Antenna subsystem with analog beam-steering transmit array and digital beam-forming receive array

Abstract

To provide an antenna subsystem that, in order to reduce aliasing, can be operated to spatially filter a receive beam pattern generated by a receive antenna with a transmit beam pattern generated by a transmit antenna.SOLUTION: An antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength. The electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength.SELECTED DRAWING: Figure 33

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Provisional Patent Application No. 62 / 430,306, filed December 5, 2016. The name of the device is "RADAR SYSTEM WITH ANALOG BEAM-STEER ING TRANSMIT ARRAY AND DIGITAL BEAM-FORM This application claims the benefit of US Provisional Patent Application No. 2006-013636, filed on May 13, 2006, entitled "Insulating Receive Array," the contents of which are incorporated herein by reference. be incorporated into the book. [Background technology]

[0002] Conventional phased array radar systems are limited in size, power requirements, and area per unit. The number of array elements per array (element density) and cost make them unsuitable for some applications. For example, the phased arrays of conventional radar systems are too dense and have poor field of view ( The FOV is scanned too slowly, and the system is not suitable for use in autonomous (self-driving) vehicles. Similarly, the phased arrays of conventional radar systems are too expensive to use. The system is too dense for use on drones or other unmanned aerial vehicles (UAVs). It is expensive, too heavy and consumes too much power.

[0003] Thus, for such applications, a lighter, less dense radar system is required than conventional radar systems. A radar system that is low cost, consumes less power, and can scan the FOV more quickly is provided. It has been developed.

[0004] Examples of such radar systems developed for use in automobiles include, for example, at least The number of antenna segments is usually 4 to 8 (the number of antenna segments depends on the number of antenna channels supported by the system circuit). number of channels (e.g. limited to one antenna segment per antenna channel) A digital beamforming (DBF) receive antenna array with separate antenna segments include.

[0005] During transmission, the system circuits receive the same signals, i.e., each having the same magnitude and phase. This effectively excites all antenna segments with the respective signals, thereby The image is then made to "spray" signal energy over a fixed FOV. , all antenna segments are fed with respective signals each having the same magnitude and phase. Simultaneous energization of the two antennas maintains a stationary, i.e., non-steered, primary transmit beam. To cover the available FOV, this transmit main beam is fairly wide. For example, the azimuth angle (AZ) is often greater than 20 degrees.

[0006] During a receive period, the system circuitry calculates the respective gains from any receive antenna segment. and phase shifts are dynamically post-processed to digitally create a receive beam that is significantly narrower than the transmit beam. and the system can be configured and operated to receive only a single location during a single reception period. Or the receive beam can be steered to multiple positions.

[0007] Unfortunately, the problem with such radar systems is that the receive DBF is determined by the transmit beam. This can only be done in the area illuminated by the receiver array segments. The number of segments / channels is used to divide a fixed transmit FOV into equal segments. , i.e., the number of receiver array segments / channels defines the receiving resolution of the DBF, This ultimately defines the reception resolution of the entire radar system. Signal resolution, often called Rayleigh resolution, is fundamental to radar performance. For example, if you illuminate a 20° FOV in the AZ during transmission and include four receive channels, A radar system such as this has a Rayleigh resolution of about 5° across this FOV. An alternative choice can be made to widen the FOV to 40° using the same four receivers. Depending on the channel, this provides a Rayleigh resolution of about 10°. In most systems, there is a fundamental tradeoff between FOV and Rayleigh resolution.

[0008] Such a radar can illuminate a large FOV during transmission and achieve high Rayleigh resolution during reception. To have this requires a large number of antenna segments / channels.

[0009] Unfortunately, there are engineering limitations to the number of channels that can be practically included in such a radar. To date, this has limited the Rayleigh performance of such radar systems.

[0010] A method for improving the Rayleigh resolution of a system with a fixed number of antenna channels The approach is to place the receiving antennas / antenna segments further apart, i.e. The aim of the present invention is to design a simple receiving array.

[0011] However, such sparse arrays can lead to spatial aliasing. This is due to the radar system's ability to detect, identify, and map objects. These create side lobes and grating lobes that can disrupt the power. One of the causes of aliasing side lobes and grating lobes is the The sparse receive antenna array of the system satisfies the Nyquist criterion for maximum segment spacing (λ / 2). For example, to obtain a Rayleigh resolution of 1° in the AZ dimension, The antenna should have a size of about 50 λ. For example, distributing 4 to 8 segments / channel results in an average segment spacing of This gives 6.25λ to 12.5λ, which is 12 to 25 times the maximum Nyquist interval of λ / 2. As a result, the system suffers from large side lobes and grating lobes. This will be the case.

[0012] Naturally, to reduce spatial aliasing, designers must consider the spacing between antenna segments. By decreasing the spacing, the effective size of the antenna can be reduced.

[0013] However, reducing the size of the antenna reduces the size of the receive beam that the radar system can generate. The minimum width is restricted.

[0014] Therefore, such sparse antenna array radar systems (i.e., larger Designers of radar systems with large antenna apertures and limited number of antenna channels faces the trade-off of beamwidth for aliasing and vice versa. That is, the narrower the receive beamwidth, the higher the level of aliasing and the The lower the rearcing level, the wider the receiving beam width. Summary of the Invention

[0015] In one embodiment, the antenna subsystem includes a sparse receive antenna and an electronically steerable The sparse receiving antennas receive each signal having a wavelength. each configured to receive 1 / 2 a wavelength from a respective adjacent one of the receive elements. The receiving element includes an array of receiving elements spaced apart by a respective first distance greater than The miniature steerable transmitting antennas are each configured to radiate a respective signal having a wavelength. each of which transmits a respective second 1 / 2 wavelength away from a respective adjacent one of the transmit elements. The antenna includes an array of transmit elements spaced a distance of 2 apart.

[0016] For example, such an antenna subsystem may include a receiver The receive beam pattern generated by the antenna is compared with the transmit beam pattern generated by the transmit antenna. Effectively and spatially filter the transmit beam pattern. For example, the envelope of the main transmit beam The entanglement can eliminate or at least reduce the side lobes of the receive beam pattern. In addition, the nulls in the side lobes of the receive beam pattern can be used to attenuate the transmit and receive The side lobe peaks of the receive beam pattern can be aligned with the side lobe peaks of the receive beam pattern. The side lobe peaks of the transmit and receive patterns should be aligned with the side lobe nulls of the transmit and receive patterns. can be done.

[0017] In one embodiment, the radar system has a significantly reduced High Rayleigh resolution (i.e., narrow half-power beamwidth ( The radar system electronically adjusts the transmit beam pattern and the receive beam pattern. Analog transmit array with the ability to act as a spatial filter for the receive antenna pattern. and a Nyquist control for generating a receiving beam relative to the main illumination beam of the transmitting antenna. and a sparse or split digital beamforming (DBF) array antenna. By properly designing and driving the receiver and receiving antenna, the radar system can achieve a narrow (e.g., ≤2° in both AZ and elevation (EL) dimensions) Moreover, radar systems are typically required for such capabilities. This can be done without requiring a large number of antenna channels (e.g., 64-128). For example, a 12-antenna chip for a receiving sparse DBF array antenna can be used. An embodiment of a radar system having only one channel has a maximum angle of approximately 2° in AZ and approximately 2° in EL. It is possible to effectively generate and steer a beam about 5° wide, and therefore such a The radar system has significantly more bandwidth than conventional radar systems with a similar number of antenna channels. It has excellent angular performance. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 illustrates a diagram of a Metamaterial Electronically Steering Array (MESA) transmit antenna section and a sparse DBF receive antenna section of a radar system, according to one embodiment. [Diagram 2] FIG. 2 illustrates the sparse DBF receive antenna section of FIG. 1 with a close-up view of one of the subarrays in accordance with one embodiment. [Diagram 3] 3 is a plot of receive beam patterns of antenna elements of the receive antenna section of FIG. 2 in the AZ and EL dimensions in accordance with one embodiment. [Figure 4] 3 is a diagram of the sparse DBF receive antenna section of FIG. 2 according to one embodiment. [Diagram 5]5 is a plot of a receive beam pattern in the AZ of the sparse DBF receive antenna section of FIG. 4 in accordance with one embodiment. [Figure 6] 5 is a plot of a receive beam pattern at EL for the sparse DBF receive antenna section of FIG. 4 in accordance with one embodiment. [Figure 7] 5 illustrates a receive beam pattern for the transmit antenna section of FIG. 1 and a receive element beam pattern and a transmit array beam pattern in the AZ for the sparse DBF receive antenna section of FIG. 4 in accordance with one embodiment. [Figure 8] 5 illustrates a receive beam pattern for the transmit antenna section of FIG. 1 and a receive element beam pattern and a transmit array beam pattern at the EL for the sparse DBF receive antenna section of FIG. 4 in accordance with one embodiment. [Figure 9] FIG. 2 is a diagram of a receive antenna array section that can be used in a radar system according to another embodiment. [Figure 10] 10 is a plot of beam and sidelobe patterns of the receive antenna array section of FIG. 9 in the AZ dimension for a single receive main beam in accordance with one embodiment. [Figure 11] 10 is a plot of beam and sidelobe patterns of the receive antenna array section of FIG. 9 in the EL dimension for a single receive main beam in accordance with one embodiment. [Figure 12] 1A-1C are plots of effective (i.e., bidirectional) beam patterns in the AZ dimension resulting from a combination of the patterns (FIGS. 10-11) of the receive antenna subelements (FIG. 2), the receive antenna array (FIG. 9), and the transmit antenna section (FIG. 1) in accordance with one embodiment. [Figure 13] 1A-1C are plots of effective (bidirectional) beam patterns in the EL dimension resulting from a combination of the patterns (FIGS. 10-11) of the receive antenna subelement (FIG. 2), the receive antenna array (FIG. 9), and the transmit antenna section (FIG. 1) in accordance with one embodiment. [Figure 14]A diagram showing a transmission antenna section having a plurality (here, two) of sub-sections according to an embodiment. [Figure 15] A plot of the transmission beam and sidelobe pattern in the EL dimension of the transmission antenna section embodiment of FIG. 14, which can be the same as the reception antenna section of FIG. 9, overlaid with the reception beam and sidelobe pattern in the EL dimension. [Figure 16] A plot of FIG. 15 according to an embodiment where EL = AZ = 0°. [Figure 17] A plot of the effective (bidirectional) beam pattern in the EL dimension obtained from the combination of the transmission beam pattern and the reception beam pattern of FIG. 15 according to an embodiment where EL = AZ = 0°. [Figure 18] A plot of the transmission beam and sidelobe pattern in the AZ dimension of the transmission antenna section embodiment of FIG. 14 that results in the transmission EL pattern of FIG. 16 according to an embodiment where EL = AZ = 0°, with the reception beam and sidelobe pattern overlaid in the AZ dimension of an embodiment of the reception antenna section that results in the reception EL pattern of FIG. 16. [Figure 19] A plot of the effective (bidirectional) beam pattern in the AZ dimension obtained from the combination of the transmission and reception beam patterns of FIG. 18 according to an embodiment where EL = AZ = 0°. [Figure 20] A plot of the transmission beam and sidelobe pattern in the EL dimension of the transmission antenna section embodiment of FIG. 14 that results in the transmission patterns of FIGS. 15 - 19 according to an embodiment where EL = 5° and AZ = 0°, with the reception beam and sidelobes overlaid in the EL dimension of an embodiment of the reception antenna section that results in the reception patterns of FIGS. 15 - 19. [Figure 21] A plot of the effective (bidirectional) beam pattern in the EL dimension obtained from the combination of the transmission beam pattern and the reception beam pattern of FIG. 20 according to an embodiment where EL = 5° and AZ = 0°. [Figure 22] 20 in the EL dimension, with the receive beam and sidelobe patterns superimposed in the AZ dimension for an embodiment of the receive antenna section of FIG. 14 , which results in the transmit pattern of FIG. 20 in the EL dimension, for an embodiment where EL=5° and AZ=0°. [Figure 23] 23 is a plot of the effective (bi-directional) beam pattern in the AZ dimension resulting from the combination of the transmit and receive beam patterns of FIG. 22 according to an embodiment where EL=5° and AZ=0°. [Figure 24] 15 is a plot of the transmit beam and sidelobe patterns in the EL dimension for an embodiment of the transmit antenna section of FIG. 14 with EL=0° and AZ=49°, with the receive beams and sidelobes superimposed in the EL dimension for an embodiment of the receive antenna section of FIG. 9 . [Diagram 25] 25 is a plot of the effective (bi-directional) beam pattern in the EL dimension resulting from the combination of the transmit and receive beam patterns of FIG. 24 according to an embodiment where EL=0° and AZ=49°. [Figure 26] 15 is a plot of the transmit beam and sidelobe patterns in the AZ dimension of an embodiment of the transmit antenna section of FIG. 14 according to an embodiment where EL=0° and AZ=49°, with the receive beam and sidelobe patterns in the AZ dimension of the receive antenna section of FIG. 9 superimposed. [Figure 27] 27 is a plot of the effective (bi-directional) beam pattern in the AZ dimension resulting from the combination of the transmit and receive beam patterns of FIG. 26 according to an embodiment where EL=0° and AZ=49°. [Figure 28] FIG. 2 is a diagram of a transmit antenna section having multiple (here two) subsections according to another embodiment. [Figure 29]29 is a plot of the transmit beam and sidelobe patterns in the EL dimension for an embodiment of the transmit antenna section of FIG. 28 according to an embodiment where EL=0° and AZ=49°, with the receive beam and sidelobe patterns in the EL dimension for an embodiment of the receive antenna section of FIG. 9 superimposed. [Diagram 30] 30 is a plot of the effective (bi-directional) beampattern in the EL dimension resulting from the combination of the transmit and receive beampatterns of FIG. 29 according to an embodiment where EL=0° and AZ=49°. [Diagram 31] 15 is a plot of the transmit beam and sidelobe patterns in the AZ dimension for an embodiment of the transmit antenna section of FIG. 14 according to an embodiment where EL=0° and AZ=49°, with the receive beam and sidelobe patterns in the AZ dimension for the embodiment of the receive antenna section of FIG. 9 superimposed. [Diagram 32] 32 is a plot of the effective (bi-directional) beam pattern in the AZ dimension resulting from the combination of the transmit and receive beam patterns of FIG. 31 according to an embodiment where EL=0° and AZ=49°. [Diagram 33] FIG. 2 is a diagram of a radar subsystem incorporating one or more of the transmit antenna sections described above in connection with FIGS. 1, 14, and 28, and one or more of the transmit antenna sections described above in connection with FIGS. 1-2, 4, and 9. [Diagram 34] FIG. 34 is a diagram of a system incorporating one or more of the radar subsystems of FIG. 33 according to one embodiment. [Diagram 35] 28A and 28B are plan views of the transmit antenna section of FIG. 1 and of subsections of the transmit antenna sections of FIGS. 14 and 28 according to one embodiment. [Diagram 36] FIG. 36 is a side view of the transmit antenna section of FIG. 35 according to one embodiment. [Figure 37] FIG. 37 is a side view and electrical schematic diagram of the transmit antenna section of FIGS. 35 and 36 according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The terms "approximately" and "substantially" are used hereinafter to refer to the physical properties described below. Due to manufacturing tolerances in construction or other design considerations, two or more quantities may not be exactly equal. can be used to indicate that the values ​​can be within ±10% of each other.

[0020] FIG. 1 illustrates a metamaterial electronic steering array (MSA) for a radar system 14, according to one embodiment. ESA) transmit antenna section 10 and sparse DBF receive antenna section 12 33-34, the radar system being further described below in conjunction with FIG. 1. It may include other components not shown, such as amplifiers, phase shifters, and other driver circuits. Further, the transmitting antenna section 10 can be used as the entire transmitting antenna of the radar system 14. The section of the transmitting antenna may include a body, or one or more other sections similar to section 10. Similarly, the receiving antenna section 12 can form only a radar section. The entire receiving antenna of the stem, or one or more other sections similar to section 12. In addition, the radar system 1 can form only the section of the receiving antenna that can be seen. 4 can be configured to operate in any conventional radar frequency band, e.g. The radar system must be configured to operate in the W-band in the range of 75 GHz to 110 GHz. and can be tuned for operation between 76 GHz and 81 GHz. MESA transmit antenna that designers can use as transmit antenna section 10 An example of the structure and operation of a section is described below with reference to Figures 35-37.

[0021] The transmit antenna section 10 may include one or more electronically steerable / switchable arrays (E SA), including, for example but not necessarily, MESA. In addition, the transmit antenna section The element 10 may be of any suitable dimensions, for example, approximately W=10λ×H=3λ, or W=12λ. ×H=4λ. These dimensions are taken as the aperture of the transmit antenna section 10. 4. Define the minimum half-power beamwidth (HPBW) of the transmit beam in the AZ and EL dimensions. This is because it is known that the HPBW is inversely proportional to the aperture size. For example, when W=12λ×H=4λ, one embodiment of the transmitting antenna section 10 is The configuration produces a transmit beam with a minimum HPBW of 5° in the AZ dimension and 10° in the EL dimension. It is possible.

[0022] Each ESA in the transmit antenna section 10 (only one ESA is shown in Figure 1) Each includes one analog RF channel input 16, where the RF signal is input in a conventional manner, e.g. For example, by waveguides, transmission lines, or microstrips, the entire ESA area and / or Distributed to ESA sub-elements.

[0023] Each ESA in transmit antenna section 10 also provides electronic control of transmit array beam steering. The control includes one or more control lines 18, digital or analog, that provide a single digital as a digital line 18, as a collection of digital lines (e.g., a digital bus), or It can be implemented as a collection of analog lines.

[0024] Additionally, one or more control lines 18 may be configured to represent the aggregate state of a control signal over time (e.g., a logic high or or a logic low, or an array of analog voltages) to determine the characteristics of the transmit array section 10. Each of the control signals is adapted to carry a respective control signal that electronically activates a configuration that describes a particular configuration. The configuration is configured to determine a particular transmit beam position, transmit beam side lobe level, transmit beam Describe HPBW etc.

[0025] In addition, the ESAs may transmit array configurations transmitted over their respective control lines 18. By coordinating and synchronizing, each operates with its own analog transmit input. The present invention can be configured to:

[0026] With further reference to FIG. 1, the receive antenna section 12 includes an array of antenna elements 22. 20, and the antenna element is also called an "antenna segment" or a "segment." The array 20 is segmented into rows 24 and columns 26 of antenna elements 22. For example, array 20 may have six columns 26 and two rows 24 for a total of twelve antenna elements. Alternatively, for example, as shown in FIG. , there may be five columns 26 and two rows 24 for a total of ten antenna elements 22. do.

[0027] Additionally, each phase center 28 of each antenna segment 22 corresponds to a single RF receive channel. 1, whereby the receive antenna section 12 is coupled to a Each receive channel is configured to be a digital beamforming (DBF) array. 1, the respective downconverters (not shown in FIG. 1), The analog-to-digital converters (ADCs) of the respective radar systems (not shown in FIG. 1) The antenna 14 measures and decodes each signal received by each corresponding antenna element 22. Includes other RF, analog, and digital components that allow for digitalization Further, the receiving antenna section 12 may have a size of, for example, approximately W=25λ× The receiving antenna may have any suitable dimensions, such as H=10λ. 4 defines the aperture of the spacer section 12 and the minimum power half of the transmitted beam in the AZ and EL dimensions. It also affects the maximum beam width (HPBW) because HPBW is inversely proportional to the aperture size. For example, when W = 25λ × H = 10λ, the receiving antenna One embodiment of the nassection 12 has a minimum HPBW of 5° in the AZ dimension and 10° in the EL dimension. A receive beam having the same amplitude as the received beam may be generated.

[0028] Additionally, the antenna elements 22 in the receive antenna array 20 may be configured to have, for example, efficiency, gain, bandwidth, etc. Any shape that provides advantageous antenna element characteristics, such as HPBW in width, AZ and EL dimensions The shape and material can be:

[0029] In addition, each of the antenna elements 22 may include one or more sub-elements. In configurations such as microstrip-fed patch arrays and CPW patch arrays, the antenna elements The element 22 may include multiple sub-elements.

[0030] With further reference to FIG. 1, the operation of radar system 14 according to one embodiment will now be described.

[0031] Generally, the ESA transmit antenna section 10 has relatively low power side lobes. The radar system 14 generates a transmit beam and a receive beam (or multiple receive beams, see below). ) in the transmit beam, which reduces the receive beam compared to conventional radar systems. The pattern side lobes significantly reduce the forward transmit energy received. Even though the side lobes of the receive beam pattern are relatively large and therefore have significant spatial Controlled ESA transmit beam pattern, even though this may result in aliasing Adding a radar signal (as opposed to a traditional radar transmission "blast" or "spray") This significantly reduces aliasing, which is relatively small compared to conventional radar systems. Systems with small transmit beam pattern side lobes are prone to transmit energy loss. A larger percentage is received by the receive beam and a lower percentage of the transmit energy is forwarded. This is because a lower percentage of the signal is received by the receive side lobes. In other words, by including the ESA transmitting antenna section 10, the radar system The array 14 is a “sparse” receive DBF array 20 (i.e., spaced by distance >> λ / 2). array by placing antenna segments 22) or else DBF array alone or paired with the "blast" or "spray" transmissions of conventional radar systems. The effective receive beam (i.e., the transmit It is possible to generate a beam (resulting from a combination of a receive beam and a receive beam).

[0032] More specifically, the radar system 14 uses one or more ESA control lines 18 to select The ESA transmit beam is directed in the selected AZ direction and the selected EL direction. These selected directions, constrained by BW, result in a significant reduction in the receive DBF array 20. These collectively define an illumination region that can operate with the specified spatial aliasing.

[0033] This illuminated area can be resolved with relatively high Rayleigh resolution by the DFB array 20. The transmitting antenna section 10 can be reconstructed as follows: Through the configuration of the antenna and its transmit beam pattern using one or more control lines 18, the antenna can detect new areas. The sequential configuration of the transmitting antenna section 10 and its transmitting beam pattern can be The current illumination area is then extracted by the dynamic reconstruction and subsequent resolution using the DBF array 20. This lighting sequence covers a very wide FOV from the current lighting area to the new lighting area. can be ordered (e.g., raster scan, conical scan) or unordered (random, Hadamard) or dynamically or intelligently ordered (time Screenable lighting, priority FOV time weighting, etc.

[0034] Still referring to FIG. 1, the radar system 14 may be configured to direct the receive array beam as follows: to steer.

[0035] In one embodiment, the radar system 14 generates transmit and receive beams simultaneously. The radar system 14 operates in a continuous wave (CW) mode. However, the radar system 14 may have one or more of its transmit beams in a continuous wave (CW) mode. It generates a "pulse" on the receiver, stops the transmit beam, turns on the receive beam, and stops the receive beam. The device may also be configured to operate in a pulsed mode, stopping the The following description assumes that the radar system 14 is operating in CW mode. The description below is also applicable to radar systems operating in pulsed mode.

[0036] The radar system 14 detects each signal received by each antenna segment 22. By selectively applying respective complex element weightings to one or more receivers, The beams are steered simultaneously, which results in a separate phase shift and and each gain is effectively applied (the gain can be less than 1, 1, or more than 1). That is, the radar system 14 uses the receive antenna array 20 as a true phase door. Act as Ray.

[0037] The radar system 14 receives a single beam using only twelve antenna segments 22. In embodiments that generate only a beam, the radar system may generate a relatively narrow beam (e.g., It is possible to generate receive beams with very fine steps (e.g. 2° HPBW) The beam can be steered in the AZ dimension in increments of 0.1° (e.g., 0.1° steps). Thus, the transmit beam superpoints the receive beam, so that the radar system 14 The transmit illumination solid angle (TISA), such as the area bounded by the HPBW of The steps are as follows: A receive beam at one position is steered to the The position may or may not overlap with an adjacent previous position in the frame.

[0038] In another embodiment, the radar system 14 may select a receive beam that is “compatible” with the TISA region. For example, if the TISA region is like a box of spaghetti, Each strand of the Getty represents a respective receive beam. In this embodiment, the receive beam bundle is To “fulfill” TISA, the radar system 14 does not need to implement the above-described embodiments. There is no need to steer the receive beam. That is, in this embodiment, the radar system 14 In contrast to the above embodiment, where multiple receive beams simultaneously cover the TISA region, The radar system sequentially steers a single receive beam between receive beam positions to achieve TISA. Cover an area over a period of time.

[0039] In yet another embodiment, the radar system 14 “fits” within the TISA region. The radar system then simultaneously generates a receive beam that does not "satisfy" the The receive beam bundle is sequentially steered between bundle positions to cover the TISA region over The position of a bundle may or may not overlap with the positions of other bundles.

[0040] In yet another embodiment, the receive beam flux is required to "fill" the TISA region. Thus, the radar system 14 may include fewer beams than the bundle. or more receive beams can be steered, so that the radar system can steer the transmit beam. Before reconfiguring the transmit ESA to Each of these areas occupies

[0041] In the following, the radar system 14 is described as generating and steering a single receive beam. However, unless otherwise specified, the description is for a system that simultaneously generates multiple (e.g., bundles) receive beams. It will be appreciated that the present invention also applies to radar systems that configure and steer.

[0042] FIG. 2 illustrates a receive antenna section 12, an array of antenna elements 22, according to one embodiment. 20, a diagram of the antenna element phase center 28 and a close-up of one of the antenna elements 22. In this embodiment, although not intended to be limiting, each antenna element 22 has It includes a microstrip-fed series sub-array of patch sub-elements 30 .

[0043] FIG. 3 shows the basic beam pattern 32 (receiving beam pattern) in the AZ and EL dimensions. 1 is a plot depicting the design of the basic beam pattern 32 and the AZ and EL. The characteristic HPBW is the bandwidth at which each receive channel, and ultimately the receive array 20 , defines the FOV in which the signal can be received. Next, the element beam patterns 32 are also , which defines the FOV in which the entire radar system can operate.

[0044] 2-3, in one embodiment, the receiving elements 22 are arranged in the receiving array 20 as AZ The number and geometry of subelements 30 provide a total HPBW of approximately 90° in the EL dimension and approximately 20° in the EL dimension. The radar system 14 is designed with a very wide FOV in the A-Z dimension. This allows for a somewhat limited FOV in the EL dimension.

[0045] FIG. 4 is a diagram showing the areas of the receive antenna section 12 and the receive array 20. As shown in FIG.

[0046] 5-6 show receive beam patterns 40 and 41 in the AZ and EL dimensions, respectively. 2, these patterns arise as a result of the geometry of the array 20. , the geometry of array 20 is commonly referred to as the "array factor."

[0047] Referring to Figures 4 to 6, the array factor beam patterns (AZ and EL receiving beam patterns) The selection of complex weights (amplitude and phase) applied to the receive channels and, as mentioned above, a very large number of possible beams or beam bundles are generated. In other words, the AZ and EL receiving beam patterns in Figs. The elements 40 and 42 are spaced apart depending on the geometry of the array 20 (i.e., the relative positions of the antenna elements 22). and the choice of complex receive weights.

[0048] The array factor receive beam pattern is determined by the HPBW, beam angle, and side lobe level. The AZ pattern has various beam characteristics, which are influenced by the selection of complex receive weights. The receive beam 40 includes a receive beam 44 and main side lobes 46 and 48. 6 and 48 are greater than half the power level of receive beam 44 (i.e., 3 dB therefrom). Similarly, the EL pattern 42 has a maximum power level that is less than the received beam 44. and main side lobes 50 and 52.

[0049] The objective of the radar system designer of the radar system 14 (Fig. 1 and Fig. 33) is to determine the AZ and E In both L dimensions, the transmit and receive patterns are aliased outside the region of interest. By maximally eliminating the side lobes on the side, the side The aim is to eliminate lobes 46, 48, 50 and 52 to the greatest extent possible.

[0050] FIG. 7 illustrates the transmit beam pattern 54 of the receive array 40 in one embodiment, FIG. 5 depicts beam patterns in the AZ dimension and the receiving element beam patterns. 56 is due to the arrangement, size, shape, etc. of the antenna sub-elements 30 (FIG. 2). As shown, most of the receive spatial aliasing occurs outside the HPBW of the transmit beam pattern 54. side, hence the transmit antenna section and the sparse receive antenna section. The combination of greatly suppresses receive spatial aliasing in the AZ.

[0051] FIG. 8 illustrates a transmit beam pattern 58 in the EL dimension for one embodiment, the receive element 1 is a diagram showing a beam pattern 60 and a beam pattern of the receiving array 42. As shown, most of the receive spatial aliasing occurs outside the HPBW of the transmit beam pattern 58. side, and therefore has a transmit antenna section and a sparse receive antenna section. This combination greatly suppresses receive spatial aliasing in the EL.

[0052] Practical limitations on the shape of the transmit beam, e.g., the extent to which the transmit beam extends from its central region to its HPB The size of the transmitted beam is determined by the amount of light that passes through the W and the amount of light that passes through the W. To the extent there are practical limitations on the shape, location, and level of the lobes, and Taking into account these limitations in both the AZ and EL, the design of the radar system 14 The inventors have discovered that it is possible to reduce the side lobes of a radar system to a desired level for a particular application. In some cases, challenges may be faced in

[0053] As a result, spatial aliasing side lobes that may be present in the AZ and EL are further reduced. To achieve this, the radar system designer must further determine, as described below in connection with FIG. A number of allowable receive array 20 geometric configurations can be exploited.

[0054] Considering the above, the number of channels required over a given coverage area is reduced. In addition to providing the advantage of reducing the number of lattice errors, it also provides the advantage of sparsifying the receive array, i.e., reducing the number of lattice errors by more than λ / 2. The significantly larger array element separation also provides an additional degree of freedom in positioning the receive elements 22. In other words, a fixed number of receivers spread over a large area. The receiving elements 22 have many possible configurations of positions where they do not collide or overlap. The number of such possible configurations increases with the area of ​​the receive antenna array 20.

[0055] FIG. 9 is a diagram of a receive antenna array section 70, which is similar to the receive antennas of FIGS. 1, 2 and 4. 3. The radar system 14 may be used in place of the tenna array section 20.

[0056] 10-11 show the received beam generated by the antenna section 70 for a single reception beam. Plots of beam and sidelobe patterns 72 and 74 in the AZ and EL dimensions, respectively. (If the radar system 14 generates a bundle of receive beams, and these beams are (One data point is for each receive beam in the bundle.)

[0057] 9 to 11, as will be described later, the receiving antenna section 70 includes a receiving antenna. The main receive side lobes 46, 48, 50 generated by the antenna 12 (FIGS. 1-2), and 52 (FIGS. 5-6) can generate a lower power main receive side lobe and In this case, aliasing caused by receive side lobes can be further reduced. This can be done.

[0058] Similar to the receiving antenna section 12 in Figs. 1-2 and 4, receiving antenna section 7 0 includes ten antenna segments 22 each having six antenna sub-elements 30. (not shown in Figures 9 to 11).

[0059] However, unlike the receiving antenna section 12 of FIG. 1-FIG. 2 and FIG. 4, the antenna segment The elements 22 are not arranged in the Cartesian vertical columns 26 and horizontal rows 24 of FIG. 1, but instead in the Cartesian vertical columns 26 and horizontal rows 24 of FIG. As will be described later, this receiving antenna pattern is the same as that of the receiving antenna in FIG. Compared to the receiving antenna section 12, the main receiving sidelobe is This significantly reduces the level of artifacts and thus further reduces aliasing.

[0060] 9-11, the AZ beam pattern of the receiving antenna section 70 72 includes a receive beam 76 and receive side lobes 78 and 80. The closest side lobe 78 is at least 11 dB below the power level of the receive beam 76. Thus, the side lobes 78 are distributed over the transmit beam in the AZ dimension. Although it may be close to and within the HPBW region of group 82, Tube 78 is a level of the aliasing generated by receive antenna section 12 of FIG. Compared to the 1000MHz ... The power level of each of the receiving antenna sections 78 is the closest to the power level generated by the receiving antenna section 12. This is because the power level is at least 10 dB lower than the power level of the side lobe 46. the lobe 80 is adjacent to the HPBW region of the transmit beam 82 in the AZ dimension; and Even if it could be within that range, the side lobes 80 would be within the receiving antenna section 1 of FIG. 2 produces a significant increase in aliasing compared to the level of aliasing produced by This provides a small reduction in the power level of each side lobe 80 relative to the receive antenna section. The power level of the nearest side lobe 48 (FIG. 5) generated by the This is because it is at least 10 dB lower.

[0061] Similarly, EL pattern 74 includes receive beam 76 and side lobes 84 and 86 . The side lobes 84 closest to the receive beam 76 are at least 100 .mu.m away from the power level of the beam 76. Each has a maximum power level 10 dB lower. Thus, the side lobes 84 are Assuming that the transmission beam 82 is close to and within the HPBW region at However, side lobes 84 are generated by the receiving antenna section 12 of FIG. This provides a significant reduction in aliasing compared to the level of aliasing, but The power level of each of the lobes 84 is the maximum power level generated by the receive antenna section 12. This is because it is at least 10 dB lower than the power level of the nearest side lobe 50 (FIG. 6). And the receive side lobe 86 closest to the receive beam 76 is the power level of the beam 76. Therefore, the side lobes 86 have a maximum power level at least 10 dB lower than the , adjacent to and within the HPBW region of the transmit beam 82 in the EL dimension. Even if it were possible, the side lobes 86 would be generated by the receive antenna section 12 of FIG. provides a significant reduction in aliasing compared to the levels of aliasing typically found in This is because the power level of each of the side lobes 86 is At least 10 dB lower than the power level of the nearest side lobe 52 thus generated This is why.

[0062] 9-11, alternative embodiments of the receive antenna section 70 are contemplated. For example, the number, pattern, and configuration of the antenna segments 22 may be different from those shown in FIGS. may differ from those shown and described above in relation thereto. For example, , the receiving antenna section 70 may include more or less than twelve antenna segments 2 2, and the antenna segments may be arranged differently than shown in FIG. Each antenna element 22 may vary in number, location, shape, and design of subelements. The sub-elements 30 may have any of the following configurations.

[0063] FIG. 12 illustrates a receive antenna sub-element 30 (FIG. 2), a receive antenna array, according to one embodiment. 20 (Fig. 9), and the pattern of the transmitting antenna section 10 (Fig. 1) (Figs. 10-11) The effective (bidirectional) AZ beam pattern obtained from the combination of 90 radar systems 14 10. In order to generate a valid pattern 90, the AZ pattern 72 in FIG. The transmit array and receive subelement beam patterns (in units of power or magnitude) are At each beam angle (in the same power or magnitude units), The effective AZ pattern 90 is the AZ receive array beam of FIG. pattern, AZ receive subelement beam pattern, or AZ transmit beam pattern, It has significantly lower side lobe levels and thus significantly better alias rejection. do.

[0064] FIG. 13 illustrates a schematic diagram of a receive antenna sub-element 30 (FIG. 2), a receive array 20 ( 9) and the pattern (Figs. 10-11) of the transmitting antenna section 10 (Fig. 1) A plot of the effective (bidirectional) EL beam pattern 92 obtained from the combination of the radar system 14. To generate the effective pattern 92, the receiving array of the EL pattern 74 of FIG. and the receive subelement beam patterns (in units of power or magnitude) are related to each other and to each beam in degrees (in the same power or magnitude units) to the transmit beam pattern of the EL pattern 74 The effective pattern 92 is the EL receive array beam pattern of FIG. Significantly lower size compared to the receive subelement beam pattern or the EL transmit beam pattern. It has a low droop level and thus significantly better alias rejection.

[0065] 14-19, the above-described implementation of radar system 14, according to one embodiment, Techniques are described to further reduce aliasing when compared to the conventional method. Specifically, the radar system 14 designers modified the ESA transmit antenna design to ( The nulls of the transmit beam and sidelobe pattern (in the AZ or EL dimensions) are align with the peaks of the receive beam and sidelobe patterns (in the EL dimension); or or the side lobe peaks of the transmit beam and side lobe pattern are compared with the receive beam and side lobe pattern. The signal can be aligned with a null in the side lobe pattern. Transmit nulls / peaks effectively offset receive peaks / nulls in the beam and sidelobe patterns. causes the "cancel" of the

[0066] FIG. 14 is a diagram of a transmit antenna section 100 according to one embodiment. The vertical distance between the geometric centers 102 and 104 of the respective MESAs is It has two MESA halves (subsections) 106 and 108 separated by a distance Δy. 1. The transmitting antenna section 10 of FIG. The element 100 may form part or all of a transmitting antenna, and Δy may be the transmit EL display. The nulls and peaks in the beam and sidelobe patterns are adjusted to shift in the EL dimension. This shift is typically symmetric about the transmit beam. For example, increasing Δy increases the nulls and side lobes of the transmitted EL beam and side lobe pattern. The lobes move closer together towards the transmit beam, and decreasing Δy reduces the transmit EL beam And the nulls and side lobes of the side lobe pattern move away from the transmit beam. Move away to get away.

[0067] FIG. 15 shows a receive antenna section similar to that of FIG. 9, according to one embodiment. The receive EL beam and side lobe pattern 112 of the receive antenna section can be superimposed. The transmit EL beam of the embodiment of the matched transmit antenna section 100 (FIG. 14) and 1 is a plot of a side lobe pattern 110. For example, the nulls of the transmitted EL pattern 110. 114 and 116 are the peaks of the side lobes 118 and 120 of the received EL pattern 112. and the nulls 122 and 124 of the receive EL pattern 112 are approximately aligned with the transmit EL pattern. 12. The peaks of the side lobes 126 and 128 of the band 110 are approximately aligned.

[0068] FIG. 16 is a plot of FIG. 15 for EL=AZ=0°.

[0069] FIG. 17 illustrates the transmit beam pattern of FIG. 15 for EL=AZ=0°, according to one embodiment. The effective EL beam pattern obtained by combining the input beam pattern 110 and the receive beam pattern 112 is This is plot number 130.

[0070] FIG. 18 illustrates the transmit EL pattern 110 of FIG. 16 according to an embodiment where EL=AZ=0°. The transmit AZ beams and sub-beams of an embodiment of the transmit antenna section 100 (FIG. 14) that result in 16. A plot of the side lobe pattern 132 resulting in the received EL pattern 112 of FIG. The receive AZ beam and side lobe patterns 134 of the receive antenna section are superimposed. It is being asked.

[0071] FIG. 19 illustrates the transmit and receive beams of FIG. 18 for EL=AZ=0°, in accordance with one embodiment. The effective AZ beam pattern 136 obtained by combining patterns 132 and 134 is shown in FIG. It is a lot.

[0072] Continuing with the explanation of Figs. 14 to 19, referring now to Figs. 20 to 23, the transmitting array and When both the receiving and receiving arrays are steered in the EL dimension, the sidelobes achieved using the above techniques are The reduction in beam and spatial aliasing is maintained.

[0073] FIG. 20 shows the transmission patterns of FIGS. 15-19 according to an embodiment where EL=5° and AZ=0°. The transmit EL beam and side lobe of the embodiment of the transmit antenna section 100 that provides the beam 15-19. The received EL beam and side lobes 142 of the antenna section are superimposed.

[0074] FIG. 21 shows the transmit beam pattern of FIG. 20 according to an embodiment with EL=5° and AZ=0°. The effective EL beam pattern obtained by combining 140 and the receive beam pattern 142 There are 144 plots.

[0075] FIG. 22 shows the transmit EL pattern of FIG. 20 according to an embodiment where EL=5° and AZ=0°. The transmit AZ beams and siblings of an embodiment of the transmit antenna section 100 resulting in a beam 140 are shown in FIG. 20. A plot of the drobe pattern 146 resulting in the received EL pattern 142 of FIG. The receive AZ beam and side lobe patterns 148 of the receive antenna section are superimposed. It is being done.

[0076] FIG. 23 shows the transmit and receive beams of FIG. 22 according to an embodiment where EL=5° and AZ=0°. The effective AZ beam pattern 150 obtained by combining the beam patterns 146 and 148 This is the plot.

[0077] In addition, in some cases, the peaks of the side lobes of the receive beam and side lobe patterns may be The peaks coincide with the peaks of the side lobes of the transmit beam and side lobe pattern. Instead of acting to reduce the magnitude of the effective side lobes, The transmit and receive side lobes are aligned / matched transmit and receive side lobe pairs. Addition acts to increase the magnitude of the effective side lobes obtained from the combination. This is true.

[0078] FIG. 24 shows the transmission power of FIGS. 15-19 according to an embodiment where EL=0° and AZ=49°. The transmit EL beam of an embodiment of the transmit antenna section 100 (FIG. 14) that results in a turn 15 to 19. The receive EL beam and side lobes 154 of the receive antenna section 70 (FIG. 9) They are superimposed.

[0079] FIG. 25 illustrates the transmit and receive of FIG. 24 according to an embodiment where EL=0° and AZ=49°. The effective (bidirectional) EL beam pattern obtained from the combination of beam patterns 152 and 154 is This is the plot for turn 156.

[0080] FIG. 26 shows the transmission power of FIGS. 15-19 according to an embodiment where EL=0° and AZ=49°. The transmit AZ beam of an embodiment of the transmit antenna section 100 (FIG. 14) that results in a turn 15-19. AZ beam and side lobe pattern of the receiving antenna section 70 (Fig. 9) 62 is superimposed.

[0081] FIG. 27 illustrates the transmit and receive of FIG. 26 according to an embodiment where EL=0° and AZ=49°. Effective (bidirectional) AZ and EL obtained from the combination of beam patterns 160 and 162 1 is a plot of a beam pattern 164.

[0082] 26-27, unfortunately, at an AZ angle of about 20°, the transmission side load The peak of the receive side lobe 166 coincides with the peak of the receive side lobe 168, thereby The combination of lobes 166 and 168 forms a significant effective side lobe 170. will be done.

[0083] FIG. 28 illustrates an embodiment in which section 180 may form part or the entirety of a transmit antenna. FIG. 1 is a diagram of a transmit antenna section 180, according to an embodiment. 0 is a vertically stacked but separate transmission subsection or portion 182 and 184, each of which can be a respective MESA.

[0084] The peaks of the transmit and receive side lobes 166 and 168 of FIG. 26 are misaligned. Alternatively, the technique for decorrelation may be implemented by configuring the transmit portion 182 of the transmit antenna section 180 to transmit The purpose of this is to shift or slide the signal 184 in the horizontal (AZ) dimension.

[0085] FIG. 29 is similar to FIG. 24, but for an embodiment where EL=0° and AZ=49°. 15-19. 15-18 are plots of the transmitted EL beam and side lobe pattern 186 of an embodiment; The receive E of an embodiment of the receive antenna section 70 (FIG. 9) resulting in 19 receive patterns The L-beam and side lobe patterns 187 are superimposed.

[0086] FIG. 30 is similar to FIG. 25, but for an embodiment where EL=0° and AZ=49°. The effective beam pattern obtained by combining the transmit and receive beam patterns 186 and 187 in FIG. 1 is a plot of an effective (bidirectional) EL beam pattern 188.

[0087] FIG. 31 shows the transmission power of FIGS. 15-19 according to an embodiment where EL=0° and AZ=49°. The transmit AZ beam of an embodiment of the transmit antenna section 180 (FIG. 28) that results in a turn 15-19. AZ beam and side lobe pattern of the receiving antenna section 70 (Fig. 9) 92 are superimposed.

[0088] FIG. 32 shows the transmit beam pattern of FIG. 31 according to an embodiment where EL=0° and AZ=49°. The effective AZ beam pattern obtained by combining the turn 190 and the receiving beam pattern 192 is This is the plot for turn 194.

[0089] 28 and 31-32, at an AZ angle of about 20°, the transmitting antenna section The AZ shift of the transmitter 182 of 180 relative to the transmitter 184 is 31 to the left, so that the peak is no longer in the receive sidelobe. In addition, this shift also reduces the transmit side The magnitude of the peak of the lobe 166 is therefore reduced. The size of the effective side lobe 170 formed by the combination of 8 is The magnitude of lobe 170 is significantly reduced (by about 15 dB).

[0090] Referring again to FIG. 27 and additionally to FIG. 14, the transmitter 184 (108) The technique of shifting the signal portion 182 (106) to the AZ (and / or shifting the EL) is Applying this to decorrelate the transmit and receive sidelobes at other beam angles in the Designers can choose the best fit for a particular application across all beam angles in the AZ dimension. Select the shift magnitude and polarity / direction that results in the best overall sidelobe decorrelation. It is possible.

[0091] A receiver that receives redirected transmit energy along one or more receive side lobes. A different technique for reducing aliasing due to the antenna is applied to each receive channel. The aim is to use multiple complex weights that can be used to calculate the weights, and the complex weight vectors are approximately the same. This can result in a receive array that has a main beam but a very different side lobe pattern. Please note that.

[0092] This technique involves calculating, for each of one or more positions of a receive beam (or a bundle of receive beams), a receive Adjusting the complex weighting of each of one or more of the antenna segments 22 (FIG. 4) can be applied to selectively reduce one or more receive side lobes by The designer should determine by simulation or measurement the location of the main receiving beams. The receive side lobes can be determined and the receive beam (or receive beam bundle) can be adjusted to the desired beam. characteristics (e.g., HPBW in AZ and EL dimensions) and the desired size for the main receive side lobe. For each antenna segment 22, a lobe characteristic (e.g., magnitude, phase) is given. The designer can then design the radar system 14 as follows: These determined complex weights are applied to the antenna segments 22, On the other hand, the receive beams can be programmed to have corresponding receive beam positions. The designer can repeat this procedure for one or more positions of the receive beam, e.g. ,The look-up table (LUT) stores the,number of antenna segments for each receive beam position. The respective complex weightings for the inputs 22 can be stored.

[0093] FIG. 33 is a block diagram of the radar subsystem 210. The radar system 210 can be the same as or replace the radar system 14 of FIG. The transmit and receive antennas of Figs. 1-2, 4, 9, 14 and 28 according to possible embodiments. Antenna groups or subsystems including one or more of 10, 12, 100, and 180 Includes system 212.

[0094] In addition to the antenna group 212, the radar subsystem 210 includes a transceiver 214. , beam steering controller 216, radar processing unit 218, and master controller 220, and these components may be hardwired or configured as data streams. Capable of executing software or subcombinations of such circuits Or it may be a circuit that is a combination.

[0095] The antenna subsystem 212 includes the transmit antenna sections 10 (FIG. 1), 100 (FIG. 1 4), and 180 (FIG. 28), or 1 to 4, which includes one or more receive antenna sections 12 (FIGS. 1 to 4). 2 and 4) or 70 (FIG. 9). As mentioned above, the transmit antenna 222 can include configured to generate one or more transmit beam patterns having one or more desired characteristics. The receive antenna 224 then transmits one or more receive beam patterns having one or more desired characteristics. whereby the transmit beam pattern corresponds to a respective receive beam. In combination with the pattern, it is adapted to form a spatial filter.

[0096] The transceiver 214 includes a transmit circuit 226 and a receive circuit 228. The transmit circuit 226 includes: It includes a voltage controlled oscillator (VCO) 230, a preamplifier 232, and a power amplifier (PA) 234. The VCO 230 operates at a frequency f 0 =c / λ 0をThe preamplifier 232 is configured to amplify the VCO signal. and PA 234 is configured to amplify the signal from the preamplifier. The receiver circuit 228 includes a respective antenna segment 22 for each antenna segment 22 of the receive antenna 224. Each of the receive channels 236 includes a low noise amplifier (LNA) 238, a mixer 240, and an amplifier. Analog-to-digital converter (ADC) 242. The LNA 238 is connected to the receiving antenna 224. The mixer 240 is configured to amplify the received signal by The ADC242 is configured to shift the frequency down to baseband and The downshifted analog signal is converted into a digital signal for processing by the processing unit 220. The scalar is configured to convert

[0097] Beam steering controller 216 controls one or more transmit antennas over control line 18 (FIG. 1). The control signal for the antenna unit, which consists of By creating a transmission beam generated by one or more MESA transmit antennas 222, By appropriately generating the control signals, the beam can be steered. The controller 216 controls one or more MEs according to the selected spatial and temporal pattern. It is configured to selectively activate and deactivate antenna elements of the SA transmit antenna 222 . Beam steering of one or more transmit antennas, such as the MESA transmit antenna 222, is shown in FIG. 37, which is described below.

[0098] The radar processing unit 218 receives a digitized baseband received signal from the receiver 228. Receive each of the received signals, process the signals, form receive beams as described above, and steer the received signals. As mentioned above, the radar processing unit 218 is configured to Then, each of the digitized signals is amplified by a respective gain, and each of the digitized signals is Each receive beam pattern is generated by shifting the phase of each By varying the gain and phase shift as a function of time, the laser The digital processing unit 218 effectively steers one or more primary receive beams of the receive beam pattern. The radar processing unit 218 then detects objects along the receive beam, for example: The formed receive beam pattern is then processed for further processing to determine the object's position and velocity. The radar data carried by the radar beam is fed to conventional data processing circuitry. The data processing circuitry analyzes the signals from the receiver 228 to determine, for example, the detected objects and their locations. and speed, and what actions, if any, the system includes or is associated with, The radar subsystem 210 can be configured to determine whether to For example, if the system is an autonomous vehicle or a self-directing drone, the data processing circuitry may What action, if any, (e.g. braking, turning) should the vehicle take in response to the detected object? Alternatively, the radar processing unit 218 may be configured to determine whether Alternatively, or in addition to, such further processing of radar data may be performed using a data processing system. The device may be configured to perform the following process:

[0099] The master controller 220 receives the radar system controller (not shown in FIG. 33). In response to the radar control signal, the transceiver 214, the beam steering controller 216, and and a radar processing unit 218. For example, one or more transmit amplifiers Tena 222, f 0 Assume that the NI 8110 is designed to operate at frequencies in the range centered on The master controller 220 then determines, for example, environmental conditions, e.g., weather, one or more transmission The average number of objects within range of the one or more receive antennas 224 and one or more transmit The amplitude of the received signal generated by the VCO230 is proportional to the average distance of the object from the antenna and the receiving antenna. The system is configured to adjust the frequency of the signal transmitted to make the transmitted signal consistent with spectrum regulations. In another example, the master controller 220 controls the beam steering controller 216 and the radar processing. The beam steering controller 216 controls the control unit 218 to generate transmit and receive beams. 216 and the radar processing unit 218. which correspond to commands.

[0100] The operation of the radar subsystem 220, according to one embodiment, is described below. Any of the system components, such as the controller 220, may store software / program instructions. The system may be stored and executed in a memory to perform the operations described below. Any system components, such as a system controller (not shown in FIG. 33), may be loaded that, when received, configures one or more of the system components to: The set, e.g., firmware, may be stored in memory or in the system controller. Hardwire any of the system components, such as the controller, to operate as described below. can be executed.

[0101] The master controller 220 controls the VCO 230 to 0Frequencies in the frequency range centered on Generates a control voltage that generates a signal with a certain number of steps. For example, 0 is about 5 gigahertz (GHz) It can be in the range of ~100 GHz.

[0102] The VCO 230 generates a signal, and the PA 232 and amplifier 234 amplify the signal. The received signal is provided to one or more transmit antennas 222 .

[0103] The amplifiers 234 are used to amplify the beam while coupling the transmit signal to one or more transmit antennas 222. The control controller 216 responds to the master controller 220 by controlling one or more transmit amplifiers. These control signals are sent to one or more antenna units. The transmitting antenna generates and steers one or more main signal transmission beams. As discussed above in relation to 10-27 and 29-32, the control signal may be one or more primary signals. The transmission beam is given desired characteristics, and the transmission side lobe is also given desired characteristics, e.g. A suitable total side lobe power and a suitable side lobe level (e.g., minimum main signal transmit beam and maximum side lobe).

[0104] Master controller 220 then causes VCO 230 to cease generating the transmit signal.

[0105] Then, while the VCO 230 is not generating a signal, the LNA 238 Each of the tenna segments 22 amplifies the signal received.

[0106] The mixer 240 then mixes the amplified signal received from the LNA 238 with a 0 Or Each frequency is down-converted to the baseband frequency.

[0107] The ADC242 then converts the analog downconverted signals to their respective digital signals. do.

[0108] The main controller 220 then generates one or more control signals to the radar processing unit 218. Send to.

[0109] These control signals allow the radar processing unit 218 to By applying a suitable respective gain and phase shift to each of the digitalized signals, 7-8, 10-27, and 2 As discussed above in relation to 9-32, the control signal instructs the radar processing unit 218 to Generate one or more main signal receive beams having characteristics and generate side lobes and having desired characteristics such as suitable total side lobe power and appropriate side lobe level. Make them do so.

[0110] The radar processing unit 218, or data processing circuitry (not shown in FIG. 33), then performs amplification and The phase-shifted digital signal is analyzed to obtain information from the signal, if any. determines what should be done in response to the information obtained from

[0111] The radar subsystem 210 may repeat the above cycle one or more times.

[0112] With further reference to FIG. 33, an alternative embodiment of the radar subsystem 210 is contemplated. For example, the radar subsystem 210 may include one or more additional components not described above. elements and may omit one or more of the above components. A function or operation attributable to one component of the radar subsystem 210 is referred to as a radar subsystem. The radar subsystem may be implemented by other components of the system or by other components external to the radar subsystem. It can be done.

[0113] FIG. 34 illustrates a vehicle system including the radar subsystem 210 of FIG. 33, according to one embodiment. 250. For example, the vehicle system 250 may be a drone or an autonomous vehicle. The vehicle may be an unmanned aerial vehicle (UAV), such as a self-driving vehicle.

[0114] In addition to the radar subsystem 210, the vehicle system 250 includes a drive assembly 242 and Includes a system controller 244.

[0115] The drive assembly 252 includes a propulsion unit 256, such as an engine or motor, a rudder, a Laperon, pitch control, or yaw control (e.g. for UAVs or drones), or steerable and a steering unit 258, such as a steering wheel (e.g., for a self-driving car) linked to a suitable wheel. nothing.

[0116] The system controller 254 controls the radar subsystem 210 and the drive assembly 252. For example, a system controller may be configured to control a 254 receives the position, size, and velocity of nearby objects from the radar subsystem 210. , for example, from a GPS receiver (not shown in FIG. 34) or from a sensor mounted on the system 250. From a sensor (e.g., an accelerometer, not shown in FIG. 34), the speed and It may be configured to receive heading.

[0117] The operation of the vehicle system 250, according to one embodiment, is described below. The software / program instructions are written to the memory by one of the system components, such as the controller 254. The system may store and execute the operations described below. Any system components, such as the controller 254, are loaded and Firmware that configures one or more of the components to perform the following functions: Alternatively, the information may be stored in a system component such as the system controller 244. Any of the components can be hardwired to perform the operations described below.

[0118] The system controller 254 activates the radar subsystem 210 and The system 210 may include one or more sensors near the vehicle system 250, as described above in connection with FIG. For example, the vehicle system 250 may provide information about the object to a system controller. If an AV or unmanned aircraft, the radar subsystem may provide forward, side and and one or more objects (e.g. birds, aircraft, and other UAVs / Alternatively, the vehicle system 250 may provide information about the autonomous vehicle (e.g., drone). If it is a vehicle, the radar subsystem 210 detects the front, sides, and rear of the vehicle system. information about one or more objects in the road (e.g., other vehicles, debris, pedestrians, bicycles) can be provided.

[0119] In response to the object information from the radar subsystem 210, the system controller 254 , the vehicle system 250 determines what action, if any, to take in response to the object information. The master controller 220 of the radar subsystem 210 (FIG. 33) makes this decision as follows: and provide it to the system controller 254.

[0120] Next, the system controller 254 (or the master controller 220 in FIG. 33) operates If the system controller determines that the drive assembly 252 should For example, the system controller 254 or the master controller 22 0 if the UAV system 250 determines that it is approaching an object in front of the UAV system , the system controller 254 controls the propulsion unit 256 to reduce the air speed. Alternatively, the system controller 254 or the master controller 220 may If the autonomous driving system 250 determines that an object in front of the autonomous driving system 250 is decelerating, the system control The Troller 254 controls the propulsion unit 256 to reduce engine speed and apply the brakes. Alternatively, the system controller 254 or the master controller 220 may ,An object in front of the vehicle system (e.g., another UAV / drone, a bird,,vehicle system 250 If the driver determines that evasive action is necessary to avoid a child running in front of the driver, then The stem controller 254 controls the propulsion unit 256 to reduce the engine speed, In the case of an autonomous vehicle, it controls the brakes and controls the steering unit 258. The vehicle system can be steered from or around an object using the vehicle positioning system.

[0121] 34, alternative embodiments of the vehicle system 250 are contemplated. For example, Vehicle system 250 may include one or more additional components not described above. and one or more of the above components may be omitted. The vehicle system may be a UAV, drone, or vehicle system other than an autonomous vehicle. Other examples of Stem 250 include ships, motorcycles, non-self-driving cars, and spacecraft. Additionally, the system including the radar subsystem 210 may be other than a vehicle system. It can be.

[0122] FIG. 35 is a plan view of the transmitting antenna portion 10 of FIG. 1 according to one embodiment. The section includes a plurality of waveguides 260 1 ~260 n and the corresponding conductive antenna element 26 2 1 ~262 n The waveguide 260 is a holographic aperture antenna having a 35. A rectangular strip transmission line waveguide of , are approximately parallel to each other. 1 ~262 n The waveguide 260 is For example, antenna element 262 is arranged in a one-dimensional array. 1 is the waveguide 26 0 1 The antenna elements 262 are arranged in a one-dimensional array on the 2 is a waveguide 260 2 One dimensional above The transmitting antenna section 10 is arranged in an array, and so on. 0 Signal at wavelength Assuming that the waveguide 260 is designed to transmit and receive signals, the waveguide 260 has a At distance d 1 ≒ λ 0 / 2 apart, and the antenna elements in each one-dimensional array 262 are at a distance d from each other. 2 <<λ 0 For example, λ 0 / 1000 <d 2 < λ0 Further, each of the waveguides 260 has a wavelength of about 3λ 0 ~20λ 0 Approximately between The length l is equal to or greater than 20λ. 0 It can be longer than that.

[0123] FIG. 36 illustrates a cross-sectional view of the transmit antenna section 10 of FIG. 35 along line A- in FIG. 35, according to one embodiment. FIG. 36 shows a side view taken along line A of the waveguide 260. 3 and the corresponding antenna Element 262 3 Although only one is shown, the following description also applies to other waveguides and antenna elements. Fits.

[0124] Waveguide 262 3 is the frequency f 0 =c / λ 0、 Has adjustable impedance near Bonding layer 270, conductive layer / strip 272 3、 dielectric layer 274, where c is the free The speed of light in space. Although not shown, the transmitting antenna section 10 is made of a dielectric In operation, the waveguide 260 includes a conductive plane, such as a ground plane, disposed beneath the layer 274. 3 By The signal to be guided is transmitted through the conductive strip 272. 3 along the dielectric layer 274 between The transmit antenna section 10 has a single coupling layer common to all the waveguides 260. 270 and a single dielectric layer 274, but the antenna portion may include one per waveguide. The strips 272 each include a separate conductive strip 272 having four strips. 2, and the corresponding antenna element 262 is at a distance d 1 (See FIG. 35).

[0125] Each antenna element 262 3, and a coupling region 27 of a layer 270 disposed under the antenna element. 6 3 Each antenna unit 278 3 For example, the antenna of layer 270 Element 262 3,5 and binding region 276 3,5 is the antenna of the transmitting antenna section 10 Unit 278 3,5 Form.

[0126] FIG. 37 illustrates the antenna unit 278 of FIG. 36, according to one embodiment. 3,5 , and antenna Waveguide 260 corresponding to the unit 3 Conductive strips 272 3 Side view of part and electrical FIG.

[0127] Combined area 276 3,5 272 conductive strip 3 and antenna element 262 3,5 With A lumped tunable impedance element 280 electrically coupled between 3,5 As a model The conductive control line 282 can be 3,5 is a lumped element 280 3,5 Directly bonded to or as shown, conductive antenna element 262 3,5 Indirectly to lumped elements via As described below, a controller (e.g., the master controller in FIG. 33) is coupled to the The antenna element 262 3,5 to, and from there to, waveguide 260 3 Along The propagating signals can be selectively combined and decombined, and thus the antenna elements Child, control line 282 3,5 Selectively vary the bias signal (e.g., bias voltage) on By this, the antenna elements can be selectively activated and deactivated. -pass filter 284 3,5 A concentrated element 280 3,5 Connected in series between the Then, the waveguide 260 3に The controller is switched off from high frequency energy from signals propagating along the It can be separated.

[0128] Antenna Unit 278 3,5 Conductive strips for 272 3 The part has a gap of 3 8 3,5を , which can be filled with the same material that forms the bonding layer 270; waveguide 260 3 to the antenna unit.

[0129] Still referring to FIG. 37, antenna unit 278 3,5 During operation, lumped elements 280 3,5 A control line 282 having a level that stops 3,5 In response to the control signal, the coupling region area 276 3,5 The gap is 286 3,5 It presents a large impedance to For this purpose, the waveguide 260 3に The signal propagating along the antenna element 262 3,5に Combine and Therefore, the antenna element 262 is prevented from exciting the 3,5 is almost or It does not radiate any energy.

[0130] In contrast, lumped element 280 3,5 A control line 282 having a level that activates 3,5 Above In response to the control signal, the coupling region 276 3,5 286 voids 3,5 Small impedance for The waveguide 260 is then oriented such that it exhibits a impedance and, in turn, the signal excites the antenna elements. 3 The signal propagating along the antenna element 262 3,5 Therefore, the excited Tena Element 262 3,5 is a waveguide 260 3に It is the same as one or more frequencies of the signal propagating along For example, lumped element 280 radiates energy at one or more frequencies. 3,5 is active When 3,5 , antenna element 262 3,5 With approximately f 0 As is known, the present invention is configured to form a series resonant circuit having a resonant frequency of At the resonant frequency, the series resonant circuit presents a low impedance, ideally zero impedance. The waveguide 260 3に The signal propagating along the 0 Since it has a frequency of Therefore, lumped elements 280 3,5 When is active, area 276 3,5 is low for the signal To implement such a selective resonant circuit, a lumped element 280 is 3,5 is a PN junction diode, a field effect transistor (FET), or , the binding region is f 0 Antenna element 262 3,5 A series resonant circuit is formed with Conductive Strip 272 3 and the antenna element, 3,5 Impedance of Change the value.

[0131] Still referring to FIG. 37, antenna unit 278 3,5 Only However, the other antenna units 278 of the transmitting antenna section 10 (FIGS. 1 and 35-36) All of the antenna portions 278 may have the same structure. 3,5 As the same It can operate like this.

[0132] Referring to FIGS. 1 and 35-37, the transmitting antenna section 10 and the antenna unit Further details of the 278 can be found in the following documents: U.S. patent application Ser. No. 14, filed Oct. 3, 2014; / 506,432, invention name: SURFACE SCATTERING ANTENN AS WITH LUMPED ELEMENTS, and the application filed on October 14, 2011 U.S. Patent No. 9,450,310, Title of Invention: SURFACE SCATTERING ELEMENTS, which are incorporated herein by reference. Further, each of the subsections 106 and 108 of the transmit antenna section 100 of FIG. And each subsection 182 and 184 of the transmit antenna section 180 of FIG. It may be similar in construction and operation to the transmit antenna section 10 .

[0133] From the foregoing, it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, the present disclosure It will be understood that various modifications can be made without departing from the spirit and scope of the present invention. Additionally, where alternatives are disclosed for a particular embodiment, the alternatives are not limited to those specifically mentioned. Furthermore, any of the described components or elements may be used in other embodiments. The operation may be performed by hardware, software, firmware, or both. Implemented / executed in any combination of two or more of the following: software, software, and firmware. Furthermore, one or more components of the described devices or systems may be In addition, the description contained herein may be omitted for other reasons. One or more components of the device or system may be omitted from the device or system. be.

Claims

1. It is an antenna subsystem, A sparse receiving antenna configured to generate a received beam pattern and including one array of receiving elements, and an electronically controllable transmitting antenna configured to spatially filter the received beam pattern and including one array of transmitting elements and at least one transmission line. Includes, Each of the receiving elements is configured to receive a corresponding signal having one wavelength, and each is spaced apart from each adjacent receiving element by a corresponding first distance exceeding half the wavelength. Each of the transmitting elements is configured to emit a corresponding transmitting signal having the wavelength in response to a reference signal, and each is spaced a corresponding second distance less than half the wavelength from each adjacent transmitting element. An antenna subsystem in which each of the at least one transmission line is configured to carry the reference signal to at least one of the transmitting elements.

2. The antenna subsystem according to claim 1, wherein the sparse receiving antenna includes no fewer than 8 receiving elements and no more than 64 receiving elements.

3. The antenna subsystem according to claim 1, wherein each of the corresponding first distances is at least five times the wavelength.

4. The antenna subsystem according to claim 1, wherein at least one of the corresponding first distances is at least 10 times the wavelength.

5. The electronically controllable transmitting antenna includes a plurality of transmitting antenna sections, The antenna subsystem of claim 1, wherein each transmitting antenna section includes transmitting elements of a corresponding subarray.

6. The aforementioned electronically controllable transmitting antenna is A first transmitting antenna section having a first subarray of the transmitting elements, A second transmitting antenna section having a second subarray of the transmitting elements and offset from the first transmitting antenna section The antenna subsystem of claim 1, including the antenna subsystem of claim 1.

7. The antenna subsystem according to claim 1, wherein each of the corresponding second distances is 1 / 10 or less of the wavelength.

8. The antenna subsystem of claim 1, wherein the electronically controllable transmitting antenna includes a metamaterial electronically controllable transmitting antenna.

9. The antenna subsystem of claim 1, wherein one array of the electronically controllable transmitting antenna is configured as an oversampling array.

10. The antenna subsystem according to claim 1, wherein the electronically controllable transmitting antenna lacks a phase shift circuit.

11. The antenna subsystem of claim 1, wherein the electronically controllable transmitting antenna includes a holographic antenna.

12. The antenna subsystem of claim 1, wherein the at least one transmission line includes at least one waveguide.

13. The antenna subsystem of claim 1, wherein the at least one transmission line includes at least one transmission line waveguide.

14. The antenna subsystem of claim 1, wherein the at least one transmission line includes at least one rectangular strip transmission line waveguide.

15. It is a method, Using an electronically controllable antenna having a transmitting element and an aperture, a transmit beam pattern is generated in response to a reference signal carried to the transmitting element by at least one transmission line, wherein the transmit beam pattern includes a main transmit beam occupying a main transmit beam region. The method involves generating a received beam pattern in response to a signal received by a sparse digital beamforming antenna having an aperture significantly larger than that of the electronically controllable antenna, wherein the received beam pattern includes a main received beam occupying the main received beam region within the main transmitted beam region. Includes, A method in which one of the transmitting beam pattern and the receiving beam pattern spatially filters the other of the transmitting beam pattern and the receiving beam pattern.

16. The main transmit beam region is defined by the power half-width of the main transmit beam, The method of claim 15, wherein the main receiving beam region is defined by the beamwidth at half maximum power of the main receiving beam.

17. The method of claim 15, wherein generating the transmitted beam pattern and the received beam pattern includes generating the transmitted beam pattern and the received beam pattern at different times.

18. The method of claim 15, wherein generating the transmit beam pattern and the receive beam pattern includes generating the transmit beam pattern and the receive beam pattern simultaneously.

19. Generating the received beam pattern includes generating the received beam pattern to include a plurality of main received beams, The method of claim 15, wherein each of the plurality of main receiving beams occupies a corresponding main receiving beam region within the main transmitting beam region.

20. A tangible, non-temporary medium for storing commands, When the aforementioned instruction is executed by the arithmetic circuit, it will be directed to the arithmetic circuit or to another circuit under the control of the arithmetic circuit. A transmitting beam pattern is generated using an electronically controllable antenna having a transmitting element and an aperture, in response to a reference signal carried to the transmitting element by at least one transmission line, wherein the transmitting beam pattern includes a main transmitting beam occupying a main transmitting beam region. The method involves generating a received beam pattern in response to a signal received by a sparse digital beamforming antenna having an aperture significantly larger than that of the electronically controllable antenna, wherein the received beam pattern includes a plurality of primary received beams, each of which occupies a corresponding primary received beam region within the primary transmitted beam region. Have them do it, A tangible, non-temporary medium in which one of the transmitting beam pattern and the receiving beam pattern spatially filters the other of the transmitting beam pattern and the receiving beam pattern.

21. It is an antenna subsystem, A sparse receiving antenna including one array of receiving elements, An electronically controllable transmitting antenna including one array of transmitting elements and at least one transmission line. Includes, Each of the receiving elements is configured to receive a corresponding signal having one wavelength, and each is spaced apart from each adjacent receiving element by a corresponding first distance exceeding half the wavelength. Each of the transmitting elements is configured to emit a corresponding transmitting signal having the wavelength in response to a reference signal, and each is spaced a corresponding second distance less than half the wavelength from each adjacent transmitting element. An antenna subsystem in which each of the at least one transmission line is configured to carry the reference signal to at least one of the transmitting elements.

22. The antenna subsystem of claim 21, wherein the sparse receiving antenna includes no fewer than 8 receiving elements and no more than 64 receiving elements.

23. The antenna subsystem of claim 21, wherein each of the corresponding first distances is at least five times the wavelength.

24. The antenna subsystem of claim 21, wherein at least one of the corresponding first distances is at least 10 times the wavelength.

25. The electronically controllable transmitting antenna includes a plurality of transmitting antenna sections, The antenna subsystem of claim 21, wherein each transmitting antenna section includes transmitting elements of one corresponding subarray.

26. The aforementioned electronically controllable transmitting antenna is A first transmitting antenna section having a first subarray of the transmitting elements, A second transmitting antenna section having a second subarray of the transmitting elements and offset from the first transmitting antenna section The antenna subsystem of claim 21, including the antenna subsystem of claim 21.

27. The antenna subsystem of claim 21, wherein each of the corresponding second distances is 1 / 10 or less of the wavelength.

28. The antenna subsystem of claim 21, wherein the electronically controllable transmitting antenna includes a metamaterial electronically controllable transmitting antenna.

29. The antenna subsystem of claim 21, wherein one array of the electronically controllable transmitting antenna is configured as an oversampling array.

30. The antenna subsystem of claim 21, wherein the electronically controllable transmitting antenna lacks a phase shift circuit.

31. The antenna subsystem of claim 21, wherein the electronically controllable transmitting antenna includes a holographic antenna.

32. The antenna subsystem of claim 21, wherein the at least one transmission line includes at least one waveguide.

33. It is a method, Using an electronically controllable antenna having a transmitting element and an aperture, a transmit beam pattern is generated in response to a reference signal carried to the transmitting element by at least one transmission line, wherein the transmit beam pattern includes a main transmit beam occupying a main transmit beam region. The method involves generating a received beam pattern in response to a signal received by a sparse digital beamforming antenna having an aperture significantly larger than that of the electronically controllable antenna, wherein the received beam pattern includes a main received beam occupying the main received beam region within the main transmitted beam region. Methods that include...

34. The main transmit beam region is defined by the power half-width of the main transmit beam, The method of claim 33, wherein the main receiving beam region is defined by the power half-maximum beamwidth of the main receiving beam.

35. The method of claim 33, wherein generating the transmitted beam pattern and the received beam pattern includes generating the transmitted beam pattern and the received beam pattern at different times.

36. The method of claim 33, wherein generating the transmit beam pattern and the receive beam pattern includes generating the transmit beam pattern and the receive beam pattern simultaneously.

37. Generating the received beam pattern includes generating the received beam pattern to include a plurality of main received beams, The method of claim 33, wherein each of the plurality of main receiving beams occupies a corresponding main receiving beam region within the main transmitting beam region.

38. A tangible, non-temporary medium for storing commands, When the aforementioned instruction is executed by the arithmetic circuit, it will be directed to the arithmetic circuit or to another circuit under the control of the arithmetic circuit. A transmitting beam pattern is generated using an electronically controllable antenna having a transmitting element and an aperture, in response to a reference signal carried to the transmitting element by at least one transmission line, wherein the transmitting beam pattern includes a main transmitting beam occupying a main transmitting beam region. The method involves generating a received beam pattern in response to a signal received by a sparse digital beamforming antenna having an aperture significantly larger than that of the electronically controllable antenna, wherein the received beam pattern includes a plurality of primary received beams, each of which occupies a corresponding primary received beam region within the primary transmitted beam region. A tangible, non-temporary medium that causes something to happen.

39. The aforementioned sparse receiving antenna has an aperture, The antenna subsystem according to claim 1, wherein the electronically controllable transmitting antenna has an aperture significantly smaller than the aperture of the sparse receiving antenna.

40. The aforementioned sparse receiving antenna has an aperture area, The antenna subsystem according to claim 1, wherein the electronically controllable transmitting antenna has an aperture area significantly smaller than the aperture area of ​​the sparse receiving antenna.

41. The antenna subsystem of claim 1, wherein the corresponding first distance is unequal.

42. The antenna subsystem of claim 1, wherein the plurality of receiving elements of the sparse receiving antenna are not arranged in vertical columns or horizontal rows.

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