JP5782015B2 - Electronic components - Google Patents

Description

  The present invention relates to an electronic component used in various communication devices and high-frequency devices.

  FIG. 9 shows a conventional electronic component used as an antenna duplexer in a wireless communication apparatus. In FIG. 9, a conventional electronic component 1000 includes a transmission filter 1001, a reception filter 1002, a common terminal 1003, a transmission terminal 1004, a reception terminal 1005, and a phase shift circuit 1006, and is connected to the transmission terminal 1004. The transmission filter 1001 and the reception filter 1002 connected to the reception terminal 1005 are connected to the common terminal 1003 via the phase shift circuit 1006.

  In the conventional electronic component 1000, the common terminal 1003 is connected to the antenna 201, the transmission terminal 1004 is connected to the transmission circuit 202, and the reception terminal 1005 is connected to the reception circuit 203 inside the communication device 200. A transmission signal generated in the transmission circuit 202 is input from the transmission terminal 1004 and output as a radio wave from the common terminal 1003 via the antenna 201. A reception signal received from the antenna 201 is input from the common terminal 1003 and output from the reception terminal 1005 to the reception circuit 203.

  As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.

International Publication No. 2010/073377

  However, in the conventional electronic component 1000, the transmission signal input from the transmission terminal 1004 is strong, whereas the reception signal input from the reception terminal 1005 is weak. Therefore, a part of the power of the transmission signal is a reception filter. It has a problem of leaking from 1002 and adversely affecting reception characteristics.

  The present invention provides an electronic component having good isolation characteristics with little leakage of a signal from one high frequency filter to the other high frequency filter between two high frequency filters connected to a common signal terminal. .

  In order to solve the above problems, the present invention provides a first filter connected between a first signal end and a second signal end and having a first passband, the first signal end and a third signal end. And a second filter having a second passband different from the first passband, and passing through the first and second filters, the second and second filters. When the circuit connecting the three signal ends is a main circuit portion, an additional circuit portion is provided between the second and third signal ends so as to be connected in parallel with the main circuit portion. A frequency region having a phase component in a direction opposite to that of the main circuit portion is provided in the first or second passband.

  With such a configuration, there is an excellent effect that an electronic component having good isolation characteristics between the two filters can be obtained.

The circuit block diagram of the electronic component in one embodiment of this invention Circuit diagram of the electronic component Wiring diagram of the same electronic component Characteristics of the electronic parts Characteristics of the electronic parts Characteristics of the electronic parts Characteristics of the electronic parts Characteristics of the electronic parts Circuit diagram of conventional electronic components

  Hereinafter, an antenna duplexer will be described with reference to the drawings as an electronic component in an embodiment of the present invention.

  FIG. 1 is a configuration diagram of an antenna duplexer 100 that is an electronic component according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the antenna duplexer 100, and FIG. 3 is a layout connection diagram of the antenna duplexer 100.

  1 and 2, the antenna duplexer 100 is used inside the communication device 200, and includes a transmission filter 101, a reception filter 102, a common terminal 103, a transmission terminal 104, a reception terminal 105, a phase shift circuit 106, and a piezoelectric substrate 107. Have. The transmission filter 101 is connected between the connection unit 109 and the transmission terminal 104, the reception filter 102 is connected between the connection unit 109 and the reception terminal 105, and the phase shift circuit 106 is connected between the connection unit 109 and the common terminal 103. Connected between. Here, a circuit connecting the transmission terminal 104 and the reception terminal 105 via the transmission filter 101, the connection unit 109, and the reception filter 102 is referred to as a main circuit unit 108. The isolation characteristic in the antenna duplexer 100 is a pass characteristic between the transmission terminal 104 and the reception terminal 105, and the signal level passing between the transmission terminal 104 and the reception terminal 105 is reduced in the transmission band and the reception band. As a result, good isolation characteristics can be obtained. And the antenna sharing device 100 which is an electronic component in one embodiment of the present invention is provided with the additional circuit unit 110 so as to be connected in parallel with the main circuit unit 108.

  The communication apparatus 200 includes an antenna duplexer 100, an antenna 201, a transmission circuit 202, and a reception circuit 203. The common terminal 103 of the antenna duplexer 100 is connected to the antenna 201, the transmission terminal 104 is connected to the transmission circuit 202, The reception terminal 105 is connected to the reception circuit 203.

  The transmission filter 101 includes a plurality of surface acoustic wave elements on a piezoelectric substrate 107, and series arm resonators S1, S2, S3, S4, and S5 are sequentially connected in series to a signal line connecting the transmission terminal 104 and the connecting portion 109. The parallel arm resonators P1, P2, P3, P4, and P5 are connected between the signal line and the ground to constitute a ladder type filter. The transmission band of the transmission filter 101 is 880 to 915 MHz.

  The reception filter 102 includes a surface acoustic wave element formed on a piezoelectric substrate 107, and is formed by cascading a one-terminal pair resonator R1, a longitudinally coupled resonator R2, and a longitudinally coupled resonator R3. The reception band of the reception filter 102 is 925 to 960 MH. The IDT (interdigital transducer) of the longitudinally coupled resonator R2 or longitudinally coupled resonator R3 inverts the phase of the main circuit unit 108 by setting the direction of connection. As a result, the phase of the main circuit unit 108 and the phase of the additional circuit unit 110 are reversed in the reception band.

  The additional circuit unit 110 is connected between the transmission terminal 104 and the reception terminal 105 so as to be connected in parallel with the main circuit unit 108. The additional circuit unit 110 is formed of electrodes on the piezoelectric substrate 107 and includes capacitors 111 and 112. Resonators 113 and 114 are provided. Here, the resonators 113 and 114 are one-terminal-pair surface acoustic wave resonators. The capacitor 111, the resonator 113, and the capacitor 112 are connected in series between the transmission terminal 104 and the reception terminal 105 in this order, and the resonator 114 is connected between the connection portion of the capacitor 111 and the resonator 113 and the ground. Connected. This is a configuration in which a ladder circuit having a resonator 113 as a series arm resonator and a resonator 114 as a parallel arm resonator is sandwiched between a capacitor 111 and a capacitor 112.

  In the additional circuit unit 110, the resonance frequency of the resonator 113 as a series arm is set to 937 MHz, the antiresonance frequency is set to 971 MHz, the resonance frequency of the resonator 114 as a parallel arm is set to 932 MHz, and the antiresonance frequency is set to 966 MHz. A region S having pass characteristics was formed in the band 925 to 960 MHz. Here, the frequency range of the region S is 945 to 960 MHz, and the resonance frequency and the antiresonance frequency of the resonator 113 that is the series arm are at the midpoint 951 MHz, and the resonance frequency and the antiresonance frequency of the resonator 114 that is the parallel arm. The region S is formed in the reception band by designing so that both of the two midpoints 954 MHz fall within the reception band 925 to 960 MHz. Here, the midpoint between the resonance frequency and the antiresonance frequency is calculated by calculating the average of the two frequencies. The capacitors 111 and 112 are elements that shift the amplitude level of the pass characteristic of the additional circuit unit 110 in the region S, and the amplitude level of the pass characteristic of the additional circuit unit 110 is set to the main circuit unit by the design of the capacitor 111 and the capacitor 112. It is possible to approximate the amplitude level of 108 pass characteristics. Since the phase of the additional circuit unit 110 and the phase of the main circuit unit 108 in the region S are opposite to each other, the amplitude of the main circuit unit 108 in the region S is canceled and the transmission terminal 104 and the reception terminal 105 are Isolation characteristics can be improved. Further, the phase of the additional circuit unit 110 can be finely adjusted by the capacitor 111 and the capacitor 112. Further, the capacitor 111 and the capacitor 112 also have a function of protecting the resonators 113 and 114 from destruction by suppressing a current flowing from the main circuit unit 108 to the additional circuit unit 110. Specifically, the capacitances of the capacitors 111 and 112 are set to capacitance values smaller than the capacitance of the resonator 113, and the capacitance 111 close to the transmission terminal 104 is set to a capacitance smaller than the capacitance 112 close to the reception terminal 105. It is set.

  FIG. 3 is a diagram showing a layout and connection when configured on the piezoelectric substrate 107 of the antenna duplexer 100, which is an electronic component according to an embodiment of the present invention. In FIG. 3, the series arm resonators S 1, S 2, S 3, S 4 and S 5, the parallel arm resonators P 1, P 2, P 3, P 4 and P 5 and the reception filter 102 constituting the transmission filter 101 are formed on one main surface of the piezoelectric substrate 107. The one-terminal-pair resonator R1, the longitudinally coupled resonator R2, the longitudinally coupled resonator R3, the capacitors 111 and 112, and the resonators 113 and 114 are formed. Thus, by forming on one piezoelectric substrate 107, it becomes possible to obtain a small antenna duplexer with excellent isolation characteristics. The common terminal 103 is formed on the long side of the piezoelectric substrate 107, and the parallel arm resonators P1, P2, P3, P4, and P5 constituting the transmission filter 101 are arranged on the end face side where the common terminal 103 is formed, and the series arm The resonators S1, S2, S3, S4, and S5 are arranged on the end face side facing the end face on which the common terminal 103 is formed. Further, the resonators 113 and 114 constituting the additional circuit unit 110 are disposed on the end face side facing the end face on which the common terminal 103 is formed. By adopting such an arrangement, the isolation characteristics are improved.

  The common terminal 103 is arranged on the receiving filter side from the center where the long side of the piezoelectric substrate 107 is equally divided. By doing so, the area occupied by the series arm resonator and the parallel arm resonator constituting the transmission filter can be increased, and the wiring on the piezoelectric substrate 107 can be shortened. An antenna duplexer with low loss can be obtained.

  Further, on the piezoelectric substrate 107, dummy terminals 123 and 124 that are not electrically connected to the resonator are provided between the common terminal 103 and the ground terminals 121 and 122 connected to the parallel arm resonator of the transmission filter 101. Provided. With such a configuration, it is possible to prevent electrical signals from wrapping around due to electromagnetic coupling from the parallel arm resonator to the common terminal 103, and to improve isolation.

  125 is a terminal for grounding the ground electrode of the longitudinally coupled resonator R2, 126 is a terminal for grounding the ground electrode of the longitudinally coupled resonator R3, and 125 and 126 are electrically separated on the piezoelectric substrate 107. It has a configuration. By doing so, it is possible to improve the attenuation characteristic of the reception filter and to improve the isolation characteristic. Reference numeral 127 denotes a ground terminal connected to the resonator 114.

  Each of 123, 124, 128, and 129 is a terminal that is not connected to any resonator and is grounded. In addition to strengthening the adhesion of the piezoelectric substrate 107, these terminals have the effect of improving isolation between the transmission terminal 104 and the common terminal 103, the reception terminal 105 and the common terminal 103, or between the transmission terminal 104 and the reception terminal 105. .

  4-8 is a figure which shows the electrical property of the antenna sharing device 100 which is an electronic component in one embodiment of this invention.

  In FIG. 4, the solid line is the pass characteristic A of the main circuit unit 108 from the transmission filter 101 through the phase circuit 106 and the reception filter 102 in the antenna duplexer 100, and the isolator of the antenna duplexer 100 without the additional circuit unit 110. Shows the characteristics of In FIG. 4, the broken line indicates the pass characteristic B of the additional circuit unit 110. As shown in FIG. 4, the pass characteristic B of the additional circuit unit 110 is provided with a rectangular pass characteristic in the region S so as to approximate the pass characteristic A in the reception band. This rectangular pass characteristic is designed so that the frequency band falls within the reception band by setting the resonance frequency and anti-resonance frequency of the resonator 113 and the resonance frequency and anti-resonance frequency of the resonator 114. By setting the capacitor 111 and the capacitor 112, the amplitude level of the pass characteristic of the additional circuit unit 110 is designed to approximate the amplitude level of the pass characteristic of the main circuit unit 108.

  FIG. 5 shows an amplitude difference C obtained by subtracting the pass characteristic A from the pass characteristic B shown in FIG. 4 and shows that the amplitude difference is reduced particularly in the region S of the reception band.

  In FIG. 6, the solid line is the phase characteristic D of the circuit in the antenna duplexer 100 that passes from the transmission filter 101 through the phase circuit 106 and the reception filter 102. In FIG. 6, the broken line indicates the phase characteristic E of the additional circuit unit 110. As shown in FIG. 6, the phase characteristic E of the additional circuit unit 110 is a phase characteristic in the opposite direction to the phase characteristic D in the region S within the reception band. Here, the phase characteristic being in the reverse direction means that the absolute value of the phase difference is 90 degrees or more within a range of −180 degrees to 180 degrees and has a phase component in the reverse direction.

  FIG. 7 shows a phase difference F obtained by subtracting the phase characteristic D from the phase characteristic E shown in FIG. 6, and in the reverse direction where the absolute value of the phase difference exceeds 90 °, particularly in the region S in the reception band. It can be seen that is around 150 degrees.

  In FIG. 8, the solid line is the isolation characteristic G of the antenna duplexer 100 in one embodiment of the present invention, the broken line is the isolation characteristic H of the comparative example, and the isolation characteristic is a large value in the negative direction. It is so good. Here, the comparative example is an isolation characteristic of only the main circuit unit 108 that does not have the additional circuit unit 110 in the antenna duplexer 100. In FIG. 8, the isolation characteristic G of the antenna duplexer 100 according to the first embodiment of the present invention can reduce the signal level particularly in the region S in the reception band, and greatly improves the characteristic. Recognize.

  As described above, the electronic component according to the embodiment of the present invention is connected between the first signal end and the second signal end, and has the first filter having the first passband, and the first filter. And a second filter having a second passband different from the first passband, and connected via the first and second filters. When the circuit connecting the second and third signal ends is a main circuit portion, an additional circuit portion is provided between the second and third signal ends so as to be connected in parallel with the main circuit portion. The additional circuit section is provided with a frequency region having a phase component in a direction opposite to that of the main circuit portion in the first or second passband, whereby the amplitude of the pass characteristic of the main circuit portion in this frequency region is provided. Can be offset to increase attenuation, whereby the first filter and the second filter In which it can greatly improve the isolation between.

  Here, the absolute value of the phase difference between the main circuit section and the additional circuit section in the frequency domain having the phase component in the opposite direction is ideally 180 degrees within a range of 0 degrees to 180 degrees. However, if the absolute value of the phase difference is 90 degrees or more, the phase component is in the reverse direction, so that it has the effect of canceling the amplitude of the pass characteristic and increasing the isolation. In the above embodiment, as shown in FIG. 7, by setting the phase difference to 110 degrees or more, it is possible to effectively cancel the amplitude of the pass characteristic and increase the isolation.

  In the electronic component according to the embodiment of the present invention, an antenna duplexer with good isolation characteristics can be obtained by using the first filter as a transmission filter and the second filter as a reception filter. Is.

  The electronic component according to the embodiment of the present invention can be realized by providing the first or second filter with a function of inverting the phase, and an additional phase inverting function is added to the additional circuit unit. There is no need, and the circuit configuration can be simplified.

  The electronic component according to one embodiment of the present invention uses a longitudinally coupled acoustic wave resonator for the first or second filter, and sets the IDT connection direction of the longitudinally coupled acoustic wave resonator. By doing so, it is possible to provide means for reversing the phases of the main circuit section and the additional circuit section, and it is not necessary to add a separate phase inversion function, and the circuit configuration can be simplified.

  In the electronic component according to the embodiment of the present invention, an element for shifting the amplitude level of the pass characteristic is provided in the additional circuit section in the region S in which the phase of the main circuit section and the phase of the additional circuit section are reversed. As a result, the amplitude of the additional circuit section in the region S can be approximated to the amplitude of the main circuit section.

  In particular, the capacitances of the capacitors 111 and 112 are set to capacitance values smaller than the capacitance of the resonator 113, and the capacitance 111 close to the transmission terminal 104 is set to a capacitance smaller than the capacitance 112 close to the reception terminal 105. As a result, the amplitude of the additional circuit section in the region S can be matched with the amplitude of the main circuit section, and the effect of improving the isolation characteristics is enhanced.

  In the electronic component according to the embodiment of the present invention, in the region S where the phase of the main circuit portion and the phase of the additional circuit portion are reversed, the amplitude of the pass characteristic of the main circuit portion and the pass characteristic of the additional circuit portion By making the absolute value of the difference in amplitude of 10 dB or less, the amplitude of the main circuit portion and the amplitude of the additional circuit portion can be reduced and the effect of cancellation can be increased, so that the isolation characteristic is improved. Great effect.

  In the electronic component according to the embodiment of the present invention, the first or second filter includes a first ladder circuit unit using an acoustic wave element, and the additional circuit unit uses an acoustic wave element. With the configuration having two ladder circuit sections, it is possible to approximate the change in the frequency characteristics of the first ladder circuit section and the change in the frequency characteristics of the additional circuit section when there is a temperature change. It is possible to reduce deterioration of isolation characteristics.

  In the electronic component according to the embodiment of the present invention, the additional circuit section includes a ladder circuit section using an acoustic wave element, and the first capacitive element is provided between the ladder circuit section and the second signal end. And providing the second capacitive element between the ladder circuit section and the third signal end protects the resonators 113 and 114 from the current flowing from the main circuit section 108, and the resonator 113, The destruction of 114 can be prevented.

  The electronic component according to the embodiment of the present invention includes a ladder circuit unit having a series arm resonator and a parallel arm resonator in the additional circuit unit, and is a midpoint between the resonance frequency and the antiresonance frequency of the series arm resonator. And by arranging the midpoint of the resonance frequency and antiresonance frequency of the parallel arm resonator in the first or second passband, an additional circuit section is formed in the first or second passband. A pass band (region S) can be arranged.

  In the electronic component according to the embodiment of the present invention, the first or second filter and the additional circuit portion have elastic wave elements formed on the same piezoelectric substrate, so that the temperature changes. When the frequency characteristics change in both the first and second filters and the additional circuit section, the degradation of the isolation characteristics can be reduced even when there is a temperature change. The effect is that an antenna duplexer with little deterioration in isolation characteristics against temperature changes can be obtained. In addition, by forming the first or second filter and the additional circuit portion on the same piezoelectric substrate, an electronic component having good isolation characteristics can be obtained without increasing the size. Further, by forming the first filter, the second filter, and the additional circuit portion on the same piezoelectric substrate, a smaller electronic component can be obtained.

  In addition, although demonstrated using the antenna sharing device 100 as an electronic component in the said one Embodiment, application of this invention is not restricted to an antenna sharing device, For example, it can also apply to a dual filter. In other words, the present invention can be applied to any circuit in which two filters are connected to a common signal terminal, and has the same effect.

  In the antenna duplexer 100 in the above embodiment, the transmission filter 101, the reception filter 102, and the resonator 113 are configured by a surface acoustic wave filter and a surface acoustic wave resonator. The reception filter 102 and the resonator 113 may be configured by a boundary acoustic wave filter and a boundary acoustic wave resonator, and the isolation characteristics can be improved as in the antenna duplexer 100 in the first embodiment. It has the effect.

  The electronic component according to the present invention is useful in configuring various communication devices.

DESCRIPTION OF SYMBOLS 100 Antenna duplexer 101 Transmission filter 102 Reception filter 103 Common terminal 104 Transmission terminal 105 Reception terminal 106 Phase shift circuit 107 Piezoelectric substrate 108 Main circuit part 110 Additional circuit part 111, 112 Capacitance 113, 114 Resonator

Claims (13)

Connected between the first signal end and the second signal end;
A first filter having a first passband;
Connected between the first signal terminal and the third signal terminal;
A second filter having a second passband different from the first passband,
When a circuit connecting the second and third signal ends via the first and second filters is a main circuit portion,
An additional circuit part is provided between the second and third signal ends so as to be connected in parallel with the main circuit part,
The additional circuit section provides a frequency region having a phase component in a direction opposite to the main circuit section in the first or second passband ,
The additional circuit section includes a ladder circuit section having a series arm resonator and a parallel arm resonator,
An electronic component in which the midpoint of the resonance frequency and antiresonance frequency of the series arm resonator and the midpoint of the resonance frequency and antiresonance frequency of the parallel arm resonator are arranged in the first or second passband. . The electronic component according to claim 1, wherein the first filter is a transmission filter, the second filter is a reception filter, and operates as an antenna duplexer. The electronic component according to claim 1, wherein at least one of the first and second filters has a function of inverting the phase. The electronic component according to claim 1, wherein at least one of the first and second filters includes a longitudinally coupled acoustic wave resonator. The electronic component according to claim 1, wherein an element for shifting an amplitude level of a pass characteristic in the frequency domain is provided in the additional circuit section. The electronic component according to claim 1, wherein an absolute value of a difference between an amplitude of the pass characteristic of the main circuit unit and an amplitude of the pass characteristic of the additional circuit unit is set to 10 dB or less in the frequency domain. The ladder circuit is a first ladder circuit portion using an elastic wave element, electrons according to claim 1, wherein the first or second filter to have a second ladder circuit portion using an elastic wave element parts. The first electronic component according to claim 1 wherein in which a capacitive element between the front Symbol parallel arm resonator and the second signal end. Before SL electronic component according to claim 8, wherein providing the second capacitor between the series arm resonator and said third signal end. The electronic component according to claim 1, wherein an elastic wave element is used for the ladder circuit unit . The first electronic component according to claim 1 wherein in which a capacitive element between the front Symbol ladder circuit portion and the second signal end. Before Stories second electronic component of claim 11 wherein providing the capacitor element between the ladder circuit portion and the third signal end. 2. The electronic component according to claim 1, wherein the first or second filter and the additional circuit section include acoustic wave elements formed on the same piezoelectric substrate.

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