Coupler

Abstract

This coupler comprises: a first line (11) that transmits power signals; a second line (12) that is configured so as to be capable of being electromagnetically coupled to the first line (11) and extracts a first power signal from among the power signals transmitted through the first line (11); an input port (P1) that is provided on one end side of the first line (11) and inputs the power signals to the first line (11); an output port (P2) that is provided on the other end side of the first line (11) and outputs a second power signal from among the power signals transmitted through the first line (11); a coupling port (P3) that is provided on one end side of the second line (12) and outputs the first power signal transmitted through the second line (12); a terminated port (P4) that is provided on the other end side of the second line (12) and terminated; and one or more filters that are connected in series to the first line (11) and include a low-pass filter or a high-pass filter.

Description

Coupler

[0001] The present disclosure relates to a coupler for distributing a power signal.

[0002] Conventionally, directional couplers known as couplers have been well known. For example, Japanese Patent Application Laid-Open Publication No. 2013-46305 (Patent Document 1) discloses a directional coupler including a main line, a sub-line that is electromagnetically coupled with the main line to extract a portion of a power signal transmitted through the main line, an input port that inputs the power signal to the main line, an output port that outputs the power signal transmitted through the main line, a coupling port provided at one end of the sub-line, and a termination port provided at the other end of the sub-line, with a low-pass filter provided between the sub-line and the coupling port. The directional coupler disclosed in Japanese Patent Application Laid-Open Publication No. 2013-46305 can form a resonance point higher than the passband (used frequency band) and flatten changes in the power signal (degree of coupling) in the used frequency band.

[0003] JP 2013-46305 A

[0004] The directional coupler disclosed in JP 2013-46305 A is a coupler configured to output a majority of a power signal transmitted through a main line from an output port, while outputting a small portion of the power signal transmitted through the main line from a coupled port via a sub-line in order to perform feedback control to maintain a constant level of the power signal output from the output port, and monitor the small portion of the power signal. In other words, the directional coupler disclosed in JP 2013-46305 A merely extracts a small portion of the power signal input from the input port from the coupled port in order to perform feedback control, and is not a coupler configured to distribute and output the power signal input from the input port to two ports, the coupled port and the output port.

[0005] If the directional coupler disclosed in JP 2013-46305 A were applied to a coupler that distributes a power signal as described above, the difference (hereinafter also referred to as the "amplitude difference") between the power signal output from the coupled port in the passband and the power signal output from the output port would become large, making it difficult to appropriately distribute the power signal input from the input port.

[0006] The present disclosure has been made to solve such problems, and its purpose is to provide a coupler that can appropriately distribute a power signal input from an input port to a coupled port and an output port.

[0007] A coupler according to an aspect of the present disclosure includes a first line that transmits a power signal, a second line that is configured to be electromagnetically coupled to the first line and that extracts a first power signal from the power signals transmitted through the first line, an input port that is provided at one end of the first line and that inputs the power signal to the first line, an output port that is provided at the other end of the first line and that outputs a second power signal from the power signals transmitted through the first line, a coupling port that is provided at one end of the second line and that outputs the first power signal transmitted through the second line, a termination port that is provided at the other end of the second line and that is terminated, and at least one filter that is connected in series to the first line and that includes a low-pass filter or a high-pass filter.

[0008] According to the coupler of the present disclosure, the attenuation characteristics of the low-pass filter or high-pass filter connected in series to the first line can minimize the amplitude difference between the power signal output from the coupled port and the power signal output from the output port in the passband, thereby allowing the power signal input from the input port to be appropriately distributed to the coupled port and the output port.

[0009] 1 is a diagram illustrating a hybrid coupler having a first configuration according to a first embodiment; FIG. 2 is a diagram illustrating characteristics of a hybrid coupler having the first configuration according to the first embodiment; FIG. 3 is a diagram illustrating amplitude difference characteristics of a hybrid coupler according to a comparative example; FIG. 4 is a diagram illustrating a hybrid coupler having a second configuration according to the first embodiment; FIG. 5 is a diagram illustrating characteristics of a hybrid coupler having the second configuration according to the first embodiment; FIG. 6 is a diagram illustrating a hybrid coupler having a third configuration according to the first embodiment; FIG. 7 is a diagram illustrating characteristics of a hybrid coupler having the third configuration according to the first embodiment; FIG. 8 is a diagram illustrating a hybrid coupler having a fourth configuration according to the first embodiment; FIG. 9 is a diagram illustrating characteristics of a hybrid coupler having the fourth configuration according to the first embodiment; FIG. 10 is a diagram illustrating a hybrid coupler having a fifth configuration according to the first embodiment; FIG. 11 is a diagram illustrating a hybrid coupler having a first circuit according to the first embodiment; FIG. 12 is a diagram illustrating characteristics of a hybrid coupler having the first circuit according to the first embodiment; FIG. 13 is a diagram illustrating a hybrid coupler having a second circuit according to the first embodiment; FIG. 14 is a diagram illustrating characteristics of a hybrid coupler having the second circuit according to the first embodiment; FIG. 15 is a diagram illustrating a hybrid coupler having a third circuit according to the first embodiment; FIG. 16 is a diagram illustrating characteristics of a hybrid coupler having the third circuit according to the first embodiment; FIG. 17 is a diagram illustrating a hybrid coupler having a fourth circuit according to the first embodiment; 1 is a diagram showing the characteristics of a hybrid coupler including a fourth circuit according to embodiment 1. FIG. 2 is a diagram showing the characteristics of a hybrid coupler including a fifth circuit according to embodiment 1. FIG. 3 is a diagram showing the characteristics of a hybrid coupler including the fifth circuit according to embodiment 1. FIG. 4 is a diagram showing the characteristics of a hybrid coupler including a sixth circuit according to embodiment 1. FIG. 5 is a diagram showing the characteristics of a hybrid coupler including the sixth circuit according to embodiment 1. FIG. 6 is a diagram showing a comparison result between the characteristics of a hybrid coupler according to embodiment 1 and the characteristics of a hybrid coupler according to a comparative example. FIG. 7 is a perspective view showing a hybrid coupler including a first laminated structure according to embodiment 1. FIG. 8 is an exploded plan view showing a hybrid coupler including the first laminated structure according to embodiment 1. FIG. 9 is a perspective view showing a hybrid coupler including a second laminated structure according to embodiment 1.1 is an exploded plan view showing a hybrid coupler having a second laminate structure according to a first embodiment. 2 is a perspective view showing a hybrid coupler having a third laminate structure according to the first embodiment. 3 is an exploded plan view showing a hybrid coupler having a third laminate structure according to the first embodiment. 4 is a diagram showing a hybrid coupler having a first configuration according to a second embodiment. 5 is a diagram showing characteristics of a hybrid coupler having a first configuration according to the second embodiment. 6 is a diagram showing a hybrid coupler having a second configuration according to the second embodiment. 7 is a diagram showing characteristics of a hybrid coupler having a second configuration according to the second embodiment. 8 is a diagram showing characteristics of a hybrid coupler having a third configuration according to the second embodiment. 9 is a diagram showing characteristics of a hybrid coupler having a third configuration according to the second embodiment. 10 is a diagram showing characteristics of a hybrid coupler having a fourth configuration according to the second embodiment. 11 is a diagram showing characteristics of a hybrid coupler having a fourth configuration according to the second embodiment. 12 is a diagram showing characteristics of a hybrid coupler having a fourth configuration according to the second embodiment. 13 is a diagram showing characteristics of a hybrid coupler having a fifth configuration according to the second embodiment. 14 is a diagram showing a hybrid coupler having a first circuit according to the second embodiment. 15 is a diagram showing characteristics of a hybrid coupler having a first circuit according to the second embodiment. 16 is a diagram showing characteristics of a hybrid coupler having a second circuit according to the second embodiment. 17 is a diagram showing characteristics of a hybrid coupler having a second circuit according to the second embodiment. 10A and 10B are diagrams illustrating the results of comparison between the characteristics of a hybrid coupler according to a comparative example and the characteristics of a hybrid coupler according to the second embodiment.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] 1 to 29, a hybrid coupler according to a first embodiment will be described. As will be described in detail later, the hybrid coupler according to the first embodiment is configured to equally distribute and output a power signal input from an input port to two ports, a coupled port and an output port.

[0012] The power of the power signal output from the coupled port (hereinafter also referred to as the "first power signal") and the power of the power signal output from the output port (hereinafter also referred to as the "second power signal") are the same or approximately the same. Specifically, theoretically, the power signal input from the input port (hereinafter also referred to as the "input power signal") is divided into two and output from the coupled port and the output port, respectively. More specifically, theoretically, the power of the first power signal output from the coupled port is half the power of the input power signal input from the input port. Also, theoretically, the power of the second power signal output from the output port is half the power of the input power signal input from the input port. Here, the gain of the hybrid coupler is expressed by the following equation (1).

[0013] When the power of the first power signal is half the power of the input power signal, according to equation (1), the power gain between the input port and the coupled port is −3 dB. Furthermore, when the power of the second power signal is half the power of the input power signal, according to equation (1), the power gain between the input port and the output port is −3 dB. Thus, theoretically, a power gain difference of 3 dB occurs between the input port and the coupled port, or between the input port and the output port. Therefore, the hybrid coupler according to the first embodiment is also referred to as a “3 dB hybrid coupler.”

[0014] Furthermore, the difference in phase between the first power signal from the coupled port and the second power signal from the output port is 90 degrees or approximately 90 degrees. Specifically, theoretically, when the phase of the input power signal is taken as the reference (0 degrees), the phase of the first power signal is 0 degrees and the phase of the second power signal is -90 degrees. Thus, theoretically, a phase difference of 90 degrees occurs between the first power signal from the coupled port and the second power signal from the output port. Therefore, the hybrid coupler according to the first embodiment is also referred to as a "90-degree hybrid coupler."

[0015] As described above, the hybrid coupler according to the first embodiment is also called a 3 dB hybrid coupler or a 90-degree hybrid coupler, and is theoretically configured to equally distribute an input power signal to two ports, a coupled port and an output port, and to output the power signals with a phase shift of 90 degrees. Hereinafter, a configuration for appropriately distributing a power signal input from an input port to the coupled port and the output port of such a hybrid coupler according to the first embodiment will be described.

[0016] [First Configuration of Hybrid Coupler According to Embodiment 1] Fig. 1 is a diagram showing a hybrid coupler 1A having a first configuration according to embodiment 1. As shown in Fig. 1, the hybrid coupler 1A includes a first line 11, a second line 12, an input port P1, an output port P2, a coupling port P3, and a termination port P4.

[0017] The first line 11 is a main line of the hybrid coupler 1A and transmits an input power signal input from the input port P1. The second line 12 is a secondary line of the hybrid coupler 1A and is disposed adjacent to the first line 11. The second line 12 is configured to be electromagnetically coupled to the first line 11. When the second line 12 is electromagnetically coupled to the first line 11, a first power signal, which is a portion of the input power signal from the input port P1 transmitting the first line 11, propagates to the second line 12. The second line 12 outputs the first power signal, which is electromagnetically coupled to the first line 11, to the coupled port P3. The remaining second power signal, which is not extracted by the second line 12, is output from the output port P2. As described above, the power of the first power signal and the second power signal are each half the power of the input power signal.

[0018] The input port P1 is provided at one end of the first line 11 and is connected to the input side of a power signal in a system in which the hybrid coupler 1A is installed. The input port P1 inputs the input power signal to the first line 11. The output port P2 is provided at the other end of the first line 11 and is connected to the output side of a power signal in a system in which the hybrid coupler 1A is installed. The output port P2 outputs a second power signal of the input power signal transmitted through the first line 11. The coupled port P3 is provided at one end of the second line 12 and is connected to the output side of a power signal different from the output port P2 in a system in which the hybrid coupler 1A is installed. The coupled port P3 outputs a first power signal extracted from the first line 11 and transmitted through the second line 12. The termination port P4 is provided at the other end of the second line 12 and is terminated at, for example, 50 ohms. Therefore, the first power signal extracted by the second line 12 is output from the coupled port P3 without being output from the termination port P4.

[0019] The hybrid coupler 1A further includes a low-pass filter 41 connected in series to the first line 11. Specifically, the low-pass filter 41 is provided between the first line 11 and the input port P1. The low-pass filter 41 passes, with minimal attenuation, frequency components lower than a specific cutoff frequency of the input power signal input from the input port P1, while attenuating frequency components higher than the cutoff frequency. The cutoff frequency can be adjusted by the design of the low-pass filter 41.

[0020] 2 is a diagram illustrating the characteristics of a hybrid coupler 1A having a first configuration according to the first embodiment. Fig. 2 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 1A. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 2, the pass band (used frequency band) of the hybrid coupler 1A is 8 GHz to 12 GHz, and the center frequency is 10 GHz.

[0021] The amplitude difference characteristic indicates the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 with respect to frequency. According to the amplitude difference characteristic of the hybrid coupler 1A, the amplitude difference in the passband is generally within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0022] 3 is a diagram showing the amplitude difference characteristics of a hybrid coupler according to a comparative example. Although not shown, the hybrid coupler according to the comparative example has a configuration similar to that of the hybrid coupler 1A, except that the low-pass filter 41 is removed. In other words, the hybrid coupler according to the comparative example has the same configuration as the hybrid coupler 1A, except that it does not have the low-pass filter 41.

[0023] As shown in FIG. 3, according to the amplitude difference characteristics of the hybrid coupler of the comparative example, the amplitude difference in the passband is more than 0.3 dB and is approximately 0.5 dB, and the amplitude difference at the center frequency is more than 0.1 dB and is approximately 0.3 dB.

[0024] In this way, the hybrid coupler 1A according to the first embodiment can reduce the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, due to the attenuation characteristics of the low-pass filter 41, more so than the hybrid coupler according to the comparative example.

[0025] 2 , the phase difference characteristic indicates the difference in phase between the power signal output from the coupled port P3 and the power signal output from the output port P2 with respect to frequency. According to the phase difference characteristic of the hybrid coupler 1A, the phase difference at the center frequency is approximately 90 degrees. In this way, the hybrid coupler 1A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 90 degrees.

[0026] The pass characteristics show the power signal (IN-Coupling) flowing from the input port P1 to the coupled port P3 versus frequency. Furthermore, the pass characteristics show the power signal (IN-Out) flowing from the input port P1 to the output port P2 versus frequency. According to the pass characteristics of the hybrid coupler 1A, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0027] As shown above in the passband characteristics, the hybrid coupler 1A can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 1A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0028] In this way, even if the hybrid coupler 1A is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filter 41 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, so that the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0029] [Second Configuration of Hybrid Coupler According to Embodiment 1] Fig. 4 is a diagram showing a hybrid coupler 1B having a second configuration according to embodiment 1. In the following, only the differences between hybrid coupler 1B and hybrid coupler 1A will be described.

[0030] 4, the hybrid coupler 1B includes a low-pass filter 42 connected in series to the first line 11 and a low-pass filter 43 connected in series to the second line 12. Specifically, the low-pass filter 42 is provided between the first line 11 and the output port P2. The low-pass filter 43 is provided between the second line 12 and the coupled port P3.

[0031] 5 is a diagram illustrating the characteristics of a hybrid coupler 1B having a second configuration according to the first embodiment. Fig. 5 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 1B. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 5, the pass band and center frequency of the hybrid coupler 1B are the same as those of the hybrid coupler 1A.

[0032] As shown in Fig. 5, the amplitude difference characteristic of the hybrid coupler 1B is substantially the same as that of the hybrid coupler 1A shown in Fig. 2. The phase difference characteristic of the hybrid coupler 1B can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 1A. Furthermore, according to the pass band characteristic of the hybrid coupler 1B, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is substantially the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0033] As shown in the pass characteristics, the hybrid coupler 1B can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the pass band, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 1B can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0034] In this way, even if the hybrid coupler 1B is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 42 and 43 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0035] 6 is a diagram showing a hybrid coupler 1C having a third configuration according to embodiment 1. In the following, only the differences between hybrid coupler 1C and hybrid coupler 1A will be described.

[0036] 6, the hybrid coupler 1C includes a low-pass filter 41 connected in series to the first line 11 and a low-pass filter 44 connected in series to the second line 12. Specifically, the low-pass filter 41 is provided between the first line 11 and the input port P1. The low-pass filter 44 is provided between the second line 12 and the termination port P4.

[0037] 7 is a diagram illustrating the characteristics of a hybrid coupler 1C having a third configuration according to the first embodiment. Fig. 7 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 1C. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 7, the pass band and center frequency of the hybrid coupler 1C are the same as those of the hybrid coupler 1A.

[0038] As shown in Fig. 7, the amplitude difference characteristic of the hybrid coupler 1C is substantially the same as that of the hybrid coupler 1A shown in Fig. 2. The phase difference characteristic of the hybrid coupler 1C can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 1A. Furthermore, according to the pass band characteristic of the hybrid coupler 1C, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is substantially the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0039] As shown above in the passband characteristics, the hybrid coupler 1C can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 1C can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approach 90 degrees.

[0040] In this way, even if the hybrid coupler 1C is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41, 44 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0041] [Fourth Configuration of Hybrid Coupler According to Embodiment 1] Fig. 8 is a diagram showing a hybrid coupler 1D having a fourth configuration according to embodiment 1. In the following, only the differences between the hybrid coupler 1D and the hybrid coupler 1A will be described.

[0042] 8 , the hybrid coupler 1D includes a low-pass filter 41 and a low-pass filter 42 connected in series to the first line 11, and a low-pass filter 43 connected in series to the second line 12. Specifically, the low-pass filter 41 is provided between the first line 11 and the input port P1. The low-pass filter 42 is provided between the first line 11 and the output port P2. The low-pass filter 43 is provided between the second line 12 and the coupled port P3.

[0043] 9 is a diagram illustrating the characteristics of a hybrid coupler 1D having a fourth configuration according to the first embodiment. Fig. 9 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 1D. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 9, the pass band and center frequency of the hybrid coupler 1D are the same as those of the hybrid coupler 1A.

[0044] As shown in Fig. 9, the amplitude difference characteristic of the hybrid coupler 1D is substantially the same as that of the hybrid coupler 1A shown in Fig. 2. The phase difference characteristic of the hybrid coupler 1D can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 1A. Furthermore, according to the pass band characteristic of the hybrid coupler 1D, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is substantially the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0045] As shown above in the passband characteristics, the hybrid coupler 1D can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 1D can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0046] In this way, even if the hybrid coupler 1D is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 43 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0047] 10 is a diagram showing a hybrid coupler 1E having a fifth configuration according to embodiment 1. In the following, only the differences between the hybrid coupler 1E and the hybrid coupler 1A will be described.

[0048] 10 , the hybrid coupler 1E includes low-pass filters 41 and 42 connected in series to the first line 11, and low-pass filters 43 and 44 connected in series to the second line 12. Specifically, the low-pass filter 41 is provided between the first line 11 and the input port P1. The low-pass filter 42 is provided between the first line 11 and the output port P2. The low-pass filter 43 is provided between the second line 12 and the coupled port P3. The low-pass filter 44 is provided between the second line 12 and the termination port P4.

[0049] [First Circuit of Hybrid Coupler According to Embodiment 1] Fig. 11 is a diagram showing a hybrid coupler 10A including a first circuit according to embodiment 1. The hybrid coupler 10A has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Fig. 10, and Fig. 11 shows a first circuit for realizing the hybrid coupler 10A (1E).

[0050] 11, hybrid coupler 10A includes an inductor L1 and a capacitor C1 that form low-pass filter 41, an inductor L2 and a capacitor C2 that form low-pass filter 42, an inductor L3 and a capacitor C3 that form low-pass filter 43, and an inductor L4 and a capacitor C4 that form low-pass filter 44. Inductors L1 to L4 are filter inductors. Capacitors C1 to C4 are filter capacitors.

[0051] Inductor L1 is provided between the first line 11 and the input port P1. Inductor L2 is provided between the first line 11 and the output port P2. Inductor L3 is provided between the second line 12 and the coupled port P3. Inductor L4 is provided between the second line 12 and the termination port P4.

[0052] The plurality of capacitors C1 to C4 are provided between each of the plurality of inductors L1 to L4 and the ground, which serves as a reference electrode. Specifically, the capacitor C1 is provided between a node N1 between the inductor L1 and the input port P1 and the ground, which serves as a reference electrode. The capacitor C2 is provided between a node N2 between the inductor L2 and the output port P2 and the ground. The capacitor C3 is provided between a node N3 between the inductor L3 and the coupled port P3 and the ground. The capacitor C4 is provided between a node N4 between the inductor L4 and the termination port P4 and the ground.

[0053] One end of capacitor C1, which is not connected to inductor L1 and input port P1, is connected to one end of capacitor C2, which is not connected to inductor L2 and output port P2. One end of capacitor C3, which is not connected to inductor L3 and coupling port P3, is connected to one end of capacitor C4, which is not connected to inductor L4 and termination port P4. One end of each of capacitors C1 to C4 is connected together to ground.

[0054] 12 is a diagram illustrating the characteristics of a hybrid coupler 10A including the first circuit according to the first embodiment. Fig. 12 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10A. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 12, the pass band (used frequency band) of the hybrid coupler 10A is 8 GHz to 12 GHz, and the center frequency is 10 GHz.

[0055] According to the amplitude difference characteristics of the hybrid coupler 10A, the amplitude difference in the passband is generally within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB. According to the phase difference characteristics of the hybrid coupler 10A, the phase difference at the center frequency deviates from 90 degrees, but the outlier is less than 5 degrees. Furthermore, according to the passband characteristics of the hybrid coupler 10A, the power signal flowing from the input port P1 to the coupled port P3 in the passband is generally the same as the power signal flowing from the input port P1 to the output port P2 in the passband. Furthermore, the passband characteristics of the hybrid coupler 10A (hybrid coupler 1E) can reduce the slope of the change in the power signal with frequency in the passband compared to the passband characteristics of the hybrid coupler 1A. Therefore, the hybrid coupler 10A can reduce return loss compared to the hybrid coupler 1A. According to the loss characteristics of the hybrid coupler 10A, the loss in the passband is approximately 0.2 to 0.7 dB.

[0056] As shown in the passband characteristics, the hybrid coupler 10A can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 10A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approach 90 degrees.

[0057] In this way, even if the hybrid coupler 10A (hybrid coupler 1E) equipped with the first circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0058] [Second Circuit of Hybrid Coupler According to First Embodiment] Figure 13 is a diagram showing a hybrid coupler 10B including a second circuit according to the first embodiment. The hybrid coupler 10B has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Figure 10, and Figure 13 shows a second circuit for realizing the hybrid coupler 10B (1E). Below, the hybrid coupler 10B will be described only in terms of differences from the hybrid coupler 10A.

[0059] 13, the hybrid coupler 10B further includes multiple inductors L1 to L4 provided between the multiple capacitors C1 to C4, respectively, and the ground, which serves as a reference electrode. The inductance of each of the inductors L1 to L4 is greater than the inductance of the inductors L11 to L14. The inductors L11 to L14 are an example of a "first inductor."

[0060] One end of inductor L11 is connected to the end of capacitor C1 that is not connected to inductor L1 and input port P1. The other end of inductor L11 is connected to ground. One end of inductor L12 is connected to the end of capacitor C2 that is not connected to inductor L2 and output port P2. The other end of inductor L12 is connected to ground. One end of inductor L13 is connected to the end of capacitor C3 that is not connected to inductor L3 and coupled port P3. The other end of inductor L13 is connected to ground. One end of inductor L14 is connected to the end of capacitor C4 that is not connected to inductor L4 and termination port P4. The other end of inductor L14 is connected to ground.

[0061] 14 is a diagram illustrating the characteristics of a hybrid coupler 10B including the second circuit according to the first embodiment. Fig. 14 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10B. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 14, the pass band and center frequency of the hybrid coupler 10B are the same as those of the hybrid coupler 10A.

[0062] As shown in FIG. 14, the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of the hybrid coupler 10B are approximately the same as the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of the hybrid coupler 10A shown in FIG.

[0063] In this way, even if the hybrid coupler 10B equipped with the second circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0064] [Third Circuit of Hybrid Coupler According to First Embodiment] Figure 15 is a diagram showing a hybrid coupler 10C including a third circuit according to the first embodiment. The hybrid coupler 10C has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Figure 10, and Figure 15 shows the third circuit for realizing the hybrid coupler 10C (1E). Below, the hybrid coupler 10C will be described only in terms of differences from the hybrid coupler 10A.

[0065] 15, the hybrid coupler 10C further includes an inductor L21 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C1 and C3, and the ground, which serves as a reference electrode. Furthermore, the hybrid coupler 10C further includes an inductor L22 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C2 and C4, and the ground. The inductance of each of the inductors L1 to L4 is greater than the inductance of the inductors L21 and L22. The inductors L21 and L22 are examples of "first inductors."

[0066] One end of inductor L21 is connected to the end of capacitor C1 that is not connected to inductor L1 and input port P1, and to the end of capacitor C3 that is not connected to inductor L3 and coupled port P3. The other end of inductor L21 is connected to ground. One end of inductor L22 is connected to the end of capacitor C2 that is not connected to inductor L2 and output port P2, and to the end of capacitor C4 that is not connected to inductor L4 and termination port P4. The other end of inductor L22 is connected to ground.

[0067] 16 is a diagram illustrating the characteristics of a hybrid coupler 10C including the third circuit according to the first embodiment. Fig. 16 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10C. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 16, the pass band and center frequency of the hybrid coupler 10C are the same as those of the hybrid coupler 10A.

[0068] As shown in FIG. 16, the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of the hybrid coupler 10C are approximately the same as the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of the hybrid coupler 10A shown in FIG.

[0069] In this way, even if the hybrid coupler 10C equipped with the third circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0070] [Fourth Circuit of Hybrid Coupler According to First Embodiment] Figure 17 is a diagram showing a hybrid coupler 10D including a fourth circuit according to the first embodiment. The hybrid coupler 10D has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Figure 10, and Figure 17 shows a fourth circuit for realizing the hybrid coupler 10D (1E). Below, the hybrid coupler 10D will be described only in terms of differences from the hybrid coupler 10A.

[0071] 17, the hybrid coupler 10D further includes an inductor L31 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C1 and C2, and the ground, which serves as a reference electrode. Furthermore, the hybrid coupler 10D further includes an inductor L32 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C3 and C4, and the ground. The inductance of each of the inductors L1 to L4 is greater than the inductance of the inductors L31 and L32. The inductors L31 and L32 are examples of "first inductors."

[0072] One end of inductor L31 is connected to the end of capacitor C1 that is not connected to inductor L1 and input port P1, and to the end of capacitor C2 that is not connected to inductor L2 and output port P2. The other end of inductor L31 is connected to ground. One end of inductor L32 is connected to the end of capacitor C3 that is not connected to inductor L3 and coupling port P3, and to the end of capacitor C4 that is not connected to inductor L4 and termination port P4. The other end of inductor L32 is connected to ground.

[0073] 18 is a diagram illustrating the characteristics of a hybrid coupler 10D including the fourth circuit according to the first embodiment. Fig. 18 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10D. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 18, the pass band and center frequency of the hybrid coupler 10D are the same as those of the hybrid coupler 10A.

[0074] As shown in Figure 18, the amplitude difference characteristic of the hybrid coupler 10D is generally the same as that of the hybrid coupler 10A shown in Figure 12. Furthermore, according to the pass characteristic of the hybrid coupler 10D, a steep attenuation pole occurs in a frequency band higher than the pass band due to the action of inductors L31 and L32. As a result, the phase difference characteristic of the hybrid coupler 10D can have a smaller slope of change in phase difference with frequency in the pass band than the phase difference characteristic of the hybrid coupler 10A. Furthermore, due to the improved phase difference characteristic, the loss characteristic of the hybrid coupler 10D can have a smaller degree of loss than the loss characteristic of the hybrid coupler 10A.

[0075] In this way, even if the hybrid coupler 10D equipped with the fourth circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0076] [Fifth Circuit of Hybrid Coupler According to First Embodiment] Figure 19 is a diagram showing a hybrid coupler 10E including a fifth circuit according to the first embodiment. The hybrid coupler 10E has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Figure 10, and Figure 19 shows the fifth circuit for realizing the hybrid coupler 10E (1E). Below, the hybrid coupler 10E will be described only in terms of differences from the hybrid coupler 10A.

[0077] 19, the hybrid coupler 10E further includes an inductor L31 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C1 and C2, and the ground, which serves as a reference electrode. Furthermore, the hybrid coupler 10D further includes an inductor L32 provided between two of the plurality of capacitors C1 to C4, namely, capacitors C3 and C4, and the ground. The inductance of each of the inductors L1 to L4 is greater than the inductance of the inductors L31 and L32. The inductors L31 and L32 are examples of "first inductors."

[0078] One end of inductor L31 is connected to the end of capacitor C1 that is not connected to inductor L1 and input port P1, and to the end of capacitor C2 that is not connected to inductor L2 and output port P2. The other end of inductor L31 is connected to ground. One end of inductor L32 is connected to the end of capacitor C3 that is not connected to inductor L3 and coupling port P3, and to the end of capacitor C4 that is not connected to inductor L4 and termination port P4. The other end of inductor L32 is connected to ground.

[0079] The hybrid coupler 10E further includes a plurality of inductors L41 to L44 connected to a plurality of points N1 to N4 between the plurality of capacitors C1 to C4 and the plurality of inductors L1 to L4, respectively. The inductors L41 to L42 are an example of a "second inductor."

[0080] One end of inductor L41 is connected to capacitor C1 and inductor L1. The other end of inductor L41 is connected to input port P1. One end of inductor L42 is connected to capacitor C2 and inductor L2. The other end of inductor L42 is connected to output port P2. One end of inductor L43 is connected to capacitor C3 and inductor L3. The other end of inductor L43 is connected to coupled port P3. One end of inductor L44 is connected to capacitor C4 and inductor L4. The other end of inductor L44 is connected to termination port P4.

[0081] 20 is a diagram illustrating the characteristics of a hybrid coupler 10E including the fifth circuit according to the first embodiment. Fig. 20 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10E. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 20, the pass band and center frequency of the hybrid coupler 10E are the same as those of the hybrid coupler 10A.

[0082] As shown in Fig. 20, the phase difference characteristic, pass characteristic, and loss characteristic of the hybrid coupler 10E are generally the same as those of the hybrid coupler 10D shown in Fig. 18. Furthermore, because the hybrid coupler 10E has inductors L41 to L44 added to the configuration of the hybrid coupler 10D, the amplitude difference characteristic of the hybrid coupler 10E can have a smaller slope of change in amplitude difference with frequency in the pass band than the amplitude difference characteristic of the hybrid coupler 10D.

[0083] In this way, even if the hybrid coupler 10E equipped with the fifth circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0084] [Sixth Circuit of Hybrid Coupler According to First Embodiment] Figure 21 is a diagram showing a hybrid coupler 10F including a sixth circuit according to the first embodiment. The hybrid coupler 10F has a configuration similar to that of the hybrid coupler 1E having the fifth configuration shown in Figure 10, and Figure 21 shows the sixth circuit for realizing the hybrid coupler 10F (1E). Below, the hybrid coupler 10F will be described only in terms of differences from the hybrid coupler 10A.

[0085] 21, the hybrid coupler 10F further includes an inductor L33 provided between the plurality of capacitors C1 to C4 and the ground, which serves as a reference electrode. The inductance of each of the inductors L1 to L4 is greater than the inductance of the inductor L33. The inductor L33 is an example of a "first inductor."

[0086] One end of the inductor L33 is connected to the end of the capacitor C1 that is not connected to the inductor L1 and the input port P1, the end of the capacitor C2 that is not connected to the inductor L2 and the output port P2, the end of the capacitor C3 that is not connected to the inductor L3 and the coupled port P3, and the end of the capacitor C4 that is not connected to the inductor L4 and the termination port P4. The other end of the inductor L33 is connected to ground.

[0087] 22 is a diagram illustrating the characteristics of a hybrid coupler 10F including the sixth circuit according to the first embodiment. Fig. 22 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 10F. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 22, the pass band and center frequency of the hybrid coupler 10F are the same as those of the hybrid coupler 10A.

[0088] As shown in FIG. 22, the phase difference characteristics, transmission characteristics, and loss characteristics of the hybrid coupler 10F are approximately the same as those of the hybrid coupler 10D shown in FIG.

[0089] In this way, even if the hybrid coupler 10F equipped with the sixth circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 41 to 44 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0090] Furthermore, the hybrid coupler 10F includes one inductor L33 instead of the two inductors L31 and L32 included in the hybrid coupler 10D. Therefore, the hybrid coupler 10F can have a smaller number of inductor components than the hybrid coupler 10D.

[0091] [Comparison with Comparative Example] Figure 23 is a diagram showing a comparison result between the characteristics of the hybrid coupler 1E according to the first embodiment and the characteristics of a hybrid coupler according to the comparative example. Here, the hybrid coupler 1E according to the first embodiment is a hybrid coupler 10A including the first circuit of Figure 11 and a hybrid coupler 10D including the fourth circuit of Figure 17. Furthermore, the hybrid coupler according to the comparative example is a hybrid coupler having a configuration similar to that of the hybrid coupler 1A described in Figure 3 except that the low-pass filter 41 has been removed. Figure 23 shows the pass characteristics of power signals passing through the hybrid coupler 10A, the hybrid coupler 10D, and the hybrid coupler according to the comparative example.

[0092] 23, according to the passband characteristics of the hybrid coupler of the comparative example, the power signal output from input port P1 to coupled port P3 in the passband is separated from the power signal flowing from input port P1 to output port P2 in the passband, and the two do not match. As a result, according to the amplitude difference characteristics of the hybrid coupler of the comparative example, as shown in FIG. 3, the amplitude difference in the passband is more than 0.3 dB, approximately 0.5 dB, and the amplitude difference at the center frequency is also more than 0.1 dB, approximately 0.3 dB.

[0093] In contrast, in the hybrid coupler 1E according to the first embodiment, according to the pass characteristics of the hybrid coupler 10A, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is substantially the same as the power signal flowing from the input port P1 to the output port P2 in the pass band. As a result, according to the amplitude difference characteristics of the hybrid coupler 10A, as shown in Fig. 12, the amplitude difference in the pass band is substantially within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0094] According to the passband characteristics of the hybrid coupler 10D, the power signal flowing from the input port P1 to the coupled port P3 in the passband is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the passband. As a result, as shown in Fig. 18, according to the amplitude difference characteristics of the hybrid coupler 10D, the amplitude difference in the passband is approximately within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0095] Furthermore, the pass characteristics of the hybrid coupler 10D create a steep attenuation pole in a frequency band higher than the pass band due to the action of inductors L31 and L32. This prevents the attenuation characteristics of the low-pass filters 41 to 44 from becoming excessive, making it possible to make the slope of the change in the power signal with respect to frequency in the pass band smaller than that of the hybrid coupler 10A.

[0096] [First Laminated Structure of Hybrid Coupler According to Embodiment 1] Fig. 24 is a perspective view showing a hybrid coupler 100A having a first laminated structure according to embodiment 1. Fig. 25 is an exploded plan view showing a hybrid coupler 100A having a first laminated structure according to embodiment 1. Note that Figs. 24 and 25 show the first laminated structure corresponding to the hybrid coupler 10A having the first circuit shown in Fig. 11.

[0097] 24 and 25, the hybrid coupler 100A includes a rectangular insulator 110 including multiple dielectric layers D1 to D7. The insulator 110 includes a top surface 101, a bottom surface 102, a front surface 103, a back surface 104, a right side surface 105, and a left side surface 106.

[0098] In the hybrid coupler 100A, a plurality of dielectric layers D1 to D7 are arranged in order from the top surface 101 toward the bottom surface 102. The dielectric layer D7 corresponds to the bottom surface 102. A conductor pattern or an electrode pattern is formed on each of the plurality of dielectric layers D1 to D7. Note that in FIG. 25 , the right side of the figure corresponds to the side where the front surface 103 is located, the left side of the figure corresponds to the side where the back surface 104 is located, the upper side of the figure corresponds to the side where the right side surface 105 is located, and the lower side of the figure corresponds to the side where the left side surface 106 is located.

[0099] On the dielectric layer D1, a rectangular conductor pattern K1 is formed slightly above the center in the figure. On the dielectric layer D2, a rectangular conductor pattern K2 is formed over substantially the entire surface. On the dielectric layer D3, a conductor pattern K31 is formed counterclockwise from the upper right in the figure. On the dielectric layer D3, a conductor pattern K32 is formed clockwise from the lower left in the figure. On the dielectric layer D4, a conductor pattern K41 is formed clockwise from the upper left in the figure. On the dielectric layer D4, a conductor pattern K42 is formed counterclockwise from the lower right in the figure.

[0100] A conductor pattern K51 is formed on the dielectric layer D5 from the upper left to near the center in the figure. A conductor pattern K52 is formed on the dielectric layer D5 from the upper right to near the center in the figure. A conductor pattern K53 is formed on the dielectric layer D5 from the lower left to near the center in the figure. A conductor pattern K54 is formed on the dielectric layer D5 from the lower right to near the center in the figure.

[0101] A convex conductor pattern K65 is formed on the upper side of the dielectric layer D6 in the figure. A convex conductor pattern K66 is formed on the lower side of the dielectric layer D6 in the figure. A conductor pattern K61 is formed on the dielectric layer D6 to the upper left of the conductor pattern K65 in the figure. A conductor pattern K62 is formed on the dielectric layer D6 to the upper right of the conductor pattern K65 in the figure. A conductor pattern K63 is formed on the dielectric layer D6 to the lower left of the conductor pattern K66 in the figure. A conductor pattern K64 is formed on the dielectric layer D6 to the lower right of the conductor pattern K66 in the figure.

[0102] A rectangular conductor pattern K71 is formed on the dielectric layer D7 at the upper left in the figure. A rectangular conductor pattern K72 is formed on the dielectric layer D7 at the left side near the center in the figure. A rectangular conductor pattern K73 is formed on the dielectric layer D7 at the lower left in the figure. A rectangular conductor pattern K74 is formed on the dielectric layer D7 at the upper right in the figure. A rectangular conductor pattern K75 is formed on the dielectric layer D7 at the right side near the center in the figure. A rectangular conductor pattern K76 is formed on the dielectric layer D7 at the lower right in the figure.

[0103] The connection portion H21 of the conductor pattern K2 on the dielectric layer D2 is connected to the connection portion H67 of the conductor patterns K65 and K66 on the dielectric layer D6 through the via V1, passing through the connection portion H33 on the dielectric layer D3, the connection portion H43 on the dielectric layer D4, and the connection portion H55 on the dielectric layer D5.

[0104] The connection portion H22 of the conductor pattern K2 on the dielectric layer D2 is connected to the connection portion H68 of the conductor patterns K65 and K66 on the dielectric layer D6 through the via V2, passing through the connection portion H34 of the dielectric layer D3, the connection portion H44 of the dielectric layer D4, and the connection portion H55 of the dielectric layer D5.

[0105] The connection portion H31 of the conductor pattern K31 on the dielectric layer D3 is connected via a via V3 to the connection portion H46 of the dielectric layer D4 and the connection portion H52 of the conductor pattern K52 on the dielectric layer D5, and then to the connection portion H622 of the conductor pattern K62 on the dielectric layer D6.

[0106] The connection portion H32 of the conductor pattern K32 on the dielectric layer D3 is connected via a via V4 to the connection portion H45 of the dielectric layer D4 and the connection portion H53 of the conductor pattern K53 on the dielectric layer D5, and then to the connection portion H631 of the conductor pattern K63 on the dielectric layer D6.

[0107] The connection portion H41 of the conductor pattern K41 on the dielectric layer D4 passes through the connection portion H51 of the conductor pattern K51 on the dielectric layer D5 via the via V5 and is connected to the connection portion H612 of the conductor pattern K61 on the dielectric layer D6.

[0108] The connection portion H42 of the conductor pattern K42 on the dielectric layer D4 passes through the connection portion H54 of the conductor pattern K54 on the dielectric layer D5 via a via V6 and is connected to the connection portion H641 of the conductor pattern K64 on the dielectric layer D6.

[0109] The connection portion H611 of the conductor pattern K61 on the dielectric layer D6 is connected to the connection portion H71 of the conductor pattern K71 on the dielectric layer D7 through a via V7.

[0110] A connection portion H651 of the conductor pattern K65 on the dielectric layer D6 is connected to a connection portion H721 of the conductor pattern K72 on the dielectric layer D7 through a via V8.

[0111] A connection portion H661 of the conductor pattern K66 on the dielectric layer D6 is connected to a connection portion H722 of the conductor pattern K72 on the dielectric layer D7 through a via V9.

[0112] The connection portion H632 of the conductor pattern K63 on the dielectric layer D6 is connected to the connection portion H73 of the conductor pattern K73 on the dielectric layer D7 through a via V10.

[0113] A connection portion H621 of the conductor pattern K62 on the dielectric layer D6 is connected to a connection portion H74 of the conductor pattern K74 on the dielectric layer D7 through a via V11.

[0114] The connection portion H652 of the conductor pattern K65 on the dielectric layer D6 is connected to the connection portion H751 of the conductor pattern K75 on the dielectric layer D7 through a via V12.

[0115] A connection portion H662 of the conductor pattern K66 on the dielectric layer D6 is connected to a connection portion H752 of the conductor pattern K75 on the dielectric layer D7 through a via V13.

[0116] The connection portion H642 of the conductor pattern K64 on the dielectric layer D6 is connected to the connection portion H76 of the conductor pattern K76 on the dielectric layer D7 through a via V14.

[0117] In the hybrid coupler 100A having the first laminated structure configured as described above, for example, the conductor patterns K1, K2, K72, and K75 correspond to the ground, which is a reference electrode. The conductor pattern K73 corresponds to the input port P1. The conductor pattern K74 corresponds to the output port P2. The conductor pattern K76 corresponds to the coupled port P3. The conductor pattern K71 corresponds to the termination port P4.

[0118] The conductor pattern K32A of the conductor pattern K32 corresponds to the inductor L1. Of the conductor pattern K31, the conductor pattern K31A corresponds to the inductor L2. Of the conductor pattern K42, the conductor pattern K42A corresponds to the inductor L3. Of the conductor pattern K41, the conductor pattern K41A corresponds to the inductor L4. Therefore, by adjusting the width and length of each of the conductor patterns K31A, K32A, K41A, and K42A, the inductance of the inductors L1 to L4 can be adjusted.

[0119] The conductor pattern K3A, which is composed of the conductor patterns K31 and K32, corresponds to the first line 11. The conductor pattern K4A, which is composed of the conductor patterns K41 and K42, corresponds to the second line 12.

[0120] In this manner, the conductor pattern K3A corresponding to the first line 11, the conductor pattern K32A corresponding to the inductor L1, and the conductor pattern K31A corresponding to the inductor L2 are arranged on the same dielectric layer D3. The dielectric layer D3 is an example of a "specific layer."

[0121] The conductor pattern K4A corresponding to the second line 12, the conductor pattern K42A corresponding to the inductor L3, and the conductor pattern K41A corresponding to the inductor L4 are arranged on the same dielectric layer D4. The dielectric layer D4 is an example of a "specific layer."

[0122] The space between the conductor patterns K53 and K66 corresponds to the capacitor C1. The space between the conductor patterns K51 and K65 corresponds to the capacitor C2. The space between the conductor patterns K54 and K64 corresponds to the capacitor C3. The space between the conductor patterns K52 and K65 corresponds to the capacitor C4.

[0123] In this manner, the capacitors C1 to C4 are disposed on the dielectric layers D5 and D6, which are closer to the bottom surface 102 of the insulator 110 than the dielectric layers D3 and D4.

[0124] The via V8 connecting the connection portion H651 of the conductor pattern K65 and the connection portion H721 of the conductor pattern K72, the via V9 connecting the connection portion H661 of the conductor pattern K66 and the connection portion H722 of the conductor pattern K72, the via V12 connecting the connection portion H652 of the conductor pattern K65 and the connection portion H751 of the conductor pattern K75, and the via V13 connecting the connection portion H662 of the conductor pattern K66 and the connection portion H752 of the conductor pattern K75 correspond to the inductor L33.

[0125] In this way, the inductor L33 is composed of vias V8, V9, V12, and V13 that connect the capacitors C1 to C4 to ground. Furthermore, the inductance of the inductor L33 can be adjusted by adjusting the width and length of the vias V8, V9, V12, and V13.

[0126] [Second Layer Structure of Hybrid Coupler According to First Embodiment] Fig. 26 is a perspective view showing a hybrid coupler 100B having a second layer structure according to the first embodiment. Fig. 27 is an exploded plan view showing a hybrid coupler 100B having a second layer structure according to the first embodiment. Note that Figs. 26 and 27 show the second layer structure corresponding to the hybrid coupler 10A having the first circuit shown in Fig. 11. Below, the hybrid coupler 100B will be described only in terms of differences from the hybrid coupler 100A.

[0127] 26 and 27 , in the hybrid coupler 100B, a conductor pattern K32A corresponding to inductor L1 is not formed on the conductor pattern K32. Similarly, in the hybrid coupler 100B, a conductor pattern K31A corresponding to inductor L2 is not formed on the conductor pattern K31. In the hybrid coupler 100B, a conductor pattern K42A corresponding to inductor L3 is not formed on the conductor pattern K42. In the hybrid coupler 100B, a conductor pattern K41A corresponding to inductor L4 is not formed on the conductor pattern K41.

[0128] The hybrid coupler 100B further includes a dielectric layer D8 and a dielectric layer D9 between the dielectric layer D4 and the dielectric layer D5, instead of the conductor pattern K31A, the conductor pattern K32A, the conductor pattern K41A, and the conductor pattern K42A.

[0129] A conductor pattern K81 is formed on the dielectric layer D8 at the upper left in the figure. A conductor pattern K82 is formed on the dielectric layer D8 at the upper right in the figure. A conductor pattern K83 is formed on the dielectric layer D8 at the lower left in the figure. A conductor pattern K84 is formed on the dielectric layer D8 at the lower right in the figure.

[0130] A conductor pattern K91 is formed on the dielectric layer D9 at the upper left in the figure. A conductor pattern K92 is formed on the dielectric layer D9 at the upper right in the figure. A conductor pattern K93 is formed on the dielectric layer D8 at the lower left in the figure. A conductor pattern K94 is formed on the dielectric layer D8 at the lower right in the figure.

[0131] The connection portion H31 of the conductor pattern K31 on the dielectric layer D3 is connected to the connection portion H921 of the conductor pattern K92 on the dielectric layer D9 via the via V3, passing through the connection portion H46 on the dielectric layer D4 and the connection portion H821 of the conductor pattern K82 on the dielectric layer D8.

[0132] The connection portion H32 of the conductor pattern K32 on the dielectric layer D3 is connected via a via V4 to the connection portion H45 of the dielectric layer D4 and the connection portion H832 of the conductor pattern K83 on the dielectric layer D8, and then to the connection portion H932 of the conductor pattern K93 on the dielectric layer D9.

[0133] The connection portion H41 of the conductor pattern K41 on the dielectric layer D4 passes through a via V5, a connection portion H811 of the conductor pattern K81 on the dielectric layer D8, and is connected to a connection portion H911 of the conductor pattern K91 on the dielectric layer D9.

[0134] The connection portion H42 of the conductor pattern K42 on the dielectric layer D4 passes through a via V6, a connection portion H842 of the conductor pattern K84 on the dielectric layer D8, and is connected to a connection portion H942 of the conductor pattern K94 on the dielectric layer D9.

[0135] The connection portion H822 of the conductor pattern K82 on the dielectric layer D8 is connected via the via V15 to the connection portion H922 of the conductor pattern K92 on the dielectric layer D9 and the connection portion H52 of the conductor pattern K52 on the dielectric layer D5, and then to the connection portion H622 of the conductor pattern K62 on the dielectric layer D6.

[0136] The connection portion H812 of the conductor pattern K81 on the dielectric layer D8 is connected via the via V16 to the connection portion H912 of the conductor pattern K91 on the dielectric layer D9 and the connection portion H51 of the conductor pattern K51 on the dielectric layer D5, and then to the connection portion H612 of the conductor pattern K61 on the dielectric layer D6.

[0137] The connection portion H841 of the conductor pattern K84 on the dielectric layer D8 is connected via the via V17 to the connection portion H941 of the conductor pattern K94 on the dielectric layer D9 and the connection portion H54 of the conductor pattern K54 on the dielectric layer D5, and then to the connection portion H641 of the conductor pattern K64 on the dielectric layer D6.

[0138] The connection portion H831 of the conductor pattern K83 on the dielectric layer D8 is connected via the via V18 to the connection portion H931 of the conductor pattern K93 on the dielectric layer D9 and the connection portion H53 of the conductor pattern K53 on the dielectric layer D5, and then to the connection portion H631 of the conductor pattern K63 on the dielectric layer D6.

[0139] In the hybrid coupler 100B having the second laminated structure configured as described above, the conductor patterns K83 and K93 correspond to the inductor L1. The conductor patterns K82 and K92 correspond to the inductor L2. The conductor patterns K84 and K94 correspond to the inductor L3. The conductor patterns K81 and K91 correspond to the inductor L4.

[0140] Thus, in the hybrid coupler 100B having the second laminated structure, the conductor patterns K81 to K84 and K91 to K94 corresponding to the inductors L1 to L4 are formed on a layer different from that of the conductor patterns K31 and K32 corresponding to the first line 11 and the conductor patterns K41 and K42 corresponding to the second line 12. This reduces the effect of the inductors L1 to L4 on the electromagnetic field coupling between the first line 11 and the second line 12, and therefore the hybrid coupler 100B can obtain better characteristics than the hybrid coupler 100A.

[0141] [Third Layer Structure of Hybrid Coupler According to First Embodiment] Fig. 28 is a perspective view showing a hybrid coupler 100C having a third layer structure according to the first embodiment. Fig. 29 is an exploded plan view showing a hybrid coupler 100C having a third layer structure according to the first embodiment. Note that Figs. 28 and 29 show the third layer structure corresponding to the hybrid coupler 10A having the first circuit shown in Fig. 11. Below, the hybrid coupler 100C will be described only in terms of differences from the hybrid coupler 100A.

[0142] As shown in Figures 28 and 29, the hybrid coupler 100C includes a plurality of dielectric layers D11 to D17 within an insulator 110. In the hybrid coupler 100C, the plurality of dielectric layers D11 to D17 are arranged in order from the top surface 101 toward the bottom surface 102. In Figure 29, the dielectric layer D11 corresponds to the top surface 101 of the hybrid coupler 100C. The dielectric layer D17 corresponds to the bottom surface 102 of the hybrid coupler 100C. The right side of the figure corresponds to the side where the front surface 103 is located, the left side of the figure corresponds to the side where the back surface 104 is located, the upper side of the figure corresponds to the side where the right side surface 105 is located, and the lower side of the figure corresponds to the side where the left side surface 106 is located.

[0143] 28, the hybrid coupler 100C includes a plurality of external electrodes 92, 94, and 96 extending from the top surface 101 through the front surface 103 to the bottom surface 102. The hybrid coupler 100C includes a plurality of external electrodes 91, 93, and 95 extending from the top surface 101 through the back surface 104 to the bottom surface 102.

[0144] The external electrode 91 includes a top electrode 91A provided on the top surface 101, a side electrode 91B provided on the back surface 104, and a bottom electrode 91C provided on the bottom surface 102. The external electrode 92 includes a top electrode 92A provided on the top surface 101, a side electrode 92B provided on the front surface 103, and a bottom electrode 92C provided on the bottom surface 102. The external electrode 93 includes a top electrode 93A provided on the top surface 101, a side electrode 93B provided on the back surface 104, and a bottom electrode 93C provided on the bottom surface 102. The external electrode 94 includes a top electrode 94A provided on the top surface 101, a side electrode 94B provided on the front surface 103, and a bottom electrode 94C provided on the bottom surface 102. The external electrode 95 includes an upper electrode 95A provided on the upper surface 101, a side electrode 95B provided on the rear surface 104, and a bottom electrode 95C provided on the bottom surface 102. The external electrode 96 includes an upper electrode 96A provided on the upper surface 101, a side electrode 96B provided on the front surface 103, and a bottom electrode 96C provided on the bottom surface 102.

[0145] A rectangular conductor pattern K101 is formed on the dielectric layer D11 slightly above the center of the drawing. The conductor pattern K101 corresponds to the conductor pattern K1 of the hybrid coupler 100A.

[0146] The dielectric layer D11 has a top surface electrode 91A formed at the upper left in the figure so as to be connected to the side electrode 91B. The dielectric layer D11 has a top surface electrode 92A formed at the upper right in the figure so as to be connected to the side electrode 92B. The dielectric layer D11 has a top surface electrode 93A formed at the center left in the figure so as to be connected to the side electrode 93B. The dielectric layer D11 has a top surface electrode 94A formed at the center right in the figure so as to be connected to the side electrode 94B. The dielectric layer D11 has a top surface electrode 95A formed at the lower left in the figure so as to be connected to the side electrode 95B. The dielectric layer D11 has a top surface electrode 96A formed at the lower right in the figure so as to be connected to the side electrode 96B.

[0147] A conductor pattern K102 is formed on substantially the entire surface of the dielectric layer D12. The conductor pattern K102 corresponds to the conductor pattern K2 of the hybrid coupler 100A. The conductor pattern K102 is connected to the side electrode 93B and the side electrode 94B.

[0148] A conductor pattern K103 is formed on the dielectric layer D13, extending from the upper right to the lower left in the figure. Similar to the conductor patterns K31 and K32 of the hybrid coupler 100A, the conductor pattern K103 includes a conductor pattern K103A corresponding to the first line 11, a conductor pattern K103B corresponding to the inductor L1, and a conductor pattern K103C corresponding to the inductor L2. The conductor pattern K103B is connected to the side electrode 95B. The conductor pattern K103C is connected to the side electrode 92B.

[0149] A conductor pattern K104 is formed on the dielectric layer D14, extending from the upper left to the lower right in the figure. Similar to the conductor patterns K41 and K42 of the hybrid coupler 100A, the conductor pattern K104 includes a conductor pattern K104A corresponding to the second line 12, a conductor pattern K104B corresponding to the inductor L3, and a conductor pattern K104C corresponding to the inductor L2. The conductor pattern K104B is connected to the side electrode 96B. The conductor pattern K104C is connected to the side electrode 91B.

[0150] A conductor pattern K105 is formed on the dielectric layer D15, extending from the upper left to near the center of the figure. The conductor pattern K105 corresponds to the conductor pattern K51 of the hybrid coupler 100A. The conductor pattern K105 is connected to the side electrode 91B.

[0151] A conductor pattern K106 is formed on the dielectric layer D15, extending from the upper right to the center of the figure. The conductor pattern K106 corresponds to the conductor pattern K52 of the hybrid coupler 100A. The conductor pattern K106 is connected to the side electrode 92B.

[0152] A conductor pattern K107 is formed on the dielectric layer D15, extending from the lower left to near the center of the figure. The conductor pattern K107 corresponds to the conductor pattern K53 of the hybrid coupler 100A. The conductor pattern K107 is connected to the side electrode 95B.

[0153] A conductor pattern K108 is formed on the dielectric layer D15, extending from the lower right to near the center of the figure. The conductor pattern K108 corresponds to the conductor pattern K54 of the hybrid coupler 100A. The conductor pattern K108 is connected to the side electrode 96B.

[0154] A conductor pattern K109 is formed on substantially the entire surface of the dielectric layer D16. The conductor pattern K109 corresponds to the conductor patterns K65 and K66 of the hybrid coupler 100A.

[0155] The dielectric layer D17 has a bottom electrode 91C formed at the upper left in the figure so as to be connected to the side electrode 91B. The dielectric layer D17 has a bottom electrode 92C formed at the upper right in the figure so as to be connected to the side electrode 92B. The dielectric layer D17 has a bottom electrode 93C formed at the center left in the figure so as to be connected to the side electrode 93B. The dielectric layer D17 has a bottom electrode 94C formed at the center right in the figure so as to be connected to the side electrode 94B. The dielectric layer D17 has a bottom electrode 95C formed at the lower left in the figure so as to be connected to the side electrode 95B. The dielectric layer D17 has a bottom electrode 96C formed at the lower right in the figure so as to be connected to the side electrode 96B.

[0156] In the hybrid coupler 100C having the third laminated structure configured as described above, for example, the conductor pattern K101, the external electrodes 93, and the external electrodes 94 correspond to the ground, which is a reference electrode. The external electrode 95 corresponds to the input port P1. The external electrode 92 corresponds to the output port P2. The external electrode 96 corresponds to the coupling port P3. The external electrode 91 corresponds to the termination port P4.

[0157] The space between the conductor patterns K107 and K109 corresponds to the capacitor C1. The space between the conductor patterns K105 and K109 corresponds to the capacitor C2. The space between the conductor patterns K108 and K109 corresponds to the capacitor C3. The space between the conductor patterns K106 and K109 corresponds to the capacitor C4.

[0158] Of the conductor patterns K109, the conductor pattern K109A connected to the external electrode 93 and the conductor pattern K109B connected to the external electrode 94 correspond to the inductor L33. Therefore, by adjusting the width and length of the conductor patterns K109A and K109B, the inductance of the inductor L33 can be adjusted.

[0159] In this way, the input port P1, the output port P2, the coupling port P3, and the termination port P4 are arranged as external electrodes 91, 92, 95, and 96 on the front surface 103 and the back surface 104, which are the side surfaces of the insulator 110.

[0160] 1 to 29, the hybrid coupler according to the first embodiment has been described. Whether the hybrid coupler according to the first embodiment is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the low-pass filters 42 and 43 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0161] 30 to 43, a hybrid coupler according to the second embodiment will be described. The following describes only the differences between the hybrid coupler according to the second embodiment and the hybrid coupler according to the first embodiment. Specifically, the hybrid coupler according to the first embodiment is different from the hybrid coupler according to the first embodiment in that the hybrid coupler according to the first embodiment includes a low-pass filter connected in series to the first line 11, whereas the hybrid coupler according to the second embodiment includes a high-pass filter connected in series to the first line 11.

[0162] [First Configuration of Hybrid Coupler According to Embodiment 2] Fig. 30 is a diagram showing a hybrid coupler 2A having a first configuration according to embodiment 2. As shown in Fig. 30, the hybrid coupler 2A includes a first line 11, a second line 12, an input port P1, an output port P2, a coupling port P3, and a termination port P4.

[0163] The hybrid coupler 2A further includes a high-pass filter 51 connected in series to the first line 11. Specifically, the high-pass filter 51 is provided between the first line 11 and the input port P1. The high-pass filter 51 passes, with minimal attenuation, frequency components higher than a specific cutoff frequency of the input power signal input from the input port P1, while attenuating frequency components lower than the cutoff frequency. The cutoff frequency can be adjusted by the design of the high-pass filter 51.

[0164] 31 is a diagram illustrating the characteristics of a hybrid coupler 2A having a first configuration according to the second embodiment. Fig. 31 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 2A. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 31, the pass band (used frequency band) of the hybrid coupler 2A is 8 GHz to 12 GHz, and the center frequency is 10 GHz.

[0165] According to the amplitude difference characteristics of the hybrid coupler 2A, the amplitude difference in the passband is generally within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0166] In this way, the hybrid coupler 2A of embodiment 2 can reduce the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band more than the hybrid coupler of the comparative example, due to the attenuation characteristics of the high-pass filter 51.

[0167] According to the phase difference characteristics of the hybrid coupler 2A, the phase difference at the center frequency is approximately 90 degrees. In this way, the hybrid coupler 2A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 90 degrees.

[0168] According to the pass characteristic of the hybrid coupler 2A, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0169] As shown above in the passband characteristics, the hybrid coupler 2A can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 1A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0170] In this way, even if the hybrid coupler 2A is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filter 51 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0171] [Second Configuration of Hybrid Coupler According to Embodiment 2] Fig. 32 is a diagram showing a hybrid coupler 2B having a second configuration according to embodiment 2. In the following, only the differences between the hybrid coupler 2B and the hybrid coupler 2A will be described.

[0172] 32, the hybrid coupler 2B includes a high-pass filter 52 connected in series to the first line 11 and a high-pass filter 53 connected in series to the second line 12. Specifically, the high-pass filter 52 is provided between the first line 11 and the output port P2. The high-pass filter 53 is provided between the second line 12 and the coupled port P3.

[0173] 33 is a diagram illustrating the characteristics of a hybrid coupler 2B having a second configuration according to the second embodiment. Fig. 33 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 2B. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 33, the pass band and center frequency of the hybrid coupler 2B are the same as the pass band and center frequency of the hybrid coupler 2A.

[0174] As shown in Fig. 33, the amplitude difference characteristic of the hybrid coupler 2B is approximately the same as the amplitude difference characteristic of the hybrid coupler 2A shown in Fig. 31. The phase difference characteristic of the hybrid coupler 2B can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 2A. Furthermore, according to the pass band characteristic of the hybrid coupler 2B, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0175] As shown above in the passband characteristics, the hybrid coupler 2B can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 2B can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0176] In this way, even if the hybrid coupler 2B is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filters 52 and 53 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0177] [Third Configuration of Hybrid Coupler According to Embodiment 2] Fig. 34 is a diagram showing a hybrid coupler 2C having a third configuration according to embodiment 2. In the following, only the differences between the hybrid coupler 2C and the hybrid coupler 2A will be described.

[0178] 34, the hybrid coupler 2C includes a high-pass filter 51 connected in series to the first line 11 and a high-pass filter 54 connected in series to the second line 12. Specifically, the high-pass filter 51 is provided between the first line 11 and the input port P1. The high-pass filter 54 is provided between the second line 12 and the termination port P4.

[0179] 35 is a diagram illustrating the characteristics of a hybrid coupler 2C having a third configuration according to the second embodiment. The amplitude difference characteristic, phase difference characteristic, and passband characteristic of a power signal that has passed through the hybrid coupler 2C are shown in FIG. Note that in each of the amplitude difference characteristic, phase difference characteristic, and passband characteristic shown in FIG. 35, the passband and center frequency of the hybrid coupler 2C are the same as those of the hybrid coupler 2A.

[0180] As shown in Fig. 35, the amplitude difference characteristic of the hybrid coupler 2C is approximately the same as the amplitude difference characteristic of the hybrid coupler 2A shown in Fig. 31. The phase difference characteristic of the hybrid coupler 2C can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 2A. Furthermore, according to the pass band characteristic of the hybrid coupler 2C, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0181] As shown in the passband characteristics, the hybrid coupler 2C can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 2C can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approach 90 degrees.

[0182] In this way, even if the hybrid coupler 2C is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filters 51 and 54 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0183] [Fourth Configuration of Hybrid Coupler According to Embodiment 2] Fig. 36 is a diagram showing a hybrid coupler 2D having a fourth configuration according to embodiment 2. The following describes the hybrid coupler 2D, focusing only on the differences from the hybrid coupler 1A.

[0184] 36 , the hybrid coupler 2D includes a high-pass filter 51 and a high-pass filter 52 connected in series to the first line 11, and a high-pass filter 53 connected in series to the second line 12. Specifically, the high-pass filter 51 is provided between the first line 11 and the input port P1. The high-pass filter 52 is provided between the first line 11 and the output port P2. The high-pass filter 53 is provided between the second line 12 and the coupled port P3.

[0185] 37 is a diagram illustrating the characteristics of a hybrid coupler 2D having a fourth configuration according to embodiment 2. Fig. 37 illustrates the amplitude difference characteristic, phase difference characteristic, and pass characteristic of a power signal that has passed through the hybrid coupler 2D. Note that in each of the amplitude difference characteristic, phase difference characteristic, and pass characteristic illustrated in Fig. 37, the pass band and center frequency of the hybrid coupler 2D are the same as the pass band and center frequency of the hybrid coupler 2A.

[0186] As shown in Fig. 37, the amplitude difference characteristic of the hybrid coupler 2D is approximately the same as the amplitude difference characteristic of the hybrid coupler 2A shown in Fig. 31. The phase difference characteristic of the hybrid coupler 2D can reduce the slope of the change in phase difference with frequency in the pass band compared to the phase difference characteristic of the hybrid coupler 2A. Furthermore, according to the pass band characteristic of the hybrid coupler 2D, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band.

[0187] As shown above in the passband characteristics, the hybrid coupler 2D can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 2D can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approximately 90 degrees.

[0188] In this way, even if the hybrid coupler 2D is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filters 51 to 53 can minimize the amplitude difference in the passband between the power signal output from the coupled port P3 and the power signal output from the output port P2, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0189] 38 is a diagram showing a hybrid coupler 2E having a fifth configuration according to embodiment 2. The following describes the hybrid coupler 2E, focusing only on the differences from the hybrid coupler 1A.

[0190] 38 , the hybrid coupler 2E includes high-pass filters 51 and 52 connected in series to the first line 11, and high-pass filters 53 and 54 connected in series to the second line 12. Specifically, the high-pass filter 51 is provided between the first line 11 and the input port P1. The high-pass filter 52 is provided between the first line 11 and the output port P2. The high-pass filter 53 is provided between the second line 12 and the coupled port P3. The high-pass filter 54 is provided between the second line 12 and the termination port P4.

[0191] [First Circuit of Hybrid Coupler According to Embodiment 2] Fig. 39 is a diagram showing a hybrid coupler 20A including a first circuit according to embodiment 2. The hybrid coupler 20A has a configuration similar to that of the hybrid coupler 2E having the fifth configuration shown in Fig. 38, and Fig. 39 shows a first circuit for realizing the hybrid coupler 20A (2E).

[0192] 39, hybrid coupler 20A includes inductor L51 and capacitor C51 that form high-pass filter 51, inductor L52 and capacitor C52 that form high-pass filter 52, inductor L53 and capacitor C53 that form high-pass filter 53, and inductor L54 and capacitor C54 that form high-pass filter 54. Inductors L51 to L54 are filter inductors. Capacitors C51 to C54 are filter capacitors.

[0193] Capacitor C51 is provided between the first line 11 and the input port P1. Capacitor C52 is provided between the first line 11 and the output port P2. Capacitor C53 is provided between the second line 12 and the coupled port P3. Capacitor C54 is provided between the second line 12 and the termination port P4.

[0194] The multiple inductors L51 to L54 are provided between each of the multiple capacitors C51 to C54 and the ground, which serves as a reference electrode. Specifically, the inductor L51 is provided between a node N11 between the capacitor C51 and the input port P1 and the ground, which serves as a reference electrode. The inductor L52 is provided between a node N12 between the capacitor C52 and the output port P2 and the ground, which serves as a reference electrode. The inductor L53 is provided between a node N13 between the capacitor C53 and the coupled port P3 and the ground, which serves as a reference electrode. The inductor L54 is provided between a node N14 between the capacitor C54 and the termination port P4 and the ground, which serves as a reference electrode.

[0195] One end of inductor L51, which is not connected to capacitor C51 and input port P1, is connected to one end of inductor L52, which is not connected to capacitor C52 and output port P2. One end of inductor L53, which is not connected to capacitor C53 and coupled port P3, is connected to one end of inductor L54, which is not connected to capacitor C54 and termination port P4. One end of each of inductors L51 to L54 is connected together to ground.

[0196] Fig. 40 is a diagram showing the characteristics of a hybrid coupler 20A including a first circuit according to embodiment 2. Fig. 40 shows the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 20A. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic shown in Fig. 40, the pass band (used frequency band) of the hybrid coupler 20A is 8 GHz to 12 GHz, and the center frequency is 10 GHz.

[0197] According to the amplitude difference characteristics of the hybrid coupler 20A, the amplitude difference in the pass band is generally within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB. According to the phase difference characteristics of the hybrid coupler 20A, the phase difference at the center frequency deviates from 90 degrees, but the outlier is less than 10 degrees. Furthermore, according to the pass characteristics of the hybrid coupler 20A, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is generally the same as the power signal flowing from the input port P1 to the output port P2 in the pass band. Furthermore, the pass characteristics of the hybrid coupler 20A (hybrid coupler 2E) are generally the same as the pass characteristics of the hybrid coupler 2A. Furthermore, according to the loss characteristics of the hybrid coupler 20A, the loss in the pass band is about 0.8 dB.

[0198] As shown in the passband characteristics, the hybrid coupler 20A can make the power signal flowing from the input port P1 to the coupled port P3 and the power signal flowing from the input port P1 to the output port P2 approximately the same in the passband, and as a result, as shown in the amplitude difference characteristics, the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the passband can be made smaller than the amplitude difference of the hybrid coupler according to the comparative example shown in Fig. 3. Furthermore, as shown in the phase difference characteristics, the hybrid coupler 20A can make the phase difference between the first power signal output from the coupled port P3 and the second power signal output from the output port P2 approach 90 degrees.

[0199] In this way, even if the hybrid coupler 20A (hybrid coupler 2E) equipped with the first circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filters 51 to 54 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0200] [Second Circuit of Hybrid Coupler According to Embodiment 2] Figure 41 is a diagram showing a hybrid coupler 20B including a second circuit according to embodiment 2. The hybrid coupler 20B has a configuration similar to that of the hybrid coupler 2E having the fifth configuration shown in Figure 38, and Figure 41 shows a second circuit for realizing the hybrid coupler 20B (2E). Below, only the differences between the hybrid coupler 20B and the hybrid coupler 20A will be described.

[0201] 41, the hybrid coupler 20B further includes a capacitor C61 provided between two inductors L51 and L52 of the multiple inductors L51 to L54 and the ground serving as a reference electrode. The hybrid coupler 20B further includes a capacitor C62 provided between two inductors L53 and L54 of the multiple inductors L51 to L54 and the ground serving as a reference electrode.

[0202] One end of capacitor C61 is connected to the end of inductor L51 that is not connected to capacitor C51 and input port P1, and to the end of inductor L52 that is not connected to capacitor C52 and output port P2. The other end of capacitor C61 is connected to ground. One end of capacitor C62 is connected to the end of inductor L53 that is not connected to capacitor C53 and coupled port P3, and to the end of inductor L54 that is not connected to capacitor C54 and termination port P4. The other end of capacitor C62 is connected to ground.

[0203] 42 is a diagram illustrating the characteristics of a hybrid coupler 20B including a second circuit according to embodiment 2. Fig. 42 illustrates the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic of a power signal that has passed through the hybrid coupler 20B. Note that in each of the amplitude difference characteristic, phase difference characteristic, pass characteristic, and loss characteristic illustrated in Fig. 42, the pass band and center frequency of the hybrid coupler 20B are the same as the pass band and center frequency of the hybrid coupler 20A.

[0204] As shown in Figure 42, the amplitude difference characteristic of the hybrid coupler 20B is generally the same as that of the hybrid coupler 20A shown in Figure 40. Furthermore, according to the pass characteristic of the hybrid coupler 20B, a steep attenuation pole occurs in a frequency band lower than the pass band due to the action of capacitors C61 and C62. As a result, the phase difference characteristic of the hybrid coupler 20B can have a smaller gradient of change in phase difference with frequency in the pass band than the phase difference characteristic of the hybrid coupler 20A. Furthermore, with the improvement in the phase difference characteristic, the loss characteristic of the hybrid coupler 20B can have a smaller degree of loss than the loss characteristic of the hybrid coupler 20A.

[0205] In this way, even if the hybrid coupler 20B equipped with the second circuit is a 3 dB hybrid coupler or a 90-degree hybrid coupler, the attenuation characteristics of the high-pass filters 51 to 54 can minimize the amplitude difference between the power signal output from the coupled port P3 and the power signal output from the output port P2 in the pass band, and therefore the power signal input from the input port P1 can be appropriately distributed to the coupled port P3 and the output port P2.

[0206] [Comparison with Comparative Example] Figure 43 is a diagram showing a comparison result between the characteristics of the hybrid coupler 2E according to the second embodiment and the characteristics of a hybrid coupler according to the comparative example. Here, a hybrid coupler 20A including the first circuit of Figure 39 and a hybrid coupler 20B including the second circuit of Figure 41 are used as the hybrid coupler 2E according to the second embodiment. Furthermore, a hybrid coupler having a configuration similar to that of the hybrid coupler 2A described in Figure 3 without the high-pass filter 51 is used as the hybrid coupler according to the comparative example. Figure 43 shows the pass characteristics of power signals that have passed through the hybrid coupler 20A, the hybrid coupler 20B, and the hybrid coupler according to the comparative example.

[0207] As shown in Fig. 43, according to the pass characteristics of the hybrid coupler of the comparative example, the power signal flowing from input port P1 to coupled port P3 in the pass band is separated from the power signal flowing from input port P1 to output port P2 in the pass band, and the two do not match. As a result, as shown in Fig. 3, according to the amplitude difference characteristics of the hybrid coupler of the comparative example, the amplitude difference in the pass band is more than 0.3 dB and is approximately 0.5 dB, and the amplitude difference at the center frequency is also more than 0.1 dB and is approximately 0.3 dB.

[0208] In contrast, in the hybrid coupler 2E according to the second embodiment, according to the pass characteristics of the hybrid coupler 20A, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is substantially the same as the power signal flowing from the input port P1 to the output port P2 in the pass band. As a result, as shown in Fig. 40, according to the amplitude difference characteristics of the hybrid coupler 20A, the amplitude difference in the pass band is substantially within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0209] According to the pass characteristics of the hybrid coupler 20B, the power signal flowing from the input port P1 to the coupled port P3 in the pass band is approximately the same as the power signal flowing from the input port P1 to the output port P2 in the pass band. As a result, as shown in Fig. 42, according to the amplitude difference characteristics of the hybrid coupler 20B, the amplitude difference in the pass band is approximately within 0.3 dB, and the amplitude difference at the center frequency is within 0.1 dB.

[0210] Furthermore, the pass characteristics of the hybrid coupler 20B cause a steep attenuation pole to be generated in a frequency band lower than the pass band due to the action of the capacitors C61 and C62. As a result, the hybrid coupler 20B can prevent the attenuation characteristics of the high-pass filters 51 to 54 from being excessively active, and can therefore make the slope of the change in the power signal with respect to frequency in the pass band smaller than that of the hybrid coupler 20A.

[0211] <Modifications> The present disclosure is not limited to the above-described embodiment, and various modifications and applications are possible. Modifications that can be applied to the present disclosure will be described below.

[0212] In the hybrid coupler according to the first embodiment, the low-pass filter 42 may be provided only between the first line 11 and the output port P2. In the hybrid coupler according to the second embodiment, the high-pass filter 52 may be provided only between the first line 11 and the output port P2.

[0213] In the hybrid coupler according to the second embodiment, each of the high-pass filters 51 to 54 may be individually connected to ground, as in the second circuit of the hybrid coupler 10B according to the first embodiment shown in Fig. 13. In addition, in the hybrid coupler according to the second embodiment, the high-pass filters 51 and 53 may be connected together to ground, and the high-pass filters 52 and 54 may be connected together to ground, as in the third circuit of the hybrid coupler 10C according to the first embodiment shown in Fig. 15.

[0214] In the hybrid coupler according to the first embodiment, the number of inductors or capacitors included in each of the low-pass filters 41 to 44 may be one or more. In the hybrid coupler according to the second embodiment, the number of inductors or capacitors included in each of the high-pass filters 51 to 54 may be one or more.

[0215] <Aspects> (Item 1) A coupler according to one aspect includes a first line that transmits a power signal, a second line configured to be electromagnetically coupled to the first line and extracting a first power signal from the power signals transmitted through the first line, an input port provided at one end of the first line and inputting the power signal to the first line, an output port provided at the other end of the first line and outputting a second power signal from the power signals transmitted through the first line, a coupling port provided at one end of the second line and outputting the first power signal transmitted through the second line, a termination port provided at the other end of the second line and terminated, and at least one filter connected in series to the first line and including a low-pass filter or a high-pass filter.

[0216] (Item 2) In the coupler described in item 1, the power of the first power signal and the power of the second power signal are the same or approximately the same.

[0217] (Item 3) In the coupler according to item 1 or 2, the difference in phase between the first power signal and the second power signal is 90 degrees or approximately 90 degrees.

[0218] (4) In the coupler according to any one of the first to third paragraphs, at least one filter is provided between the first line and the input port.

[0219] (Item 5) In the coupler according to any one of items 1 to 3, at least one filter is provided between the first line and the output port.

[0220] (Item 6) In the coupler according to any one of items 1 to 3, at least one filter is provided between the first line and the output port and between the second line and the coupled port.

[0221] (Item 7) In the coupler according to any one of items 1 to 3, at least one filter is provided between the first line and the input port and between the second line and the termination port.

[0222] (Item 8) In the coupler described in any one of items 1 to 3, at least one filter is provided between the first line and the input port, between the first line and the output port, and between the second line and the coupled port.

[0223] (Item 9) In the coupler described in any one of items 1 to 3, at least one filter is provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port.

[0224] (Item 10) In the coupler described in Item 9, at least one filter is a plurality of low-pass filters, and the plurality of low-pass filters include a plurality of inductors provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port, respectively, and a plurality of capacitors provided between each of the plurality of inductors and the reference electrode.

[0225] (Item 11) The coupler according to item 10 further includes a plurality of first inductors provided between each of the plurality of capacitors and the reference electrode.

[0226] (Item 12) The coupler according to item 10 further includes a first inductor provided between two of the plurality of capacitors and the reference electrode.

[0227] (13) The coupler according to any one of the 10th to 12th paragraphs further comprises a plurality of second inductors connected to each of a plurality of points between each of the plurality of capacitors and the plurality of inductors.

[0228] (Item 14) In the coupler according to item 13, the plurality of second inductors are provided between the plurality of points and each of the input port, the output port, the coupled port, and the termination port.

[0229] (Item 15) The coupler according to item 10 further includes a first inductor provided between the plurality of capacitors and the reference electrode.

[0230] (Item 16) In the coupler according to item 15, the inductance of each of the plurality of inductors is greater than the inductance of the first inductor.

[0231] (Item 17) The coupler according to item 15 or 16 includes an insulator including multiple layers. The multiple inductors are arranged on the same layer as the specific layer on which the first line or the second line is arranged or on a different layer. The input port, output port, coupling port, and termination port are arranged on the surface of the insulator. The multiple capacitors are arranged on a layer closer to the surface than the specific layer. The first inductor is formed by a via that connects the multiple capacitors and a reference electrode.

[0232] (Item 18) In the coupler according to item 17, the input port, the output port, the coupling port, and the termination port are arranged on the side of the insulator.

[0233] (Item 19) In the coupler according to item 9, the at least one filter is a plurality of high-pass filters, each of which includes a plurality of capacitors provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port, and a plurality of inductors provided between each of the plurality of capacitors and the reference electrode.

[0234] (Item 20) The coupler according to item 19 further comprises a capacitor provided between two of the plurality of inductors and the reference electrode.

[0235] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0236] 1A, 1B, 1C, 1D, 1E, 2A, 2B, 2C, 2D, 2E, 10A, 10B, 10C, 10D, 10E, 10F, 20A, 20B, 100A, 100B, 100C Hybrid coupler, 11 First line, 12 Second line, 41, 42, 43, 44 Low-pass filter, 51, 52, 53, 54 High-pass filter, 91, 92, 93, 94, 95, 96 External electrode, 91A, 92A, 93A, 94A, 95A, 96A Top electrode, 91B, 92B, 93B, 94B, 95B, 96B Side electrode, 91C, 92C, 93C, 94C, 95C, 96C Bottom electrode, 101 Top surface, 102 Bottom, 103 Front, 104 Back, 105 Right side, 106 Left side, 110 Insulator, C1, C2, C3, C4, C51, C52, C53, C54, C61, C62 Capacitors, L1, L2, L3, L4, L11, L12, L13, L14, L21, L22, L31, L32, L33, L41, L42, L43, L44, L51, L52, L53, L54 Inductors, P1 Input port, P2 Output port, P3 Coupled port, P4 Termination port.

Claims

1. A coupler for distributing electric power signals, comprising: a first line for transmitting the electric power signal; a second line configured to be electromagnetically coupled to the first line and extracting a first electric power signal from the electric power signals transmitted through the first line; an input port provided at one end of the first line for inputting the electric power signal to the first line; an output port provided at the other end of the first line for outputting a second electric power signal from the electric power signals transmitted through the first line; a coupling port provided at one end of the second line for outputting the first electric power signal transmitted through the second line; a termination port provided at the other end of the second line, which is terminated; and at least one filter connected in series to the first line, including a low-pass filter or a high-pass filter.

2. The coupler of claim 1, wherein the power of the first power signal and the power of the second power signal are the same or substantially the same.

3. A coupler according to claim 1 or claim 2, wherein the difference in phase between the first power signal and the second power signal is 90 degrees or approximately 90 degrees.

4. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the input port.

5. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the output port.

6. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the output port, and between the second line and the coupled port.

7. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the input port, and between the second line and the termination port.

8. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the input port, between the first line and the output port, and between the second line and the coupled port.

9. A coupler according to any one of claims 1 to 3, wherein the at least one filter is provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port.

10. The coupler according to claim 9, wherein the at least one filter is a plurality of low-pass filters, each of which includes a plurality of inductors provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port, and a plurality of capacitors provided between each of the plurality of inductors and a reference electrode.

11. The coupler of claim 10, further comprising a plurality of first inductors disposed between each of the plurality of capacitors and the reference electrode.

12. The coupler of claim 10, further comprising a first inductor disposed between two of said plurality of capacitors and said reference electrode.

13. A coupler according to any one of claims 10 to 12, further comprising a plurality of second inductors connected to respective points between each of the plurality of capacitors and the plurality of inductors.

14. The coupler of claim 13, wherein each of the plurality of second inductors is provided between each of the plurality of points and the input port, the output port, the coupled port, and the termination port.

15. The coupler of claim 10, further comprising a first inductor disposed between said plurality of capacitors and said reference electrode.

16. The coupler of claim 15, wherein the inductance of each of the plurality of inductors is greater than the inductance of the first inductor.

17. A coupler as described in claim 15 or claim 16, comprising an insulator including a plurality of layers, wherein the plurality of inductors are arranged on the same layer as or a different layer from the specific layer on which the first line or the second line is arranged, the input port, the output port, the coupling port, and the termination port are arranged on the surface of the insulator, the plurality of capacitors are arranged on a layer closer to the surface than the specific layer, and the first inductor is formed by a via that connects the plurality of capacitors and the reference electrode.

18. The coupler of claim 17, wherein the input port, the output port, the coupling port, and the termination port are disposed on sides of the insulator.

19. The coupler according to claim 9, wherein the at least one filter is a plurality of high-pass filters, each of which includes a plurality of capacitors provided between the first line and the input port, between the first line and the output port, between the second line and the coupled port, and between the second line and the termination port, and a plurality of inductors provided between each of the plurality of capacitors and a reference electrode.

20. The coupler of claim 19, further comprising a capacitor disposed between two of the plurality of inductors and the reference electrode.

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