A method and device for improving radar transmission power and millimeter wave radar

Abstract

The present application discloses a method, device and millimeter wave radar for improving radar transmission power. The method of the present application includes: dividing one antenna into N small antennas; feeding the N small antennas simultaneously to synthesize the power of the N small antennas; transmitting radar signals through the N small antennas after power synthesis. The present application utilizes mainstream commercial millimeter wave radar chips and improves radar transmission power through multi-channel space / circuit transmission synthesis technology. A higher performance and lower cost millimeter wave radar solution is achieved.

Description

Technical Field

[0001] The present application relates to the field of millimeter wave radar, and in particular to a method and device for improving radar transmission power and a millimeter wave radar. Background Art

[0002] At present, with the rise of the unmanned driving craze, 77GHz millimeter wave radar sensors are attracting more and more attention. Compared with the traditional 24Ghz frequency band solution, the 77GHz product has a smaller size, higher system integration, and more advanced and rich integrated radar algorithms. At the same time, 77GHz millimeter wave radar is also widely used in the transportation field, such as urban intersections and highways, and is an important sensor for future vehicle-road collaboration. As a radar system, the main function of the radar is to realize the perception of the distance, speed, and angle of the surrounding objects. Through different radar systems and various advanced radar algorithms, we can better obtain the above three dimensions of information. However, the basis of all this information is the signal-to-noise ratio of the radar link, which directly affects the radar's range, distance measurement, speed measurement, and angle measurement accuracy. The higher the signal-to-noise ratio, the stronger the radar's ranging capability, the more it can detect weak targets, and the higher the accuracy of the measurement results.

[0003] The current mainstream commercial 77GHz millimeter wave radar chips, such as Ti, NXP, etc., usually have a transmission power of 13dBm. Due to process limitations, this value is difficult to increase. Therefore, various manufacturers have increased the transmission power in disguise from the algorithm level. Technologies such as BPM-MIMO and DDMA-MIMO all use phase shifters, which transmit coherent superposition through multiple antennas at the same time, and improve the transmission EIRP through the idea of ​​array. The main problem with this method of using phase shifters is that it increases the difficulty of chip design and the complexity of subsequent radar signal processing. In addition, complex calibration technology is required in actual application to ensure that the phase of the phase shifter is output according to the designed value in high and low temperature environments, which increases the development cost.

[0004] Therefore, the above-mentioned technical problems existing in the related technology need to be solved urgently. Summary of the invention

[0005] The present application aims to solve one of the technical problems in the related art. To this end, the embodiments of the present application provide a method, a device and a millimeter wave radar for increasing the transmission power of a radar, which can increase the transmission power of the radar at a relatively low cost.

[0006] According to one aspect of an embodiment of the present application, a method for increasing radar transmission power is provided, the method comprising:

[0007] Divide one antenna into N small antennas;

[0008] Feeding the N small antennas simultaneously to synthesize the power of the N small antennas;

[0009] The N small antennas after power synthesis transmit radar signals through antennas;

[0010] Wherein, N is less than or equal to the number of transmitting channels of the radar.

[0011] In one embodiment, the method further comprises:

[0012] Get the number of radar transmission channels;

[0013] Get an unoccupied transmit channel.

[0014] In one embodiment, the simultaneously feeding the N small antennas includes:

[0015] The N small antennas are fed simultaneously through the unoccupied transmission channels.

[0016] In one embodiment, the synthesizing the power of the N small antennas includes:

[0017] The power of the N small antennas is synthesized by using a spatial power synthesis technology;

[0018] The spatial power synthesis technology at least includes spatial power synthesis within the waveguide and antenna far-field power synthesis.

[0019] In one embodiment, the synthesizing the power of the N small antennas includes:

[0020] The power of the N small antennas is synthesized through a microwave circuit structure;

[0021] The microwave circuit structure at least includes a ring coupler and a Wilkins power divider.

[0022] In one embodiment, the method further comprises:

[0023] The radar signal is transmitted through the antenna while maintaining the maximum range of the radar.

[0024] In one embodiment, the synthesizing the power of the N small antennas includes:

[0025] Synthesize the power of M small antennas as needed;

[0026] Where M is less than or equal to N.

[0027] According to one aspect of an embodiment of the present application, a device for increasing radar transmission power is provided, the device comprising:

[0028] The first module is used to divide one antenna into N small antennas;

[0029] The second module is used to feed the N small antennas simultaneously and synthesize the power of the N small antennas;

[0030] The third module is used to transmit the radar signal through the antenna of the N small antennas after power synthesis;

[0031] Wherein, N is less than or equal to the number of transmitting channels of the radar.

[0032] According to one aspect of an embodiment of the present application, a device for increasing radar transmission power is provided, the device comprising:

[0033] at least one processor;

[0034] at least one memory, the memory being used to store at least one program;

[0035] When at least one of the programs is executed by at least one of the processors, a method for increasing radar transmission power as described in the previous embodiment is implemented.

[0036] According to one aspect of an embodiment of the present application, a millimeter wave radar is provided, including an antenna, a transceiver, a controller and a power synthesis device, wherein the power synthesis device is used to synthesize the power of N small antennas.

[0037] The beneficial effects of a method, device and millimeter wave radar for improving radar transmission power provided by the embodiments of the present application are as follows: the present application divides one antenna into N small antennas; feeds the N small antennas simultaneously to synthesize the power of the N small antennas; and transmits radar signals through the antennas of the N small antennas after power synthesis. The present application utilizes mainstream commercial millimeter wave radar chips and improves radar transmission power through multi-channel space / circuit transmission synthesis technology. A higher performance and lower cost millimeter wave radar solution is achieved.

[0038] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A flowchart of a method for increasing radar transmission power provided in an embodiment of the present application;

[0041] Figure 2A schematic diagram of power synthesis of multiple small antennas provided in an embodiment of the present application;

[0042] Figure 3 A schematic diagram of a device for increasing radar transmission power provided in an embodiment of the present application;

[0043] Figure 4 A schematic diagram of another device for increasing radar transmission power provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0045] The terms "first", "second", "third" and "fourth" etc. in the specification, claims and drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] At present, with the rise of the unmanned driving craze, 77GHz millimeter wave radar sensors are attracting more and more attention. Compared with the traditional 24Ghz frequency band solution, the 77GHz product has a smaller size, higher system integration, and more advanced and rich integrated radar algorithms. At the same time, 77GHz millimeter wave radar is also widely used in the transportation field, such as urban intersections and highways, and is an important sensor for future vehicle-road collaboration. As a radar system, the main function of the radar is to realize the perception of the distance, speed, and angle of the surrounding objects. Through different radar systems and various advanced radar algorithms, we can better obtain the above three dimensions of information. However, the basis of all this information is the signal-to-noise ratio of the radar link, which directly affects the radar's range, distance measurement, speed measurement, and angle measurement accuracy. The higher the signal-to-noise ratio, the stronger the radar's ranging capability, the more it can detect weak targets, and the higher the accuracy of the measurement results.

[0048] The current mainstream commercial 77GHz millimeter wave radar chips, such as Ti, NXP, etc., usually have a transmission power of 13dBm. Due to process limitations, this value is difficult to increase. Therefore, each manufacturer has increased the transmission power in disguise from the algorithm level. Technologies such as BPM-MIMO and DDMA-MIMO all use phase shifters, which transmit coherent superposition through multiple antennas at the same time, and improve the transmission EIRP through the idea of ​​array. The main problem with this method of using phase shifters is that it increases the difficulty of chip design and the complexity of subsequent radar signal processing. In addition, complex calibration technology is required in actual application to ensure that the phase of the phase shifter is output according to the designed value in high and low temperature environments, which increases the development cost. If you choose to increase the antenna aperture and the area of ​​the antenna, it will inevitably lead to a narrowing of the antenna beam angle. The antenna design of the radar needs to be determined according to the system FOV (Field of View radar field of view). Too small a beam angle will cause the FOV indicator to fail, which will lead to radar selective blindness, that is, the edge area within the field of view cannot be detected. In the 77GHz frequency band, as the antenna aperture increases, the antenna plate and ohmic loss will increase, which will lead to a decrease in antenna efficiency.

[0049] In order to solve the above problems, this application proposes a method, device and millimeter wave radar for improving radar transmission power, aiming to use the existing commercial millimeter wave radar chip architecture to achieve a low-cost radar signal-to-noise ratio enhancement solution through spatial power synthesis or circuit-level power synthesis. The specific idea is: the signal-to-noise ratio is related to many factors. The calculation formula of the signal-to-noise ratio is:

[0050] SNR=Pr / N=Pt*Gt*σ*Gr / [(4π)^3*r^4*N]

[0051] Among them, SNR is the signal-to-noise ratio, Pr is the received power, Gt is the transmitting antenna gain, Gr is the receiving antenna gain, σ is the scattering cross-sectional area of ​​the target, r is the distance between the target and the radar, and N is the receiver noise. Therefore, this application improves the transmit and receive antenna gain by increasing the transmit power from the perspective of the transmitting end and the antenna.

[0052] Figure 1 A flowchart of a method for increasing radar transmission power provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, a method for increasing radar transmission power proposed in this application includes:

[0053] S101, dividing one antenna into N small antennas.

[0054] Exemplarily, in step S101, one antenna can be divided into N small antennas by coherent accumulation. The energy of a single pulse of the radar is limited, and a single received pulse is usually not used for detection and judgment. Before the judgment, multiple pulses need to be processed to improve the signal-to-noise ratio. This processing method based on multiple pulses is accumulation. Coherent accumulation refers to the accumulation of radar echo complex data (i.e., data containing amplitude and phase after orthogonal demodulation), and directly summing multiple independent measurement values. Since each measurement value is added in the same direction, the energy is effectively accumulated. For a single-antenna pulse radar, independent measurement is simply the echo data of multiple pulses. Slow time usually refers to each pulse in the time dimension, so its accumulation process is the same-direction superposition of slow time dimension data. The phase of each pulse is not the same. Through fast Fourier processing, it can be simply understood as compensating for different phases and achieving same-direction superposition. Coherent accumulation uses the phase relationship between received pulses to add up the amplitudes of signals. The advantage of using coherent accumulation in this embodiment to divide one antenna into N small antennas is that all radar echo energies can be directly added together. Incoherent accumulation is performed after taking the signal envelope. At this time, the information of the complex signal is removed, and only the modulus value is retained without a strict phase relationship.

[0055] S102: Feed the N small antennas simultaneously to synthesize the power of the N small antennas.

[0056] In step S102, the simultaneously feeding the N small antennas includes: simultaneously feeding the N small antennas through the unoccupied transmission channels, wherein N is less than or equal to the number of transmission channels of the radar.

[0057] Furthermore, the synthesizing the power of the N small antennas includes: synthesizing the power of the N small antennas by using a spatial power synthesis technology; the spatial power synthesis technology includes at least spatial power synthesis in a waveguide and antenna far-field power synthesis. Alternatively, synthesizing the power of the N small antennas may also include synthesizing the power of the N small antennas by using a microwave circuit structure; the microwave circuit structure includes at least a ring coupler and a Wilkins power divider.

[0058] In this embodiment, the methods for synthesizing the power of the N small antennas include spatial power synthesis and microwave circuit structure synthesis. Spatial power synthesis mainly includes spatial power synthesis in waveguides, antenna far-field power synthesis, etc. The spatial power synthesis in waveguides mainly uses different structural forms of millimeter-wave devices to place them in a quasi-optical cavity for power synthesis; the antenna far-field power synthesis mainly utilizes the radiation and mutual coupling characteristics of the antenna to synthesize the radiation power of each millimeter-wave device in free space, which can be suitable for larger power synthesis of multiple devices. Microwave circuit structure synthesis mainly realizes power synthesis by means of traditional devices. For example, power synthesis can be performed through a ring coupler and a Wilkins power divider.

[0059] S103: The N small antennas with combined power transmit radar signals through antennas.

[0060] This application uses mainstream commercial millimeter-wave radar chips and multi-path space / circuit transmission synthesis technology to improve radar transmission power, thus achieving a higher performance and lower cost millimeter-wave radar solution.

[0061] At present, mainstream millimeter-wave radar chips generally integrate 4, 3 or 2 transmission channels. In chip design and packaging design, all manufacturers have adopted equal length design for the transmission path length of each transmission channel, which means that all transmission outputs are in phase, or phase coherent. On the other hand, the current mainstream radar design generally does not use up all the transmission channels, and there will always be extra transmission channels idle. This application uses idle transmission channels to increase the radar transmission power, so it is necessary to obtain the number of radar transmission channels and obtain unoccupied transmission channels.

[0062] Figure 2 A schematic diagram of power synthesis of multiple small antennas provided in an embodiment of the present application is shown in FIG. Figure 2As shown, after the N small antennas after power synthesis transmit radar signals through the antenna, it can directly bring 10*log(N) SNR (signal-to-noise ratio) gain to the radar, and 2-way synthesis can bring 3dB SNR gain, which leads to a 1.2-fold increase in the maximum ranging capability. If 4-way power synthesis is used, it can bring 6dB SNR gain, which leads to a 1.4-fold increase in the maximum ranging capability. If the maximum ranging is kept unchanged, and the radar signal is transmitted through the antenna while keeping the maximum ranging of the radar unchanged, the improvement of SNR will directly reduce the false alarm rate of the radar, allowing the radar to detect weaker targets and improve the measurement reliability of the radar.

[0063] Optionally, the technician can synthesize the power of the N small antennas according to the need to improve the signal-to-noise ratio. The specific adjustment method includes: synthesizing the power of M small antennas according to the need, where M is less than or equal to N. As described in the above embodiment, 2-way synthesis can bring 3dB SNR gain, 4-way power synthesis can bring 6dB SNR gain, and the two increase in sequence. The technician can select small antennas of different paths for power synthesis according to actual needs to achieve different degrees of signal-to-noise ratio improvement.

[0064] like Figure 3 As shown, this embodiment also provides a device for increasing radar transmission power, the device comprising:

[0065] The first module 301 is used to divide one antenna into N small antennas;

[0066] The second module 302 is used to feed the N small antennas simultaneously to synthesize the power of the N small antennas;

[0067] The third module 303 is used to transmit the radar signal through the antenna by the N small antennas after power synthesis;

[0068] Wherein, N is less than or equal to the number of transmitting channels of the radar.

[0069] like Figure 4 As shown, this embodiment also provides a device for increasing radar transmission power, the device comprising:

[0070] at least one processor 401;

[0071] At least one memory 402, the memory 402 is used to store at least one program;

[0072] When at least one of the programs is executed by at least one of the processors 401, a method for increasing radar transmission power as described in the previous embodiment is implemented.

[0073] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0074] In addition, this embodiment also provides a millimeter wave radar, including an antenna, a transceiver, a controller and a power synthesis device, wherein the power synthesis device is used to synthesize the power of N small antennas. The power synthesis device includes a device capable of synthesizing the power of multiple small antennas in the above embodiment, such as a power synthesizer, which first synthesizes the multi-channel power and then transmits it through the antenna, which can bring about an increase in the transmission gain of the millimeter wave radar. The millimeter wave radar provided in this embodiment is a radar that works in the millimeter wave band (millimeter wave) detection. Usually millimeter waves refer to the 30-300GHz frequency domain (wavelength of 1-10mm), the wavelength is between microwaves and centimeter waves, and has the advantages of microwave radars and photoelectric radars. The millimeter wave radar of the present application can be applied to high-precision multidimensional search measurement, target feature extraction and classification recognition, including but not limited to vehicle navigation and terrain tracking, ship navigation and other aspects.

[0075] In some selectable embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the application is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. Selectable embodiments are expected, wherein the order of various operations is changed and the sub-operation of a part described as a larger operation is performed independently.

[0076] In addition, although the present application is described in the context of functional modules, it should be understood that, unless otherwise specified, one or more of the functions and / or features can be integrated into a single physical device and / or software module, or one or more functions and / or features can be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the present application. More specifically, in view of the properties, functions, and internal relationships of the various functional modules in the device disclosed herein, the actual implementation of the module will be understood within the conventional techniques of the engineer. Therefore, those skilled in the art can implement the present application set forth in the claims without excessive experimentation using ordinary techniques. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present application, which is determined by the full scope of the attached claims and their equivalents.

[0077] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0078] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0079] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0080] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0081] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

[0082] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for increasing radar transmission power, characterized in that: The method comprises: Divide one antenna into N small antennas; Feeding the N small antennas simultaneously to synthesize the power of the N small antennas; Transmitting radar signals through the N small antennas after power synthesis; Where N is less than or equal to the number of radar transmission channels; The synthesizing the power of the N small antennas includes: The power of the N small antennas is synthesized by using a spatial power synthesis technology; The spatial power synthesis technology at least includes spatial power synthesis in waveguide and antenna far-field power synthesis; The synthesizing the power of the N small antennas includes: The power of the N small antennas is synthesized through a microwave circuit structure; The microwave circuit structure at least includes a ring coupler and a Wilkins power divider.

2. A method for increasing radar transmission power according to claim 1, characterized in that: The method further comprises: Get the number of radar transmission channels; Get an unoccupied transmit channel.

3. A method for increasing radar transmission power according to claim 2, characterized in that: The N small antennas are fed simultaneously, including: The N small antennas are fed simultaneously through the unoccupied transmission channels.

4. A method for increasing radar transmission power according to claim 1, characterized in that: The method further comprises: The radar signal is transmitted through the antenna while maintaining the maximum range of the radar.

5. The method for increasing radar transmission power according to claim 1, characterized in that: The synthesizing the power of the N small antennas includes: Synthesize the power of M small antennas as needed; Where M is less than or equal to N.

6. A device for increasing radar transmission power, characterized in that: The device comprises: The first module is used to divide one antenna into N small antennas; The second module is used to feed the N small antennas simultaneously and synthesize the power of the N small antennas; The third module transmits radar signals through the N small antennas after power synthesis; Where N is less than or equal to the number of radar transmission channels; The second module is further used for: The power of the N small antennas is synthesized by using a spatial power synthesis technology; The spatial power synthesis technology at least includes spatial power synthesis in waveguide and antenna far-field power synthesis; The second module is further used for: The power of the N small antennas is synthesized through a microwave circuit structure; The microwave circuit structure at least includes a ring coupler and a Wilkins power divider.

7. A device for increasing radar transmission power, characterized in that: The device comprises: at least one processor; at least one memory, the memory being used to store at least one program; When at least one of the programs is executed by at least one of the processors, a method for increasing radar transmission power as described in any one of claims 1 to 5 is implemented.

8. A millimeter wave radar, characterized in that: The millimeter wave radar implements a method for improving radar transmission power as described in any one of claims 1 to 5, and the millimeter wave radar includes an antenna, a transceiver, a controller and a power synthesis device, wherein the power synthesis device is used to synthesize the power of N small antennas.

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