Wireless communications device, wireless communication method and method of generating output power correction coefficient

Abstract

The present invention provides a wireless communication device, which may include a controller configured to obtain a first output value of a first power detector after setting a first power amplifier to a first gain in a calibration mode, and to obtain a second output value of the first power detector after setting the first power amplifier to a second gain, wherein the controller can estimate the output power of a first antenna from the output value of the first power detector based on a correction coefficient calculated using the first output value and the second output value in a normal mode.

Description

Technical Field

[0001] The present disclosure is generally related to wireless communication, and more particularly, to an apparatus and method for estimating the output power of an array antenna. Cross - Reference to Related Applications

[0002] This application claims priority based on and claims the benefit of Korean Patent Application No. 10 - 2021 - 0162792, filed on November 23, 2021, and Korean Patent Application No. 10 - 2022 - 0069577, filed on June 8, 2022, with the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entireties. Prior Art

[0003] To increase the data transmission amount in wireless communication, an extended frequency band may be used, such that a wireless communication device may need the ability to process signals having high frequencies. For example, the allocation of 5th - generation (5G) millimeter - wave (mmWave) frequencies defined by the 3rd Generation Partnership Project (3GPP) includes high - frequency bands of 20 GHz or higher. However, signals having such high frequencies have high transmission losses in free space, thereby reducing the received power at the receiving device.

[0004] To alleviate this problem, an array antenna at the transmitting device may be used to increase the antenna gain and thereby compensate for the high transmission losses. However, there is a trade - off between the amount of output power at the transmitting device and power consumption / heat emission. Therefore, it is desirable to reduce the output power when a lower output power will satisfy a specific communication environment. For this purpose, it is desirable to accurately measure the output power dynamically. Summary of the Invention

[0005] Embodiments of the inventive concept provide an apparatus and method for accurately estimating the output power of an array antenna.

[0006] According to an aspect of the present invention concept, a wireless communication device is provided, including: an array antenna including a plurality of antennas; a plurality of power amplifiers including a first power amplifier configured to drive a first antenna among the plurality of antennas; a plurality of power detectors including a first power detector configured to detect the output power of the first power amplifier; and a controller configured to, in a calibration mode, obtain a first output value of the first power detector after setting the first power amplifier to a first gain and obtain a second output value of the first power detector after setting the first power amplifier to a second gain when the plurality of antennas are respectively driven by the plurality of power amplifiers, wherein the controller can estimate the output power of the first antenna from the output value of the first power detector based on a correction coefficient calculated using the first output value and the second output value in a normal mode.

[0007] According to another aspect of the present invention concept, a wireless communication method via an array antenna is provided. The wireless communication method includes: controlling a plurality of power amplifiers in a calibration mode such that a plurality of antennas included in the array antenna are driven; in the calibration mode, setting a first power amplifier that drives a first antenna among the plurality of antennas to a first gain and generating a first output value by detecting the output power of the first power amplifier; in the calibration mode, setting the first power amplifier to a second gain and generating a second output value by detecting the output power of the first power amplifier; in the normal mode, generating a third output value by detecting the output power of the first power amplifier; and in the normal mode, estimating the output power of the first antenna from the third output value based on a correction coefficient calculated using the first output value and the second output value.

[0008] According to another aspect of the present invention concept, a method for generating a correction coefficient for estimating the output power of an array antenna is provided. The method includes, in a calibration mode: driving a plurality of antennas included in an array antenna by a plurality of power amplifiers included in a device including the array antenna respectively; setting a first power amplifier among the plurality of power amplifiers to a first gain and a second gain respectively; obtaining a first output value and a second output value corresponding to the first gain and the second gain respectively by detecting the output power of the first power amplifier; obtaining a first measurement value and a second measurement value corresponding to the first gain and the second gain respectively by measuring the output power of the array antenna; calculating a correction coefficient based on the first output value, the second output value, the first measurement value, and the second measurement value; and storing the correction coefficient in the device.

[0009] According to another aspect, a wireless communication device includes: an array antenna including a plurality of antennas; a plurality of power amplifiers including a first power amplifier configured to drive a first antenna among the plurality of antennas; a plurality of power detectors including a first power detector configured to detect the output power of the first power amplifier; a memory; and a controller configured to perform operations of the wireless device in a normal mode during communication with a second wireless communication device. The operations include estimating the output power of the first antenna from an output value of the first power detector based on a correction coefficient stored in the memory, where the correction coefficient is a coefficient previously calculated using a first output value and a second output value of the first power detector, the first output value and the second output value being obtained in a calibration mode by setting the first power amplifier to a first gain and a second gain, respectively, while the plurality of antennas are driven by the plurality of power amplifiers, respectively. Brief Description of the Drawings

[0010] Embodiments of the inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a diagram illustrating a wireless communication system according to an example embodiment. FIG. 2 is a block diagram illustrating a user equipment according to an example embodiment. FIGS. 3A and 3B are diagrams each illustrating a method of obtaining a correction value for estimating the output power of an array antenna according to an example embodiment. FIG. 4 is a graph depicting example reflection coefficients of antenna elements in a single antenna element environment and an active array antenna environment. FIGS. 5A and 5B are diagrams each illustrating a radiation pattern of an array antenna according to an example embodiment. FIG. 6 is a flowchart illustrating a method of estimating the output power of an array antenna according to an example embodiment. FIGS. 7A and 7B are message diagrams each illustrating an example of a method of estimating the output power of an array antenna according to an example embodiment. FIG. 8 is a flowchart illustrating a method of estimating the output power of an array antenna according to an example embodiment. FIG. 9 is a diagram illustrating an example of a correction coefficient according to an example embodiment. FIG. 10 is a graph depicting an active modulation phenomenon according to an example embodiment. FIG. 11 is a diagram illustrating an example of a correction coefficient according to an example embodiment. FIG. 12 is a flowchart illustrating a method of estimating the output power of an array antenna according to an example embodiment. Embodiments

[0011] FIG. 1 is a diagram showing a wireless communication system 5 according to an example embodiment. Some examples of the wireless communication system 5 include cellular networks, such as 5th generation wireless (5G) systems, Long Term Evolution (LTE) systems, advanced LTE systems, Code Division Multiple Access (CDMA) systems, or Global System for Mobile Communications (GSM) systems, wireless personal area network (WPAN) systems. Hereinafter, although the description will mainly refer to a wireless communication system using a cellular network, it should be understood that the embodiments of the present inventive concept are not limited thereto and can be applied to any suitable wireless communication system.

[0012] The base station 1 generally may refer to a fixed station that communicates with a user equipment and / or another base station and can exchange data and control information by communicating with the user equipment and / or another base station. For example, the base station 1 may be referred to as a Node B, an evolved-Node B (eNB), a next generation Node B (gNB), a sector, a site, a base transceiver system (BTS), an access point (AP), a relay node, a remote radio head (RRH), a radio unit (RU), a small cell, or the like. As used herein, the term "base station" or "cell" may have a general meaning representing some area or function covered by the following: a base station controller (BSC) in CDMA, a Node B in WCDMA, an eNB in LTE, a gNB in 5G, a sector (site), or the like, and may include all various coverage areas, such as macro cells, massive macro cells, micro cells, pico cells, femto cells, relay nodes, RRHs, RUs, and small cell communication ranges.

[0013] The user equipment 10 may refer to any wireless communication device, which may be stationary or mobile, and can transmit and / or receive data and / or control information by wirelessly communicating with a base station (e.g., the base station 1). For example, the user equipment 10 may be referred to as a terminal, a terminal device, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a handheld device, or the like. Hereinafter, although the embodiments of the present inventive concept will be described by mainly regarding the user equipment 10 as a wireless communication device for reference purposes, it should be understood that the embodiments of the present inventive concept are not limited thereto.

[0014] The wireless communication network between the user equipment 10 and the base station 1 can support a large number of users to communicate with each other by sharing available network resources. For example, in a wireless communication network, information can be transmitted by various multiple connection schemes, such as CDMA, frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA, and the like. As shown in FIG. 1, the user equipment 10 can communicate with the base station 1 via an uplink (UL) and a downlink (DL). In some embodiments, such as in Device-to-Device (D2D) communication, user equipment can communicate with each other via a sidelink. As depicted in FIG. 1, the user equipment 10 can include an array antenna 12, a front-end circuit system ("module") 14, a back-end circuit system ("module") 16, and a signal processing circuit 18. In some embodiments, the array antenna 12, the front-end module 14, and the back-end module 16 can be embedded in one antenna module.

[0015] The array antenna 12 can include multiple antennas (interchangeably, "antenna elements") and can be connected to the front-end module 14. The array antenna 12 can be used for various purposes, such as spatial diversity, polarization diversity, spatial multiplexing, beamforming, or the like. Each of the multiple antennas in the array antenna 12 can include any suitable type of antenna, for example, a patch antenna, a dipole antenna, or the like.

[0016] To increase throughput, high microwave and millimeter wave (mmWave) frequencies such as frequency range 2 (FR2) band (24.25 GHz to 52.6 GHz) can be selected for communication. MmWave frequencies and higher range microwave frequencies have high transmission losses in free space. It should be noted that microwave frequencies are generally defined as frequencies in the range of 300 MHz to 300 GHz, while mmWave frequencies are generally defined as frequencies in the range of 30 GHz to 300 GHz. The embodiments herein are applicable to any frequency where it is desired to accurately measure the output power of an array antenna. For high transmission loss situations, in order to compensate for the high transmission loss, the user equipment 10 can include an array antenna 12 that increases the antenna gain, and the target or required effective isotropically radiated power (EIRP) can be achieved via the array antenna 12. At the same time, the amount of required transmission power can depend on the UL channel state: when the UL channel state is poor, high transmission power may be required, but when the UL channel state is good, low transmission power can suffice. However, since high transmission power can increase the power consumption of the user equipment 10, it is necessary to optimize the transmission power to achieve high efficiency of the user equipment 10. In other words, it may be necessary to limit the transmission power to a transmission power that is satisfactory (but not excessive) for the current UL channel conditions. Herein, the transmission power, which is the power radiated by the array antenna 12 (e.g., defined by EIRP), can be referred to as the output power of the array antenna 12.

[0017] The front-end module 14 can be connected to the array antenna 12. The front-end module 14 can generate a signal output via the array antenna 12 in the transmission mode, and can process the signal received via the array antenna 12 in the reception mode. As described below with reference to FIG. 2, the front-end module 14 can include a power detector and can detect the power of the signal output via the front-end module 14. As described below, for example, with reference to FIGS. 3A, 3B, and 4, the output power of the front-end module 14 can be different from the output power of the array antenna 12, and therefore, it may be necessary to estimate the output power of the array antenna 12 relative to the output power of the front-end module 14. For example, there may be significant mismatch losses between the front-end module 14 and the array antenna 12. As described below, a correction coefficient for estimating the output power of the array antenna 12 can be accurately calculated. Therefore, the output power of the array antenna 12 can be accurately estimated, allowing for accurate control of the transmission power. By accurately controlling the transmission power, the power consumption and heat emission of the user equipment 10 can be reduced.

[0018] The backend module 16 can process the signals provided by the signal processing circuit 18 and provide the signals to the frontend module 14 in the transmission mode. For example, the backend module 16 can generate a radio frequency (RF) band signal up-converted from a baseband signal according to a local oscillation signal in the transmission mode. Additionally, the backend module 16 can process the signals provided by the frontend module 14 and provide the signals to the signal processing circuit 18 in the reception mode. For example, the backend module 16 can generate a baseband signal down-converted from an RF band signal according to a local oscillation signal in the reception mode. In some embodiments, the backend module 16 can include a phased locked loop (PLL) that generates a local oscillation signal.

[0019] The signal processing circuit 18 can generate a baseband signal containing information intended to be transmitted to the base station 1 and provide the baseband signal to the backend module 16 in the transmission mode. Additionally, the signal processing circuit 18 can extract information from the baseband signal received from the backend module 16 in the reception mode. In some embodiments, the signal processing circuit 18 can include programmable components such as a central processing unit (CPU) or a digital signal processor (DSP); reconfigurable components such as a field programmable gate array (FPGA); and / or components providing fixed functions such as an intellectual property (IP) core.

[0020] FIG. 2 is a block diagram showing a user equipment 20 according to an example embodiment. As depicted in FIG. 2, the user equipment 20 can include an array antenna 21, a frontend module 22, a controller 23, and a memory 24. In some embodiments, the controller 23 and the memory 24 in FIG. 2 can be included in the signal processing circuit 18 of FIG. 1. The memory 24 can store correction factors for accurate output power measurement as described below. Additionally, the memory 24 (non-transitory recording medium) can store program instructions that can be read and executed by a processor in the controller 23 to perform controller operations as described below.

[0021] The array antenna 21 may include a first antenna A1 to a fourth antenna A4. The front-end module 22 may include a first front-end circuit FE1 to a fourth front-end circuit FE4 corresponding to the first antenna A1 to the fourth antenna A4 respectively, wherein the first front-end circuit FE1 to the fourth front-end circuit FE4 may each have the same structure. As shown in FIG. 2, the first front-end circuit FE1 may include a transmission phase shifter 22_1, a power amplifier (PA) 22_2, a transmit / receive (T / R) switch 22_3, a low noise amplifier (LNA) 22_4, a receive phase shifter 22_5, a coupler 22_8, and a power detector 22_6. Hereinafter, although an array antenna including four antennas as shown in FIG. 2 will be mainly described, it should be noted that embodiments of the inventive concept are not limited thereto.

[0022] In the transmission mode, the transmission phase shifter 22_1 may adjust the phase of the signal TXIN1 received from the rear-end module 16 of FIG. 1. The power amplifier 22_2 may amplify the output signal TX1 of the transmission phase shifter 22_1. The output signal TXOUT1 of the power amplifier 22_2 may be provided to the T / R switch 22_3 and may be provided to the first antenna A1 by the T / R switch 22_3 set to the transmission mode. In the reception mode, the T / R switch 22_3 may provide the signal RXIN1 received via the first antenna A1 to the LNA 22_4. The LNA 22_4 may amplify the signal RXIN1 provided by the T / R switch 22_3. The receive phase shifter 22_5 may adjust the phase of the output signal RX1 of the LNA 22_4, and the output signal RXOUT1 of the receive phase shifter 22_5 may be provided to the rear-end module 16 of FIG. 1. Here, it should be noted that in other embodiments, the antennas A1 to A4 are exclusively used for transmission and are not shared for reception operations. In this case, the T / R switch 22_3 may be omitted, and the receive path components may be directly connected to other (only receive) antenna elements.

[0023] The power detector 22_6 may detect the output power of the first power amplifier 22_2 by detecting a small part of the output power coupled via the coupler 22_8. For example, the power detector 22_6 may sample the output signal TXOUT1 of the power amplifier 22_2 and may generate a first detection signal PDET1 by detecting the output power of the power amplifier 22_2. The value of the first detection signal PDET1 may represent the magnitude of the output power of the power amplifier 22_2 and may be referred to as the output value of the power detector 22_6 herein.

[0024] The controller 23 can receive a first detection signal PDET1 from the power detector 22_6 and can provide a first gain control signal GCTR1 to the power amplifier 22_2. Additionally, the controller 23 can receive a first correction coefficient CORR1 from the memory 24. The controller 23 can estimate the output power of the first antenna A1 based on the value of the first detection signal PDET1 and the first correction coefficient CORR1. The controller 23 can adjust the gain of the power amplifier 22_2 via the first gain control signal GCTR1 based on the estimated output power of the first antenna A1. Thus, the output power of the first antenna A1 can be adjusted. Although not shown for clarity of illustration, the controller 23 can receive a second detection signal PDET2, a third detection signal PDET3, and a fourth detection signal PDET4 from the second front-end circuit FE2 to the fourth front-end circuit FE4 respectively, and can provide a second gain control signal to the fourth gain control signal to the second front-end circuit FE2 to the fourth front-end circuit FE4 in a similar manner respectively. Each gain control signal can be based on a respective one of PDET2, PDET3, or PDET4 and a respective correction coefficient CORR2, a respective correction coefficient CORR3, or a respective correction coefficient CORR4 (not shown in the figure).

[0025] The memory 24 can store the first correction coefficient CORR1 and can provide the first correction coefficient CORR1 to the controller 23. As described above, the output power of the first antenna A1 can be calculated based on the first correction coefficient CORR1, and thus, the accuracy of the output power of the first antenna A1 can depend on the first correction coefficient CORR1. The memory 24 can store a second correction coefficient CORR2, a third correction coefficient CORR3, and a fourth correction coefficient CORR4 corresponding to the second antenna A2 to the fourth antenna A4 respectively. Examples of the correction coefficients stored in the memory 24 will be described below with reference to FIGS. 9 and 11. The memory 24 can have any suitable structure for storing the correction coefficients. For example, the memory 24 can include: a volatile memory, such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), or a non-volatile memory, such as a flash memory.

[0026] FIGS. 3A and 3B are diagrams each showing a method of obtaining a correction value for estimating the output power of an array antenna according to an example embodiment. The method of FIG. 3A and the method of FIG. 3B can be sequentially executed in a calibration mode during the process of manufacturing the user equipment 31.

[0027] Referring to FIG. 3A, the user equipment 31 may include a first antenna A1 to a fourth antenna A4. The signal analyzer 32 may receive the signals transmitted by the user equipment 31 via the antenna A0 and may measure the transmission power of the user equipment 31. Herein, the magnitude of the transmission power measured by the signal analyzer 32 may be referred to as the measured value. As shown in FIG. 3A, the user equipment 31 may drive only the first antenna A1 among the first antenna A1 to the fourth antenna A4. For example, in the user equipment 31, only one of the first power amplifier to the fourth power amplifier respectively corresponding to the first antenna A1 to the fourth antenna A4 (e.g., the power amplifier 22_2 of the front-end circuit FE1 in FIG. 2) may be enabled, and the remaining power amplifiers may be disabled (e.g., their bias voltages are disconnected).

[0028] The signal analyzer 32 may measure the output power of the first antenna A1 by measuring the power of the received signal and then multiplying it by a multiplier to obtain the measured value. The measured value may be based on EIRP. In this case, the multiplier may be based on both the RF input power to the transmission antenna and the free space loss, where the free space loss is positively correlated with the distance between the user equipment 31 and the signal analyzer 32. In the user equipment 31, a power detector associated with the first antenna A1 (e.g., the power detector 22_6 in FIG. 2) may generate an output value PDET1 by detecting the power of the signal provided to the first antenna A1 (i.e., the output power of the first power amplifier). The correction value may be calculated as the difference between the measured value of the signal analyzer 32 and the output value of the power detector. The correction value may be calculated by the user equipment 31, as described below with reference to FIG. 7A, or may be calculated by the signal analyzer 32, as described below with reference to FIG. 7B. In a manner similar to the way described above, correction values for the second antenna A2 to the fourth antenna A4 may be calculated. Therefore, correction values corresponding to the first antenna A1 to the fourth antenna A4, i.e., antenna correction values, may be obtained.

[0029] Referring to FIG. 3B, the user equipment 31 may drive all of the first antenna A1 to the fourth antenna A4. For example, in the user equipment 31, all of the first power amplifier to the fourth power amplifier respectively corresponding to the first antenna A1 to the fourth antenna A4 may be enabled, and the first power amplifier to the fourth power amplifier may drive the first antenna A1 to the fourth antenna A4 respectively.

[0030] The signal analyzer 32 can measure the collective output power of the first antenna A1 to the fourth antenna A4 by measuring the power of the received signal and performing the same adjustment based on the estimated free space loss as described above if necessary. In the user equipment 31, the first power detector to the fourth power detector corresponding to the first antenna A1 to the fourth antenna A4 respectively can generate four output values by detecting the power of the signals provided to the first antenna A1 to the fourth antenna A4 (i.e., the output powers of the first power amplifier to the fourth power amplifier). The user equipment 31 can then estimate the output power of each of the first antenna A1 to the fourth antenna A4 from the four output values generated in FIG. 3B respectively based on the correction values calculated in FIG. 3A (i.e., the four antenna correction values corresponding to the first antenna A1 to the fourth antenna A4 respectively). For this purpose, the correction value of the array antenna including the first antenna A1 to the fourth antenna A4 can be calculated as the difference between the measured value of the signal analyzer 32 and the sum of the estimated output powers. The correction value of the array antenna can be calculated by the user equipment 31 as described below with reference to FIG. 7A, or can be calculated by the signal analyzer 32 as described below with reference to FIG. 7B.

[0031] The correction values obtained in FIG. 3A (i.e., the antenna correction values) and the correction values obtained in FIG. 3B (i.e., the correction values of the array antenna) are available for the user equipment 31 to estimate the output power of the array antenna including the first antenna A1 to the fourth antenna A4 from the output values of the first power detector to the fourth power detector in the normal mode (e.g., the mode of communicating with a base station (e.g., the base station 1 in FIG. 1)). As described below with reference to FIG. 4, the correction values obtained by the methods of FIGS. 3A and 3B and the output power of the array antenna estimated by using the correction values may each include errors.

[0032] FIG. 4 is a graph depicting the example reflection coefficients of antenna elements, and shows how the reflection coefficients can be different in an active array antenna environment and a single antenna element environment. In the graph of FIG. 4, the horizontal axis represents the frequency, and the vertical axis represents the reflection coefficient. In the following, the description of FIG. 4 will be made with reference to FIGS. 3A and 3B.

[0033] In the normal mode, for example, the mode of communicating with a base station (e.g., base station 1 in FIG. 1), all the first antennas A1 to the fourth antennas A4 included in the array antenna can be driven. Therefore, as described above with reference to FIG. 3A, the power measured by the signal analyzer 32 when driving only one antenna can be different from the normalized power measured in the actual normal mode (normalized for a single antenna, e.g., one-fourth of the array antenna power). For example, in FIG. 3A, the first antenna A1 may not be affected by the second antenna A2 to the fourth antennas A4, e.g., mismatch (due to the transmission of other antennas) coupling to / from other antennas ( "mutual coupling") and the like. Therefore, the state of driving only the first antenna A1 in FIG. 3A can correspond to the S parameter "S11" in the graph of FIG. 4 ( "observing" the reflection coefficient of the first antenna A1) (where the lowest loss due to S11 appears at the lowest point in the graph). On the other hand, as described above with reference to FIG. 3B, the reflection coefficient measured for the first antenna A1 when driving all the first antennas A1 to the fourth antennas A4 can correspond to the active S parameter in FIG. 4. In the example of FIG. 4, a higher loss due to S11 appears at most frequencies in the case of the active S parameter.

[0034] As depicted in FIG. 4, the S parameter and the active S parameter can be significantly different from each other within a wide range of frequencies. The load impedance of the power amplifier can depend on the reflection coefficient of the antenna, and thus, when the correction value obtained by driving only one antenna is applied to the state of driving the array antenna in the normal mode, an error can occur.

[0035] FIGS. 5A and 5B are diagrams each showing the radiation pattern of an array antenna according to an example embodiment. Specifically, the array antenna radiation pattern of FIG. 5A represents a beam formed in the boresight direction, and the array antenna radiation pattern of FIG. 5B represents a beam formed in the direction 30 degrees off-axis. Hereinafter, the description of FIGS. 5A and 5B will be made with reference to FIG. 2.

[0036] Although the beam is formed by the array antenna 21, when the gain of the power amplifier driving one antenna is slightly changed, the beam can generally maintain its pointing angle but can exhibit a change in EIRP. Therefore, in the calibration mode, the correction coefficient can be calculated based on the change in EIRP corresponding to the change in the gain of the power amplifier, and in the normal mode, the correction coefficient can be used to accurately estimate the EIRP.

[0037] Referring to FIG. 5A, reference curve 50a represents the main lobe and side lobes formed in the boresight direction. The first curve 51a represents the beam formed when the gain of the first power amplifier 22_2 driving the first antenna A1 is increased by one step from the gain corresponding to the reference curve 50a. As depicted in FIG. 5A, the first curve 51a may have a boresight direction similar to that of the reference curve 50a and have a higher EIRP than the reference curve 50a. The second curve 52a represents the beam formed when the gain of the first power amplifier 22_2 driving the first antenna A1 is increased by three steps from the gain corresponding to the reference curve 50a. As depicted in FIG. 5A, the second curve 52a may have a boresight direction similar to that of the reference curve 50a and the first curve 51a and have a higher EIRP than the reference curve 50a and the first curve 51a.

[0038] Referring to FIG. 5B, reference curve 50b represents the main lobe and side lobes formed in the direction 30 degrees off-axis. The first curve 51b represents the beam formed when the gain of the first power amplifier 22_2 driving the first antenna A1 is increased by one step from the gain corresponding to the reference curve 50b. As depicted in FIG. 5B, the first curve 51b may have a 30-degree direction similar to that of the reference curve 50b and have a higher EIRP than the reference curve 50b. The second curve 52b represents the beam formed when the gain of the first power amplifier 22_2 driving the first antenna A1 is increased by three steps from the gain corresponding to the reference curve 50b. As depicted in FIG. 5B, the second curve 52b may have a 30-degree direction similar to that of the reference curve 50b and the first curve 51b and have a higher EIRP than the reference curve 50b and the first curve 51b.

[0039] FIG. 6 is a flowchart showing a method of estimating the output power of an array antenna according to an example embodiment. As depicted in FIG. 6, the method of estimating the output power of an array antenna may include a plurality of operations S61 to S69. Herein, the method of estimating the output power of an array antenna may be referred to as a wireless communication method via an array antenna. In some embodiments, the method of FIG. 6 may be executed by the user equipment 20 of FIG. 2. Hereinafter, a description of FIG. 6 is given with reference to FIG. 2.

[0040] As described with reference to FIGS. 5A to 5B, when the gain of the power amplifier driving one of the antennas included in the array antenna is slightly changed, the direction of the beam formed by the array antenna may be maintained, but its EIRP may change. Therefore, as described hereinafter with reference to FIG. 6, a correction coefficient may be calculated based on output values and measurement values corresponding to two or more different gains. By using this technique, the correction coefficient may be highly accurate.

[0041] Referring to FIG. 6, in operation S61, a calibration mode can be set. For example, as described above with reference to FIGS. 3A and 3B, during the process of manufacturing the user equipment 20, a signal analyzer can be used to measure the output power of the array antenna 21. The user equipment 20 can be set to the calibration mode, and appropriate signals can be transmitted via the array antenna 21 according to the conditions described below.

[0042] In operation S62, a plurality of antennas can be driven. For example, the controller 23 can control the front-end module 22 such that all the first antennas A1 to the fourth antennas A4 of the array antenna 21 are driven. Accordingly, the power amplifiers respectively included in the first front-end circuit FE1 to the fourth front-end circuit FE4 can drive the first antenna A1 to the fourth antenna A4 respectively.

[0043] In operation S63, the first power amplifier can be set to a first gain. For example, the controller 23 can generate a first gain control signal GCTR1 to set the gain of the first power amplifier 22_2 that drives the first antenna A1 among the first antenna A1 to the fourth antenna A4 of the array antenna 21 to the first gain. The first gain can be different from the second gain described below. The second antenna A2 to the fourth antenna A4 can also be driven by their respective power amplifiers, and the power amplifiers can be biased to have respective gains that are the same as the gains they have in the normal mode (the "normal mode gain"). These gains can be different from the first gain. In other words, the first gain of the first power amplifier can be a gain changed from its normal mode gain. It should be noted that in some embodiments, all the antennas A1 to A4 are driven with the same power in the normal mode (which can be achieved by setting the same gain for each of the power amplifiers). In other embodiments, different powers are applied to different ones of the antennas A1 to A4 in the normal mode.

[0044] In operation S64, the output power of the first power amplifier can be detected. For example, the first power detector 22_6 can sample the output signal TXOUT1 of the first power amplifier 22_2 and can generate a first detection signal PDET1 by detecting the output power of the first power amplifier 22_2. The controller 23 can identify the magnitude of the output power of the first power amplifier 22_2 based on the value of the first detection signal PDET1 corresponding to the first gain (the "first output value" of the first power amplifier 22_2). Additionally, a signal analyzer at a specific distance from the user equipment 20 (e.g., the signal analyzer 32 of FIGS. 3A and 3B) can measure the output power of the array antenna 21, which includes the first antenna A1 driven by the first power amplifier 22_2 set to the first gain, and can generate a first measurement value. For example, the first measurement value defined according to EIRP can be obtained by a signal analyzer that measures the received signal power and multiplies it by a multiplier. The multiplier can be based on the free space loss and the RF input power at the transmitting antenna, where the RF input power is associated with the first gain.

[0045] In operation S65, the first power amplifier can be set to a second gain. For example, the controller 23 can generate a first gain control signal GCTR1 to set the gain of the first power amplifier 22_2, which drives the first antenna A1 among the first antenna A1 to the fourth antenna A4 of the array antenna 21, to the second gain. The second gain can be different from the first gain described above and can be different from the normal mode gain of the first power amplifier. The remaining power amplifiers driving the second antenna A2 to the fourth antenna A4 can be biased to have the same gain as in operation S63. In some embodiments, the difference between the first gain and the second gain can correspond to the minimum step size of the gain of the first power amplifier 22_2. In some embodiments, the difference between the first gain and the second gain can have a magnitude that causes no change or only a slight change in the radiation pattern of the array antenna (e.g., the main lobe still points in the same direction within the tolerance range). In operation S66, the output power of the first power amplifier can be detected again in the same manner as described above for operation S64 to obtain a second output value of the first power amplifier 22_2. Correspondingly, the signal analyzer can generate a second measurement value in the same manner as described above.

[0046] The calibration coefficient of the first antenna A1 can be calculated based on the first output value and the first measurement value corresponding to the first gain, and the second output value and the second measurement value corresponding to the second gain. The calibration coefficient of the first antenna A1 can be calculated based on the difference between the first output value and the second output value and the difference between the first measurement value and the second measurement value. For example, the calibration coefficient C1 of the first antenna A1 can be calculated based on Equation 1:

[0047] [Equation 1]

[0048] In Equation 1, EIRP1 and EIRP2 are the first measurement value and the second measurement value respectively, and OUT1 and OUT2 are the first output value and the second output value respectively. The calibration coefficient can be calculated by the user equipment 20, as described below with reference to FIG. 7A, or by the signal analyzer receiving signals from the user equipment 20, as described below with reference to FIG. 7B. The calculated calibration coefficient can be stored in the memory 24. It should be noted here that EIRP1 can refer to an isotropic radiator driven by the first RF input power associated with the first gain, and EIRP2 can refer to an isotropic radiator driven by the second RF input power associated with the second gain. Therefore, the first measurement value and the second measurement value can be obtained by multiplying the actual individual received power at the signal analyzer by different individual multipliers, which reflect the same free space loss but different RF input powers, referring to a hypothetical lossless, effective isotropic radiator in both cases.

[0049] In operation S67, the normal mode can be set. For example, the process of manufacturing the user equipment 20 can be completed, and the user equipment 20 can be set to the normal mode. The user equipment 20 can communicate with another wireless communication device (e.g., the base station 1 in FIG. 1) via the array antenna 21 in the normal mode.

[0050] In operation S68, the output power of the first power amplifier 22_2 can be detected based on the value of the first detection signal PDET1 obtained in the same manner as in the calibration mode.

[0051] In operation S69, the output power of the first antenna A1 can be estimated. For example, the controller 23 can estimate the output power of the first antenna A1 based on the calibration coefficient calculated in the calibration mode and the output value obtained in operation S68. For example, when defined in terms of EIRP, the output power of the first antenna A1 can be calculated based on Equation 2.

[0052] [Equation 2]

[0053] In Equation 2, C1 can be the calibration coefficient of Equation 1, and OUT can be the output value obtained in operation S68. As described below with reference to FIG. 12, the controller 23 can estimate the respective output powers of the first antenna A1 to the fourth antenna A4, and can control the respective gains of the first power amplifier to the fourth power amplifier based on the estimated output powers.

[0054] FIGS. 7A and 7B are message diagrams respectively showing examples of methods for estimating the output power of an array antenna according to an exemplary embodiment. Specifically, the message diagrams of FIGS. 7A and 7B respectively show the operations of the signal analyzers 72a and 72b and the user equipments 71a and 71b set to the calibration mode over time.

[0055] Referring to FIG. 7A, in operation S71a, the user equipment 71a can transmit a first signal to the signal analyzer 72a. For example, the user equipment 71a can transmit the first signal to the signal analyzer 72a via the array antenna, and the signal analyzer 72a can receive the first signal via the antenna. During the transmission of the first signal, the user equipment 71a can set the first power amplifier driving the first antenna among the antennas included in the array antenna to a first gain.

[0056] In operation S72a, the user equipment 71a can detect the output power of the first power amplifier. For example, the first power detector included in the user equipment 71a can detect the output power of the first power amplifier and can generate a first output value. In operation S73a, the signal analyzer 72a can measure the power of the first signal. For example, the signal analyzer 72a can measure the power of the first signal received from the user equipment 71a in operation S71a, and can generate a first measurement value in the manner described above.

[0057] In operation S74a, the user equipment 71a can transmit a second signal to the signal analyzer 72a. For example, the user equipment 71a can transmit the second signal to the signal analyzer 72a via the array antenna, and the signal analyzer 72a can receive the second signal via the antenna. During the transmission of the second signal, the user equipment 71a can set the first power amplifier driving the first antenna among the antennas included in the array antenna to a second gain.

[0058] In operation S75a, the user equipment 71a can detect the output power of the first power amplifier. For example, a first power detector included in the user equipment 71a can detect the output power of the first power amplifier and can generate a second output value. In operation S76a, the signal analyzer 72a can measure the power of the second signal. For example, the signal analyzer 72a can measure the power of the second signal received from the user equipment 71a in operation S74a, and can generate a second measurement value as described above.

[0059] In operation S77a, the signal analyzer 72a can provide the first measurement value and the second measurement value to the user equipment 71a. In some embodiments, the signal analyzer 72a can transmit a signal including the first measurement value and the second measurement value to the user equipment 71a via an antenna, and the user equipment 71a can receive the signal including the first measurement value and the second measurement value via an array antenna. In some embodiments, the signal analyzer 72a and the user equipment 71a can have a communication channel different from the wireless communication channel via the array antenna of the user equipment 71a (e.g., a wired or wireless communication channel), and the signal analyzer 72a can provide the first measurement value and the second measurement value to the user equipment 71a via the corresponding communication channel.

[0060] In operation S78a, the user equipment 71a can calculate a correction coefficient. For example, the user equipment 71a or a controller in the user equipment 71a can calculate the correction coefficient based on the first output value and the second output value obtained in operations S72a and S75a respectively, and the first measurement value and the second measurement value provided by the signal analyzer 72a in operation S77a. In some embodiments, the user equipment 71a can calculate the correction coefficient based on Equation 1.

[0061] In operation S79a, the user equipment 71a can store the correction coefficient. For example, the controller of the user equipment 71a can store the correction coefficient calculated in operation S78a in a memory. In the normal mode, the correction coefficient stored in the memory can be used by the user equipment 71a to estimate the output power of the array antenna.

[0062] The operations of FIG. 7A can be repeated for each of the remaining antennas A2 to A4 of the antenna array, resulting in the calculation and storage of individual correction coefficients associated with each of antennas A1 to A4.

[0063] Referring to FIG. 7B, except for using the user device 71b and the signal analyzer 72b, operations S71b, S72b, S73b, S74b, S75b, and S76b can be the same as operations S71a to S76a of FIG. 7A described above.

[0064] In operation S77b, the user device 71b can provide the first output value and the second output value to the signal analyzer 72b. The user device 71b can transmit a signal including the first output value and the second output value to the signal analyzer 72b via the array antenna, and the signal analyzer 72b can receive the signal including the first output value and the second output value via the antenna. It should be noted that the signal analyzer 72b and the user device 71b can have a communication channel different from the wireless communication channel via the array antenna of the user device 71b (e.g., a wired or wireless communication channel), and the signal analyzer 72b can receive the first output value and the second output value from the user device 71b via the corresponding communication channel.

[0065] In operation S78b, the signal analyzer 72b can calculate the correction coefficient. For example, the signal analyzer 72b can calculate the correction coefficient based on the first measurement value and the second measurement value obtained in operations S73b and S75b respectively, and the first output value and the second output value provided by the user device 71b in operation 77b. The signal analyzer 72b can calculate the correction coefficient based on Equation 1.

[0066] In operation S79b, the signal analyzer 72b can provide the correction coefficient to the user device 71b. For example, the signal analyzer 72b can provide the correction coefficient calculated in operation S78b to the user device 71b via the communication channel through which the first output value and the second output value are received from the user device 71b in operation S77b.

[0067] In operation S80b, the user device 71b can store the correction coefficient. For example, the controller of the user device 71b can store the correction coefficient provided by the signal analyzer 72b in operation S79b in the memory. In the normal mode, the correction coefficient stored in the memory can be used by the user device 71b to estimate the output power of the array antenna.

[0068] The operations of FIG. 7B can be repeated for each of the remaining antennas A2 to A4 of the antenna array, resulting in the calculation and storage of individual correction coefficients associated with each of antennas A1 to A4.

[0069] FIG. 8 is a flowchart showing a method of estimating the output power of an array antenna according to an exemplary embodiment. As depicted in FIG. 8, the method of estimating the output power of an array antenna may include a plurality of operations S81 to S86. As described above with reference to FIGS. 7A and 7B, the method of FIG. 8 may be performed by a user equipment or a signal analyzer. Hereinafter, although it is assumed that the method of FIG. 8 is performed by the user equipment 20, it should be noted that embodiments of the inventive concept are not limited thereto. Hereinafter, the description of FIG. 8 will be made with reference to FIG. 2.

[0070] Referring to FIG. 8, in operation S81, a first output value and a first measurement value may be obtained. For example, the first output value may be generated by detecting the output power of the first power amplifier 22_2 by the first power detector 22_6 when the first power amplifier 22_2 is set to a first gain. Additionally, the first measurement value may be generated by measuring the output power of the array antenna 21 by a signal analyzer when the first power amplifier 22_2 is set to the first gain.

[0071] In operation S82, a second output value and a second measurement value may be obtained. For example, the second output value may be generated by detecting the output power of the first power amplifier 22_2 by the first power detector 22_6 when the first power amplifier 22_2 is set to a second gain different from the first gain. Additionally, the second measurement value may be generated by measuring the output power of the array antenna 21 by a signal analyzer when the first power amplifier 22_2 is set to the second gain.

[0072] In operation S83, a first correction coefficient may be calculated. For example, the controller 23 may calculate the first correction coefficient based on the first output value and the first measurement value obtained in operation S81 and the second output value and the second measurement value obtained in operation S82. In some embodiments, the controller 23 may calculate the first correction coefficient based on Equation 1.

[0073] In operation S84, a third output value and a third measurement value may be obtained. For example, the third output value may be generated by detecting the output power of the first power amplifier 22_2 by the first power detector 22_6 when the first power amplifier 22_2 is set to a third gain different from the first gain and the second gain. Additionally, the third measurement value may be generated by measuring the output power of the array antenna 21 by a signal analyzer when the first power amplifier 22_2 is set to the third gain. In some embodiments, the second gain may correspond to a gain obtained by increasing the first gain by up to a step size, and the third gain may correspond to a gain obtained by decreasing the first gain by up to a step size.

[0074] In operation S85, a second correction coefficient may be calculated. In some embodiments, the controller 23 may calculate the second correction coefficient based on the first output value and the first measurement value obtained in operation S81 and the third output value and the third measurement value obtained in operation S84. In some embodiments, the controller 23 may calculate the second correction coefficient based on the second output value and the second measurement value obtained in operation S82 and the third output value and the third measurement value obtained in operation S84. For example, the controller 23 may calculate the second correction coefficient based on Equation 1.

[0075] In operation S86, a final correction coefficient may be calculated. For example, the controller 23 may calculate the correction coefficient of the first antenna based on the first correction coefficient calculated in operation S83 and the second correction coefficient calculated in operation S85. In some embodiments, the controller 23 may calculate the average value of the first correction coefficient and the second correction coefficient as the final correction coefficient. Although FIG. 8 shows an example of calculating the final correction coefficient from two correction coefficients, in some embodiments, the final correction coefficient may also be calculated based on three or more than three correction coefficients.

[0076] FIG. 9 is a diagram showing an example of correction coefficients according to an exemplary embodiment. In some embodiments, the memory 24 of FIG. 2 may store the correction coefficients of FIG. 9. Hereinafter, a description of FIG. 9 will be made with reference to FIG. 2.

[0077] The memory 24 may store four correction coefficients C1 to C4 corresponding to the first antenna A1 to the fourth antenna A4 included in the array antenna 21, respectively. As described above with reference to FIGS. 6, 7A, 7B, and 8, in the calibration mode, each of the four correction coefficients C1 to C4 may be calculated, and the controller 23 may store the four correction coefficients C1 to C4 in the memory 24. In the normal mode, the controller 23 may read the four correction coefficients C1 to C4 from the memory 24, and may accurately estimate the output power of the array antenna 21 based on the four correction coefficients C1 to C4 and the output values of the first power detector to the fourth power detector. For example, the output power of the array antenna 21 may be calculated based on Equation 3, that is, EIRPest:

[0078] [Equation 3]

[0079] In Equation 3, Ck is a calibration coefficient corresponding to the k-th antenna, and OUTk is the output power of the k-th power amplifier driving the k-th antenna.

[0080] FIG. 10 is a graph depicting the "active reflection coefficient" versus frequency in an array antenna. In the graph of FIG. 10, the horizontal axis represents frequency, and the vertical axis represents the active S parameter ("active S11"), which represents the reflection coefficient of observing one of the antenna elements when all the antenna elements of the array are actively driven. Hereinafter, the description of FIG. 10 will be made with reference to FIG. 1.

[0081] In the normal mode (e.g., the mode of communicating with base station 1), the phases of the signals respectively provided to the antennas included in the array antenna 12 can be changed according to beam steering. Therefore, the reflection coefficients of the respective antenna elements of the array antenna 12 can be changed according to the angle of the beam, and the change of the reflection coefficients can cause a change in the load impedance of the power amplifier. For example, the graph of FIG. 10 shows the active S11 of the antenna elements during the respective beamforming environments of six beams (e.g., beam #0 to beam #5) having different angles respectively. As depicted in FIG. 10, when beams having different angles are formed, the active S11 for the antenna elements can be different between the beams within a wide range of frequencies. Therefore, for an accurate estimation of the EIRP, the angle of the beam can be considered.

[0082] FIG. 11 is a diagram showing an example of the calibration coefficients according to an example embodiment. In some embodiments, the memory 24 of FIG. 2 can store the calibration coefficients of FIG. 11. Hereinafter, the description of FIG. 11 will be made with reference to FIG. 2.

[0083] The memory 24 can store the calibration coefficients corresponding to each of the first antenna A1 to the fourth antenna A4 included in the array antenna 21. For example, as depicted in FIG. 11, the memory 24 can store the calibration coefficient C11 to the calibration coefficient C1n corresponding to the first antenna A1, and can store the calibration coefficient C41 to the calibration coefficient C4n corresponding to the fourth antenna A4 (where n is an integer greater than 1). In addition, the memory 24 can store the calibration coefficients according to beam steering. For example, as depicted in FIG. 11, the memory 24 can store the calibration coefficients corresponding to the first angle θ1 of the beam (e.g., C11, C41, and the like), and can store the calibration coefficients corresponding to the n-th angle θn of the beam (e.g., C1n, C4n, and the like).

[0084] Each of the calibration coefficients in FIG. 11 can be calculated based on the power detected and measured when forming a beam having an angle corresponding to each of the calibration coefficients in the array antenna 21. For example, when the phase shifter of the front-end module 22 is set such that the beam formed by the array antenna 21 has a first angle θ1, the calibration coefficient C11 corresponding to the first antenna A1 and the first angle θ1 can be calculated based on the output value and the measured value obtained by changing the gain of the first power amplifier 22_2 that drives the first antenna A1. Similarly, when the phase shifter of the front-end module 22 is set such that the beam formed by the array antenna 21 has an nth angle θn, the calibration coefficient C1n corresponding to the first antenna A1 and the nth angle θn can be calculated based on the output value and the measured value obtained by changing the gain of the first power amplifier 22_2 that drives the first antenna A1. In the normal mode, the controller 23 can read the calibration coefficient corresponding to the angle of the beam from the memory 24, and can estimate the output power of the array antenna 21 based on the calibration coefficient and the output value, and thus, can accurately estimate the output power corresponding to the angle of the beam.

[0085] FIG. 12 is a flowchart showing a method for estimating the output power of an array antenna according to an exemplary embodiment. Specifically, the flowchart of FIG. 12 represents a method executed by a user equipment in the normal mode. As depicted in FIG. 12, the method for estimating the output power of an array antenna may include a plurality of operations S121 to S124. In some embodiments, the method of FIG. 12 may be executed by the user equipment 20 of FIG. 2, and hereinafter, the description of FIG. 12 will be made with reference to FIG. 2.

[0086] Referring to FIG. 12, in operation S121, a plurality of output values can be obtained. For example, in the normal mode, the user equipment 20 can communicate with another wireless communication device (e.g., the base station 1 of FIG. 1), and can transmit a signal to the other wireless communication device via the array antenna 21. During the transmission of the signal via the array antenna 21, the first power detector to the fourth power detector can respectively detect the output power of the first power amplifier to the fourth power amplifier, and can respectively generate detection signals. The controller 23 can identify the output power of the first power amplifier to the fourth power amplifier based on the values of the detection signals (the "output values").

[0087] In operation S122, a plurality of calibration coefficients can be obtained. For example, the controller 23 can read from the memory 24 four calibration coefficients corresponding to the first antenna A1 to the fourth antenna A4 respectively. In some embodiments, as described above with reference to FIG. 11, when the memory 24 stores calibration coefficients corresponding to various angles of the beam, the controller 23 can identify the angle of the beam formed by the array antenna 21, and can read from the memory 24 the calibration coefficient corresponding to the identified angle.

[0088] In operation S123, the output power of the array antenna can be estimated. For example, the controller 23 can estimate the output power of the array antenna 21 based on the plurality of output values obtained in operation S121 and the plurality of calibration coefficients obtained in S122. In some embodiments, the controller 23 can estimate the output power of the first antenna A1 based on the output value and the calibration coefficient corresponding to the first antenna A1. Similarly, the controller 23 can estimate the respective output powers of the second antenna A2 to the fourth A4, and can estimate the output power of the array antenna 21 by summing the estimated output powers.

[0089] In operation S124, the gains of a plurality of power amplifiers can be controlled. For example, the controller 23 can compare the output power of the array antenna 21 estimated in operation S123 with the target transmission power. The target transmission power can refer to the power to be transmitted or the transmission power required for communication with another wireless communication device, and can be defined based on an error rate, such as a bit error rate (BER), a block error rate (BLER), or the like. For example, the target transmission power can be defined by the base station 1 in FIG. 1 and provided to the user equipment 20, or can be defined by the user equipment 20. The controller 23 can compare the output power of the array antenna 21 estimated in operation S123 with the target transmission power. When the estimated output power is lower than the target transmission power, the controller 23 can increase the gains of the first power amplifier to the fourth power amplifier. On the other hand, when the estimated output power is higher than the target transmission power, the controller 23 can decrease the gains of the first power amplifier to the fourth power amplifier. Due to the accurately estimated output power of the array antenna 21, the gains of the first power amplifier to the fourth power amplifier can be accurately set according to the target transmission power. Therefore, the power consumption by the first power amplifier to the fourth power amplifier can be optimally controlled, and the transmission of signals with incorrect power levels can be prevented.

[0090] Exemplary embodiments of the inventive concept have been depicted herein with reference to signal arrows, block diagrams, flowcharts, and / or algorithmic expressions. Each block in the block diagram and combinations of blocks in the block diagram and operations in accordance with the algorithmic expressions can be implemented by hardware (e.g., the processing circuitry of controller 23 in cooperation with memory 24 accompanied by computer program instructions). Such computer program instructions can be stored in a non-transitory computer-readable medium (e.g., memory 24), which can direct a computer, other programmable data processing devices, or other devices to act in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture that includes instructions for implementing the functions / actions specified in the block diagram.

[0091] Although the inventive concept has been specifically shown and described with reference to embodiments of the inventive concept, it will be understood that various changes can be made to its form and details without departing from the spirit and scope of the following claims.

[0092] 1: Base station 5: Wireless communication system 10, 20, 31, 71a, 71b: User equipment 12, 21: Array antenna 14, 22: Front-end module 16: Rear-end module 18: Signal processing circuit 22_1: Transmission phase shifter 22_2: Power amplifier 22_3: Transmission / reception switch 22_4: Low-noise amplifier 22_5: Reception phase shifter 22_6: Power detector 22_8: Coupler 23: Controller 24: Memory 32, 72a, 72b: Signal analyzer 50a, 50b: Reference curve 51a, 51b: First curve 52a, 52b: Second curve A0: Antenna A1: First antenna A2: Second antenna A3: Third antenna A4: Fourth antenna C1, C2, C3, C4, C11~C1n, C41~C4n: Correction coefficients CORR1: First correction coefficient CORR2: Second correction coefficient CORR3: Third correction coefficient CORR4: Fourth correction coefficient FE1: First front-end circuit FE2: Second front-end circuit FE3: Third front-end circuit FE4: Fourth front-end circuit GCTR1: First gain control signal PDET1: First detection signal PDET2: Second detection signal PDET3: Third detection signal PDET4: Fourth detection signal RXIN1, TXIN1: Signals S61, S62, S63, S64, S65, S66, S67, S68, S69, S71a, S71b, S72a, S72b, S73a, S73b, S74a, S74b, S75a, S75b, S76a, S76b, S77a, S77b, S78a, S78b, S79a, S79b, S80b, S81, S82, S83, S84, S85, S86, S121, S122, S123, S124: Operations RXOUT1, RX1, TX1, TXOUT1: Output signals θ1, θn: Angles

Claims

1. A wireless communication device, comprising: An array antenna, including multiple antennas; multiple power amplifiers, including a first power amplifier configured to drive a first antenna among the multiple antennas; Multiple power detectors, including a first power detector configured to detect the output power of the first power amplifier; The controller is configured to: In calibration mode, when the plurality of antennas are driven by the plurality of power amplifiers respectively, obtain a first output value of the first power detector after setting the first power amplifier to a first gain, and obtain a second output value of the first power detector after setting the first power amplifier to a second gain; In normal mode, the output power of the first antenna is estimated from the fourth output value of the first power detector based on the correction coefficient calculated using the first output value and the second output value.

2. The wireless communication device as claimed in claim 1, wherein the controller in the calibration mode is further configured to: receive a first measurement value and a second measurement value, the first measurement value being generated by measuring the output power of the array antenna when the first power amplifier is set to the first gain, and the second measurement value being generated by measuring the output power of the array antenna when the first power amplifier is set to the second gain; and calculate the correction coefficient based on the first output value, the second output value, the first measurement value, and the second measurement value.

3. The wireless communication device as claimed in claim 2, wherein the controller is further configured to: in the calibration mode, calculate the correction coefficient based on a first difference between the first output value and the second output value and a second difference between the first measurement value and the second measurement value; and in the normal mode, calculate the product of the fourth output value of the first power detector and the correction coefficient as the output power of the first antenna.

4. The wireless communication apparatus of claim 3, wherein the controller is further configured in the calibration mode to: set the first power amplifier to a third gain when the plurality of antennas are respectively driven by the plurality of power amplifiers, and then obtain a third output value of the first power detector; receive a third measurement value generated by measuring the output power of the array antenna when the first power amplifier is set to the third gain; calculate a first correction coefficient based on a first difference and a second difference; calculate a second correction coefficient based on the difference between the first output value and the third output value and the difference between the first measurement value and the third measurement value; and calculate the correction coefficient based on the first correction coefficient and the second correction coefficient.

5. The wireless communication device as claimed in claim 1, further comprising a memory, wherein the controller is further configured to: write the correction coefficients into the memory in the calibration mode; and read the correction coefficients from the memory in the normal mode.

6. The wireless communication device as claimed in claim 5, wherein the memory stores a plurality of correction coefficients corresponding to the plurality of antennas, and the controller is further configured in the normal mode to: receive the plurality of correction coefficients from the memory; and estimate the output power of the array antenna based on a plurality of output values ​​of the plurality of power detectors and the plurality of correction coefficients.

7. The wireless communication device as claimed in claim 6, wherein the controller is further configured to control the gains of the plurality of power amplifiers based on the output power of the array antenna in the normal mode.

8. The wireless communication device of claim 5, wherein the memory stores a plurality of correction coefficients corresponding to a plurality of angles of a beam formed by the array antenna, and the controller is further configured in the normal mode to: read at least one correction coefficient from the memory corresponding to an angle of the beam; and estimate the output power of the array antenna based on a plurality of output values ​​of the plurality of power detectors and the at least one correction coefficient.

9. The wireless communication device of claim 1, wherein the controller is further configured in the calibration mode to: provide the first output value and the second output value to an external device; and receive the correction coefficient from the external device.

10. The wireless communication device as claimed in claim 1, wherein the difference between the second gain and the first gain is the step size of the gain of the first power amplifier.

11. A wireless communication method via an array antenna, the wireless communication method comprising: In calibration mode, multiple power amplifiers are controlled to drive multiple antennas in the array antenna; In the calibration mode, the first power amplifier driving the first antenna among the plurality of antennas is set to a first gain, and a first output value is generated by detecting the output power of the first power amplifier; in the calibration mode, the first power amplifier is set to a second gain, and a second output value is generated by detecting the output power of the first power amplifier; in the normal mode, a third output value is generated by detecting the output power of the first power amplifier. In the normal mode, the output power of the first antenna is estimated from the third output value based on the correction coefficient calculated using the first output value and the second output value.

12. The wireless communication method as described in claim 11 further includes: In the calibration mode, a first measurement value is received, generated by measuring the output power of the array antenna when the first power amplifier is set to the first gain; in the calibration mode, a second measurement value is received, generated by measuring the output power of the array antenna when the first power amplifier is set to the second gain; and the correction coefficient is calculated based on the first output value, the second output value, the first measurement value, and the second measurement value.

13. The wireless communication method of claim 12, wherein calculating the correction coefficient is based on the difference between the first output value and the second output value and the difference between the first measurement value and the second measurement value, and estimating the output power of the first antenna includes calculating the product of the third output value and the correction coefficient as the output power of the first antenna.

14. The wireless communication method as claimed in claim 11 further includes writing the correction coefficients into memory in the calibration mode, wherein estimating the output power of the first antenna includes reading the correction coefficients from the memory.

15. The wireless communication method of claim 14, wherein the memory stores a plurality of correction coefficients corresponding to the plurality of antennas, and wherein the wireless communication method further comprises: In the normal mode, the plurality of correction coefficients are received from the memory; In the normal mode, the output power of the array antenna is estimated based on a plurality of output values ​​and a plurality of correction coefficients, the plurality of output values ​​corresponding to the output power of the plurality of power amplifiers, respectively.

16. The wireless communication method as claimed in claim 15 further includes controlling multiple gains of the plurality of power amplifiers based on the output power of the array antenna in the normal mode.

17. The wireless communication method of claim 14, wherein the memory stores a plurality of correction coefficients corresponding to a plurality of angles of a beam formed by the array antenna, and wherein the wireless communication method further comprises: In the normal mode, multiple output values ​​are generated by detecting the power of the multiple power amplifiers; in the normal mode, at least one correction coefficient corresponding to the angle of the beam is read from the memory, the memory storing the multiple correction coefficients respectively corresponding to the multiple angles of the beam formed by the array antenna; and the output power of the array antenna is estimated based on the multiple output values ​​and the at least one correction coefficient.

18. The wireless communication method as described in claim 11, further comprising: In the calibration mode, the first output value and the second output value are provided to an external device including the array antenna; And in the calibration mode, the correction coefficient is received from the external device.

19. A method for generating correction coefficients for estimating the output power of an array antenna, the method comprising: In calibration mode: Multiple antennas in the array antenna are driven by multiple power amplifiers in the device including the array antenna; The first power amplifier among the plurality of power amplifiers is set to a first gain and a second gain, respectively; a first output value and a second output value corresponding to the first gain and the second gain are obtained by detecting the output power of the first power amplifier; a first measurement value and a second measurement value corresponding to the first gain and the second gain are obtained by measuring the output power of the array antenna; a correction coefficient is calculated based on the first output value, the second output value, the first measurement value, and the second measurement value; and the correction coefficient is stored in the device.

20. The method of claim 19, wherein the correction coefficient is calculated based on the difference between the first output value and the second output value and the difference between the first measurement value and the second measurement value.

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