Millimeter wave sensor chips and millimeter wave radar

Abstract

The present invention discloses a millimeter wave radar chip and a millimeter wave radar, wherein the millimeter wave chip includes: a radio frequency transceiver for transmitting and receiving millimeter wave signals; an analog signal processing unit for performing low-pass or band-pass filtering on the intermediate frequency signal generated by the echo signal, and generating a corresponding digital baseband signal after analog-to-digital conversion; a hardware acceleration circuit including a distance FFT module for calculating the distance information of the target by performing fast Fourier transform on the digital signal, and when there are multiple target objects, sorting the distances of the multiple targets according to the energy of the received millimeter wave signal; a signal generator for generating a frequency control word; and a frequency synthesizer for generating the required frequency modulation continuous wave frequency signal according to the frequency control word. The millimeter wave radar chip can solve the problems of complex system and inconvenient configuration in the prior art.

Description

Technical Field

[0001] The present invention relates to chip technology, and in particular to a millimeter wave sensor chip and a millimeter wave radar. Background Art

[0002] Millimeter waves refer to electromagnetic waves with a wavelength of 0.1 to 1 cm, and the corresponding frequency range is 30 to 300 GHz. Millimeter wave radars are widely used in automotive radars, intelligent robots, vital sign measurement, gesture recognition and other fields. Therefore, millimeter wave radar chips have also emerged.

[0003] Traditional millimeter wave radar chips generally only include a TR component to achieve simple transceiver functions, such as Infineon's BGT24 series chips. Such products need to be used with a large number of other functional chips, such as frequency chips or voltage-controlled oscillator chips that generate RF signals, ADC chips for analog baseband, DSP chips for signal processing, etc. While increasing system costs, the system is also very complex, requiring developers or users to have a clear understanding of the specifications of various chips in order to design a good system.

[0004] Another type of millimeter-wave radar chip is represented by TI's IWR series, which integrates all the functions required by millimeter-wave radar chips into one chip. Taking IWR1642 as an example, in addition to integrating 2 RF transmitters and 4 RF receivers, the chip also integrates analog baseband and complex DSP signal processing. However, the biggest problem with this is that the chip is too large, has many pins, and is very troublesome to configure. Customers often need to spend a lot of energy to study how to use this chip. Summary of the invention

[0005] The technical problem to be solved by the embodiments of the present invention is how to solve the problem of complex millimeter wave radar chip system and inconvenient configuration in the prior art.

[0006] In order to solve the above problems, the technical solution provided by the present invention is as follows:

[0007] A millimeter wave radar chip, including: a radio frequency transceiver for transmitting and receiving millimeter wave signals; an analog signal processing unit for performing low-pass or band-pass filtering on an intermediate frequency signal generated by an echo signal, and generating a corresponding digital baseband signal after analog-to-digital conversion; a hardware acceleration circuit, including a distance FFT module, for calculating the distance information of a target by performing fast Fourier transform on the digital signal; and when there are multiple target objects, sorting the distances of the multiple targets according to the energy of the received millimeter wave signals; a signal generator for generating a frequency control word; and a frequency synthesizer for generating a required frequency modulated continuous wave frequency signal according to the frequency control word.

[0008] Preferably, in the above-mentioned millimeter-wave radar chip, the signal generator is also used to send an indication signal to perform timing control on the hardware acceleration circuit.

[0009] Preferably, in the above-mentioned millimeter-wave radar chip, the indication signal includes: a frame start mark, used to indicate that the next received data is a data frame, until the next frame start mark is received; a linear frequency modulation signal start mark, used to indicate that the next received data is an analog-to-digital conversion generated by a linear frequency modulation signal, until the next linear frequency modulation signal start mark is received.

[0010] Preferably, in the above-mentioned millimeter-wave radar chip, when there are multiple millimeter-wave radar chips in cascade, each of the millimeter-wave radar chips receives the frame start mark sent by the main chip as a synchronization signal to indicate that the data received thereafter are all outputs from the same frame.

[0011] Preferably, in the above-mentioned millimeter wave radar chip, the parameters in the frequency control word include: the number of linear frequency modulation signals of the frequency modulated continuous wave, the shape and time of each linear frequency modulation signal, the frequency scanning range, and the number of linear frequency modulation signals in a frame.

[0012] Preferably, in the above-mentioned millimeter wave radar chip, the analog signal processing unit includes: an intermediate frequency filter for performing low-pass or band-pass filtering on the intermediate frequency signal; and an analog-to-digital conversion circuit for performing analog-to-digital conversion.

[0013] Preferably, in the above-mentioned millimeter-wave radar chip, the hardware acceleration circuit also includes a Doppler FFT module, which is used to calculate the speed information of the target object by performing a fast Fourier transform on the digital signal; and when there are multiple target objects, the speeds of the multiple targets are sorted according to the energy of the received millimeter-wave signal.

[0014] Preferably, in the above-mentioned millimeter wave radar chip, the hardware acceleration circuit also includes a downsampling module, which is used to downsample the digital baseband signal to reduce the subsequent data processing scale.

[0015] Preferably, in the above-mentioned millimeter wave radar chip, it is characterized in that the result generated by the hardware acceleration circuit is output to the MCU or external circuit through the interface circuit.

[0016] In order to solve the above technical problems, the present invention also discloses a millimeter wave radar, including the above-mentioned millimeter wave radar chip.

[0017] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0018] In the present invention, a millimeter wave radar chip is proposed. By integrating a radio frequency transceiver, an analog signal processing unit, a hardware acceleration circuit, a signal generator and a frequency synthesizer for generating a frequency modulated continuous wave frequency signal, the millimeter wave radar chip itself can realize a complete frequency modulated continuous wave millimeter wave sensing function, thereby overcoming the problem that a large number of supporting chips are required for traditional radar solutions, resulting in a complex and costly entire system, or the chip itself is too large in size and has a complex configuration, thereby achieving the purpose of flexibility and portability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a millimeter wave radar chip according to an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 A structural schematic diagram of a digital DSP module in a millimeter wave radar chip shown;

[0021] Figure 3 yes Figure 1 The timing of the Pattern Generator module in the millimeter-wave radar chip is shown.

[0022] Reference numerals

[0023] Millimeter wave radar chip 100

[0024] Millimeter wave transmitter module 101

[0025] Phase-locked loop 102

[0026] Pattern Generator Module 103

[0027] Millimeter wave receiving module 104

[0028] IF filter 105

[0029] Analog-to-digital conversion circuit 106

[0030] Digital DSP module 107

[0031] Interface circuit 108

[0032] Downsampling submodule 201

[0033] Range FFT submodule 202

[0034] Doppler FFT submodule 203

[0035] Interface circuit 204 DETAILED DESCRIPTION

[0036] In traditional millimeter-wave radar sensors, since usually only one TR component is included to realize simple transceiver functions, a large number of other functional chips need to be used in the process of use. Therefore, while increasing the system cost, the system is also very complicated, requiring developers or users to have a clear understanding of the specifications and parameters of various chips in order to design a good system. Or the chip integrates all the functions required by the millimeter-wave radar chip into one chip, resulting in the chip being too large in size, with many pins, and the configuration is very troublesome. Customers often need to spend a lot of energy to study how to use this chip. The embodiment of the present invention proposes a millimeter-wave radar chip, which integrates a radio frequency transceiver, an analog signal processing unit, a hardware acceleration circuit, a signal generator, and a frequency synthesizer that generates a frequency modulated continuous wave frequency signal, so that the millimeter-wave radar chip itself can realize a complete frequency modulated continuous wave millimeter wave sensing function, thereby overcoming the problem that the traditional radar solution requires a large number of supporting chips, resulting in the complexity and high cost of the entire system, or the problem that the chip itself is too large in size and complex in configuration, and achieves the purpose of flexibility and lightness.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] Example 1

[0039] Combination Figures 1 to 3 As shown, a millimeter wave radar chip 100 of the present embodiment includes a radio frequency transceiver composed of a millimeter wave transmitting module 101, a millimeter wave receiving module 104 and a transceiver antenna, an intermediate frequency filter 105 and an analog-to-digital conversion circuit 106 constituting an analog signal processing unit, a digital DSP module 107 as a hardware acceleration circuit, a Pattern Generator module 103 as a signal generator, and a Phase Locked Loop (PLL) 102 as a frequency synthesizer.

[0040] Among them, the Pattern Generator module 103 is a digital module, which is mainly used to generate a frequency control word. By configuring the Pattern Generator module 103, the number of chirps of the Frequency Modulated Continuous Wave (FMCW) signal, the shape and time of each chirp, the frequency scanning range, the number of chirps in a Frame, and all other parameters related to FMCW can be set.

[0041] The phase locked loop (PLL) 102 generates the required FMCW signal by using the parameters generated by the pattern generator module 103. The radio frequency signal passes through the millimeter wave transmitting module 101 of the radio frequency transceiver and is transmitted through the antenna TX.

[0042] The transmitted signal is reflected by an object and passes through the millimeter wave receiving module 104 to generate an intermediate frequency signal. The intermediate frequency signal is low-pass or band-pass filtered by the intermediate frequency filter 105 and enters the analog-to-digital conversion circuit 106 to generate original ADC data. The subsequent digital DSP module 107 performs calculations based on the output of the ADC to obtain the results of 1D or 2D FFT, and outputs the results to the MCU (not shown in the figure) or other external circuits (not shown in the figure) through the interface circuit 108.

[0043] Figure 2 It is a specific implementation of the hardware accelerated digital DSP module 107 of the present invention. The intermediate frequency signal enters the digital DSP module 107 after being converted by the analog-to-digital conversion circuit 106. This module mainly includes a downsampling submodule 201, a distance FFT submodule 202, and a Doppler FFT submodule 203, which are used to calculate the distance information and speed information of the target or multiple targets by performing Fast Fourier Transform (FFT) on the digital signal. Among them, the downsampling submodule 201 downsamples the original data obtained by the analog-to-digital conversion circuit 106 to reduce the scale of the subsequent distance FFT and Doppler FFT, thereby saving hardware resources and power consumption. The downsampled data will be sent to the distance FFT submodule 202. The distance FFT submodule 202 is also called a 1D-FFT submodule. Its main function is to directly perform FFT operation on the downsampled data to calculate the distance information of the target. If there are multiple targets, multiple targets can also be sorted according to the energy they receive. The output of 1D-FFT is sent to Doppler FFT submodule 203.

[0044] The Doppler FFT submodule 203 is also called 2D-FFT. The main function of this submodule is to calculate the speed information of the target object. If there are multiple targets, the speeds of the multiple targets can also be sorted. The result of the Doppler FFT submodule 203 can be directly sent to the interface circuit 204 and sent out from the chip. In addition, the raw data and the result of the range FFT can also be directly sent from the interface circuit 204. If the chip contains two or more receiving channels, the angle information can be calculated based on the output data.

[0045] In order to perform digital signal processing on the raw data of the ADC, the digital DSP module 107 must know some timing information, such as when the ADC data is valid data, which can be used for FFT analysis. Figure 1 Another function of the Pattern Generator module 103 is to control the timing of the digital DSP module 107. Figure 3 It is an implementation form of the timing diagram of the present invention. In addition to generating FMCW related parameters, the Pattern Generator module 103 also generates two indication signals, namely, the frame start mark (frame head) and the linear frequency modulation signal start mark (chirp head). The frame head is generated at the beginning of each frame, and the chirp head is generated at the beginning of each chirp. Figure 3 In the embodiment, a high level for a period of time can be used as a feature of a frame head and a chirp head. When the digital DSP module receives a frame head, it indicates that the next data received is a frame, until the next frame head signal is received. When the digital DSP module 107 receives a chirp head, it indicates that the next data is the data of the ADC generated by a chirp, until the next chirphead signal is received. The digital DSP module 107 can decide when to start the 1D-FFT signal processing of the raw data of the ADC according to the chirp head signal, and the corresponding digital DSP module can decide which raw data of the ADC to perform 2D-FFT signal processing on according to the frame head signal.

[0046] The frame head signal can also be used to generate a synchronization signal. When multiple chips are cascaded, all chips can receive the sync signal sent by one of the main chips. After receiving the sync signal, it indicates that the data of each subsequent chip is from the output of the same frame. This facilitates unified array signal processing of the obtained data.

[0047] The above is a specific description of the implementation of the present invention, but those skilled in the art will understand that the foregoing implementation is exemplary and is for the purpose of clarity and understanding, and is not limited to the scope of the present invention. It is intended that after reading the digital instructions and studying the drawings, those skilled in the art will understand that all replacement forms, enhanced forms, equivalent forms, combined forms, and improved forms are included in the essential scope of the present invention.

[0048] A person skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, which can include: ROM, RAM, disk or CD, etc.

[0049] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A millimeter wave radar chip, characterized in that: include: RF transceiver, used for sending and receiving millimeter wave signals; The analog signal processing unit is used to perform low-pass or band-pass filtering on the intermediate frequency signal generated by the echo signal, and to generate a corresponding digital baseband signal after analog-to-digital conversion; The hardware acceleration circuit includes a distance FFT module, which is used to calculate the distance information of the target by performing a fast Fourier transform on the digital baseband signal; When there are multiple target objects, the multiple targets are sorted by distance according to the energy of the received millimeter wave signals; A signal generator, used to generate a frequency control word, the signal generator is also used to send an indication signal to perform timing control on the hardware acceleration circuit, the parameters in the frequency control word include: the number of linear frequency modulation signals of the frequency modulated continuous wave, the shape and time of each linear frequency modulation signal, the frequency scanning range, and the number of linear frequency modulation signals in a frame; A frequency synthesizer, used to generate the required frequency modulated continuous wave frequency signal according to the frequency control word, The indication signal includes: The frame start marker is used to indicate that the next received data is a data frame until the next frame start marker is received; The linear frequency modulation signal start mark is used to indicate that the next received data is an analog-to-digital conversion generated by a linear frequency modulation signal until the next linear frequency modulation signal start mark is received. When multiple millimeter-wave radar chips are used in cascade, each millimeter-wave radar chip receives the frame start mark sent by the main chip as a synchronization signal to indicate that the data received thereafter are all outputs from the same frame.

2. The millimeter wave radar chip according to claim 1, characterized in that: The analog signal processing unit comprises: An intermediate frequency filter is used to perform low-pass or band-pass filtering on the intermediate frequency signal; The analog-to-digital conversion circuit is used for performing analog-to-digital conversion.

3. The millimeter wave radar chip according to claim 1, characterized in that: The hardware acceleration circuit also includes a Doppler FFT module, which is used to calculate the speed information of the target object by performing a fast Fourier transform on the digital baseband signal; and when there are multiple target objects, the speeds of the multiple targets are sorted according to the energy of the received millimeter wave signal.

4. The millimeter wave radar chip according to claim 1, characterized in that: The hardware acceleration circuit also includes a downsampling module, which is used to downsample the digital baseband signal to reduce the subsequent data processing scale.

5. The millimeter wave radar chip according to any one of claims 1 to 4, characterized in that: The result generated by the hardware acceleration circuit is output to the MCU or external circuit through the interface circuit.

6. A millimeter wave radar, characterized in that: It comprises the millimeter wave radar chip as described in any one of claims 1 to 4.

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