Antenna module and electronic apparatus

Abstract

Provided are an antenna module that does not exhibit reduced radiation efficiency even when a plurality of antennas are arranged in a narrow area, and an electronic apparatus. The antenna module according to the present disclosure comprises a first antenna having a first resonance frequency, a second antenna having a second resonance frequency, and a first band stop filter connected to the second antenna. The first antenna includes a first electric power supply circuit and a first radiation element that is connected to the first electric power supply circuit. The second antenna includes a second electric power supply circuit and a second radiation element that is connected to the second electric power supply circuit. The first band stop filter cuts off the first resonance frequency, and the first radiation element and the second radiation element are coupled by at least one of an electric field or a magnetic field, whereby a first path that passes from the ground through the second radiation element via the first band stop filter operates as a parasitic antenna having a third resonance frequency.

Description

Antenna module and electronic device

[0001] The present disclosure relates to an antenna module and an electronic device, and more particularly to an antenna module and an electronic device that do not degrade radiation efficiency even when multiple antennas are arranged in a small area.

[0002] An antenna module equipped with multiple antennas to widen the available frequency band is disclosed in Japanese Patent No. 7176667 (Patent Document 1). In this antenna module, one of the multiple antennas is provided with a series resonant circuit, which is essentially grounded, thereby preventing interference from one antenna and maintaining high radiation efficiency of the other antenna.

[0003] Patent No. 7176667

[0004] However, in the antenna module disclosed in Patent Publication No. 7176667 (Patent Document 1), although there may be no interference in the high frequency range, one antenna can be considered to be GND from the other antenna, and the electromagnetic waves radiated from the other antenna will be absorbed by one antenna, which may degrade the radiation efficiency of the other antenna.

[0005] The present disclosure has been made to solve such problems, and its purpose is to provide an antenna module and electronic device that do not degrade radiation efficiency even when multiple antennas are arranged in a small area.

[0006] An antenna module according to the present disclosure includes a first antenna having a first resonant frequency, a second antenna having a second resonant frequency, and a first bandstop filter connected to the second antenna. The first antenna includes a first feed circuit and a first radiating element connected to the first feed circuit. The second antenna includes a second feed circuit and a second radiating element connected to the second feed circuit. The first bandstop filter blocks the first resonant frequency, and the first radiating element and the second radiating element are coupled by at least one of an electric field and a magnetic field, so that a first path from ground through the first bandstop filter and the second radiating element operates as a parasitic antenna having a third resonant frequency.

[0007] An electronic device according to the present disclosure includes the above antenna module and a substrate on which the antenna module is mounted.

[0008] In the antenna module according to the present disclosure, the first bandstop filter blocks the first resonant frequency, and the first radiating element and the second radiating element are coupled by at least one of an electric field and a magnetic field, so that the first path from ground through the first bandstop filter and the second radiating element operates as a parasitic antenna having a third resonant frequency, and therefore radiation efficiency is not degraded even when multiple antennas are arranged in a small area.

[0009] FIG. 1 is a diagram showing the configuration of an antenna module according to a first embodiment. FIG. 2 is a diagram showing a circuit diagram of a bandstop filter in the antenna module according to the first embodiment. FIG. 3 is a diagram showing a circuit diagram of a bandstop filter in a modified example. FIG. 4 is a diagram showing a circuit diagram of a bandstop filter in an antenna module according to another modified example. FIG. 5 is a diagram showing an example of the characteristics of a bandstop filter. FIG. 6 is a diagram showing the configuration of an antenna module in which a reactor is provided in a first path. FIG. 7 is a diagram showing an example of the radiation efficiency of a first antenna in the first embodiment. FIG. 8 is a diagram showing an example of the radiation efficiency of a second antenna in the first embodiment. FIG. 9 is a diagram showing the configuration of an electronic device according to the first embodiment. FIG. 10 is a diagram showing the configuration of an antenna module according to a modified example of the first embodiment. FIG. 11 is a diagram showing the configuration of a modified bandstop filter. FIG. 12 is a diagram showing the configuration of an antenna module according to a 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 their description will not be repeated. Furthermore, the radiation efficiency in this disclosure indicates the ratio of the output power radiated from the antenna to the power supplied from the feed circuit. That is, it is the efficiency that includes losses due to circuit losses and matching mismatches with respect to the power supplied from the feed circuit, and the smaller the negative value at the top of the graph, the better the radiation efficiency.

[0011] 1 is a diagram showing the configuration of an antenna module 1 according to the first embodiment. The antenna module 1 includes a first antenna 100, a second antenna 200, and a bandstop filter 10 (first bandstop filter) connected to the second antenna 200. The first antenna 100 includes a feed circuit RF1 (first feed circuit) and a first radiating element 101. The second antenna 200 includes a feed circuit RF2 (second feed circuit) and a second radiating element 201.

[0012] The antenna module 1 is mounted on a mobile terminal such as a mobile phone, a smartphone, or a tablet, or a communication device such as a smart watch or a personal computer with a communication function. The first antenna 100 is, for example, a monopole antenna. The second antenna 200 is, for example, a monopole antenna.

[0013] The feeder circuit RF1 supplies a high-frequency signal in the f1 band frequency band (first resonant frequency) to the first radiating element 101. The first radiating element 101 can radiate the f1 band high-frequency signal supplied from the feeder circuit RF1 into the air as radio waves. The f1 band frequency band is, for example, a band that includes n77 (3.3-4.2 GHz).

[0014] The feeder circuit RF2 supplies a high-frequency signal in the f2 frequency band (second resonant frequency) to the second radiating element 201. The second radiating element 201 can radiate the f2 frequency signal supplied from the feeder circuit RF2 into the air as radio waves. The f2 frequency band includes, for example, the 5 GHz band of Wi-Fi (registered trademark).

[0015] A band-stop filter 10 is connected between the second radiating element 201 and ground. The band-stop filter 10 blocks or attenuates high-frequency signals in the f1 frequency band. The band-stop filter 10 is configured to pass high-frequency signals in the f2 frequency band.

[0016] As will be described later, the first radiating element 101 and the second radiating element 201 are mounted on the same substrate. The first radiating element 101 and the second radiating element 201 are provided on the same substrate, but they may also be provided on different substrates as long as they are provided within the same antenna module 1. By providing them on the same substrate in this way, the distance between the antennas becomes constant, and therefore the coupling state between the first radiating element 101 and the second radiating element 201 can always be constant.

[0017] The first radiating element 101 and the second radiating element 201 are coupled by at least one of an electric field and a magnetic field. The bandstop filter 10 is disposed between the second radiating element 201 and the ground. As a result, the path from the ground through the bandstop filter 10 and the second radiating element 201 functions as a parasitic antenna for the f3 frequency band (third resonant frequency). Note that the f3 frequency band (third resonant frequency) may be the same communication band as the f1 frequency band (first resonant frequency).

[0018] 2A is a diagram showing a circuit diagram of the bandstop filter 10 in the antenna module 1 according to the first embodiment. The bandstop filter 10 includes a first filter circuit connected between ground and the second radiating element 201 and resonating in series, and a second filter circuit connected to the second radiating element 201 and resonating in parallel. In the second filter circuit, a second capacitor C2 and a second coil L2 are connected in parallel between the second radiating element 201 and the feed circuit RF2. In the first filter circuit, a first capacitor C1 and a first coil L1 are connected in series between one end of the second filter circuit and the ground. In the bandstop filter 10, the second filter circuit is connected closer to the feed circuit RF2 than the first filter circuit.

[0019] The bandstop filter 10 is configured to block or attenuate high-frequency signals in the f1 frequency band and pass high-frequency signals in the f2 frequency band. Figure 3 is a diagram showing an example of the characteristics of the bandstop filter 10. The horizontal axis of Figure 3 is frequency [GHz], the vertical axis on the right is return loss (S11) [dB], and the vertical axis on the left is insertion loss (S21) [dB]. The solid line indicates return loss and the dashed line indicates insertion loss. The characteristics of the bandstop filter 10 are high return loss (S11) and low insertion loss (S21) at frequencies between 3.3 and 4.2 GHz.

[0020] The antenna module 1 includes a bandstop filter 10 in the second antenna 200 that blocks or attenuates high-frequency signals in the f1 band frequency band. This blocks or attenuates high-frequency signals in the f1 band frequency band from the first antenna 100, thereby maintaining high radiation efficiency of the first antenna 100. Furthermore, the antenna module 1 operates as a parasitic antenna with an f3 band frequency band via the first path T1 shown in FIG. 2A , which runs from ground through the bandstop filter 10 to the second radiating element 201. Because the first path T1 operates as a parasitic antenna with an f3 band frequency band, the antenna module 1 prevents electromagnetic waves radiated from the first antenna 100 from being absorbed by the second antenna 200, thereby suppressing degradation of the radiation efficiency of the first antenna 100. Using the bandstop filter 10 in this manner allows the radiation efficiency to be maintained even when the two antennas are placed close to each other.

[0021] In order to operate the first path T1 as a parasitic antenna having the f3 frequency band, the first path T1 is set to resonate at, for example, a quarter wavelength of the f3 frequency band. The first path T1 includes a first filter circuit (a first capacitor C1 and a first coil L1), but if the first path T1 does not resonate at a quarter wavelength of the f3 frequency band, this may be adjusted by providing at least one element of a reactor and a capacitor.

[0022] Next, a modified example of the bandstop filter 10 will be described. Fig. 2B is a diagram showing a circuit diagram of the bandstop filter in the modified example. The bandstop filter 10 shown in Fig. 2B includes a first filter circuit connected between ground and the second radiating element 201, in which a series resonant circuit and an inductor circuit are connected in parallel, and a second filter circuit connected to the second radiating element 201 and resonating in parallel. The first filter circuit includes a series resonant circuit in which a first capacitor C1 and a first coil L1 are connected in series between one end of the second filter circuit and the ground, and an inductor circuit including a third coil L3, connected in parallel.

[0023] By connecting a series resonant circuit and an inductance circuit in parallel as in the first filter circuit shown in Fig. 2B, it is possible to more optimally set the pass characteristics of each of the first to third resonant frequencies. In particular, the first filter circuit shown in Fig. 2B can reduce the signal of the second resonant frequency flowing to ground while maintaining the pass characteristics of the third resonant frequency, thereby improving the radiation efficiency of the second resonant frequency.

[0024] Next, another modified example of the bandstop filter 10 will be described. Fig. 2C is a diagram showing a circuit diagram of a bandstop filter in another modified example. The bandstop filter 10 shown in Fig. 2C includes a first filter circuit connected between ground and a second radiating element 201, and having a series resonant circuit and a capacitance circuit connected in parallel, and a second filter circuit connected to the second radiating element 201 and resonating in parallel. The first filter circuit includes a series resonant circuit in which a first capacitor C1 and a first coil L1 are connected in series between one end of the second filter circuit and the ground, and a capacitance circuit including a third capacitor C3 connected in parallel.

[0025] By connecting a series resonant circuit and a capacitance circuit in parallel as in the first filter circuit shown in FIG. 2C, it is possible to more optimally set the pass characteristics of each of the first to third resonant frequencies.

[0026] 4 is a diagram showing the configuration of an antenna module 1a in which an inductor is provided in the first path T1. The antenna module 1a is provided with a coil La so that the first path T1 of the bandstop filter 10a provided in the first antenna 100a resonates at a quarter wavelength of the f3 frequency band. The coil La is provided between the first filter circuit and the second radiating element 201. The bandstop filter 10a may be provided with at least one of an inductor and a capacitor so that the first path T1 resonates at a quarter wavelength of the f3 frequency band.

[0027] Fig. 5 is a diagram showing an example of the radiation efficiency of the first antenna 100 according to the first embodiment. Fig. 6 is a diagram showing an example of the radiation efficiency of the second antenna 200 according to the first embodiment. In Figs. 5 and 6, the horizontal axis represents frequency [GHz] and the vertical axis represents radiation efficiency [dB]. In Figs. 5 and 6, the radiation efficiencies of the first antenna 100 and the second antenna 200 according to the first embodiment are shown by solid waveforms A and C, and the radiation efficiencies of the first antenna 100 and the second antenna 200 without the bandstop filter 10 are shown by dashed waveforms B and D.

[0028] 5, in a band including n77 (3.3-4.2 GHz), which is the frequency band of the f1 band of the high frequency signal supplied by the power feed circuit RF1, the radiation efficiency of the solid line waveform A is higher than the radiation efficiency of the dashed line waveform B. Therefore, it can be seen that the radiation efficiency of the first antenna 100 of the antenna module 1 is improved by providing the bandstop filter 10.

[0029] 6, in the 5 GHz band, which is the f2 frequency band of the high frequency signal supplied by the power feed circuit RF2, the radiation efficiency of the solid waveform C is not deteriorated as much as the radiation efficiency of the dashed waveform D. On the other hand, it can be seen that the second antenna 200 of the antenna module 1 blocks the band including n77 (3.3-4.2 GHz) by providing the bandstop filter 10.

[0030] Next, an electronic device having an antenna module 1 mounted on a substrate will be described. FIG. 7 is a diagram showing the configuration of an electronic device 5 according to the first embodiment. The electronic device 5 shown in FIG. 7 is a mobile terminal capable of communication in a band including n77 (3.3-4.2 GHz) and the 5 GHz band, for example. Therefore, the electronic device 5 includes an antenna module 1 having a first antenna 100 excited in a band including n77 and a second antenna 200 excited in the 5 GHz band. The electronic device 5 has the antenna module 1 mounted on a substrate 300. The electronic device 5 is, for example, a mobile phone, a smartphone, or a tablet.

[0031] In the antenna module 1, the first radiating element 101 and the second radiating element 201 are patterned in a narrow non-ground area 302 of the substrate 300, and the feed circuits RF1 and RF2 and the bandstop filter 10 are mounted in a circuit area 301 of the substrate 300. The first radiating element 101 is electrically connected to the feed circuit RF1 via wiring (not shown). The circuit area 301 is also a ground area that includes a ground layer inside the substrate, but in a lower-frequency antenna module, the circuit area 301 may also be located in a non-ground area. The second radiating element 201 is electrically connected to the bandstop filter 10 and the feed circuit RF1 via wiring (not shown).

[0032] As shown in FIG. 7 , the first radiating element 101 is configured with a linear conductor pattern extending leftward in the figure, and the second radiating element 201 is configured with a linear conductor pattern extending leftward in the figure inside the substrate 300 from the first radiating element 101. Both the first radiating element 101 and the second radiating element 201 function as monopole antennas. However, the type of antenna is not limited to a monopole, and a dipole, inverted-F, or other antenna may also be used. Furthermore, the f3 frequency band may be the same as or a different frequency band from the f1 frequency band. If the f3 frequency band and the f1 frequency band are the same, the radiation efficiency of the first antenna 100 can be improved. If the f3 frequency band is different from the f1 frequency band, resonance in a frequency band different from the f1 frequency band is added to the first antenna 100, thereby widening the bandwidth.

[0033] (Modification) As described in FIG. 2A , the second filter circuit of the bandstop filter 10 is connected closer to the power feed circuit RF2 than the first filter circuit. However, the bandstop filter is not limited to this, and the first filter circuit may be connected closer to the power feed circuit RF2 than the second filter circuit. FIG. 8 is a diagram showing the configuration of an antenna module 1b according to a modification of the first embodiment. Note that in the antenna module 1b shown in FIG. 8 , the same components as those in the antenna module 1 shown in FIG. 2A are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0034] The antenna module 1b includes a first antenna 100, a second antenna 200b, and a bandstop filter 10b (first bandstop filter) connected to the second antenna 200. The first antenna 100 includes a feed circuit RF1 (first feed circuit) and a first radiating element 101. The second antenna 200b includes a feed circuit RF2 (second feed circuit) and a second radiating element 201.

[0035] A band-stop filter 10b is connected between the second radiating element 201 and ground. The band-stop filter 10b blocks or attenuates high-frequency signals in the f1 frequency band. The band-stop filter 10b is configured to pass high-frequency signals in the f2 frequency band.

[0036] 8, the bandstop filter 10b includes a first filter circuit connected between ground and the second radiating element 201 and resonating in series, and a second filter circuit connected to the second radiating element 201 and resonating in parallel. In the first filter circuit, a first capacitor C1 and a first coil L1 are connected in series between the second radiating element 201 and ground. In the second filter circuit, a second capacitor C2 and a second coil L2 are connected in parallel between the second radiating element 201 and the feed circuit RF2. In the bandstop filter 10, the first filter circuit is connected closer to the feed circuit RF2 than the second filter circuit.

[0037] 3, which runs from the ground through the band-stop filter 10 to the second radiating element 201, the first path T1a operates as a parasitic antenna having an f3 frequency band. By having the first path T1a operate as a parasitic antenna having an f3 frequency band, the antenna module 1 prevents electromagnetic waves radiated from the first antenna 100 from being absorbed by the second antenna 200, and can suppress deterioration of the radiation efficiency of the first antenna 100.

[0038] In the band-stop filter 10b, the first filter circuit is connected closer to the power feed circuit RF2 than the second filter circuit, and therefore the second filter circuit is included in the first path T1a. The first path T1a, including the second filter circuit, is configured to resonate at a quarter wavelength of the f3 frequency band. The first path T1a includes the first filter circuit (first capacitor C1 and first coil L1) and the second filter circuit (second capacitor C2 and second coil L2). However, if the first path T1a does not resonate at a quarter wavelength of the f3 frequency band, this may be adjusted by providing at least one element selected from an inductor and a capacitor.

[0039] Furthermore, although the bandstop filter circuit has been described as being configured with a two-stage filter circuit including a first filter circuit and a second filter circuit, it may also be configured with a multi-stage filter circuit. Figure 9 shows the configuration of a modified bandstop filter. The bandstop filter 10c shown in Figure 9(a) is configured with a three-stage filter circuit in which a third filter circuit that resonates in parallel with the first filter circuit and the second filter circuit is added. In the third filter circuit, a third capacitor C3 and a third coil L3 are connected in parallel to the second radiating element 201.

[0040] 9(b) is configured as a three-stage filter circuit in which a fourth filter circuit that resonates in series with the first filter circuit and the second filter circuit is added. In the fourth filter circuit, a fourth capacitor C4 and a fourth coil L4 are connected in series between the second radiating element 201 and ground. The bandstop filter provided in the second antenna 200 may be configured to further include at least one of a filter circuit that resonates in series with the first filter circuit and the second filter circuit and a filter circuit that resonates in parallel with the first filter circuit and the second filter circuit.

[0041] [Embodiment 2] Fig. 10 is a diagram showing the configuration of antenna module 2 in embodiment 2. In antenna module 2 shown in Fig. 10, the same components as those in antenna module 1 shown in Fig. 2A are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0042] The antenna module 2 includes a first antenna 100a, a second antenna 200, a bandstop filter 10 (first bandstop filter) connected to the second antenna 200, and a bandstop filter 20 (second bandstop filter) connected to the first antenna 100a. The first antenna 100a includes a feed circuit RF1 (first feed circuit) and a first radiating element 101. The second antenna 200 includes a feed circuit RF2 (second feed circuit) and a second radiating element 201.

[0043] A band-stop filter 20 is connected to the first radiating element 101 and is also connected to ground. The band-stop filter 20 passes high-frequency signals in the f1 frequency band. The band-stop filter 20 is configured to block or attenuate high-frequency signals in the f2 frequency band.

[0044] A band-stop filter 10 is connected between the second radiating element 201 and ground. The band-stop filter 10 blocks or attenuates high-frequency signals in the f1 frequency band. The band-stop filter 10 is configured to pass high-frequency signals in the f2 frequency band.

[0045] The bandstop filter 20 includes a fifth filter circuit connected between ground and the first radiating element 101 and resonating in series, and a sixth filter circuit connected to the first radiating element 101 and resonating in parallel. In the fifth filter circuit, a capacitor CA and a coil LA are connected in series between the first radiating element 101 and ground. In the sixth filter circuit, a capacitor CB and a coil LB are connected in parallel between the first radiating element 101 and the feed circuit RF1. In the bandstop filter 20, the sixth filter circuit is arranged on the feed circuit RF1 side, and the fifth filter circuit is arranged on the first radiating element 101 side.

[0046] The antenna module 2 operates as a parasitic antenna having an f4 frequency band (fourth resonant frequency) via a second path T2 that runs from the ground of the first antenna 100a through the bandstop filter 20 and the first radiating element 101. By having the second path T2 operate as a parasitic antenna having an f4 frequency band, the electromagnetic waves radiated from the second antenna 200 are not absorbed by the first antenna 100, and deterioration of the radiation efficiency of the second antenna 200 can be suppressed.

[0047] In order to operate the second path T2 as a parasitic antenna having the f4 frequency band, the second path T2 is set to resonate at, for example, a quarter wavelength of the f4 frequency band. The second path T2 includes a fifth filter circuit (capacitor CA and coil LA), but if the second path T2 does not resonate at a quarter wavelength of the f4 frequency band, this may be adjusted by providing at least one element of a reactor and a capacitor.

[0048] The circuit configuration of the bandstop filter 20 may be the same as that of the bandstop filter 10b shown in FIG. 8, the bandstop filter 10c shown in FIG. 9(a), or the bandstop filter 10d shown in FIG. 9(b). The f4 frequency band may be the same as or a different frequency band from the f2 frequency band. When the f4 frequency band is the same as the f2 frequency band, the radiation of the first antenna 100a is added to the second antenna 200, improving the radiation efficiency. When the f4 frequency band is different from the f2 frequency band, resonance of a frequency band different from the f2 frequency band is added to the second antenna 200, thereby widening the bandwidth.

[0049] (Other Modifications) In each embodiment, the antenna device is described as a monopole antenna, but the antenna device may be another type of antenna, such as an inverted F antenna.

[0050] [Aspects] (1) An antenna module according to the present disclosure comprises: a first antenna having a first resonant frequency; a second antenna having a second resonant frequency; and a first band-stop filter connected to the second antenna, wherein the first antenna includes a first feed circuit and a first radiating element connected to the first feed circuit; the second antenna includes a second feed circuit and a second radiating element connected to the second feed circuit; the first band-stop filter blocks the first resonant frequency; and the first radiating element and the second radiating element are coupled by at least one of an electric field and a magnetic field, so that a first path from ground through the first band-stop filter and the second radiating element operates as a parasitic antenna having a third resonant frequency.

[0051] (2) The antenna module according to (1), wherein the first path resonates at a quarter wavelength of the third resonant frequency and operates as a parasitic antenna having the third resonant frequency.

[0052] (3) The antenna module according to (2), wherein the first path includes at least one of a reactor and a capacitor to resonate at a quarter wavelength of the third resonant frequency.

[0053] (4) The antenna module according to any one of (1) to (3), wherein the third resonant frequency is in the same communication band as the first resonant frequency.

[0054] (5) An antenna module according to any one of (1) to (4), wherein the first band-stop filter includes: a first filter circuit connected between the ground and the second radiating element and resonating in series; and a second filter circuit connected between the second radiating element and the feeding circuit and resonating in parallel.

[0055] (6) An antenna module according to any one of (1) to (4), wherein the first band-stop filter includes: a first filter circuit connected between the ground and the second radiating element, in which a series resonant circuit and an inductor circuit are connected in parallel; and a second filter circuit connected between the second radiating element and the feeding circuit, in which parallel resonation occurs.

[0056] (7) An antenna module according to any one of (1) to (4), wherein the first band-stop filter includes: a first filter circuit connected between the ground and the second radiating element, in which a series resonant circuit and a capacitance circuit are connected in parallel; and a second filter circuit connected between the second radiating element and the feeding circuit, in which parallel resonation occurs.

[0057] (8) The antenna module according to any one of (5) to (7), wherein the first band-stop filter is connected such that the second filter circuit is closer to the second feed circuit than the first filter circuit.

[0058] (9) The antenna module according to any one of (5) to (7), wherein the first band-stop filter is connected such that the first filter circuit is closer to the second feed circuit than the second filter circuit.

[0059] (10) The antenna module according to any one of (5) to (9), wherein the first band-stop filter further includes at least one of a series-resonant filter circuit and a parallel-resonant filter circuit in the first filter circuit and the second filter circuit.

[0060] (11) The antenna module according to any one of (1) to (10), further comprising a second band-stop filter connected to the first antenna, the second band-stop filter blocking a fourth resonant frequency.

[0061] (12) The antenna module according to (11), wherein the first radiating element and the second radiating element are coupled by at least one of an electric field and a magnetic field, so that the second path from the ground via the second band-stop filter and the first radiating element resonates at a quarter wavelength of the fourth resonant frequency, and operates as a parasitic antenna having the fourth resonant frequency.

[0062] (13) The antenna module according to (11) or (12), wherein the fourth resonant frequency is in the same communication band as the second resonant frequency.

[0063] (14) An electronic device according to the present disclosure includes: the antenna module according to any one of (1) to (13); and a substrate on which the antenna module is mounted.

[0064] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention 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.

[0065] 1, 2 Antenna module, 10, 20 Bandstop filter, 100, 100a First antenna, 200, 200a, 200b Second antenna, 101, 201 Radiating element, 300 Substrate, RF1, RF2 Power supply circuit.

Claims

1. An antenna module comprising: a first antenna having a first resonant frequency; a second antenna having a second resonant frequency; and a first bandstop filter connected to the second antenna, wherein the first antenna includes a first feed circuit and a first radiating element connected to the first feed circuit, and the second antenna includes a second feed circuit and a second radiating element connected to the second feed circuit, the first bandstop filter blocks the first resonant frequency, and the first radiating element and the second radiating element are coupled by at least one of an electric field and a magnetic field, so that a first path from ground through the first bandstop filter and the second radiating element operates as a parasitic antenna having a third resonant frequency.

2. The antenna module according to claim 1, wherein the first path resonates at 1 / 4 wavelength of the third resonant frequency and operates as a parasitic antenna having the third resonant frequency.

3. The antenna module according to claim 2, wherein the first path includes at least one of a reactor and a capacitor for resonating at a quarter wavelength of the third resonant frequency.

4. The antenna module according to any one of claims 1 to 3, wherein the third resonant frequency is in the same communication band as the first resonant frequency.

5. An antenna module as described in any one of claims 1 to 4, wherein the first bandstop filter includes: a first filter circuit connected between the ground and the second radiating element and resonating in series; and a second filter circuit connected between the second radiating element and the second feed circuit and resonating in parallel.

6. An antenna module as described in any one of claims 1 to 4, wherein the first bandstop filter includes: a first filter circuit connected between the ground and the second radiating element, and in which a series resonant circuit and an inductor circuit are connected in parallel; and a second filter circuit connected between the second radiating element and the second feed circuit, and resonating in parallel.

7. An antenna module as described in any one of claims 1 to 4, wherein the first bandstop filter includes: a first filter circuit connected between the ground and the second radiating element, and in which a series resonant circuit and a capacitance circuit are connected in parallel; and a second filter circuit connected between the second radiating element and the second feed circuit, and resonating in parallel.

8. An antenna module according to any one of claims 5 to 7, wherein the first bandstop filter is connected such that the second filter circuit is connected closer to the second power supply circuit than the first filter circuit.

9. An antenna module according to any one of claims 5 to 7, wherein the first bandstop filter is connected such that the first filter circuit is connected closer to the second power supply circuit than the second filter circuit.

10. An antenna module as described in any one of claims 5 to 9, wherein the first bandstop filter further includes at least one of a series-resonating filter circuit and a parallel-resonating filter circuit in the first filter circuit and the second filter circuit.

11. An antenna module as described in any one of claims 1 to 10, further comprising a second bandstop filter connected to the first antenna, the second bandstop filter blocking a fourth resonant frequency.

12. The antenna module described in claim 11, wherein the first radiating element and the second radiating element are coupled in at least one of an electric field and a magnetic field, so that a second path from ground through the second bandstop filter and the first radiating element resonates at 1 / 4 wavelength of the fourth resonant frequency, and operates as a parasitic antenna having the fourth resonant frequency.

13. The antenna module according to claim 11 or 12, wherein the fourth resonant frequency is in the same communication band as the second resonant frequency.

14. An electronic device comprising: an antenna module according to any one of claims 1 to 13; and a substrate on which the antenna module is mounted.

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