third communication system to the switch circuit SP3T1 without going through the branching circuit or the like, and by switching the transmission path of the third communication system and other paths by the switch circuit, The insertion loss of the transmission path of the third communication system can be reduced, and the power consumption during transmission of the third communication system can be reduced. Further, interference with the wireless LAN system can be suppressed.

  Since parts other than the circuit configuration between the switch circuit SP3T1 and the first transmission terminal Tx3-1 of the third communication system are the same as those in the embodiment of FIG. 1, the description thereof is omitted. Between the switch circuit SP3T1 and the first transmission terminal Tx3-1 of the third communication system, the low-pass filter circuit LPF3, the detection circuit DET3, the third high-frequency amplifier circuit PA3, and the eleventh in order from the switch circuit SP3T1 side. A band pass filter BPF11 is disposed. The function of each circuit element is the same as that of each circuit element in the transmission path of the high-frequency circuit shown in FIG.

(Third embodiment)
The high frequency circuit of the circuit block shown in FIG. 9 has the following circuit portion added to the high frequency circuit shown in FIG. That is, the second branch circuit SPL2 is connected to the input side of the first high-frequency amplifier circuit PA1. The second branch circuit SPL2 has a path connected to the first transmission terminal Tx1-1 for the first communication system and a path connected to the first transmission terminal Tx3-1 for the third communication system. It is a circuit that branches into and out. In such a configuration, the first high-frequency amplifier circuit PA1 is shared by the transmission of the first communication system and the transmission of the third communication system. In the configuration shown in FIG. 9, the first band-pass filter BPF1, the detection circuit DET1, and the low-pass filter circuit LPF1 are also shared by the transmission of the first communication system and the transmission of the third communication system, thereby reducing the number of circuit elements. As a result, it is possible to reduce the size of the high-frequency circuit and further the high-frequency components constituting the high-frequency circuit.

(Fourth embodiment)
The high frequency circuit of the circuit block shown in FIG. 3 has the following circuit portion added to the high frequency circuit shown in FIG. That is, the second antenna terminal Ant2, the second reception terminal Rx1-2 for the first communication system, the second reception terminal Rx2-2 for the second communication system, and the third communication system The second receiving terminal Rx3-2 and the first transmitting terminal Tx3-1 are added. The high-frequency circuit includes a common terminal connected to the second antenna terminal Ant2, a first switching terminal to which another transmission path is connected, or a second switching terminal to which another reception path is connected. A second switch circuit SPDT2 for switching the connection. Further, another reception path connected to the second switching terminal of the switch circuit SPDT2 is connected to the second reception terminal Rx1-2 for the first communication system and the second reception for the third communication system. A third branching circuit Dip3 branches according to the frequency to the second common path connected to the terminal Rx3-2 and the path connected to the second reception terminal Rx2-2 for the second communication system. Have The second common path includes a path connected to the second reception terminal Rx1-2 for the first communication system and a second reception terminal for the third communication system. A third branch circuit SPL3 that branches to the path connected to Rx3-2 is arranged. On the other hand, the first transmission terminal Tx3-1 for the third communication system is connected to the second switching terminal of the second switch circuit SPDT2.

  By adding a circuit portion connected to the second antenna terminal Ant2, one communication system is provided with a plurality of reception terminals capable of receiving simultaneously, and is a SIMO (Single-input Multi-output) type, Is capable of MIMO (Multi-input Multi-output) type communication. The configuration of the second switch circuit SPDT2 connected to the second antenna terminal Ant2 via the high-pass filter circuit HPF2 and the other reception path connected to the second switching terminal of the switch circuit are the first antenna terminal Since it is the same structure as the part connected to Ant1, description is abbreviate | omitted. Hereinafter, the transmission path connected to the first switching terminal of the second switch circuit SPDT2 will be described. Between the first switching terminal of the second switch circuit SPDT2 and the first transmission terminal Tx3-1 for the third communication system, the low-pass filter circuit LPF3 and the detection circuit DET3 are sequentially arranged from the second switch circuit SPDT2 side. The third high-frequency amplifier circuit PA3 and the eleventh bandpass filter circuit BPF11 are connected. The functions of these circuit elements are the same as those in the paths of the first and second communication systems. As described above, WiMAX used as the third communication system has a higher signal strength than the wireless LAN. Therefore, the transmission path of the third communication system is connected to the second switch circuit SPDT2 without using a branching circuit or the like, and the switch circuit switches between the transmission path of the third communication system and another path. Thus, the insertion loss of the transmission path of the third communication system can be reduced, and the power consumption during transmission of the third communication system can be reduced. Further, interference with the wireless LAN system can be suppressed. In addition, since the first transmission terminal for the third communication system can be connected to the second antenna terminal, the transmission of the third communication system is connected to the first antenna terminal. It is also possible to control the transmission of the second communication system and the second communication system independently.

(Fifth embodiment)
The high-frequency circuit of the circuit block shown in FIG. 4 is an embodiment in which the position of the bandpass filter circuit connected to the first and second branch circuits in the high-frequency circuit shown in FIG. 3 is changed. Other portions are the same as those in the embodiment shown in FIG. In the embodiment of FIG. 3, bandpass filter circuits are respectively connected to the second branch circuit Dip2 side of the first branch circuit SPL1 and the third branch circuit Dip3 side of the third branch circuit SPL3. Yes. On the other hand, in the embodiment shown in FIG. 4, between the first branch circuit SPL1 and the first reception terminal Rx1-1 of the first communication system, and between the first branch circuit SPL1 and the third communication system. Between the first receiving terminal Rx3-1, between the third branch circuit SPL3 and the second receiving terminal Rx1-2 of the first communication system, and between the third branch circuit SPL3 and the third communication system. Each band-pass filter circuit is connected between the second receiving terminals Rx3-2. The function of the band-pass filter circuit arranged at such a position is the same as that of the embodiment shown in FIG.

(Sixth embodiment)
In the high frequency circuit of the circuit block shown in FIG. 10, by adding the following circuit portion to the high frequency circuit shown in FIG. 9, one communication system is provided with a plurality of reception terminals that can receive simultaneously. Communication of (Single-input Multi-output) type and further, MIMO (Multi-input Multi-output) type is possible. That is, the second antenna terminal Ant2, the second reception terminal Rx1-2 for the first communication system, the second reception terminal Rx2-2 for the second communication system, and the third communication system The second receiving terminal Rx3-2 is added. Such a high-frequency circuit switches the connection between a common terminal connected to the second antenna terminal Ant2 and a first switching terminal to which a terminating resistor is connected or a second switching terminal to which another receiving path is connected. The second switch circuit SPDT2 is provided. Further, other reception paths connected to the second switching terminal of the second switch circuit SPDT2 are connected to the second reception terminal Rx1-2 for the first communication system and the second reception terminal for the third communication system. A third branch that branches depending on the frequency between the second common path connected to the second receiving terminal Rx3-2 and the path connected to the second receiving terminal Rx2-2 for the second communication system. A wave circuit Dip3 is included. The second common path includes a path connected to the second reception terminal Rx1-2 for the first communication system and a second reception terminal for the third communication system. A third branch circuit SPL3 that branches to the path connected to Rx3-2 is arranged. The configuration after the third demultiplexing circuit of the other reception path connected to the second switching terminal of the second switch circuit SPDT2 is the same as the portion connected to the second switch circuit SPDT2 shown in FIG. The detailed description is omitted because of the configuration. A capacitor element Ct for cutting a direct current is connected to the first switching terminal of the second switch circuit SPDT2, and a termination resistor Rt is connected between the first switching terminal and the ground. The termination resistance Rt is preferably set to about 40 to 60Ω, but other values can be selected as appropriate. By controlling the second switch circuit SPDT2 to be connected to the termination resistor Rt at the time of transmission, it is possible to prevent a transmission signal from Ant1 from leaking into Ant2 and malfunctioning of the reception circuit. Further, harmonic signals generated from the third low noise amplifier circuit LNA3 and the fourth low noise amplifier circuit LNA4 that are in the non-operating state can be suppressed.

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 having the high-frequency circuit shown in FIG. 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.

  The ceramic multilayer substrate is mounted with semiconductor elements for the switch circuit SPDT, the high frequency amplifier circuit PA, and the low noise amplifier circuit LNA. And it connects to a ceramic laminated substrate with a wire bond, 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 circuit block of other embodiments 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 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 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. It is a circuit block of other embodiments 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.

Explanation of symbols

SPL1, SPL2, SPL3: Branch circuit Ant1, Ant2: Antenna terminal SPDT1, SPDT2, SP3T1: Switch circuit DET1-3: Detection circuit BPF1-11: Band pass filter circuit HPF1-2: High pass filter circuit LPF1-3: Low pass filter circuit PA1-3: Amplifier circuit LNA1-4: Low noise amplifier circuit Rx1-1, Rx1-2: Reception terminal of first communication system Rx2-1, Rx2-2: Reception terminal of second communication system Rx3-1, Rx3-2: reception terminal of the third communication system Tx1-1: transmission terminal of the first communication system Tx2-1: transmission terminal of the second communication system Tx3-1: transmission terminal of the third communication system P1 4: Terminals Cb1 to 5, SC, Ct: Capacitance elements lb1, lb2, SL1, S 2, CL1, CL2: inductance element SR, CR, Rt: resistance

Claims (15)

A first antenna terminal;
A first transmission terminal and a first reception terminal for a first communication system;
A first transmission terminal and a first reception terminal for a second communication system;
A first receiving terminal for a third communication system;
A first terminal that switches connection between a common terminal connected to the first antenna terminal and at least a first switching terminal to which a transmission path is connected or a second switching terminal to which a reception path is connected. A switch circuit;
The transmission path is branched according to the frequency into a path connected to the first transmission terminal for the first communication system and a path connected to the first transmission terminal for the second communication system A first branching circuit that
A first common path connected to a first reception terminal for the first communication system and a first reception terminal for the third communication system; and for the second communication system. A second branching circuit that branches depending on a frequency to a path connected to the first receiving terminal of
The first common path is branched into a path connected to the first reception terminal for the first communication system and a path connected to the first reception terminal for the third communication system. A high-frequency circuit having a first branch circuit.   A first low noise amplifier circuit is connected between the second branching circuit and the first branch circuit, and the second branching circuit and the first receiving terminal for the second communication system are connected. 2. The high frequency circuit according to claim 1, wherein a second low noise amplifier circuit is connected therebetween.   A first high frequency amplifier circuit is connected between the first demultiplexing circuit and the first transmission terminal for the first communication system, and the first demultiplexing circuit and the second communication system are used. The high-frequency circuit according to claim 1, wherein a second high-frequency amplifier circuit is connected between the first transmission terminals. Having a first transmission terminal for the third communication system;
The switch circuit includes a third switching terminal;
The high-frequency circuit according to claim 1, wherein the first transmission terminal for the third communication system is connected to the third switching terminal.   5. The high-frequency circuit according to claim 4, wherein a third high-frequency amplifier circuit is disposed in a path connected to the first transmission terminal for the third communication system.   A second branch circuit is connected to an input side of the first high-frequency amplifier circuit, and the second branch circuit is connected to a first transmission terminal for the first communication system; The first high-frequency amplifier circuit is shared by the transmission of the first communication system and the transmission of the third communication system. The high-frequency circuit according to claim 1, wherein   The high-frequency circuit according to claim 1, wherein a band-pass filter circuit is connected to the second branch circuit side of the first branch circuit.   Band-pass filters between the first branch circuit and the first reception terminal of the first communication system and between the first branch circuit and the first reception terminal of the third communication system, respectively. The high-frequency circuit according to claim 1, wherein a circuit is connected. A second antenna terminal;
A second receiving terminal for the first communication system;
A second receiving terminal for the second communication system;
A second receiving terminal and a first transmitting terminal for the third communication system;
Switching the connection between the common terminal connected to the second antenna terminal and the first switching terminal to which another transmission path is connected or the second switching terminal to which another reception path is connected. Two switch circuits;
A second common path connected to the second reception terminal for the first communication system and a second reception terminal for the third communication system; and the second communication. A third branching circuit that branches depending on the frequency to a path connected to the second receiving terminal for the system;
The second common path is branched into a path connected to the second receiving terminal for the first communication system and a path connected to the second receiving terminal for the third communication system. A third branch circuit;
4. The high-frequency circuit according to claim 1, wherein a first transmission terminal for the third communication system is connected to a second switching terminal of the second switch circuit. . A second antenna terminal;
A second receiving terminal for the first communication system;
A second receiving terminal for the second communication system;
A second receiving terminal for the third communication system;
The other receiving path connected to the second antenna terminal is connected to the second receiving terminal for the first communication system and the second receiving terminal for the third communication system. A third branching circuit that branches depending on the frequency into a common path and a path connected to the second receiving terminal for the second communication system;
The second common path is branched into a path connected to the second receiving terminal for the first communication system and a path connected to the second receiving terminal for the third communication system. The high-frequency circuit according to claim 4, further comprising a third branch circuit.   A band-pass filter circuit is connected to each of the second branch circuit side of the first branch circuit and the third branch circuit side of the third branch circuit. Item 11. The high-frequency circuit according to Item 9 or 10. Between the first branch circuit and the first receiving terminal of the first communication system, between the first branch circuit and the first receiving terminal of the third communication system,
And between the third branch circuit and the second receiving terminal of the first communication system, and between the third branch circuit and the second receiving terminal of the third communication system,
The high-frequency circuit according to claim 9 or 10, wherein a band-pass filter circuit is connected thereto.   The high-frequency circuit according to claim 1, wherein the third communication system has a larger transmission signal output than the first and second communication systems. 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 14.

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