Method for calibrating relative phase from transmitter to receiver and millimeter wave antenna module

Abstract

The present invention provides a method for calibrating the relative phase of a transmitter to a receiver (T2R) and a millimeter wave antenna module. The method includes generating a first calibration signal based on a first transmitter TX input signal and transmitting the first calibration signal to a second antenna via a first antenna; receiving the first calibration signal via the second antenna and obtaining a first loopback receiver RX signal based on the first calibration signal; generating a second calibration signal based on a second TX input signal and transmitting the second calibration signal to the first antenna via the second antenna; receiving the second calibration signal via the first antenna and obtaining a second loopback RX signal based on the second calibration signal; and calibrating the T2R relative phase based on the phase difference between the first and second loopback RX signals. Through the present invention, better reciprocity can be achieved between the transmit and receive paths, beamforming loss can be improved, and better beam correspondence can be achieved between the transmit and receive paths.

Description

Technical Field

[0001] The present invention relates to an antenna system in mobile wireless communications, and more particularly to a method for calibrating a transmitter-to-receiver (T2R) relative phase in a millimeter wave beamforming system and a related millimeter wave antenna module. Background Art

[0002] As technology evolves, bandwidth shortages are driving mobile operators to explore the underutilized millimeter wave (mmWave) spectrum between 3 GHz and 300 GHz. Fifth-generation (5G) mobile wireless communication systems are expected to provide high data rates in the mmWave band. Because mmWaves have large path loss and poor penetration, antenna design requires the use of antenna arrays to generate highly directional and adjustable dynamic beam scanning to provide sufficient signal strength. The antenna array and radio frequency integrated circuit (RFIC) can be packaged into a mmWave antenna module (AM), which includes multiple antenna elements to increase beamforming gain.

[0003] In a beamforming system, the transmitter (TX) and receiver (RX) beam directions with the same array weight vector (AWV) settings (i.e., defined beam correspondence) should ideally be identical. Ideally, the TX and RX beams have perfect correspondence, and the transmitter-to-receiver (T2R) relative phase should be zero. However, the TX and RX beams do not always have perfect correspondence, as the phases of the TX and RX paths may differ. Therefore, a novel method is urgently needed to calibrate the relative phase of T2R. Summary of the Invention

[0004] Therefore, one of the objectives of the present invention is to provide a method for calibrating the relative phase of T2R in a millimeter wave beamforming system and a related millimeter wave antenna module to solve the above-mentioned problem.

[0005] In one embodiment of the present invention, a method for calibrating a transmitter-to-receiver (T2R) relative phase in a millimeter-wave beamforming system is provided. The method comprises: generating a first calibration signal based on a first transmitter TX input signal, and transmitting the first calibration signal to a second antenna of the millimeter-wave beamforming system via a first antenna of the millimeter-wave beamforming system; receiving the first calibration signal via the second antenna, and obtaining a first loopback receiver RX signal based on the first calibration signal received by the second antenna; generating a second calibration signal based on a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; receiving the second calibration signal via the first antenna, and obtaining a second loopback RX signal based on the second calibration signal received by the first antenna; and calibrating the T2R relative phase based on a phase difference between the first loopback RX signal and the second loopback RX signal.

[0006] In another embodiment of the present invention, a millimeter wave antenna module is provided, which includes a first millimeter wave transceiver path, a second millimeter wave transceiver path, and a calibration engine. The first millimeter wave transceiver path includes a first antenna, a first TX path, and a first RX path. The first TX path is used to generate a first calibration signal based on a first TX input signal and transmit the first calibration signal to a second antenna via the first antenna; the first RX path is used to receive a second calibration signal via the first antenna and obtain a second loopback RX signal based on the second calibration signal received by the first antenna. The second millimeter wave transceiver path includes a second antenna, a second TX path, and a second RX path. The second TX path is used to generate a second calibration signal based on a second TX input signal and transmit the second calibration signal to the first antenna via the second antenna; and the second RX path is used to receive the first calibration signal via the second antenna and obtain a first loopback RX signal based on the first calibration signal received by the second antenna. The calibration engine is used to calibrate the T2R relative phase using the first loopback RX signal and the second loopback RX signal.

[0007] Through the method of the present invention, the millimeter wave antenna module can have better reciprocity between the TX and RX paths, and can also improve beamforming loss, thereby having better beam correspondence between the TX and RX paths of the antenna units in the antenna module.

[0008] These and other objects of the present invention will become apparent to those skilled in the art after reading the following detailed description of the preferred embodiment illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1FIG2 is a schematic diagram illustrating a millimeter wave antenna module according to an embodiment of the present invention.

[0010] Figure 2 FIG. 4 is a flow chart illustrating a method for calibrating a T2R relative phase T2R_RP in a millimeter wave beamforming system according to an embodiment of the present invention.

[0011] Figure 3 FIG. 4 is a schematic diagram illustrating calibration of a smaller antenna array of T2R relative phases of 16 antenna elements according to an embodiment of the present invention.

[0012] Figure 4 2 is a schematic diagram illustrating calibration of a larger antenna array of T2R relative phases of 64 antenna elements according to an embodiment of the present invention. DETAILED DESCRIPTION

[0013] Certain words are used in the specification and claims to refer to specific components. It should be understood by those skilled in the art that electronic equipment manufacturers may use different terms to refer to the same component. This specification and claims do not distinguish components by differences in name, but rather by differences in the functions of the components. The term "including" mentioned throughout the specification and subsequent claims is an open-ended term and should be interpreted as "including but not limited to". In addition, the term "coupled" is used herein to include any direct and indirect electrical connection means. Therefore, if the text describes a first device as being electrically connected to a second device, it means that the first device can be directly connected to the second device, or indirectly connected to the second device through other devices or connection means.

[0014] Figure 1 1 is a schematic diagram illustrating a millimeter wave (mmWave) antenna module (AM) 100 according to an embodiment of the present invention. The millimeter wave antenna module 100 may include multiple millimeter wave transceiver paths 10 and 12 and a calibration engine (calibration module) 26, and the millimeter wave transceiver paths 10 and 12 have multiple antennas 22 and 24 respectively. For example, the millimeter wave transceiver paths (antenna arrays) 10 and 12 can both be part of a millimeter wave antenna module. In the following, the terms "millimeter wave transceiver path" and "antenna array" can be interchangeable. In order to better understand the technical features of the present invention, Figure 1 1 and 2. Only two millimeter wave transceiver paths / antenna arrays 10 and 12 are shown. In practice, the millimeter wave antenna module 100 may include more than two millimeter wave transceiver paths / antenna arrays, depending on actual design considerations.

[0015] The millimeter wave transceiver path 10 with the antenna 22 may include a radio frequency (RF) circuit 11 having a first TX path 14 and a first RX path 18, wherein a local oscillator (LO) signal LO_TX1 is used for up-conversion of the first TX path 14, and a LO signal LO_RX1 is used for down-conversion of the first RX path 18. The first TX path 14 may be arranged to send a calibration signal (calibrated signal) BFS_1 based on a TX input signal (e.g., an intermediate frequency (IF) signal) TX_IN_1, and transmit the calibration signal BFS_1 to the antenna 24 via the antenna 22 (for simplicity, the TX path of the calibration signal BFS_1 is referred to as Figure 1 The RX path 18 may be used to receive a calibration signal BFS_2 (which is an RF signal) through the antenna 22 (for simplicity, the RX path of the calibration signal BFS_2 is marked with a dotted arrow), and obtain a loopback RX signal (e.g., an IF signal) LPRX_OUT_2 based on the calibration signal BFS_2 received by the antenna 22. The millimeter wave transceiver path 12 with the antenna 24 may include an RF circuit 13 having a second TX path 16 and a second RX path 20, wherein the LO signal LO_TX2 is used for up-conversion of the second TX path 16, and the LO signal LO_RX2 is used for down-conversion of the second RX path 20. The second TX path 16 may be arranged to send a calibration signal (which is an RF signal) BFS_2 based on the TX input signal (e.g., an IF signal) TX_IN_2, and transmit the calibration signal BFS_2 to the antenna 22 through the antenna 24 (for simplicity, the TX path of the calibration signal BFS_2 is marked with a dotted arrow). Figure 1 The second RX path 20 can be used to receive a calibration signal (which is an RF signal) BFS_1 via antenna 24 (for simplicity, the receive path of calibration signal BFS_1 is indicated by a dashed arrow), and obtain a return RX signal (e.g., an IF signal) LPRX_OUT_1 based on the calibration signal BFS_1 received by antenna 24. The calibration engine 26 can use a built-in algorithm to calculate the phase difference (T2R relative phase T2R_RP) between the RX signals LPRX_OUT_1 and LPRX_OUT_2 returned from RX paths 18 and 20, and compensate the first TX path or the second TX path with the T2R relative phase T2R_RP to adjust their phase offset.

[0016] In this embodiment, the loopback RX signal LPRX_OUT_1 may include three phases: an α phase P1, a β phase P2, and a θ phase P3 (i.e., Phase(LPRX_OUT_1)=P1+P2+P3), where the α phase P1 is calculated by adding the phase mismatch of the signal path of the TX path 14 (i.e., the TX path) to the phase mismatch of the signal path of the RX path 20 (i.e., the RX path), the β phase P2 (which is caused by the LO routing trace) is calculated by subtracting the phase mismatch of the LO signal path of the RX path 20 from the phase mismatch of the LO signal path of the TX path 14, and the θ phase P3 is calculated by subtracting the initial phase of the LO signal path of the RX path 20 from the initial phase of the LO signal path of the TX path 14. In addition, the looped-back RX signal LPRX_OUT_2 may also include three phases: an α phase P4, a β phase P5, and a θ phase P6 (i.e., Phase(LPRX_OUT_2)=P4+P5+P6), where the α phase P4 is calculated by adding the phase mismatch of the signal path of the TX path 16 (i.e., the TX path) to the phase mismatch of the signal path of the RX path 18 (i.e., the RX path), the β phase P5 is calculated by subtracting the phase mismatch of the LO signal path of the RX path 18 from the phase mismatch of the LO signal path of the TX path 16, and the θ phase P6 is calculated by subtracting the initial phase of the LO signal path of the RX path 18 from the initial phase of the LO signal path of the TX path 16.

[0017] In addition, the T2R relative phase T2R_RP can be calculated by subtracting the phase of the loopback RX signal LPRX_OUT_2 from the phase of the loopback RX signal LPRX_OUT_1 (i.e., T2R_RP=Phase(LPRX_OUT_1)-Phase(LPRX_OUT_2), i.e., T2R_RP=(P1+P2+P3)-(P4+P5+P6)=(P1-P4)+(P2-P5)+(P3-P6)). Therefore, the T2R relative phase T2R_RP can be the sum of the three phase differences: α phase difference A1, β phase difference A2, and θ phase difference A3 (i.e., T2R relative phase T2R_RP=A1+A2+A3), wherein the α phase difference A1 can be obtained by subtracting the phase difference PD1 from the phase difference PD2 (i.e., A1=PD2-PD1), the phase difference PD1 is the phase mismatch of the signal path of the RX path 18 minus the phase mismatch of the signal path of the RX path 20, and the phase difference PD2 is the phase mismatch of the signal path of the TX path 14 minus the phase mismatch of the signal path of the TX path 16; the β phase difference A2 can be calculated by adding the phase difference PD3 to the phase difference PD4 (i.e., A2=PD3+PD4), and the phase difference PD3 can be obtained by The phase difference A3 can be calculated by adding the phase difference PD5 and the phase difference PD6 (i.e., A3=PD5+PD6). The phase difference PD5 can be calculated by subtracting the initial phase of the LO signal path of the TX path 14 from the initial phase of the LO signal path of the TX path 16. The phase difference PD6 can be calculated by subtracting the initial phase of the LO signal path of the RX path 20 from the initial phase of the LO signal path of the RX path 18.

[0018] Figure 2 is a flow chart showing a method for calibrating the T2R relative phase T2R_RP in a millimeter wave beamforming system according to an embodiment of the present invention. Figure 2 Perform these steps in the exact order shown. For example, Figure 2 The illustrated method may be used in the millimeter wave antenna module 100 .

[0019] In step S80 , a calibration signal BFS_1 is generated in the first TX path according to the TX input signal TX_IN_1 , and the calibration signal BFS_1 is transmitted to the antenna 24 via the antenna 22 .

[0020] In step S82 , the calibration signal BFS_1 is received via the antenna 24 , and a loopback RX signal LPRX_OUT_1 is obtained in the second RX path according to the calibration signal BFS_1 received by the antenna 24 .

[0021] In step S84 , a calibration signal BFS_2 is generated in the second TX path according to the TX input signal TX_IN_2 , and the calibration signal BFS_2 is transmitted to the antenna 22 via the antenna 24 .

[0022] In step S86 , the calibration signal BFS_2 is received via the antenna 22 , and a loopback RX signal LPRX_OUT_2 is obtained in the first RX path according to the calibration signal BFS_2 received by the antenna 22 .

[0023] In step S88 , the T2R relative phase T2R_RP is calculated according to the phase difference between the returned RX signals LPRX_OUT_1 and LPRX_OUT_2 , and the phase offset in the first TX path or the second TX path is adjusted according to the calculated T2R relative phase T2R_RP, thereby calibrating the T2R relative phase T2R_RP.

[0024] Since those skilled in the relevant art can easily understand the details of the steps after reading the above paragraphs about the millimeter wave antenna module 100, further description is omitted here for the sake of brevity.

[0025] Figure 3is a schematic diagram illustrating a smaller antenna array calibration of the T2R relative phase of 16 antenna elements according to an embodiment of the present invention. The 16 antenna elements a1-a16 contained in the same antenna module (AM) 300 are for illustrative purposes only and are not intended to limit the present invention. Each of the antenna elements a1-a16 has two points representing two different polarizations, V and H, respectively, each connected to a TX path or an RX path. It should be noted that if signals are directly transmitted and received between antenna elements a1 and a16 (located at opposite corners of the antenna module 300), the signal quality may be correspondingly reduced. Therefore, in the method of the present invention, first, the 16 antenna elements a1-a16 are horizontally divided into four groups G1-G4, where group G1 includes antenna elements a1-a4, group G2 includes antenna elements a5-a8, group G3 includes antenna elements a9-a12, and group G4 includes antenna elements a13-a16. The number of groups, division directions, and number of antenna elements within a group in this embodiment are for illustrative purposes only and are not intended to limit the present invention. For example, the antenna units in the antenna module 300 can also be divided vertically into 8 groups, two per group. Assume that antenna units a4, a8, a12, and a16 are set as anchor points for groups G1, G2, G3, and G4, respectively. First, the T2R relative phase of each group is calibrated using the method of the present invention (for example, the T2R relative phase of antenna units a1-a4, the T2R relative phase of antenna units a5-a8, the T2R relative phase of antenna units a9-a12, and the T2R relative phase of antenna units a13-a16). Then, antenna units a4, a8, a12, and a16 are set in the same group G5, with antenna unit a16 set as the anchor point of the G5 group. It should be noted that the selection of anchor points a4, a8, a12, and a16 for each group in this embodiment is for illustration only and does not constitute a limitation of the present invention. After calibrating the T2R relative phase of group G5 (ie, the T2R relative phase of antenna elements a4, a8, a12, and a16), the T2R relative phase of antenna elements a1-a16 can be obtained based on the T2R relative phase of groups G1-G5.

[0026] In group G1, the T2R relative phase between antenna units a1 and a4, the T2R relative phase between antenna units a2 and a4, and the T2R relative phase between antenna units a3 and a4 are first calibrated using the method of the present invention. Assume that when the polarization V of antenna unit a4 is connected to the TX path, the polarization H of antenna units a1-a4 is connected to the RX path. The signal of antenna unit a4 is transmitted from the TX path of antenna unit a4 to the RX path of antenna units a1-a4, respectively. In addition, when the polarization V of antenna unit a4 is connected to the RX path, the polarization H of antenna units a1-a4 is connected to the TX path. The calibration signals of antenna units a1-a4 are transmitted from the TX path of antenna units a1-a4 to the RX path of antenna unit a4, respectively. According to the above embodiment, the T2R relative phase can be the sum of the three phase differences: α phase difference, β phase difference, and θ phase difference (i.e., T2R relative phase = α phase difference + β phase difference + θ phase difference).

[0027] However, it should be noted that this embodiment only focuses on the T2R relative phase of the same polarization. Therefore, for the θ phase difference of the T2R relative phase of antenna elements a1-a4, the θ phase difference is calculated by adding the phase difference SPD to the phase difference FPD, and then subtracting the phase differences TPD and CPD (i.e., θ phase difference = FPD + SPD – TPD – CPD). The phase difference FPD is calculated by subtracting the initial phase of the LO signal path of the TX path of antenna elements a1-a3 (connected to polarization H) from the initial phase of the LO signal path. The phase difference SPD is calculated by subtracting the initial phase of the LO signal path of the TX path of antenna elements a1-a3 (connected to polarization H) from the initial phase of the LO signal path. The phase difference TPD is calculated by subtracting the initial phase of the LO signal path of the RX path of antenna unit a4 (connected to polarization V) from the initial phase of the LO signal path of the TX path of antenna unit a4 (connected to polarization H), and the phase difference CPD is calculated by subtracting the initial phase of the LO signal path of the RX path of antenna unit a4 (connected to polarization V) from the initial phase of the LO signal path of the TX path of antenna unit a4 (connected to polarization H).

[0028] Therefore, the θ phase difference is equal to the sum of the phase difference GPD and the phase difference HPD (i.e., θ phase difference = FPD + SPD – TPD – CPD = GPD + HPD), where the phase difference GPD is calculated by subtracting the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a1 to a3 from the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a1 to a3, and the phase difference HPD is calculated by subtracting the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a4 from the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a1 to a3. Therefore, the θ phase difference of the relative T2R phases of antenna elements a1 to a4 is in the same polarization (i.e., polarization H).

[0029] Similarly, in group G2, the θ phase difference of the T2R relative phases of antenna elements a5-a8 can be calculated by adding a phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a5-a7 from the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a5-a7) and another phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a8 from the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a5-a7).

[0030] In the G3 group, the θ phase difference of the T2R relative phases of the antenna elements a9-a12 can be calculated by adding a phase difference (the phase difference can be calculated by subtracting the initial phase of the LO signal path of the TX path (connected to polarization H) of the antenna elements a9-a11 from the initial phase of the LO signal path of the TX path (connected to polarization H) of the antenna elements a9-a11) and another phase difference (the phase difference can be calculated by subtracting the initial phase of the LO signal path of the RX path (connected to polarization H) of the antenna elements a12 from the initial phase of the LO signal path of the RX path (connected to polarization H) of the antenna elements a9-a11).

[0031] In the G4 group, the θ phase difference of the T2R relative phases of the antenna units a13-a16 can be calculated by adding a phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the TX path (connected to polarization H) of the antenna units a13-a15 from the initial phase of the LO signal path of the TX path (connected to polarization H) of the antenna units a13-a15) and another phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the RX path (connected to polarization H) of the antenna units a16 from the initial phase of the LO signal path of the RX path (connected to polarization H) of the antenna units a13-a15).

[0032] In group G5, the θ phase difference of the T2R relative phases of antenna elements a4, a8, a12, and a16 can be calculated by adding a phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a16 from the initial phase of the LO signal path of the TX path (connected to polarization H) of antenna elements a4, a8, and a12) to another phase difference (which can be calculated by subtracting the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a16 from the initial phase of the LO signal path of the RX path (connected to polarization H) of antenna elements a4, a8, and a12). Therefore, based on the θ phase difference of the T2R relative phases of groups G1 to G5, the θ phase difference of the T2R relative phases of antenna elements a1 to a16 can be obtained.

[0033] Similarly, the α phase difference and β phase difference of the T2R relative phases of the antenna units a1-a16 can also be obtained by the method of the present invention. For the sake of brevity, similar descriptions are not repeated here.

[0034] By adding together the α phase difference, β phase difference, and θ phase difference of the T2R relative phase of antenna units a1-a16, the T2R relative phase of antenna units a1-a16 in the same antenna module 300 can be obtained, and based on the T2R relative phase, the phase offset in the transmission path is adjusted to minimize the calibrated T2R relative phase. After calibrating the T2R relative phase using the method of the present invention, the millimeter wave antenna module using antenna module 300 can have better reciprocity between the TX and RX paths. In addition, the beamforming loss can be improved, thereby having better beam correspondence between the TX and RX paths of antenna units a1-a16 in the antenna module 300.

[0035] Figure 4 Schematic diagram illustrating calibration of a larger antenna array of T2R relative phases of 64 antenna elements according to an embodiment of the present invention. Figure 4As shown, there are 4 antenna modules (AM), including AM "a", AM "b", AM "c" and AM "d", where AM "a" includes 16 antenna elements a1-a16, AM "b" includes 16 antenna elements b1-b16, AM "c" includes 16 antenna elements c1-c16, and AM "d" includes 16 antenna elements d1-d16 (i.e., 64 antenna elements include antenna elements a1-a16, b1-b16, c1-c16 and d1-d16). In addition, the intra-AM T2R relative phases of antenna elements a1-a16, b1-b16, c1-c16 and d1-d16 can be respectively obtained by the above Figure 3 The embodiment shown is obtained. For the sake of brevity, similar descriptions are not repeated here. After obtaining the intra-AM T2R relative phases of antenna elements a1-a16, b1-b16, c1-c16, and d1-d16, antenna elements a16, b13, c4, and d1 belonging to different AMs are placed in the same group G6, with antenna element a16 being set as the anchor point of group G6. It should be noted that the selection of antenna elements b13, c4, and d1 and anchor point a16 in this embodiment is for illustration only and does not constitute a limitation of the present invention.

[0036] For AM "b," by referencing antenna element b13 to anchor point a16, the θ phase difference in the relative T2R phases of antenna elements a16 and b13 can be calculated by adding a phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's TX path (connected to polarization H) from the initial phase of the LO signal path of antenna element b13's TX path (connected to polarization H)) to another phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's RX path (connected to polarization H) from the initial phase of the LO signal path of antenna element b13's RX path (connected to polarization H). Similarly, the α and β phase differences in the relative T2R phases of antenna elements a16 and b13 can be obtained using the methods of the present invention. For the sake of brevity, similar descriptions are not repeated here. The T2R relative phase of antenna elements a16 and b13 can be obtained by adding the α phase difference, β phase difference and θ phase difference of the T2R relative phase of antenna elements a16 and b13. Figure 3 The T2R relative phases of the antenna units b1-b16 obtained in the illustrated embodiment are added to the T2R relative phases of the antenna units a16 and b13 to obtain the T2R relative phases of the antenna units b1-b16 and a16.

[0037] For AM "c," by referencing antenna element c4 to anchor point a16, the θ phase difference in the relative T2R phases between antenna elements a16 and c4 can be calculated by adding a phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's TX path (connected to polarization H) from the initial phase of the LO signal path of antenna element c4's TX path (connected to polarization H)) to another phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's RX path (connected to polarization H) from the initial phase of the LO signal path of antenna element c4's RX path (connected to polarization H). Similarly, the α and β phase differences in the relative T2R phases between antenna elements a16 and c4 can be obtained using the methods of the present invention. For the sake of brevity, similar descriptions are not repeated here. The T2R relative phase of antenna elements a16 and c4 can be obtained by adding the α phase difference, β phase difference and θ phase difference of the T2R relative phase of antenna elements a16 and c4. Figure 3 The T2R relative phases of antenna elements c1-c16 obtained in the illustrated embodiment are added to the T2R relative phases of antenna elements a16 and c4 to obtain the T2R relative phases of antenna elements c1-c16 and a16.

[0038] For AM "d," by referencing antenna element d1 to anchor point a16, the θ phase difference in the relative T2R phases between antenna elements a16 and d1 can be calculated by adding a phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's TX path (connected to polarization H) from the initial phase of the LO signal path of antenna element d1's TX path (connected to polarization H)) to another phase difference (which can be obtained by subtracting the initial phase of the LO signal path of antenna element a16's RX path (connected to polarization H) from the initial phase of the LO signal path of antenna element d1's RX path (connected to polarization H). Similarly, the α and β phase differences in the relative T2R phases between antenna elements a16 and d1 can be obtained using the methods of the present invention. For the sake of brevity, similar descriptions are not repeated here. The T2R relative phase of antenna elements a16 and d1 can be obtained by adding the α phase difference, β phase difference and θ phase difference of the T2R relative phase of antenna elements a16 and d1. Figure 3 The T2R relative phases of antenna elements d1-d16 obtained in the illustrated embodiment are added to the T2R relative phases of antenna elements a16 and d1 to obtain the T2R relative phases of antenna elements d1-d16 and a16.

[0039] Finally, according to the above Figure 3The T2R relative phases of antenna elements a1-a16, antenna elements b1-b16 and a16, antenna elements c1-c16 and a16, and antenna elements d1-d16 and a16 obtained in the illustrated embodiment can be used to determine the T2R relative phases of 64 antenna elements in different antenna modules. After calibrating the T2R relative phases using the method of the present invention, a millimeter-wave antenna module using multiple antenna modules can achieve better beam alignment between the TX and RX beams.

[0040] Those skilled in the art will readily recognize that various modifications and variations can be made to the apparatus and method while retaining the teachings of the present invention.Accordingly, the foregoing should be interpreted as being limited only by the metes and bounds of the appended claims.

Claims

1. A method for calibrating a transmitter-to-receiver T2R relative phase, for use in a millimeter-wave beamforming system, the method comprising: generating a first calibration signal in a first TX path according to a first transmitter TX input signal, and transmitting the first calibration signal to a second antenna of the millimeter wave beamforming system via a first antenna of the millimeter wave beamforming system; receiving the first calibration signal in a second RX path through the second antenna, and obtaining a first loopback RX signal based on the first calibration signal received by the second antenna; generating a second calibration signal in a second TX path according to a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; receiving the second calibration signal in a first RX path through the first antenna, and obtaining a second loopback RX signal based on the second calibration signal received by the first antenna; as well as calculating the T2R relative phase according to a phase difference between the first loopback RX signal and the second loopback RX signal, and providing the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes a difference between a first phase difference and a second phase difference, wherein the first phase difference is a difference between a phase mismatch of a signal path of the first TX path and a phase mismatch of a signal path of the second TX path, and the second phase difference is a difference between a phase mismatch of a signal path of the first RX path and a phase mismatch of a signal path of the second RX path.

2. The method according to claim 1, wherein The first TX path, the first RX path, the first antenna, the second TX path, the second RX path, and the second antenna are all packaged in the same antenna module.

3. The method according to claim 1, wherein The first calibration signal is generated and transmitted by the first TX path, the second calibration signal is generated and transmitted by the second TX path, the second calibration signal is received by the first RX path, and the first calibration signal is received by the second RX path; the first TX path, the first RX path, and the first antenna are encapsulated in a first antenna submodule; and the second TX path, the second RX path, and the second antenna are encapsulated in a second antenna submodule.

4. A method for calibrating a transmitter-to-receiver T2R relative phase, for use in a millimeter-wave beamforming system, the method comprising: generating a first calibration signal in a first TX path according to a first transmitter TX input signal, and transmitting the first calibration signal to a second antenna of the millimeter wave beamforming system via a first antenna of the millimeter wave beamforming system; receiving the first calibration signal in a second RX path through the second antenna, and obtaining a first loopback RX signal based on the first calibration signal received by the second antenna; generating a second calibration signal in a second TX path according to a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; receiving the second calibration signal in a first RX path through the first antenna, and obtaining a second loopback RX signal based on the second calibration signal received by the first antenna; as well as calculating the T2R relative phase according to a phase difference between the first loopback RX signal and the second loopback RX signal, and providing the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes a sum of a third phase difference and a fourth phase difference, wherein the third phase difference is a difference between a phase mismatch of a local oscillator (LO) signal path of the first TX path and a phase mismatch of an LO signal path of the second TX path, and the fourth phase difference is a difference between a phase mismatch of a LO signal path of the first RX path and a phase mismatch of an LO signal path of the second RX path.

5. A method for calibrating a transmitter-to-receiver T2R relative phase in a millimeter-wave beamforming system, the method comprising: generating a first calibration signal in a first TX path according to a first transmitter TX input signal, and transmitting the first calibration signal to a second antenna of the millimeter wave beamforming system via a first antenna of the millimeter wave beamforming system; receiving the first calibration signal in a second RX path through the second antenna, and obtaining a first loopback RX signal based on the first calibration signal received by the second antenna; generating a second calibration signal in a second TX path according to a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; receiving the second calibration signal in a first RX path through the first antenna, and obtaining a second loopback RX signal based on the second calibration signal received by the first antenna; as well as calculating the T2R relative phase according to a phase difference between the first loopback RX signal and the second loopback RX signal, and providing the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes the sum of a fifth phase difference and a sixth phase difference, wherein the fifth phase difference is the difference between the initial phase of the LO signal path of the first TX path and the initial phase of the LO signal path of the second TX path, and the sixth phase difference is the difference between the initial phase of the LO signal path of the first RX path and the initial phase of the LO signal path of the second RX path.

6. A millimeter wave antenna module, comprising: The first mmWave transceiver path, including: First antenna; a first TX path for generating a first calibration signal based on a first TX input signal, and transmitting the first calibration signal to a second antenna via the first antenna; and a first RX path, configured to receive a second calibration signal via the first antenna, and obtain a second loopback RX signal based on the second calibration signal received by the first antenna; The second mmWave transceiver path includes: Second antenna; a second TX path for generating a second calibration signal based on a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; and a second RX path, configured to receive the first calibration signal via the second antenna, and obtain a first loopback RX signal based on the first calibration signal received by the second antenna; and a calibration engine configured to calculate a T2R relative phase using the first loopback RX signal and the second loopback RX signal, and provide the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes a difference between a first phase difference and a second phase difference, wherein the first phase difference is a difference between a phase mismatch of a signal path of the first TX path and a phase mismatch of a signal path of the second TX path, and the second phase difference is a difference between a phase mismatch of a signal path of the first RX path and a phase mismatch of a signal path of the second RX path. 7 . The millimeter wave antenna module according to claim 6 , wherein the first TX path, the first RX path, the first antenna, the second TX path, the second RX path, and the second antenna are all packaged in the same antenna module.

8. The millimeter wave antenna module according to claim 6, wherein: The first TX path, the first RX path, and the first antenna are packaged in a first antenna submodule; and the second TX path, the second RX path, and the second antenna are packaged in a second antenna submodule.

9. A millimeter wave antenna module, comprising: The first mmWave transceiver path, including: First antenna; a first TX path for generating a first calibration signal based on a first TX input signal, and transmitting the first calibration signal to a second antenna via the first antenna; and a first RX path, configured to receive a second calibration signal via the first antenna, and obtain a second loopback RX signal based on the second calibration signal received by the first antenna; The second mmWave transceiver path includes: Second antenna; a second TX path for generating a second calibration signal based on a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; and a second RX path, configured to receive the first calibration signal via the second antenna, and obtain a first loopback RX signal based on the first calibration signal received by the second antenna; and a calibration engine configured to calculate a T2R relative phase using the first loopback RX signal and the second loopback RX signal, and provide the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes a sum of a third phase difference and a fourth phase difference, wherein the third phase difference is a difference between a phase mismatch of the LO signal path of the first TX path and a phase mismatch of the LO signal path of the second TX path, and the fourth phase difference is a difference between a phase mismatch of the LO signal path of the first RX path and a phase mismatch of the LO signal path of the second RX path.

10. A millimeter wave antenna module, comprising: The first mmWave transceiver path, including: First antenna; a first TX path for generating a first calibration signal based on a first TX input signal, and transmitting the first calibration signal to a second antenna via the first antenna; and a first RX path, configured to receive a second calibration signal via the first antenna, and obtain a second loopback RX signal based on the second calibration signal received by the first antenna; The second mmWave transceiver path includes: Second antenna; a second TX path for generating a second calibration signal based on a second TX input signal, and transmitting the second calibration signal to the first antenna via the second antenna; and a second RX path, configured to receive the first calibration signal via the second antenna, and obtain a first loopback RX signal based on the first calibration signal received by the second antenna; and a calibration engine configured to calculate a T2R relative phase using the first loopback RX signal and the second loopback RX signal, and provide the calculated T2R relative phase to the first TX path or the second TX path; The T2R relative phase includes the sum of a fifth phase difference and a sixth phase difference, wherein the fifth phase difference is the difference between the initial phase of the LO signal path of the first TX path and the initial phase of the LO signal path of the second TX path, and the sixth phase difference is the difference between the initial phase of the LO signal path of the first RX path and the initial phase of the LO signal path of the second RX path.

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