Patent ID: 12255399

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated.

First Embodiment

(Basic Configuration of Communication Apparatus)

FIG.1is an example of a block diagram of a communication apparatus10to which an antenna module100according to a first embodiment is applied. The communication apparatus10is, for example, a mobile terminal such as a mobile phone, a smart phone, and a tablet or a personal computer having a communication function. As a frequency band of radio waves that are used in the antenna module100in the embodiment, radio waves in a millimeter wave band, which have center frequencies of 28 GHz, 39 GHz, 60 GHz, and the like, are exemplified. Radio waves in frequency bands other than the above-described ones can however be applied, such as a band up to 300 GHz.

Referring toFIG.1, the communication apparatus10includes the antenna module100and a BBIC200configuring a baseband signal processing circuit. The antenna module100includes an RFIC110that is an example of a feeding circuit, an antenna device120, and a filter device105. The communication apparatus10up-converts a signal transmitted from the BBIC200to the antenna module100into radio frequency signals in the RFIC110and radiates the signals from the antenna device120after passing through the filter device105. The communication apparatus10transmits radio frequency signals received by the antenna device120to the RFIC110for down conversion after passing through the filter device105and the down-converted signal is processed in the BBIC200.

FIG.1illustrates only configurations corresponding to four feeding elements121among a plurality of feeding elements121(radiation elements) configuring the antenna device120for ease of description, and illustration of configurations corresponding to the other feeding elements121having similar configurations is omitted. In this context “feeding element” may be construed as the radiation element itself. However, “feeding element” may also include, as a separate component, the feed path that conveys RF to/from each radiating element with other circuitry such as filter105. AlthoughFIG.1illustrates an example in which the antenna device120is formed of the plurality of feeding elements121arranged in a two-dimensional array, a one-dimensional array in which the plurality of feeding elements121is arranged in a line may be used. In the embodiment, the feeding elements121are patch antennas having substantially square flat plate shapes.

The RFIC110includes switches111A to111D,113A to113D, and117, power amplifiers112AT to112DT, low noise amplifiers112AR to112DR, attenuators114A to114D, phase shifters115A to115D, a signal multiplexer/demultiplexer116, a mixer118, and an amplifier circuit119.

When the radio frequency signal is transmitted, the switches111A to111D and113A to113D are switched to the side of the power amplifiers112AT to112DT, and the switch117is connected to a transmission-side amplifier of the amplifier circuit119. When the radio frequency signals are received, the switches111A to111D and113A to113D are switched to the side of the low noise amplifiers112AR to112DR, and the switch117is connected to a reception-side amplifier of the amplifier circuit119.

The signal transmitted from the BBIC200is amplified by the amplifier circuit119and up-converted by the mixer118. The transmission signal, which is the up-converted radio frequency signal, is divided into four by the signal multiplexer/demultiplexer116, passes through four signal paths, and is fed to respective different feeding elements121. At this time, the directivity of the antenna device120can be adjusted by individually adjusting the phase shift degrees of the phase shifters115A to115D arranged in the respective signal paths.

The reception signals, which are the radio frequency signals received by the feeding elements121, pass through four different signal paths and are multiplexed by the signal multiplexer/demultiplexer116. The multiplexed reception signal is down-converted by the mixer118, amplified by the amplifier circuit119, and transmitted to the BBIC200.

The filter device105includes filters105A to105D. The filters105A to105D are respectively connected to the switches111A to111D in the RFIC110. The filters105A to105D have a function of attenuating signals in a specific frequency band. The filters105A to105D may be band pass filters, high pass filters, low pass filters, or combinations thereof. The radio frequency signals from the RFIC110pass through the filters105A to105D and are supplied to the corresponding feeding elements121.

In the case of the radio frequency signal in the millimeter wave band, a longer transmission line tends to cause noise components to be easily mixed. Therefore, it is preferable that a distance between the filter device105and the feeding elements121be as short as possible. That is, it is possible to suppress unnecessary waves from being radiated from the feeding elements by causing the radio frequency signals to pass through the filter device105immediately before being radiated from the feeding elements121. It is also possible to remove unnecessary waves included in the reception signals by causing the reception signals to pass through the filter device105immediately after being received by the feeding elements121.

Although the filter device105and the antenna device120are separately illustrated inFIG.1, in the present disclosure, the filter device105is formed inside the antenna device120, as will be described later.

The RFIC110is formed as, for example, a one-chip integrated circuit component including the above-described circuit configuration. Alternatively, devices (switches, power amplifiers, low noise amplifiers, attenuators, and phase shifters) corresponding to the respective feeding elements121in the RFIC110may be formed as one-chip integrated circuit components for the corresponding feeding elements121.

(Configuration of Antenna Module)

Next, the configuration of the antenna module100in the first embodiment will be described in detail with reference toFIGS.2and3.FIG.2is a plan perspective view of the antenna module100, andFIG.3is a side perspective view of the antenna module.

Although the case where the antenna module100is an array antenna including two feeding elements1211and1212as the radiation elements will be described inFIGS.2and3as an example, the number of feeding elements may be equal to or more than three, and further, the feeding elements may be two-dimensionally arrayed. The antenna module includes, in addition to the feeding elements1211and1212and the RFIC110, a dielectric substrate130, feeding wiring141and feeding wiring142, filters151and152, connection wiring161and connection wiring162, and a ground electrode GND. In the following description, a normal direction (radiation direction of radio waves) of the dielectric substrate130is defined as a Z-axis direction, and a plane perpendicular to the Z-axis direction is defined by an X axis and a Y axis. In addition, a positive direction and a negative direction of the Z axis in each drawing may be referred to as an upper side and a lower side, respectively.

The dielectric substrate130is, for example, a low temperature co-fired ceramics (LTCC) multilayer substrate, a multilayer resin substrate formed by laminating a plurality of resin layers made of resin such as epoxy or polyimide, a multilayer resin substrate formed by laminating a plurality of resin layers made of liquid crystal polymer (LCP) having a lower dielectric constant, a multilayer resin substrate formed by laminating a plurality of resin layers made of fluorine-based resin, or a ceramic multilayer substrate other than LTCC. The dielectric substrate130does not necessarily have a multilayer structure and may be a single-layer substrate.

The dielectric substrate130has a substantially rectangular shape, and the feeding elements1211and1212are arranged on an upper surface131(a surface in the positive direction of the Z axis) or an internal layer thereof. The feeding elements1211and1212are patch antennas having substantially square planar shapes. The feeding elements1211and1212are arranged adjacent to each other along the X-axis direction of the dielectric substrate130. When the wavelength of the radio waves that are radiated from the antenna module is λ, the feeding element1211and the feeding element1212are arranged such that their plane centers (intersection points of diagonal lines) are spaced apart by substantially λ/2.

In the dielectric substrate130, the ground electrode GND having a flat plate shape is arranged in a layer closer to a lower surface132(surface in the negative direction of the Z axis) than the feeding elements1211and1212so as to face the feeding elements1211and1212. The RFIC110is mounted on the lower surface132of the dielectric substrate130with solder bumps170interposed therebetween. The RFIC110may be connected to the dielectric substrate130using a multi-pole connector instead of the solder connection.

A radio frequency signal is supplied from the RFIC110to a feeding point SP1of the feeding element1211after passing through the connection wiring161, the filter151, and the feeding wiring141. Further, a radio frequency signal is supplied from the RFIC110to a feeding point SP2of the feeding element1212after passing through the connection wiring162, the filter152, and the feeding wiring142. In the example ofFIG.2, the feeding point of each feeding element is arranged at a position offset from the center of the feeding element in the negative direction of the Y axis. By setting the feeding point at such a position, radio waves having a polarization direction being the Y-axis direction are radiated from each feeding element.

Each of the feeding wiring and the connection wiring is formed by a wiring pattern formed between layers of the dielectric substrate130and a via penetrating through the layers. In the antenna module100, conductors configuring the radiation elements, wiring patterns, electrodes, vias, and the like are made of metal containing aluminum (Al), copper (Cu), gold (Au), silver (Ag), or an alloy thereof as a main component.

The filters151and152correspond to the filter device105illustrated inFIG.1. Although the filters151and152are arranged between the lower surface132of the dielectric substrate130and the ground electrode GND in the example ofFIG.3, the filters151and152may be arranged in a layer between the feeding elements1211and1212and the ground electrode GND as in an example ofFIG.4. InFIG.2and subsequent plan perspective views, each filter is expressed by a rectangular shape being a region that can be occupied by the filter. The region may however have a substantially square shape or a more elongated rectangular shape depending on the configuration of the filter. Here, the “region that can be occupied by each filter” is not a region that is occupied by shapes of the resonant lines but a region including all of the resonant lines and expressed by a rectangular shape.

In the configuration of an antenna module100A inFIG.4, when the thickness of the dielectric substrate130is the same, a distance between the radiation elements and the ground electrode GND can be made larger than that in the antenna module100inFIG.3. Therefore, an advantage such as broadening of the frequency band width of the antenna module can be obtained. On the other hand, in the antenna module100A, parts of the filters may face the radiation elements. Therefore, there is a possibility that directivity or the like is affected by electromagnetic coupling between the radiation elements and the filters. In the antenna module100inFIG.3, coupling between the filters and the radiation elements is suppressed by the ground electrode GND. However, it is necessary to secure a distance between the ground electrode GND and the lower surface132, and there is a possibility that the frequency band or the like is affected when the distance between the radiation element and the ground electrode GND cannot be secured. Which of the configurations illustrated inFIGS.3and4is to be employed is determined in consideration of desired antenna characteristics, a device size, manufacturing cost, and the like.

Referring again toFIG.2, when the antenna module100is viewed in plan from the normal direction, each of the filters151and152is arranged so as to cross a virtual line CL1equidistant from the feeding element1211and the feeding element1212. Here, since the virtual line CL1is equidistant from the two feeding elements, the virtual line CL1extends in a second direction (negative direction of the Y axis) orthogonal to a first direction (positive direction of the X axis) toward the feeding element1212from the feeding element1211. That is, the filter151and the filter152are arranged side by side in the second direction. The filter151is arranged further on the second direction side with respect to the feeding point SP1, and the filter152is arranged on the opposite side (positive direction of the Y axis) to the second direction with respect to the feeding point SP1.

The filter151and the filter152do not overlap with each other when the antenna module100is viewed in plan. Further, the filter151does not overlap with the feeding element1212, and the filter152does not overlap with the feeding element1211.

The filters151and152are so-called resonant line-type filters. The resonant line-type filters have a configuration in which a plurality of lines each having a length of λ/4 or λ/2 is adjacent to each other in a non-connected state and function as filters by electromagnetic field coupling between the resonant lines. The resonant line-type filter can be formed by a wiring pattern or a combination of a wiring pattern and a via, thereby obtaining an advantage that it can be relatively easily formed inside the dielectric substrate of the antenna array.

FIG.5is a view illustrating some examples of the configuration of resonant line-type filters corresponding to the filters151and152. Each of the filters illustrated inFIGS.5(a) to5(c)is formed in the dielectric substrate130.

A filter150inFIG.5(a)includes two lines1503and1506each having a length of λ/4 and a line1505having a length of λ/2. The lines1503,1505, and1506are formed in the same layer. The line1503is connected to an input terminal1501, and the line1506is connected to an output terminal1502. The line1503and the line1506have substantially L shapes, and one ends of the L shapes are connected to a ground potential by vias1504and1507, respectively. The line1503and the line1506are arranged such that the ends thereof to which the vias are connected face each other and are spaced apart from each other and the other ends thereof extend in opposite directions. The line1505formed of a linear line is arranged between the line1503and the line1506.

A filter150A inFIG.5(b)includes two lines1503A and1506A each having a length of λ/4 and a line1505A having a length of λ/2. The line1503A and the line1506A have substantially L shapes, and one ends of the L shapes are connected to an input terminal1501A and an output terminal1502A, respectively. The line1505A is formed in a layer different from that of the lines1503A and1506A. The line1505A has a crank shape, one end of the line1505A is capacitively coupled to the other end of the line1503A, and the other end of the line1505A is capacitively coupled to the other end of the line1506A. Additional lines are connected to an end of the line1503A, which is connected to the input terminal1501A, and an end of the line1506A, which is connected to the output terminal1502A. Characteristics of the filter150A can thus be adjusted by providing the additional lines between the input terminal1501A and the output terminal1502A.

A filter150B inFIG.5(c)includes two lines1503B and1506B each having a length of λ/4 and a line1505B and a line1508B each having a length of λ/2. The line1505B is formed in a layer different from that of the lines1503B and1506B. The line1503B and the line1506B have substantially C shapes and are connected to an input terminal1501B and an output terminal1502B, respectively, at substantially central portions of the C shapes. One ends of the line1503B and the line1506B are connected to a ground potential by vias1504B and1507B, respectively. The other end of the line1503B is capacitively coupled to one end of the linear line1505B, and the other end of the line1506B is capacitively coupled to the other end of the line1505B. The line1508B is a linear line arranged parallel to the line1505B, and both ends thereof are connected to the ground potential by vias. Characteristics of the filter150B can be adjusted by providing the line1508B.

In the first embodiment, a configuration other than the filter illustrated inFIG.5may be applied as long as the configuration is a resonant line-type filter.

As described above, since the resonant line-type filter can be easily formed inside the dielectric substrate, it is suitable for a case where the filter is formed in the immediate vicinity of the radiation element. On the other hand, the resonant line-type filter requires a larger area than that when an LC filter realized by a coiled inductor and a capacitor formed by two flat plate electrodes, which is formed in a multilayer substrate, or a chip-type filter mounted on a substrate is used. In the case of the array antenna in which the plurality of radiation elements is arranged, there is a restriction on the interval between the adjacent radiation elements. For this reason, the size of the whole array antenna possibly increases unless the filters are appropriately arranged.

FIG.6is a plan perspective view of an antenna module100#in a comparative example. In the example of the antenna module100#, filters151#and152#are arranged such that positions of the filters with respect to feeding elements are the same, and parts of the filters protrude from regions of λ/4 from the corresponding feeding elements. In this case, the dielectric substrate130needs to be enlarged such that protruding portions are encompassed in the dielectric substrate130, and the sizes of the antenna module and the whole antenna array increase.

On the other hand, in the antenna module100in the first embodiment illustrated inFIG.2, the two filters are arranged between the feeding elements so as to cross the virtual line equidistant from the feeding elements and are arranged side by side in the direction orthogonal to the array direction of the feeding elements. With such arrangement, the filters can be formed in the regions of the distance of λ/4 from the two feeding elements, so that increase in the size of the antenna module in the array antenna can be suppressed.

(Modification)

FIG.7is a plan perspective view of an antenna module100B in a modification. The antenna module100B has a configuration in which a plurality of feeding points for radiating radio waves in the same polarization direction is provided for each feeding element.

To be specific, referring toFIG.7, a feeding point SP1A and a feeding point SP1B are provided for the feeding element1211, and a feeding point SP2A and a feeding point SP2B are provided for the feeding element1212.

The feeding point SP1A is arranged at a position offset from the center of the feeding element1211in the negative direction of the Y axis, and the feeding point SP1B is arranged at a position offset from the center of the feeding element1211in the positive direction of the Y axis. Similarly, the feeding point SP2A is arranged at a position offset from the center of the feeding element1212in the negative direction of the Y axis, and the feeding point SP2B is arranged at a position offset from the center of the feeding element1212in the positive direction of the Y axis. That is, the feeding points SP1B and SP2B are arranged at positions offset from the center points (plane centers) of the feeding elements in the direction opposite to the offset direction of the feeding points SP1A and SP2A.

All of the feeding points SP1A, SP1B, SP2A, and SP2B are offset in the Y-axis direction from the center points of the feeding elements. Therefore, when radio frequency signals are supplied to these feeding points, radio waves having the polarization direction being the Y-axis direction are emitted from the feeding elements.

The feeding point SP1A is connected to the feeding point SP1B by lines191. Further, the feeding point SP2A is connected to the feeding point SP2B by lines192. When the wavelength of the radio waves that are radiated from each radiation element is λ, the lengths of the lines191and192are set to be λ/2. Accordingly, the phase of the radio frequency signal that is supplied to the feeding point SP1B is inverted with respect to the phase of the radio frequency signal that is supplied to the feeding point SP1A. Similarly, the phase of the radio frequency signal that is supplied to the feeding point SP2B is inverted with respect to the phase of the radio frequency signal that is supplied to the feeding point SP2A. This makes it possible to improve the cross polarization discrimination (XPD) indicating the degree of separation between main polarization and cross polarization in each feeding element.

In the antenna module100B, a radio frequency signal from the filter151corresponding to the feeding element1211is supplied to the feeding point SP1A after passing through the feeding wiring141. On the other hand, a radio frequency signal from the filter152corresponding to the feeding element1212is supplied to the feeding point SP2B after passing through the feeding wiring142.

When the antenna module100B is viewed in plan (from the radiating side of the radiation elements), the filter151and the filter152are arranged side by side in a second direction (Y-axis direction) orthogonal to a first direction (positive direction of the X axis) toward the feeding element1212from the feeding element1211. With such arrangement, the filters can be formed in the regions of the distance of λ/4 from the two feeding elements, so that increase in the size of the antenna module in the array antenna can be suppressed.

In the first embodiment and the modification, the “feeding element1211” and the “feeding element1212” correspond to a “first radiation element” and a “second radiation element” in the present disclosure, respectively, and the “filter151” and the “filter152” correspond to a “first filter” and a “second filter” in the present disclosure, respectively.

Second Embodiment

In the first embodiment, the configuration has been described in which the radio waves having one polarization direction are radiated from each radiation element. A second embodiment describes filter arrangement in the case of a so-called dual polarization type in which two radio waves having different polarization directions can be radiated from each radiation element.

(Basic Configuration of Communication Apparatus)

FIG.8is a block diagram of a communication apparatus to which an antenna module according to the second embodiment is applied. Referring toFIG.8, a communication apparatus10A includes an antenna module100C and the BBIC200. The antenna module100C includes an RFIC110A, an antenna device120A, and a filter device106.

The antenna device120A is a dual polarization-type antenna device, and a radio frequency signal for first polarization and a radio frequency signal for second polarization are supplied to each feeding element121from the RFIC110A.

The RFIC110A includes switches111A to111H,113A to113H,117A, and117B, power amplifiers112AT to112HT, low noise amplifiers112AR to112HR, attenuators114A to114H, phase shifters115A to115H, signal multiplexers/demultiplexers116A and116B, mixers118A and118B, and amplifier circuits119A and119B. Among them, the configurations of the switches111A to111D,113A to113D, and117A, the power amplifiers112AT to112DT, the low noise amplifiers112AR to112DR, the attenuators114A to114D, the phase shifters115A to115D, the signal multiplexer/demultiplexer116A, the mixer118A, and the amplifier circuit119A are circuits for the radio frequency signals for the first polarization. The configurations of the switches111E to111H,113E to113H, and117B, the power amplifiers112ET to112HT, the low noise amplifiers112ER to112HR, the attenuators114E to114H, the phase shifters115E to115H, the signal multiplexer/demultiplexer116B, the mixer118B, and the amplifier circuit119B are circuits for the radio frequency signals for the second polarization.

When the radio frequency signals are transmitted, the switches111A to111H and113A to113H are switched to the side of the power amplifiers112AT to112HT, and the switches117A and117B are connected to transmission-side amplifiers of the amplifier circuits119A and119B. When the radio frequency signals are received, the switches111A to111H and113A to113H are switched to the side of the low noise amplifiers112AR to112HR, and the switches117A and117B are connected to reception-side amplifiers of the amplifier circuits119A and119B.

The filter device106includes filters106A to106H. The filters106A to106H are connected to the switches111A to111H in the RFIC110A, respectively. Each of the filters106A to106H has a function of attenuating radio frequency signals in a specific frequency band.

The signals transmitted from the BBIC200are amplified by the amplifier circuits119A and119B and up-converted by the mixers118A and118B. The transmission signals, which are the up-converted radio frequency signals, are divided into four by the signal multiplexers/demultiplexers116A and116B, pass through corresponding signal paths, and are fed to the respective different feeding elements121.

The radio frequency signals from the switches111A and111E are supplied to a feeding element121A after passing through the filters106A and106E, respectively. Similarly, the radio frequency signals from the switches111B and111F are supplied to a feeding element121B after passing through the filters106B and106F, respectively. The radio frequency signals from the switches111C and111G are supplied to a feeding element121C after passing through the filters106C and106G, respectively. The radio frequency signals from the switches111D and111H are supplied to a feeding element121D after passing through the filters106D and106H, respectively.

The directivity of the antenna device120A can be adjusted by individually adjusting the phase shift degrees of the phase shifters115A to115H arranged on the respective signal paths.

The reception signals, which are radio frequency signals received by the feeding elements121, are transmitted to the RFIC110after passing through the filter device106. Then, the reception signals pass through four different signal paths and are multiplexed in the signal multiplexers/demultiplexers116A and116B. The multiplexed reception signals are down-converted by the mixers118A and118B, amplified by the amplifier circuits119A and119B, and transmitted to the BBIC200.

(Configuration of Antenna Module)

FIG.9is an example of a plan perspective view of the antenna module100C inFIG.8. Referring toFIG.9, the antenna module100C has a configuration in which radio wave filters1512and1522(filters X) having polarization directions being the X-axis direction are added to the configuration of the antenna module100in the first embodiment described with reference toFIG.2. Filters1511and1521(filters Y) having polarization directions being the Y-axis direction inFIG.9correspond to the filters151and152inFIG.2. All of the filters1511,1512,1521, and1522are the resonant line-type filters.

In the feeding element1211, the radio frequency signal that has passed through the filter1511is supplied to a feeding point SP11after passing through feeding wiring1411, and the radio frequency signal that has passed through the filter1512is supplied to a feeding point SP12after passing through feeding wiring1412. In the feeding element1212, the radio frequency signal that has passed through the filter1512is supplied to a feeding point SP21after passing through feeding wiring1421, and the radio frequency signal that has passed through the filter1522is supplied to a feeding point SP22after passing through feeding wiring1422.

The feeding points SP11and SP21are arranged at positions offset from the centers of the feeding elements in the negative direction of the Y axis. When the radio frequency signals are supplied to the feeding points SP11and SP21, radio waves having the polarization directions being the Y-axis direction are radiated from each of the feeding elements. Further, the feeding points SP12and SP22are arranged at positions offset from the centers of the feeding elements in the positive direction of the X axis. When the radio frequency signals are supplied to the feeding points SP12and SP22, radio waves having the polarization directions being the X-axis direction are radiated from each of the feeding elements.

Each of the filters1511,1512,1521, and1522is arranged in a layer between the lower surface132of the dielectric substrate130and the ground electrode GND as illustrated inFIG.3in the first embodiment or in a layer between the feeding elements1211and1212and the ground electrode GND as illustrated inFIG.4.

Similarly to the filters151and152in the first embodiment, the filters1511and1521are arranged so as to cross the virtual line CL1equidistant from the feeding element1211and the feeding element1212when the antenna module100C is viewed in plan from the normal direction. The filter1511and the filter1521are arranged side by side in a second direction (negative direction of the Y-axis) orthogonal to a first direction (positive direction of the X axis) toward the feeding element1212from the feeding element1211. The filter1511is arranged further on the second direction side with respect to the feeding point SP11, and the filter1512is arranged in the direction (positive direction of the Y axis) opposite to the second direction with respect to the feeding point SP12.

The filter1512for polarization in the X-axis direction for the feeding element1211is arranged in the direction (negative direction of the X axis) opposite to the first direction with respect to the feeding point SP12in a region in the direction (positive direction of the Y axis) opposite to the second direction with respect to the center of the feeding element1211. On the other hand, the filter1522for polarization in the X-axis direction for the feeding element1212is arranged in a region in the first direction (positive direction of the X axis) with respect to the center of the feeding element1212.

With such arrangement, all of the filters1511,1512,1521, and1522can be arranged in the regions of the distance of λ/4 from the feeding elements1211and1212, so that increase in the size of the antenna module in the array antenna can be suppressed.

In the antenna module100C inFIG.9, the “filter1511” and the “filter1521” correspond to the “first filter” and the “second filter”, respectively, in the present disclosure, and the “filter1512” and the “filter1522” correspond to a “third filter” and a “fourth filter”, respectively, in the present disclosure.

Note that the filters arranged in the region between the feeding elements1211and1212are not required to be the filters for the same polarization. For example, as in an antenna module100C1illustrated inFIG.10, the filter1511for polarization in the Y-axis direction for the feeding element1211and the filter1522for polarization in the X-axis direction for the feeding element1212may be arranged in the region between the feeding elements1211and1212. Although not illustrated in the drawing, the filter1512for polarization in the X-axis direction for the feeding element1211and the filter1521for polarization in the Y-axis direction for the feeding element1212may be arranged in the region between the feeding elements1211and1212.

In the antenna module100C1inFIG.10, the “filter1511” and the “filter1522” correspond to the “first filter” and the “second filter”, respectively, in the present disclosure, and the “filter1512” and the “filter1521” correspond to the “third filter” and the “fourth filter”, respectively, in the present disclosure.

As described above, in the dual polarization-type antenna module as well, all of the filters can be formed in the regions of the distance of λ/4 from the two feeding elements by arranging any filter for one radiation element and any filter for the other radiation element side by side in the direction orthogonal to the array direction of the feeding elements. Therefore, increase in the size of the antenna module in the array antenna can be suppressed.

Third Embodiment

In the first embodiment, the configuration has been described in which the radio waves in one frequency band are radiated from each radiation element. A third embodiment describes filter arrangement in the case of a so-called dual band-type in which two radio waves having different frequency bands can be radiated from each radiation element with reference toFIGS.11to13.

FIG.11is a block diagram of a communication apparatus10B to which an antenna module100D according to the third embodiment is applied.FIGS.12and13are a plan perspective view and a side perspective view, respectively, of an antenna module including two radiation elements.

Referring toFIG.11, the communication apparatus10B includes the antenna module100D and the BBIC200. The antenna module100D includes an RFIC110B, an antenna device120B, and a filter device107.

The antenna device120B includes, as radiation elements, the plurality of feeding elements121and parasitic elements122provided so as to correspond to the respective feeding elements121. The antenna device120B is a so-called dual band-type antenna device capable of radiating radio waves in two different frequency bands.

As illustrated inFIGS.12and13, the antenna module100D includes, as radiation elements, the feeding elements1211and1212and parasitic elements1221and1222. The parasitic element1221is arranged in a layer between the feeding element1211and the ground electrode GND in the dielectric substrate130. Feeding wiring141A penetrates through the parasitic element1221and is connected to the feeding point SP1of the feeding element1211. Similarly, the parasitic element1222is arranged in a layer between the feeding element1212and the ground electrode GND in the dielectric substrate130. Feeding wiring142A penetrates through the parasitic element1222and is connected to the feeding point SP2of the feeding element1212.

The sizes of the parasitic elements1221and1222are larger than the sizes of the feeding elements1211and1212. Therefore, the resonant frequencies of the parasitic elements1221and1222are lower than the resonant frequencies of the feeding elements1211and1212. Radio waves having frequencies lower than those of the feeding elements1211and1212can be radiated from the parasitic elements1221and1222by supplying radio frequency signals corresponding to the resonant frequencies of the parasitic elements1221and1222to the feeding wiring141A and the feeding wiring142A, respectively.

The RFIC110B is configured to be able to supply radio frequency signals in two frequency bands. Since the configuration of the RFIC110B is basically similar to that of the RFIC110A described in the second embodiment, detailed description thereof will not be repeated. In the RFIC110B, the configurations of the switches111A to111D,113A to113D, and117A, the power amplifiers112AT to112DT, the low noise amplifiers112AR to112DR, the attenuators114A to114D, the phase shifters115A to115D, the signal multiplexer/demultiplexer116A, the mixer118A, and the amplifier circuit119A inFIG.11are circuits for the radio frequency signals in a low frequency band. The configurations of the switches111E to111H,113E to113H, and117B, the power amplifiers112ET to112HT, the low noise amplifiers112ER to112HR, the attenuators114E to114H, the phase shifters115E to115H, the signal multiplexer/demultiplexer116B, the mixer118B, and the amplifier circuit119B inFIG.11are circuits for the radio frequency signals in a high frequency band.

The filter device107includes diplexers107A to107D. Each diplexer includes a low pass filter (filter107A1,107B1,107C1, or107D1) that transmits the radio frequency signals in the low frequency band and a high pass filter (filter107A2,107B2,107C2, or107D2) that transmits the radio frequency signals in the high frequency band. The filters107A1,107B1,107C1, and107D1are respectively connected to the switches111A to111D in the RFIC110B. The filters107A2,107B2,107C2, and107D2are respectively connected to the switches111E to111H in the RFIC110B. Each of the diplexers107A to107D is connected to the corresponding feeding element121.

Transmission signals from the switches111A to111D in the RFIC110B are radiated from the corresponding parasitic elements122after passing through the filters107A1to107D1, respectively. Transmission signals from the switches111E to111H in the RFIC110B are radiated from the corresponding feeding elements121after passing through the filters107A2to107D2, respectively.

InFIGS.12and13, for example, filters151A and152A correspond to the high pass filters of the diplexers, and filters151B and152B correspond to the low pass filters of the diplexers. The radio frequency signals in the high frequency band from the RFIC110B are supplied to the feeding point SP1of the feeding element1211after passing through the filter151A and the feeding wiring141A and supplied to the feeding point SP2of the feeding element1212after passing through the filter152A and the feeding wiring142A. The radio frequency signals in the low frequency band from the RFIC110B are supplied to the feeding point SP1of the feeding element1211after passing through the filter151B and the feeding wiring141B and supplied to the feeding point SP2of the feeding element1212after passing through the filter152B and the feeding wiring142B.

Each of the filters151A,151B,152A, and152B is arranged in a layer between the lower surface132of the dielectric substrate130and the ground electrode GND or in a layer between the parasitic element1221or1222and the ground electrode GND.

In such a dual band-type antenna module as well, as illustrated inFIG.12, all of the filters can be formed in the regions of the distance λ/4 from two feeding elements by arranging one of the filters151A and151B for the feeding element1211and one of the filters152A and152B for the feeding element1212so as to cross the virtual line CL1equidistant from the feeding element1211and the feeding element1212and arranging them side by side in a second direction (negative direction of the Y axis) orthogonal to a first direction (positive direction of the X axis) toward the feeding element1212from the feeding element1211. Therefore, increase in the size of the antenna module in the array antenna can be suppressed.

In the antenna module100D inFIG.12, the “feeding element1211” and the “parasitic element1221” correspond to the “first radiation element” in the present disclosure, and the “feeding element1212” and the “parasitic element1222” correspond to the “second radiation element” in the present disclosure. In the antenna module100D, the “filter151A” and the “filter152A” correspond to the “first filter” and the “second filter”, respectively, in the present disclosure, and the “filter151B” and the “filter152B” correspond to the “third filter” and the “fourth filter”, respectively, in the present disclosure.

Fourth Embodiment

A fourth embodiment describes a case of a dual polarization/dual band-type antenna module obtained by combining the second embodiment and the third embodiment with reference toFIGS.14and15.

FIG.14is a block diagram of a communication apparatus10C to which an antenna module100E according to the fourth embodiment is applied.

Referring toFIG.14, the communication apparatus10C includes the antenna module100E and the BBIC200. The antenna module100E includes RFICs110C1to110C4, an antenna device120C, and a filter device108.

The antenna device120C includes, as radiation elements, the plurality of feeding elements121and the parasitic elements122provided so as to correspond to the feeding elements121. In addition, a radio frequency signal for first polarization and a radio frequency signal for second polarization are supplied to each feeding element121. The antenna device120C is an antenna device capable of radiating radio waves in two different frequency bands in two different polarization directions.

As inFIG.13, each of the parasitic elements122is arranged in a layer between the corresponding feeding element121and the ground electrode GND. Radio frequency signals from each RFIC are transmitted to the corresponding feeding elements after passing through feeding wiring lines that penetrate through the parasitic elements122and reach each of the feeding elements.

The antenna module100E includes the RFICs110C1and110C3for supplying radio frequency signals in a low frequency band and the RFICs110C2and110C4for supplying radio frequency signals in a high frequency band. The RFIC110C1and RFIC110C2are circuits for the radio frequency signals for the first polarization, and the RFIC110C3and the RFIC110C4are circuits for the radio frequency signals for the second polarization. Since the configurations of the RFICs are the same,FIG.14illustrates only the circuit configuration of the RFIC110C1and omits illustration of the circuit configurations of the RFICs110C2to110C4. Since the configuration of each RFIC is similar to that of the RFIC110inFIG.1, detailed description thereof will not be repeated.

The filter device108includes diplexers108A to108H. Each of the diplexers includes a low pass filter (any of filters108A1to108H1) that transmits the radio frequency signals in the low frequency band and a high pass filter (any of filters108A2to108H2) that transmits the radio frequency signals in the high frequency band. Each of the filters108A1to108H1is connected to a corresponding switch in the RFIC. Output of each of the diplexers108A to108H is connected to the corresponding feeding element121. All of the filters included in the diplexers108A to108H are resonant line-type filters.

FIG.15is a plan perspective view of the antenna module100E including two radiation elements. Referring toFIG.15, the antenna module100E includes, as radiation elements, the feeding elements1211and1212and the parasitic elements1221and1222. As inFIG.13in the third embodiment, in the dielectric substrate130, the parasitic element1221is arranged in the layer between the feeding element1211and the ground electrode GND, and the parasitic element1222is arranged in the layer between the feeding element1212and the ground electrode GND.

A radio frequency signal from a diplexer155A is supplied to the feeding point SP11of the feeding element1211, and a radio frequency signal from a diplexer155B is supplied to the feeding point SP12. Similarly, a radio frequency signal from a diplexer156A is supplied to the feeding point SP21of the feeding element1212, and a radio frequency signal from a diplexer156B is supplied to the feeding point SP22.

The diplexers155A,155B,156A, and156B inFIG.15correspond to the diplexers included in the filter device108inFIG.14. Each diplexer is arranged in a layer between the lower surface132of the dielectric substrate130and the ground electrode GND or in a layer between the parasitic element1221or1222and the ground electrode GND.

The diplexer155A and the diplexer156A are arranged so as to cross the virtual line CL1equidistant from the feeding element1211and the feeding element1212and are arranged side by side in a second direction (negative direction of the Y axis) orthogonal to a first direction (positive direction of the X axis) toward the feeding element1212from the feeding element1211.

The diplexer155B for polarization in the X-axis direction for the feeding element1211is arranged in the direction (negative direction of the X axis) opposite to the first direction with respect to the feeding point SP12in a region in the direction (positive direction of the Y axis) opposite to the second direction with respect to the center of the feeding element1211. On the other hand, the diplexer156B for polarization in the X-axis direction for the feeding element1212is arranged in a region in the first direction (positive direction of the X-axis) with respect to the center of the feeding element1212.

All of the diplexers155A,155B,156A, and156B can be arranged in the regions of the distance of λ/4 from the feeding elements1211and1212by arranging the diplexers in this manner, so that increase in the size of the antenna module in the array antenna can be suppressed.

Also in the fourth embodiment, the diplexers arranged between the feeding element1211and the feeding element1212may be the diplexers155B and156B or diplexers for different polarizations.

In the antenna module100E in the fourth embodiment, the dual band-type antenna module in which the feeding elements1211and1212and the parasitic elements1221and1222are stacked has been described. However, a dual band-type antenna module may be configured by using radiation elements in which two feeding elements are stacked by replacing the parasitic elements1221and1222with the feeding elements.

In the antenna module100E inFIG.15, the “feeding element1211” and the “parasitic element1221” correspond to the “first radiation element” in the present disclosure, and the “feeding element1212” and the “parasitic element1222” correspond to the “second radiation element” in the present disclosure. In addition, in the antenna module100E, the “diplexer155A” and the “diplexer156A” correspond to the “first filter” and the “second filter” in the present disclosure, respectively, and the “diplexer155B” and the “diplexer156B” correspond to the “third filter” and the “fourth filter” in the present disclosure, respectively.

Fifth Embodiment

In the above-described embodiments, the configuration has been described in which the radio frequency signal that has passed through each filter is supplied to one corresponding feeding element. A fifth embodiment describes a case where a radio frequency signal from each filter is supplied to a plurality of feeding elements.

FIG.16is a block diagram of a communication apparatus10D to which an antenna module100F according to the fifth embodiment is applied.

Referring toFIG.16, the communication apparatus10D includes the antenna module100F and the BBIC200. The antenna module100F includes an RFIC110D, an antenna device120D, and a filter device109.

The antenna device120D includes the plurality of feeding elements121as radiation elements. The antenna device120D is a dual polarization-type antenna device as in the second embodiment, and a radio frequency signal for first polarization and a radio frequency signal for second polarization are supplied from the RFIC110D to each feeding element121.

The RFIC110D includes switches181A to181D,183A to183D,187A, and187B, power amplifiers182AT to182DT, low noise amplifiers182AR to182DR, attenuators184A to184D, phase shifters185A to185D, signal multiplexers/demultiplexers186A and186B, mixers188A and188B, and amplifier circuits189A and189B. Among them, the configurations of the switches181A,181B,183A,183B, and187A, the power amplifiers182AT and182BT, the low noise amplifiers182AR and182BR, the attenuators184A and184B, the phase shifters185A and185B, the signal multiplexer/demultiplexer186A, the mixer188A, and the amplifier circuit189A are circuits for the radio frequency signals for the first polarization. In addition, the configurations of the switches181C,181D,183C,183D, and187B, the power amplifiers182CT and182DT, the low noise amplifiers182CR and182DR, the attenuators184C and184D, the phase shifters185C and185D, the signal multiplexer/demultiplexer186B, the mixer188B, and the amplifier circuit189B are circuits for the radio frequency signals for the second polarization.

When the radio frequency signal is transmitted, the switches181A to181D and183A to183D are switched to the side of the power amplifiers182AT to182DT, and the switches187A and187B are connected to transmission-side amplifiers of the amplifier circuits189A and189B. When the radio frequency signals are received, the switches181A to181D and183A to183D are switched to the side of the low noise amplifiers182AR to182DR, and the switches187A and187B are connected to reception-side amplifiers of the amplifier circuits189A and189B.

The filter device109includes filters109A to109D. The filters109A to109D are respectively connected to the switches181A to181D in the RFIC110D. Each of the filters109A to109D has a function of attenuating the radio frequency signals in a specific frequency band.

The signals transmitted from the BBIC200are amplified by the amplifier circuits189A and189B and up-converted by the mixers188A and188B. The transmission signals, which are up-converted radio frequency signals, are divided into two by the signal multiplexers/demultiplexers186A and186B, pass through corresponding signal paths, and are fed to the feeding elements121.

The radio frequency signal from the switch181A passes through the filter109A and is branched into two systems by a branch circuit210A to be supplied to the feeding element121A and the feeding element121B. The radio frequency signal from the switch181B passes through the filter109B and is branched into two systems by a branch circuit210B to be supplied to the feeding element121C and the feeding element121D. The radio frequency signal from the switch181C passes through the filter109C and is branched into two systems by a branch circuit210C to be supplied to the feeding element121A and the feeding element121B. The radio frequency signal from the switch181D passes through the filter109D and is branched into two systems by a branch circuit210D to be supplied to the feeding element121C and the feeding element121D.

The directivity of the antenna device120D can be adjusted by individually adjusting the phase shift degrees of the phase shifters185A to185D arranged on the respective signal paths.

In such an antenna module, one filter is provided for two feeding elements for each polarization.

FIG.17is a plan perspective view of the antenna module100F. Referring toFIG.17, the antenna module100F includes feeding elements1211to1214as radiation elements. Further, the antenna module100F includes filters1571,1572,1581, and1582. All of the filters1571,1572,1581, and1582are resonant line-type filters and correspond to the filters included in the filter device109inFIG.16.

The feeding elements1211to1214are two-dimensionally arrayed in 2×2. The feeding element1211and the feeding element1212form a sub antenna SA1arrayed in 1×2. Further, the feeding element1213and the feeding element1214form a sub antenna SA2arrayed in 1×2. That is, the array antenna has a configuration in which the sub antennas SA1and SA2are arranged adjacent to each other. Assuming that a direction (negative direction of the Y axis) toward the sub antenna SA2from the sub antenna SA1is a first direction, the feeding elements included in each sub antenna are arrayed in a second direction (X-axis direction) orthogonal to the first direction.

Each of the filter1571and the filter1581is connected to the feeding elements1211and1212included in the sub antenna SA1. The radio frequency signal that has passed through the filter1571is supplied to the feeding point SP11of the feeding element1211and the feeding point SP21of the feeding element1212. The radio frequency signal that has passed through the filter1581is supplied to the feeding point SP12of the feeding element1211and the feeding point SP22of the feeding element1212.

Each of the filter1572and the filter1582is connected to the feeding elements1213and1214included in the sub antenna SA2. The radio frequency signal that has passed through the filter1572is supplied to a feeding point SP31of the feeding element1213and a feeding point SP41of the feeding element1214. The radio frequency signal that has passed through the filter1582is supplied to a feeding point SP32of the feeding element1213and a feeding point SP42of the feeding element1214.

The feeding points SP11, SP21, SP31, and SP41are arranged at positions offset from the centers of the feeding elements in the negative direction of the Y axis. When the radio frequency signals are supplied to the feeding points SP11, SP21, SP31, and SP41, radio waves having the polarization direction being the Y-axis direction are radiated from each of the feeding elements. Further, the feeding points SP12, SP22, SP32, and SP42are arranged at positions offset from the centers of the feeding elements in the positive direction of the X axis. When the radio frequency signals are supplied to the feeding points SP12, SP22, SP32, and SP42, radio waves having the polarization direction being the X-axis direction are radiated from each of the feeding elements.

When the antenna module100F is viewed in plan from the normal direction, the filters1571and1572are arranged so as to cross a virtual line CL2equidistant from the feeding elements of the sub antenna SA1and the feeding elements of the sub antenna SA2. Further, the filter1571and the filter1572are arranged side by side in the second direction (X-axis direction) orthogonal to the first direction (negative direction of Y axis) toward the sub antenna SA2from the sub antenna SA1.

The filter1581for polarization in the X-axis direction for the feeding elements1211and1212is arranged between the feeding element1211and the feeding element1212. On the other hand, the filter1582for polarization in the X-axis direction for the feeding elements1213and1214is arranged between the feeding element1213and the feeding element1214.

As described above, all of the filters can be formed in the regions of the distance of λ/4 from the feeding elements included in the two sub antennas by arranging the filters corresponding to the adjacent sub antennas side by side in the direction orthogonal to the array direction of the sub antennas. Therefore, increase in the size of the antenna module in the array antenna can be suppressed.

In the antenna module100F inFIG.17, the “sub antenna SA1” and the “sub antenna SA2” correspond to a “first sub antenna” and a “second sub antenna” in the present disclosure, respectively. Further, the “filter1571” and the “filter1572” correspond to the “first filter” and the “second filter” in the present disclosure.

(First Modification)

In the antenna module according to each of the above-described embodiments, the configuration has been described in which the feeding elements and the ground electrode are formed in the dielectric substrate formed of a dielectric having a single dielectric constant. A first modification describes a configuration in which a dielectric substrate is formed of dielectric layers having different dielectric constants.

FIG.18is a side perspective view of an antenna module100G in the first modification. In the antenna module100G, the dielectric substrate130of the antenna module100illustrated inFIG.3is replaced by a dielectric substrate130A. InFIG.18, description of components overlapping with those inFIG.3will not be repeated.

Referring toFIG.18, the dielectric substrate130A of the antenna module100G is formed of a first dielectric1301and a second dielectric1302having different dielectric constants. The first dielectric1301includes an upper surface131A. More specifically, the second dielectric1302is made of a material having a dielectric constant higher than that of the first dielectric1301. The first dielectric1301is arranged above the second dielectric1302. The RFIC110is mounted on the lower surface of the second dielectric1302(that is, a lower surface132A of the dielectric substrate130A) with the solder bumps170interposed therebetween.

In the antenna module100G, the feeding elements1211and1212are formed in the first dielectric1301, and the ground electrode GND is formed in the second dielectric1302. The filters151and152are also formed in the second dielectric1302. In the example ofFIG.18, the ground electrode GND is arranged at the boundary between the first dielectric1301and the second dielectric1302. The ground electrode GND may be arranged in an inner layer of the second dielectric1302.

In general, in order to broaden the frequency bandwidth of radio waves that are radiated from the feeding elements, it is preferable that the dielectric constant between the feeding elements and the ground electrode be lowered. On the other hand, in order to increase Q values of the filters, it is preferable that the dielectric constant of the dielectric in which the filters are formed be increased. As described above, antenna characteristics and filter characteristics may have a trade-off relationship for the dielectric constant. Therefore, when the dielectric substrate is formed of a dielectric having a single dielectric constant, the dielectric constant is not necessarily suitable for the two characteristics in some cases.

In the antenna module100G in the first modification, the dielectric (first dielectric1301) between the feeding elements1211and1212and the ground electrode GND is formed of the dielectric having the relatively low dielectric constant. Further, the dielectric (second dielectric1302) below the ground electrode GND in which the filters151and152are formed is formed of the dielectric having the higher dielectric constant than that of the first dielectric1301. Thus, it is possible to improve both the antenna characteristics and the filter characteristics by forming the dielectric substrate using two dielectric layers having different dielectric constants and making the dielectric constant of the dielectric in which the filters are formed higher than the dielectric constant of the dielectric formed between the feeding elements and the ground electrode.

(Second Modification)

In the antenna module according to each of the above-described embodiments, the configuration that the feeding elements and the ground electrode are formed in the same dielectric substrate has been described. A second modification describes a configuration in which feeding elements and a ground electrode are formed in different dielectric substrates separated from each other.

FIG.19is a side perspective view of an antenna module100H in the second modification. In the antenna module100H, the dielectric substrate130of the antenna module100illustrated inFIG.3is replaced by two dielectric substrates130B and130C separated from each other. The dielectric substrate130C includes an upper surface131C. InFIG.19, description of components overlapping with those inFIG.3will not be repeated.

Referring toFIG.19, the feeding element1211and the feeding element1212are formed in the dielectric substrate130B in the antenna module100H. On the other hand, the ground electrode GND and the filters151and152are formed in the dielectric substrate130C separated from the dielectric substrate130B. The RFIC110is mounted on a lower surface132C of the dielectric substrate130C with the solder bumps170interposed therebetween.

The dielectric substrate130B and the dielectric substrate130C are connected by a connection member. Although solder bumps171and172are used as the connection member in the example ofFIG.19, the connection member may be a flexible cable or a connector.

The feeding wiring141electrically connects the filter151and the feeding element1211with the solder bump171interposed therebetween. Similarly, the feeding wiring142electrically connects the filter152and the feeding element1212with the solder bump172interposed therebetween. When the dielectric substrate130C is viewed in plan from the normal direction, each of the filters151and152is arranged between the solder bump171and the solder bump172so as to cross the virtual line CL1equidistant from the solder bumps171and172.

As described above, the feeding elements can be flexibly arranged in the communication apparatus by separating the dielectric substrate in which the feeding elements are formed from the dielectric substrate in which the ground electrode and the filters are formed.

In addition, as in the first modification described above, both the antenna characteristics and the filter characteristics can also be improved by relatively decreasing the dielectric constant of the dielectric substrate in which the feeding elements are formed and relatively increasing the dielectric constant of the dielectric substrate in which the ground electrode and the filters are formed.

The “dielectric substrate130C” in the second modification corresponds to a “circuit substrate” in the present disclosure. The “solder bump171” and the “solder bump172” in the second modification correspond to a “first terminal” and a “second terminal” of the present disclosure, respectively.

Sixth Embodiment

In the above-described embodiments, the configuration has been described in which the filters are formed on the feeding wiring extending from the RFIC to the radiation elements in the antenna device. A sixth embodiment describes a configuration in which filters are formed on paths before signal branching in the RFIC.

FIG.20is a block diagram of a communication apparatus10E to which an antenna module100I according to the sixth embodiment is applied. Referring toFIG.20, the communication apparatus10E includes the antenna module100I and the BBIC200. The antenna module100I includes an RFIC110E, the antenna device120A, and filters105X and105Y.

The antenna device120A is a dual polarization-type antenna device similarly to the antenna module100C illustrated inFIG.8, and a radio frequency signal for first polarization and a radio frequency signal for second polarization are supplied from the RFIC110I to each of the feeding elements1211and1212.

In the antenna module100C (FIG.8) in the second embodiment, the radio frequency signals from the RFIC110A are transmitted to the antenna device120A after passing through the filter device106. In the antenna module100I in the sixth embodiment, the RFIC110E and the antenna device120A are directly connected to each other by feeding wiring, and each of the filters105X and105Y is connected between the signal multiplexer/demultiplexer and the switch in the RFIC110E. To be more specific, the filter105X is a filter for the first polarization and is connected between the signal multiplexer/demultiplexer116A and the switch117A. The filter105Y is a filter for the second polarization and is connected between the signal multiplexer/demultiplexer116B and the switch117B. The filters105X and105Y are arranged outside the RFIC110E. Specifically, they are formed inside the antenna device120A as will be described later with reference toFIGS.21and22. Other components constituting the RFIC110E are similar to those of the RFIC110A inFIG.8, and overlapping description of the components will not be repeated.

FIGS.21and22illustrate a detailed configuration of the antenna module100I inFIG.20.FIG.21is a plan perspective view of the antenna module100I.FIG.22is a side perspective view of the antenna module100I. In the plan view ofFIG.21, the dielectric of the dielectric substrate130and the ground electrode GND are omitted for ease of description.

Referring toFIGS.21and22, the antenna module100I is an array antenna in which the two feeding elements1211and1212are arrayed in the X-axis direction, similarly to the antenna module100C illustrated inFIG.9. The feeding elements1211and1212are arranged on the upper surface131of the dielectric substrate130or in an internal layer thereof. In the dielectric substrate130, the ground electrode GND having a flat plate shape is arranged in a layer closer to the lower surface132than the feeding elements1211and1212so as to face the feeding elements1211and1212. The RFIC110is mounted on the lower surface132of the dielectric substrate130with the solder bumps170interposed therebetween.

In the dielectric substrate130, the filters105X and105Y are arranged on the lower surface132side of the ground electrode GND. The filter105X is connected to the RFIC110by connection wiring1611and connection wiring1612. Further, the filter105Y is connected to the RFIC110by connection wiring1621and connection wiring1622. When the antenna module100I is viewed in plan from the normal direction, each of the filters105X and105Y is arranged so as to cross the virtual line CL1equidistant from the feeding element1211and the feeding element1212. The filters105X and105Y are arranged side by side in the Y-axis direction.

The feeding points SP11and SP12of the feeding element1211are directly connected to the RFIC110E by feeding wiring141Y and feeding wiring141X, respectively. When a radio frequency signal is supplied to the feeding point SP12, radio waves having the polarization direction being the X-axis direction are radiated from the feeding element1211. When a radio frequency signal is supplied to the feeding point SP11, radio waves having the polarization direction being the Y-axis direction are radiated from the feeding element1211.

Similarly, the feeding points SP21and SP22of the feeding element1212are directly connected to the RFIC110E by feeding wiring142Y and feeding wiring142X, respectively. When a radio frequency signal is supplied to the feeding point SP22, radio waves having the polarization direction being the X-axis direction are radiated from the feeding element1212. When a radio frequency signal is supplied to the feeding point SP21, radio waves having the polarization direction being the Y-axis direction are radiated from the feeding element1212.

The filter105X is a filter device for radio waves having the polarization direction being the X-axis direction in the feeding elements1211and1212. The radio frequency signal that has passed through the filter105X is supplied to the feeding point SP12of the feeding element1211and the feeding point SP22of the feeding element1212. The filter105Y is a filter device for radio waves having the polarization direction being the Y-axis direction in the feeding elements1211and1212. The radio frequency signal that has passed through the filter105Y is supplied to the feeding point SP11of the feeding element1211and the feeding point SP21of the feeding element1212.

It is possible to reduce the number of filters formed in the antenna module by adopting the configuration in which common filters are provided for the circuits in the respective polarization directions as in the antenna module100I. Therefore, further miniaturization of the whole antenna module can be realized. Further, increase in the size of the antenna module can be suppressed by arranging the filters so as to cross the virtual line equidistant from two adjacent feeding elements.

In the sixth embodiment, the “feeding element1211” and the “feeding element1212” correspond to the “first radiation element” and the “second radiation element” in the present disclosure, respectively, and the “filter105X” and the “filter105Y” correspond to the “first filter” and the “second filter” in the present disclosure, respectively. The “X-axis direction” and the “Y-axis direction” in the sixth embodiment correspond to a “first direction” and a “second direction” in the present disclosure, respectively. In the sixth embodiment, the “feeding point SP11” and the “feeding point SP21” correspond to a “first feeding point” in the present disclosure, and the “feeding point SP12” and the “feeding point SP22” correspond to a “second feeding point” in the present disclosure.

It should be considered that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present disclosure is defined not by description of the above-described embodiments but by the scope of the claims and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

REFERENCE SIGNS LIST

10AND10A to10E COMMUNICATION APPARATUSSP1, SP1A, SP1B, SP2, SP2A, SP2B, SP11, SP12, SP21, SP22, SP31, SP32, SP41, AND SP42FEEDING POINT100AND100A to100I ANTENNA MODULE105,106,107,108, AND109FILTER DEVICE105A TO105D,105X,105Y,106A TO106H,107A1TO107D1,107A2TO107D2,108A1,108A2,108H1,108H2,109A TO109D,150,150A,150B,151,151A,151B,152,152A,152B,156B,1511,1512,1521,1522,1571,1572,1581, AND1582FILTER107A to107D,108A to108H,155, AND156DIPLEXER111,113,117,181,183, AND187SWITCH110AND110A TO110E RFIC112AR TO112HR AND182AR TO182DR LOW NOISE AMPLIFIER112AT to112HT AND182AT to182DT POWER AMPLIFIER114AND184ATTENUATOR115AND185PHASE SHIFTER116AND186SIGNAL MULTIPLEXER/DEMULTIPLEXER118AND188MIXER119AND189AMPLIFIER CIRCUIT120ANTENNA DEVICE121FEEDING ELEMENT122PARASITIC ELEMENT130AND130A TO130C DIELECTRIC SUBSTRATE1301AND1302DIELECTRIC141AND142FEEDING WIRING161,162,1611,1612,1621, AND1622CONNECTION WIRING170to172SOLDER BUMP191,192,1503,1505,1506, AND1508LINE210BRANCH CIRCUIT1501INPUT TERMINAL1502OUTPUT TERMINAL1504AND1507VIA200BBICGND GROUND ELECTRODESA1AND SA2SUB ANTENNA