Antenna module and communication device equipped with same

Abstract

An antenna module (100) comprises: a dielectric substrate (130); radiation elements (121) that are arranged in a row on the dielectric substrate (130); and phase shift circuits (115A–115D). The phase shift circuits adjust the phases of high-frequency signals that are supplied to the radiation elements (121). Each phase shift circuit includes N phase shifters that are connected in series. When the resolution, which is the minimum variation of the phase difference between mutually adjacent radiation elements, is denoted by R, the maximum phase difference between mutually adjacent radiation elements is R×(2N / 2). The maximum phase difference between the phase shift circuit (115A) and the phase shift circuit (115D) is R×(2N / 2)×3. Each of the phase shift circuits (115A, 115D) can be set to each R×3 with respect to a settable range of R×(2N / 2)×3. Each of the phase shift circuits (115B, 115C) can be set to each R with respect to a settable range of R×(2N / 2).

Description

Antenna module and communication device equipped with same

[0001] The present disclosure relates to an antenna module and a communication device equipped with the same, and more particularly to a technique for miniaturizing an array antenna capable of beamforming.

[0002] International Publication No. 2021 / 131285 (Patent Document 1) discloses an array antenna in which a plurality of radiating elements are arranged on a dielectric substrate, and a phase shifter is arranged in a signal path for each radiating element. In the array antenna of International Publication No. 2021 / 131285 (Patent Document 1), beamforming that changes the directivity of the entire array antenna is possible by individually adjusting the phase angle of each phase shifter.

[0003] International Publication No. 2021 / 131285

[0004] Such an array antenna may be used in a mobile terminal such as a mobile phone or a smartphone.

[0005] When communicating between a base station and a terminal, beamforming can be used to align the radiation direction and reception direction of radio waves (beams) between the base station and the terminal, thereby improving communication quality by increasing reception strength and / or improving the S / N ratio, and reducing losses within the equipment. In this case, to easily align the radiation direction and reception direction, it is necessary to be able to finely set the azimuth angle of the beam. The azimuth angle of the beam can be set more precisely by finely adjusting the unit phase amount, i.e., the resolution, of the phase shift circuit arranged in the signal path.

[0006] A conventional method for increasing the resolution of a phase shift circuit is to configure the phase shift circuit using multiple stages of phase shifters connected in series, but increasing the number of stages of the phase shifters increases the area required to form the phase shift circuit on the substrate, which leads to an increase in the overall size of the array antenna.

[0007] As mentioned above, array antennas are sometimes used in mobile terminals, but there is still a strong demand for smaller and thinner mobile terminals, and this demand also requires smaller array antennas themselves. Therefore, if the dimensions of the array antenna increase in order to improve the resolution of the phase shift circuit, this can become a factor that hinders the miniaturization of mobile terminals.

[0008] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to subdivide the setting of the azimuth angle of a beam in an antenna module capable of beamforming while suppressing an increase in device dimensions.

[0009] The antenna module according to the present disclosure comprises a dielectric substrate, first to fourth radiating elements arranged in a row on the dielectric substrate, and first to fourth phase shift circuits. The first to fourth phase shift circuits are configured to adjust the phase of high frequency signals supplied to the first to fourth radiating elements, respectively. Each of the first to fourth phase shift circuits includes N phase shifters connected in series. If the resolution, which is the minimum amount of variation in the phase difference between adjacent radiating elements, is R, the maximum phase difference between adjacent radiating elements is R×(2 Ｎ The maximum phase difference between the first and fourth phase shift circuits is R×(2 Ｎ / 2)×3. Each of the first and fourth phase shift circuits has a phase ratio of R×(2 Ｎ Each of the second and third phase shift circuits can be set in increments of R×3 within a settable range of R×(2 / 2). Ｎ / 2), it can be set for each R.

[0010] In the antenna module according to the present disclosure, by devising a combination of phase settings of the phase shifters, it is possible to achieve a conventional level of resolution with fewer stages of phase shifters than in the past. Therefore, in an antenna module capable of beamforming, it is possible to finely set the azimuth angle of the beam while suppressing an increase in the device size.

[0011] 11 is a block diagram of a communication device equipped with an antenna module according to a first embodiment. FIG. 12 is a diagram for explaining the configuration of a phase shift circuit in FIG. 1. FIG. 13 is a diagram showing an example of the circuit configuration of a phase shifter included in the phase shift circuit. FIG. 14 is a diagram for explaining a phase difference between adjacent radiating elements in beamforming. FIG. 15 is a diagram for explaining an example of the configuration of each phase shifter in the antenna module according to the first embodiment. FIG. 16 is a diagram for explaining the setting of a phase shift circuit for realizing the azimuth angle of a beam in the case of FIG. 5. FIG. 17 is a diagram for explaining the configuration of each phase shifter in an antenna module of a comparative example. FIG. 18 is a diagram for explaining the setting of a phase shift circuit for realizing the azimuth angle of a beam in the case of FIG. 7. FIG. 19 is a diagram for explaining the configuration of each phase shifter in an antenna module of a first modification. FIG. 19 is a diagram for explaining the setting of a phase shift circuit for realizing the azimuth angle of a beam in the case of FIG. 16. FIG. 19 is a diagram for explaining the configuration of each phase shifter in an antenna module of a second modification. FIG. 20 is a diagram for explaining the setting of a phase shift circuit for realizing the azimuth angle of a beam in the case of FIG. 22. FIG. 23 is a diagram for explaining the setting of a phase shift circuit for realizing the azimuth angle of a beam in the case of FIG. 23.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0013] [First Embodiment] (Basic Configuration of Communication Device) Fig. 1 is an example of a block diagram of a communication device 10 according to a first embodiment. The communication device 10 is, for example, a mobile terminal such as a mobile phone, a smartphone, or a tablet, a personal computer with a communication function, or a base station. An example of the frequency band of radio waves used in the antenna module 100 according to the first embodiment is millimeter-wave radio waves with center frequencies of 28 GHz, 39 GHz, and 60 GHz, for example, but radio waves in other frequency bands are also applicable.

[0014] 1 , a communication device 10 includes an antenna module 100 and a BBIC 200 that constitutes a baseband signal processing circuit. The antenna module 100 includes an RFIC 110, which is an example of a power supply circuit, and an antenna device 120. The communication device 10 upconverts a signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal and radiates the signal from the antenna device 120, and downconverts the high-frequency signal received by the antenna device 120 and processes the signal in the BBIC 200.

[0015] The antenna device 120 of the first embodiment is an array antenna in which a plurality of radiating elements 121 are arranged on a dielectric substrate 130. For ease of explanation, Fig. 1 shows an example of a one-dimensional array in which four radiating elements 121 are arranged in a line on the dielectric substrate 130. Note that the antenna device 120 may also be an array antenna in which a plurality of radiating elements 121 are arranged in a two-dimensional array. In the first embodiment, the radiating element 121 is described as a patch antenna having a substantially square plate shape, but the shape of the radiating element 121 may also be a circle, an ellipse, or another polygon such as a hexagon.

[0016] The RFIC 110 includes switches 111A to 111D, 113A to 113D, and 117, power amplifiers 112AT to 112DT, low-noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase-shift circuits 115A to 115D, a signal combiner / demultiplexer 116, a mixer 118, and an amplifier circuit 119.

[0017] When transmitting a high frequency signal, the switches 111A to 111D and 113A to 113D are switched to the side of the power amplifiers 112AT to 112DT, and the switch 117 is connected to the transmitting amplifier of the amplifier circuit 119. When receiving a high frequency signal, the switches 111A to 111D and 113A to 113D are switched to the side of the low noise amplifiers 112AR to 112DR, and the switch 117 is connected to the receiving amplifier of the amplifier circuit 119.

[0018] The signal transmitted from the BBIC 200 is amplified by the amplifier circuit 119 and up-converted by the mixer 118. The up-converted high-frequency transmission signal is split into four by the signal combiner / splitter 116, passes through four signal paths (channels CH1 to CH4), and is fed to different radiating elements 121, respectively. At this time, the directivity of the antenna device 120 can be adjusted by individually adjusting the phase shift degree of the phase shift circuits 115A to 115D arranged in each signal path. Furthermore, the attenuators 114A to 114D adjust the strength of the transmission signal.

[0019] The received signals, which are high-frequency signals received by the radiating elements 121, are respectively passed through four different signal paths CH1 to CH4 and combined by the signal combiner / demultiplexer 116. The combined received signal is down-converted by the mixer 118, amplified by the amplifier circuit 119, and transmitted to the BBIC 200.

[0020] The RFIC 110 is formed as, for example, a one-chip integrated circuit component including the above circuit configuration. Alternatively, the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shift circuits) corresponding to each radiating element 121 in the RFIC 110 may be formed as one-chip integrated circuit components for each corresponding radiating element 121.

[0021] (Configuration of Phase Shift Circuit) FIG. 2 is a diagram illustrating the configuration of phase shift circuits 115A to 115D in FIG. 1. Each phase shift circuit is composed of multiple phase shifters connected in series. In the example of FIG. 2, each phase shift circuit includes four phase shifters. For example, channel CH1 includes phase shifters PS11 to PS14, channel CH2 includes phase shifters PS21 to PS24, channel CH3 includes phase shifters PS31 to PS34, and channel CH4 includes phase shifters PS41 to PS44.

[0022] Each phase shifter is configured to be able to switch between two phases, as shown in Fig. 3. In the phase shifter PS of the example of Fig. 3, two paths RT1 and RT2 are switched by a switch SW1 connected to the input terminal in and a switch SW2 connected to the output terminal out.

[0023] The path RT1 includes capacitors C11 and C12 connected in series between the switches SW1 and SW2 and a shunt inductor L11 connected to the connection node of these capacitors. The path RT2 includes an inductor L21 connected between the switches SW1 and SW2, a shunt capacitor C21 connected to one end of the inductor L21, and a shunt capacitor C22 connected to the other end of the inductor L21.

[0024] When the switches SW1 and SW2 are used to switch to route RT1, the phase advances, and when the switches SW1 and SW2 are used to switch to route RT2, the phase delays. The amount of phase change can be adjusted by adjusting the capacitance value of the capacitor and the inductance value of the inductor of each route.

[0025] The configuration of the phase shifter PS shown in Figure 3 is merely an example, and other circuits may be formed in each path as long as the phase of one path is set to lead or lag relative to the other path. For example, both paths RT1 and RT2 may include circuits that lag the phase, and the phase of path RT2 may be set to lag further than the phase of path RT1. In this case, each phase can be set simply by adjusting the path lengths of paths RT1 and RT2 without using elements such as inductors and capacitors, thereby simplifying the circuit configuration of the phase shifter PS.

[0026] (Explanation of Beamforming) Next, the phase difference between adjacent radiating elements when beamforming is performed will be explained using Fig. 4. Referring to Fig. 4, consider a case in which, in a one-dimensional array antenna device 120 in which four radiating elements 121 are arranged in a row in the X-axis direction as shown in Fig. 1, the inter-element distance is d, and beamforming of a main beam is performed at an azimuth angle of θ from the normal direction (Z-axis direction) of the dielectric substrate 130.

[0027] At this time, by sequentially delaying the phase of the radio waves radiated from radiating element 121-1 in the positive direction of the X-axis, a main beam is radiated at an azimuth angle of θ. For example, the wavefronts of the same phase as a certain wavefront W11 of the radio waves radiated from radiating element 121-1 are wavefront W12 for radiating element 121-2 and wavefront W13 for radiating element 121-3. Therefore, if an equiphase surface tangent to these in-phase wavefronts is designated S10, the radio waves propagate in a direction perpendicular to the equiphase surface S10. Similarly, for wavefronts that advance one wavelength λ from the equiphase surface S10, an equiphase surface S20 is formed by the wavefront W22 of the radio waves from radiating element 121-2, the wavefront W23 of the radio waves from radiating element 121-3, the wavefront W24 of the radio waves from radiating element 121-4, etc. For wavefronts that advance further by one wavelength λ, an equiphase surface S30 is formed by the wavefront W33 of the radio waves from radiating element 121-3, etc.

[0028] If the phase difference between adjacent elements is δ, the relationship of the following equation (1) holds: λ(δ / 2π)=d·sin θ (1) Therefore, the phase difference δ can be calculated from equation (1) as follows:

[0029] δ=(2π / λ)·d·sin θ (2) Generally, the inter-element distance d is often set to λ / 2, so when d=λ / 2, equation (2) is transformed into equation (3).

[0030] δ=π·sin θ (3) That is, the azimuth angle θ of the main beam can be set by adjusting the phase difference δ between adjacent elements. Therefore, for example, when the phase difference δ between adjacent elements is 90° (=π / 2), the azimuth angle θ of the main beam is 30°.

[0031] Fig. 5 is a diagram illustrating an example of the configuration of each phase shifter in the antenna module 100 according to the first embodiment. In the example of Fig. 5, each of the phase shift circuits 115A to 115D is configured with three phase shifters. Fig. 5 shows the phase angles that can be set by each phase shifter.

[0032] In the phase shift circuit 115A, the phase shifter PS11 is configured to be switchable between a phase of 0° and 67.5°, the phase shifter PS12 is switchable between a phase of −67.5° and 0°, and the phase shifter PS13 is switchable between a phase of −67.5° and 67.5°.

[0033] In the phase shift circuit 115B, the phase shifter PS21 is configured to be switchable between a phase of 0° and 22.5°, the phase shifter PS22 is switchable between a phase of −22.5° and 22.5°, and the phase shifter PS23 is switchable between a phase of −45.0° and 22.5°.

[0034] In the phase shift circuit 115C, the phase shifter PS31 is configured to be switchable between a phase of 0° and 22.5°, the phase shifter PS32 is switchable between a phase of −22.5° and 22.5°, and the phase shifter PS33 is switchable between a phase of −45.0° and 22.5°.

[0035] In the phase shift circuit 115D, the phase shifter PS41 is configured to be switchable between a phase of 0° and 67.5°, the phase shifter PS42 is switchable between a phase of −67.5° and 0°, and the phase shifter PS43 is switchable between a phase of −67.5° and 67.5°.

[0036] In each phase shift circuit, the phase of the three phase shifters can be appropriately switched to adjust the phase of the phase shift circuit.

[0037] Fig. 6 is a diagram for explaining the settings of the phase shift circuits for realizing the beam azimuth angle in the case of Fig. 5. As explained in Fig. 4, the beam azimuth angle θ can be adjusted by the phase difference δ between adjacent elements. Fig. 6 shows the phases achieved by the phase shift circuits of each channel when the phase difference between predetermined channels is changed from -90° to 90° in increments (resolution) of 22.5°.

[0038] For example, when the phase difference between channels is set to 90°, the phases of channels CH1 to CH4 are set to −135°, −45°, 45°, and 135°, respectively.

[0039] More specifically, in the phase shift circuit 115A of channel CH1, the phase shifter PS11 is set to 0°, and the phase shifters PS12 and PS13 are set to −67.5°. In the phase shift circuit 115B of channel CH2, the phase shifter PS21 is set to 22.5°, the phase shifter PS22 is set to −22.5°, and the phase shifter PS23 is set to −45°.

[0040] In the phase shift circuit 115C of channel CH3, the phase shifter PS31 is set to 0°, and the phase shifters PS32 and PS33 are set to 22.5°. In the phase shift circuit 115D of channel CH4, the phase shifters PS41 and PS43 are set to 67.5°, and the phase shifter PS42 is set to 0°.

[0041] FIG. 7 is a diagram for explaining the configuration of each phase shifter in a comparative example of a conventional antenna module.

[0042] In the antenna module of the comparative example, each of the phase shift circuits 115A to 115D has the same configuration including four stages of phase shifters. More specifically, the first-stage phase shifters PS11, PS21, PS31, and PS41 are all switchable between phases of 0° and 22.5°. The second-stage phase shifters PS12, PS22, PS32, and PS42 are all switchable between phases of 0° and 45°. The third-stage phase shifters PS13, PS23, PS33, and PS43 are all switchable between phases of 0° and 90°. The fourth-stage phase shifters PS14, PS24, PS34, and PS44 are all switchable between phases of 0° and 180°.

[0043] Fig. 8 is a diagram for explaining the settings of the phase shift circuits 115A and 115D for realizing the azimuth angles of the beams in the case of Fig. 7. As shown in the diagram, in the antenna module of the comparative example, the inter-channel phase difference can be set from -180° to 180° with a resolution of 22.5°.

[0044] When each phase-shift circuit has the same configuration as in the comparative example, if the resolution of the inter-channel phase difference is to be finer, it is necessary to increase the number of stages of the phase shifter in each phase-shift circuit. For example, if the inter-channel phase difference is to be changed with a resolution of 22.5°, four stages of phase shifters are required in each phase-shift circuit. However, increasing the number of stages of the phase shifter increases the area of ​​the phase shifter within the RFIC, which leads to an increase in the overall dimensions of the array antenna. This can be an obstacle to the demand for further miniaturization of the device.

[0045] In the antenna module 100 of embodiment 1 described in Figures 5 and 6, by differentiating the settings of the phase shifters in the phase shift circuit for each channel, the same resolution as when using the four-stage phase shift circuit of the comparative example is achieved with a three-stage phase shift circuit.

[0046] In the antenna module 100 of the first embodiment, the phase difference between adjacent elements, i.e., the phase difference between channels, is a maximum of 90°, which is smaller than the maximum phase difference of 180° in the comparative example. In other words, in the antenna module 100, the maximum azimuth angle θ of the beam is narrower than in the antenna module of the comparative example. Specifically, in the antenna module 100 of the first embodiment, θ = ±30°, and in the comparative example, θ = ±90°.

[0047] However, in practice, beams are rarely emitted when the azimuth angle θ is 90°, i.e., horizontally. Therefore, beamforming within a 60° range (θ = ±30°) often satisfies the specified coverage range. Therefore, by reducing the number of phase shifter stages constituting the phase shift circuit and appropriately configuring each phase shifter, as in the antenna module 100 of the first embodiment, the mounting area of ​​the RFIC 110 can be reduced, suppressing increases in device dimensions, while the azimuth angle of the beam can be subdivided to a level equivalent to that of a four-stage phase shift circuit. Furthermore, by reducing the number of phase shifter stages, losses in each signal path can be reduced.

[0048] The setting of the phase shift circuit in the first embodiment can be generalized as follows.

[0049] The number of phase shifters included in each phase shift circuit is N, and the minimum fluctuation width (resolution) of the phase difference between adjacent radiating elements is R. In this case, the maximum phase difference between adjacent radiating elements (inter-channel phase difference) is R×(2 Ｎ / 2), and the maximum phase difference between channel CH1 and channel CH4 can be expressed as R×(2 Ｎ / 2) × 3.

[0050] As in the above example, in the case of a three-stage configuration (N=3) and a resolution R=22.5°, the maximum inter-channel phase difference is 22.5°×(2 ３ / 2)=90°, and the maximum phase difference between channel CH1 and channel CH4 is 270°.

[0051] The phases of channels CH1 and CH4 are R×(2 Ｎ The phase of channels CH2 and CH3 can be expressed as R×(2 Ｎ / 2) can be set for each R.

[0052] 6, the phase of channels CH1 and CH4 can be set in a 270° range from −135° to 135° in increments of 67.5°, while the phase of channels CH2 and CH3 can be set in a 90° range from −45° to 45° in increments of 22.5°.

[0053] The "radiating element 121" in the first embodiment corresponds to the "first to fourth radiating elements" in the present disclosure. The "phase shift circuits 115A to 115D" in the first embodiment correspond to the "first to fourth phase shift circuits" in the present disclosure.

[0054] (Modification 1) In the antenna module 100 of the first embodiment, a case has been described in which a leading phase (negative phase) and a lagging phase (positive phase) are set in the phase shifter of the phase shift circuit.

[0055] In Modification 1, a configuration will be described in which the settings of each phase shifter are offset overall, and the phase that can be set by each phase shifter is set to a delay phase while maintaining the relative phase difference between channels. In this case, as explained in FIG. 3, there is an advantage in that the configuration of each phase shifter can be simplified.

[0056] Fig. 9 is a diagram for explaining the configuration of each phase shifter in the antenna module of Modification 1. Fig. 10 is a diagram for explaining the setting of the phase shift circuit for realizing the azimuth angle of the beam in the case of Fig. 9.

[0057] 9, in the antenna module of Modification 1, each of the phase shift circuits 115A to 115D has three stages of phase shifters connected in series, similar to the antenna module 100 of Embodiment 1. However, the second-stage phase shifters PS12, PS22, PS32, and PS42 and the third-stage phase shifters PS13, PS23, PS33, and PS43 in each phase shift circuit are set to be offset by +67.5° compared to the case of FIG.

[0058] Specifically, in the phase shift circuits 115A and 115D, the second-stage phase shifters PS12 and PS42 can be switched between phases of 0° and 67.5°, and the third-stage phase shifters PS13 and PS43 can be switched between phases of 0° and 135°. Similarly, in the phase shift circuits 115B and 115C, the second-stage phase shifters PS22 and PS32 can be switched between phases of 45° and 90°, and the third-stage phase shifters PS23 and PS33 can be switched between phases of 22.5° and 90°.

[0059] 10, the phase of each channel can be adjusted in the delay direction, and the channel phase difference can be set with the same resolution as that of the antenna module 100 of embodiment 1. Therefore, while each phase shifter has a simpler configuration, it is possible to suppress an increase in device size, subdivide the azimuth angle of the beam, and reduce loss in each signal path.

[0060] (Modification 2) In Modification 2, a configuration will be described in which the coverage range is expanded using a three-stage phase shift circuit similar to that of the first embodiment.

[0061] Fig. 11 is a diagram for explaining the configuration of each phase shifter in the antenna module of Modification 2. Fig. 12 is a diagram for explaining the setting of the phase shift circuit for realizing the azimuth angle of the beam in the case of Fig. 11.

[0062] 11 , in the antenna module of Modification 2, each of phase shift circuits 115A to 115D has three stages of phase shifters connected in series, similar to antenna module 100 of Embodiment 1. However, the settings of the phase shifters in each phase shift circuit are different.

[0063] Specifically, in the phase shift circuits 115A and 115D, the first-stage phase shifters PS11 and PS41 are switchable between phases of 0° and 90°, the second-stage phase shifters PS12 and PS42 are switchable between phases of −90° and 0°, and the third-stage phase shifters PS13 and PS43 are switchable between phases of −90° and 90°. Similarly, in the phase shift circuits 115B and 115C, the first-stage phase shifters PS21 and PS31 are switchable between phases of 0° and 30°, the second-stage phase shifters PS22 and PS32 are switchable between phases of −30° and 30°, and the third-stage phase shifters PS23 and PS33 are switchable between phases of −60° and 30°.

[0064] By making such settings, the phase difference between channels can be changed from −120° to 120° with a resolution of 30°, as shown in FIG. 12 . That is, in Modification 2, although the resolution is slightly coarser than in Embodiment 1, a coverage range of ±42° can be achieved for the azimuth angle θ. In this way, by appropriately changing the phase of each phase shifter according to the required resolution and coverage range, it is possible to suppress an increase in device size and reduce losses in each signal path while satisfying the required specifications.

[0065] Note that if the resolution value is increased, it becomes difficult to match the beam emission direction and reception direction between the base station and the terminal, so it is desirable to set the resolution to a maximum of about 45°.

[0066] Second Embodiment In the first embodiment, a circuit configuration has been described in which a phase shift circuit conventionally configured with four-stage phase shifters is realized with a three-stage configuration with the same resolution.

[0067] In the second embodiment, a circuit configuration will be described in which a phase shift circuit having a four-stage configuration is realized instead of the conventional five-stage configuration in order to further subdivide the resolution.

[0068] Fig. 13 is a diagram for explaining an example of the configuration of each phase shifter in the antenna module according to embodiment 2. Fig. 14 is a diagram for explaining the setting of the phase shift circuit for realizing the azimuth angle of the beam in the case of Fig. 13.

[0069] In the antenna module of embodiment 2, the resolution of the inter-channel phase difference is set to 11.25°, half that of embodiment 1, and each phase shift circuit 115A to 115D is composed of four phase shifters connected in series.

[0070] In the phase shift circuit 115A, the phase shifter PS11 is configured to be switchable between a phase of 0° and 33.75°. The phase shifter PS12 is switchable between a phase of −33.75° and 0°. The phase shifter PS13 is switchable between a phase of −33.75° and 33.75°, and the phase shifter PS14 is switchable between a phase of −67.5° and 67.5°.

[0071] In the phase shift circuit 115B, the phase shifter PS21 is configured to be switchable between a phase of 0° and 11.25°. The phase shifter PS22 is switchable between a phase of −11.25° and 11.25°. The phase shifter PS23 is switchable between a phase of −22.5° and 11.25°, and the phase shifter PS24 is switchable between a phase of −33.75° and 33.75°.

[0072] In the phase shift circuit 115C, the phase shifter PS31 is configured to be switchable between a phase of 0° and 11.25°. The phase shifter PS32 is switchable between a phase of −11.25° and 11.25°. The phase shifter PS33 is switchable between a phase of −22.5° and 22.5°, and the phase shifter PS34 is switchable between a phase of −33.75° and 22.5°.

[0073] In the phase shift circuit 115D, the phase shifter PS41 is configured to be switchable between a phase of 0° and 33.75°. The phase shifter PS42 is switchable between a phase of −33.75° and 0°. The phase shifter PS43 is switchable between a phase of −33.75° and 33.75°, and the phase shifter PS44 is switchable between a phase of −67.5° and 67.5°.

[0074] By setting each phase shifter as described above, the inter-channel phase difference can be changed in a range of -90° to 90° with a resolution of 11.25°. As shown in Figure 14, for channels CH1 and CH4, the phase can be set in increments of 33.75° within a settable range of 270° (-135° to 135°). For channels CH2 and CH3, the phase can be set in increments of 11.25° within a settable range of 90° (-45° to 45°).

[0075] In other words, in a four-stage configuration (N=4) with a resolution of R=11.25°, the maximum phase difference between channels is 11.25°×(2 ４ / 2)=90°, and the maximum phase difference between channel CH1 and channel CH4 is 11.25°×(2 ４ / 2) × 3 = 270°. The settable range of the phase of channels CH1 and CH4 is 270°, from -135° to 135°, and can be set in increments of 33.75°. The settable range of the phase of channels CH2 and CH3 is 90°, from -45° to 45°, and can be set in increments of 11.25°.

[0076] In this way, the resolution of 11.25°, which was conventionally achieved by a five-stage phase shift circuit, can be achieved by a four-stage phase shift circuit in embodiment 2. Therefore, it is possible to suppress an increase in device size, to subdivide the azimuth angle of the beam, and to reduce loss in each signal path.

[0077] Aspects It will be understood by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0078] (Item 1) An antenna module according to one aspect comprises a dielectric substrate, first to fourth radiating elements arranged in a row on the dielectric substrate, and first to fourth phase shift circuits. The first to fourth phase shift circuits are configured to adjust the phase of a high frequency signal supplied to the first to fourth radiating elements, respectively. Each of the first to fourth phase shift circuits includes N phase shifters connected in series. If the resolution, which is the minimum amount of variation in the phase difference between adjacent radiating elements, is R, the maximum phase difference between adjacent radiating elements is R×(2 Ｎ The maximum phase difference between the first and fourth phase shift circuits is R×(2 Ｎ / 2)×3. Each of the first and fourth phase shift circuits has a phase ratio of R×(2 Ｎ Each of the second and third phase shift circuits can be set in increments of R×3 within a settable range of R×(2 Ｎ / 2), it can be set for each R.

[0079] (Item 2) In the antenna module described in item 1, the maximum resolution is 45°.

[0080] (Item 3) In the antenna module described in item 2, the resolution is either 11.25°, 22.5° or 30°.

[0081] (4) In the antenna module described in any one of paragraphs 1 to 3, the number of phase shifters included in each of the first to fourth phase shift circuits is three or four.

[0082] (Item 5) In the antenna module described in any one of items 1 to 4, the minimum phase in the first phase shift circuit and the fourth phase shift circuit is 0°.

[0083] (Item 6) In the antenna module according to any one of items 1 to 5, each phase shifter is configured to be able to switch between two phases.

[0084] (7) A communication device equipped with the antenna module according to any one of the above items 1 to 6.

[0085] 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.

[0086] 10 Communication device, 100 Antenna module, 110 RFIC, 111A to 111D, 113A to 113D, 117, SW1, SW2 Switch, 112AR to 112DR Low noise amplifier, 112AT to 112DT Power amplifier, 114A to 114D Attenuator, 115A to 115D Phase shift circuit, 116 Signal combiner / brancher, 118 Mixer, 119 Amplifier circuit, 120 Antenna device, 121 Radiating element, 130 Dielectric substrate, 200 BBIC, C11, C12, C21, C22 Capacitor, CH1 to CH4 Channel, L11, L21 Inductor, PS, PS11 to PS14, PS21 to PS24, PS31 to PS34, to PS44 Phase shifter, RT1, RT2 Path, in: input terminal, out: output terminal.

Claims

1. A device comprising: a dielectric substrate; first to fourth radiating elements arranged in a row on the dielectric substrate; and first to fourth phase shift circuits configured to adjust the phases of high frequency signals supplied to the first to fourth radiating elements, respectively; each of the first to fourth phase shift circuits includes N phase shifters connected in series; and, assuming that a resolution, which is a minimum variation in the phase difference between adjacent radiating elements, is R, the maximum phase difference between adjacent radiating elements is R×(2 Ｎ / 2), and the maximum phase difference between the first phase shift circuit and the fourth phase shift circuit is R×(2 Ｎ / 2)×3, and each of the first phase shift circuit and the fourth phase shift circuit is R×(2 Ｎ Each of the second phase shift circuit and the third phase shift circuit can be set in increments of R×3 for a settable range of R×(2 Ｎ / 2) for each R of the settable range.

2. The antenna module according to claim 1, wherein the maximum value of the resolution is 45°.

3. The antenna module according to claim 2, wherein the resolution is either 11.25°, 22.5° or 30°.

4. The antenna module according to any one of claims 1 to 3, wherein the number of phase shifters included in each of the first phase shift circuit to the fourth phase shift circuit is three or four.

5. The antenna module according to any one of claims 1 to 4, wherein the minimum phase in the first phase shift circuit and the fourth phase shift circuit is 0°.

6. The antenna module according to any one of claims 1 to 5, wherein each phase shifter is configured to be able to switch between two phases.

7. A communication device equipped with the antenna module according to any one of claims 1 to 6.

Images