NODAL METAMATERIAL ANTENNA SYSTEM
The present invention is a nodal radar system having a metamaterial-based object detection system. An intelligent antenna metamaterial interface (IAM) associates specific metamaterial unit cells into subarrays to adjust the beam width of a transmitted signal. The nodal radar system is positioned on infrastructure to complement sensor information from mobile vehicles and devices within an environment.
This application is a continuation of U.S. patent application Ser. No. 15/984,222 entitled “NODAL METAMATERIAL ANTENNA SYSTEM,” filed May 18, 2018 which claims priority to U.S. Provisional Patent Application No. 62/515,045 entitled “INTELLIGENT ANTENNA METAMATERIAL METHOD AND APPARATUS,” filed Jun. 5, 2017; U.S. Patent Application No. 62/613,675 entitled “METHOD AND APPARATUS FOR OBJECT DETECTION USING CONVOLUTIONAL NEURAL NETWORK SYSTEMS,” filed Jan. 4, 2018; and U.S. Provisional Patent Application No. 62/651,050, entitled “METHOD AND APPARATUS ANTENNA WITH DECISION CONTROL”, filed Mar. 30, 2018.
FIELD OF THE INVENTIONThe present invention relates to intelligent antennas using metamaterial structures and providing dynamic control of metamaterial unit cells in the metamaterial structures for radar systems.
BACKGROUNDAntennas are used in everyday life for communication systems, sensing devices, radar systems and so forth. Recently there is attention given to autonomous, or self-driving, vehicles. The designs and products contemplated today do not consider all the weather conditions, power consumption constraints and timing required for effective control of a vehicle. There is a need to provide a sensing system that works over the range of road, weather, temperature, visibility, traffic conditions and so forth, while maintaining consistent reliable service.
Embodiments of the present invention are described with respect to the figures. These are not drawn to scale and are drawn to clearly identify what applicant claims as the invention.
Autonomous driving is quickly moving from the realm of science fiction to becoming an achievable reality. Already in the market are Advanced-Driver Assistance Systems (“ADAS”) that automate, adapt and enhance vehicles for safety and better driving. The next step will be vehicles that increasingly assume control of driving functions such as steering, accelerating, braking and monitoring the surrounding environment and driving conditions to respond to events, such as changing lanes or speed when needed to avoid traffic, crossing pedestrians, animals, and so on.
An aspect of making this work is the ability to detect and classify objects in the surrounding environment at the same or possibly even better level as humans. Humans are adept at recognizing and perceiving the world around them with an extremely complex human visual system that essentially has two main functional parts: the eye and the brain. In autonomous driving technologies, the eye may include a combination of multiple sensors, such as camera, radar, and lidar, while the brain may involve multiple artificial intelligence, machine learning and deep learning systems. The goal is to have full understanding of a dynamic, fast-moving environment in real time and human-like intelligence to act in response to changes in the environment.
In addition to moving vehicles and devices, the present invention presents metamaterial antenna arrays for infrastructure and stationary structures to facilitate additional views, information and warnings to a moving vehicle. The antenna arrays are positioned to scan the area around them and identify objects as a complementary source of information for the vehicle. In addition, these fixed radar systems are flexible and responsive; they may be used to alert to severe weather conditions, such as flooding or snow, they may anticipate actions of a pedestrian or vehicle, and they may predict traffic congestion, alert to safety and/or security concerns, and act as a digital eye for the surrounding area. This information may be used as feedback to the vehicle, to the infrastructure control, to environmental agencies and so forth. In some examples, the radar detects traffic levels and then uses this information to provide real time data to the traffic controls, such as traffic signals. These digital eyes may respond to requests from throughout the environment, such as to interface with Internet of Things (IoT) devices.
The proliferation of devices and sensors enables rapid responses over a range of applications. For example, a radar sensor applied to a traffic light would be able to detect bicycles and pedestrians in specific locations and lanes. The MTM radar disclosed herein may use a coarse scan for such identification. Similarly, an MTM radar on highways would be able to communicate with a vehicle's GPS and provide advance warning of an upcoming exit or lane change. Similarly, an MTM radar sensor near a fueling location may provide an indication to vehicles that this is the last fueling station for a given distance and provide directions for fueling.
The present invention describes an antenna system having an antenna configured with metamaterial (MTM) cells and controlled by an Intelligent Antenna MTM interface (IAM). The antenna system may be used in applications including cellular communication networks, vehicle-to-vehicle communication systems, object detection systems, autonomous vehicle sensor systems, drone control and communication systems, and so forth. The MTM antenna structure is dynamically controlled by the IAM; control may be done by changing the electrical or electromagnetic configuration of the antenna structure. In some embodiments, varactors are coupled to the MTM antenna structure to enable adjustment of the radiation pattern. In some embodiments, the MTM unit cells may be configured into subarrays that have specific characteristics. For use in an autonomous vehicle, the system may perform a coarse focus with a large beam width as an ambient condition, and then narrow the beam width when an echo is received, indicating an object is within the field of view of the antenna structure's radiation pattern. In this way, the larger beam width may sweep the full Field of View (FoV) of the antenna structure, reducing the time to scan the FoV. In some embodiments, the IAM is able to detect the area of the FoV of a detected object and map that to a specific configuration of MTM unit cells and/or subarrays to focus the beam, i.e. narrow the beam width. Additionally, in some embodiments, the specific dimensions and other properties of the detected object, such as traveling velocity with respect to the antenna structure, are analyzed and a next action(s) or course of action(s) is determined. The detected object in some embodiments is then provided as a visual or graphic display, which may act as a back-up security feature for the passenger in the vehicle.
The nodal radar system 100 has an object detection capability to recognize objects and movement within the area. This may be an artificial intelligence system or other method. As the nodal radar system 100 operates, it is able to capture real time data and determine if it is operating sufficiently. For example, when the nodal radar system 100 sends a message to a vehicle incorrectly identifying a dog in the road, the vehicle may respond with a more specific identification of a cardboard box. Note that the nodal radar system 100 may have fewer object recognition capabilities and less processing power than some vehicle radars. In this way, the nodal radar system 100 is able to enhance and improve its object recognition capabilities, such as through training of a neural network or expert system, and by capturing real time data from surrounding vehicle radars and other such devices.
The nodal radar system 100 may be collocated with a fixed wireless system, wherein the nodal radar system 100 includes object detection capability. While the nodal radar system 100 is able to communicate with other devices and vehicles, it is also able to operate independently. The nodal radar system 100 may act in concert with the fixed wireless system, wherein communications from the nodal radar system 100 are processed through the fixed wireless system. Within the nodal radar system 100 is an object detection module to classify detected objects. This information may also be used to modify behavior of the fixed wireless system, such as to provide non-line of sight signals when there is a large truck or other obstacle to wireless transmission. When such an object is detected, the nodal radar system 100 instructs the fixed wireless system accordingly, and in response the fixed wireless system may initiate actions to avoid the dead spot, such as to use a reflect array or other method to continue coverage.
The system 160 may have multiple antenna arrays within MTM antenna structure 170, for radar and communications. These arrays may be divided into transmit and receive arrays or may be duplex-style where an array is used for both transmit and receive. The signals are generated according to the transceiver operation. For operation of the antenna, including beam forming and beam steering, a rule base and decision engine 166 provides guidance. The engine 166 determines when and where to direct the radiation beams and then determines if the decision was optimum. The engine 166 learns from the behavior of the system 160 and trains to improve its decision-making. The object detection module 165 uses radar information to determine if an object is in the area, or field of view, of the radar. The object detection module 165 may also use information from the wireless communication system 154 to identify objects that are causing a dead zone, or to respond to information, such as from a central controller or from a vehicle. The communication system 154 may support vehicle-to-device, or V2X, communications to enhance the radar operations. In this way, the vehicle can probe the system 160 for additional information to better understand the environment and the activity therein.
An MTM unit cell, such as cell 140, may be composed of multiple microstrips, gaps, patches, vias, and so forth having a behavior that is the equivalent to a reactance element, such as a combination of series capacitors and shunt inductors. Various configurations, shapes, designs and dimensions are used to implement specific designs and meet specific constraints. In some embodiments, the number of dimensional freedom determines the characteristics of the MTM antenna structure 110, wherein a device having a number of edges and discontinuities may model a specific-type of electrical circuit and behave in a similar manner. In this way, an MTM unit cell radiates according to its configuration and changes to the reactance parameters of the MTM unit cell change its radiation pattern. Where the radiation pattern is changed to achieve a phase change or phase shift, the resultant structure is a powerful antenna or radar, as small changes to the MTM unit cell result in large changes to the beamform.
The MTM antenna structure 110 may be configured as an array of MTM unit cells, a lattice pattern of MTM unit cells, and so forth. These array formations may then be divided into subarrays, which group unit cells together. The subarray may be controlled by a common controller. For example, in the subarray 145 within array 143, the MTM unit cells, such as cell 141, are all controlled by a single voltage. In this way, a same change is made to the reactance of all cells within a subarray 145.
An TAM 50 acts to control the operational parameters of the MTM antenna structure 110. In some embodiments, these parameters include voltages applied to individual MTM unit cells, such as unit cell 140. IAM 50 includes modules and components that capture, measure, store, analyze and provide instructions. The extent of the capabilities of the IAM 50 is strong and flexible; as more and more information is required for an application, the IAM 50 can build additional capabilities. In this way, the IAM 50 is a software programmable module implemented in hardware, having an IAM controller 52 that governs actions within the IAM 50.
In the present embodiment described herein, the application is for an autonomous car, wherein the system 100 is a sensing system that uses radar to identify objects. The use of radar provides a reliable way to detect objects in difficult weather conditions. For example, historically a driver will slow down dramatically in thick fog, as the driving speed decreases with decreases in visibility. On a highway in Europe, for example, where the speed limit is 115 km/h, a driver may need to slow down to 40 km/h when visibility is poor. Using the present embodiment, the driver (or driverless car) may maintain the maximum safe speed without regard to the weather conditions. Even if other drivers slow down, the car enabled with the present embodiment will be able to detect those slow-moving cars and obstacles in the way and avoid/navigate around them.
Additionally, in highly congested areas, it is necessary for an autonomous car to detect objects in sufficient time to react and take action. The present invention increases the sweep time of a radar signal so as to detect any echoes in time to react. Supplemental to the MTM antenna structure 110 is the nodal radar system, such as system 100 of
All of these detection scenarios, analysis and reactions may be stored in the IAM 50 and used for later analysis or simplified reactions. For example, if there is an increase in the echoes received at a given time of day or on a specific highway, that information is fed into the IAM controller 52 to assist in proactive preparation and configuration of the MTM antenna structure 110. Additionally, there may be some subarray combinations that perform better, such as to achieve a desired result, and this is stored in the IAM memory 54.
In operation, the MTM antenna structure 110 provides radar radiation pattern(s) to scan the FoV of the system 100. In some embodiments, an FoV composite data unit 112 stores information that describes the FoV. This may be historical data used to track trends and anticipate behaviors and traffic conditions or may be instantaneous or real time data that describes the FoV at a moment in time or over a window in time. The ability to store this data enables the IAM 50 to make decisions that are strategically targeted at a particular point or area within the FoV. For example, the FoV may be clear (no echoes received) for five minutes, and then one echo arrives from a specific region in the FoV; this is similar to detecting the front of a car. In response, the IAM 50 may determine to narrow the beam width for a more focused view of that sector or area in the FoV. The next scan may indicate the objects' length or other dimension, and if the object is a car, the IAM 50 may consider what direction the object is moving and focus the beams on that area. Similarly, the echo may be from a spurious object, such as a bird, which is small and moving quickly out of the path of the car. There are a variety of other uses for the FoV composite data 112, including the ability to identify a specific type of object based on previous detection.
The object detection module 114 receives control information from the IAM controller 52, and determines the adjustments, if any, to be made. In some embodiments, the scan begins with a coarse scan having a large bandwidth. On object detection, the beam width narrows. The variable beam dimension module 116 responds to the object detection module 114 and may vary the beam width as quickly or slowly as desired. In some embodiments, the beam width is a binary value, and in others it may take on continuous values. The object detection module 114 instructs the beam direction module 118 where to direct the beam, such as from a subarray. From the received information (echoes) the object dimension analysis module 120 determines parameters and dimensions of the detected object.
Object detection may be enhanced with object classification to identify the type of object and its activity parameters. For example, a deep learning system may be incorporated into the object detection module 114 to identify a person from a car, and to identify the velocity of that object. Such systems train on labelled data and actual radar signals after which they are able to perceive objects with a high probability of certainty. Such object classification systems and capabilities may be additional to the rule base and decision engine 60.
Continuing with system 100, the transceiver 130 is controlled by controller 132 and controls the transmit and receive paths to and from MTM antenna structure 110. There may a portion of the unit cells, such as unit cell 140, that is dedicated to receive, and another portion that is dedicated to transmit, or the MTM antenna structure 110 may be a transmit and receive antenna. In some embodiments, the IAM 50 may allocate specific unit cells, or subarrays, as receive only, transmit only or as transmit and receive. There are any number of combinations and designs for these embodiments.
There are many methods that systems that the MTM antenna structure 110 may use with respect to the IAM 50 for applying, embedding, controlling and so forth. An embodiment for dynamic control of the MTM antenna structure 110 is illustrated in
The transmission signal controller 108 may generate a cellular modulated signal, such as an orthogonal frequency division multiplexing (OFDM) signal. The transmission feed structure may be used in a variety of systems. In some systems, the signal is provided to the system 100 and the transmission signal controller 108 may act as an interface, translator or modulation controller, or otherwise as required for the signal to propagate through a transmission line system.
The present invention is described with respect to a radar system, where the radiating structure 200 is a transmission array-fed radiating array, where the signal radiates through slots in the transmission array to the radiating array of MTM elements that radiate a directional signal. Continuing with
In some embodiments a reactance control element includes a capacitance control mechanism controlled by antenna controller 112, which may be used to control the phase of a radiating signal from radiating array structures, transmission array structure for elevation 122 and transmission array structure for azimuth 124. In operation, the antenna controller 112 receives information from other modules in system 300 indicating a next radiation beam, wherein a radiation beam may be specified by parameters such as beam width, transmit angle, transmit direction and so forth. The antenna controller 112 determines a voltage matrix to apply to the reactance control mechanisms coupled to the radiating structure to achieve a given phase shift or other parameters. In these embodiments, the radiating array structure 200 is adapted to transmit a directional beam without using digital beam forming methods, but rather through active control of the reactance parameters of the individual elements that make up the array. Transceiver 110 prepares a signal for transmission, such as a signal for a radar device, wherein the signal is defined by modulation and frequency. The signal is received by each element of the radiating structure 200 and the phase of the radiating array structure 200 is adjusted by the antenna controller 112. In some embodiments, transmission signals are received by a portion, or subarray, of the radiating array structure 200. These radiating array structures are applicable to many applications, including radar and cellular antennas. The present embodiments consider application in autonomous vehicles as a sensor to detect objects in the environment of the car. Alternate embodiments may use the present inventions for wireless communications, medical equipment, sensing, monitoring, and so forth. Each application type incorporates designs and configurations of the elements, structures and modules described herein to accommodate their needs and goals.
In system 300, a signal is specified by antenna controller 112, which may be in response to Artificial Intelligence (AI) module 114 from previous signals, or may be from the interface to sensor fusion 104, or may be based on program information from memory storage 128. There are a variety of considerations to determine the beam formation, wherein this information is provided to antenna controller 112 to configure the various elements of arrays 122, 124, which are described herein. The transmission signal controller 108 generates the transmission signal and provides same to feed distribution module 116, which provides the signal to feed structure 126 and transmission arrays 122, 124.
As illustrated, radiating structure 200 includes the transmission arrays 122, 124, composed of individual radiating elements discussed herein. The transmission arrays 122, 124 may take a variety of forms and are designed to operate in coordination with the feed distribution module 116, wherein individual radiating elements 20 correspond to elements within the transmission arrays 122, 124. As illustrated, each of the transmission arrays 122, 124 is an 8×16 array of unit cell elements 20, wherein each of the unit cell elements 20 has a uniform size and shape; however, some embodiments incorporate different sizes, shapes, configurations and array sizes. When a transmission signal is provided to the radiating structure 200, such as through a coaxial cable or other connector, the signal propagates through the feed distribution module 116 to the transmission arrays 122, 124 for transmission through the air.
The impedance matching element 118 and the reactance control element 120 may be positioned within the architecture of feed distribution module 116; one or both may be external to the feed distribution module 116 for manufacture or composition as an antenna or radar module. The impedance matching element 118 works in coordination with the reactance control element 120 to provide phase shifting of the radiating signal(s) from transmission arrays 122, 124. The present invention is a dramatic contrast to the traditional complex systems incorporating multiple antennas controlled by digital beam forming. The present invention increases the speed and flexibility of conventional systems, while reducing their footprint and expanding performance.
As illustrated, there are multiple arrays for transmission, where at least one of the arrays is for transmission in the azimuth, or horizontal, direction, e.g., transmission array structure for azimuth 124, and the other is for receiving signal over the elevation of the array, e.g., receive array for elevation 122. The two antenna arrays share a common feed 126, but have orthogonal radiation beams. The two antenna arrays may also use separate feeds if desired.
As illustrated in
The system 200 then accesses the target or broadcast communication information, 210, and sends the message, 212. The message is to identify a detected object and assist in vehicle driver assist or autonomous driving. The message may be a simple identification of a location of an object, or may be detailed information about the object and its velocity/acceleration/potential movement. The information may also be to provide an instruction as to how to circumnavigate and avoid a collision, as the nodal radar may see areas in the environment that enable a quick escape route. The system 200 may also receive a communication from the vehicle or other device within the environment, 218. The received communication may be from another nodal radar system or may be from a wireless communication system. The system 200 then determines an action for the target, 220, based on the received communication, such as to provide an indication of the capabilities of the vehicle and so forth. The communication from the vehicle may be from a rule base or decision engine that provides a preferred action. The system 200 may then continue to communicate with the target vehicle, 222 or multiple vehicles/devices.
Each of the unit cells 340(i,j) in the antenna structure 300 may operate individually or as part of a subarray. As illustrated, the IAM 350 has associated or grouped specific unit cells into subarrays 302, 304, 306 and 308. The IAM 350 determines where the radiated beam is to be directed, the shape of the beam and the dimensions of the beam. The beam may be a coarse or large bandwidth beam, a midsized beam or a small, narrow bandwidth beam depending on the situation, the object detected and the timing of the detection, as well as other considerations. The IAM 350 may preconfigure one or more of the subarrays to anticipate a next action, or may use a default configuration, such as to start with a broad bandwidth which enables a faster scan capability or sweep time. For each sweep, the FoV is divided into portions, which may have consistent dimensions, different dimensions or may be dynamically adjusted. In some embodiments, the IAM selects specific directions to have a narrow beam, such as directly in front of the vehicle; other directions, such as on the edges of the FoV may be scanned with a wide beam. These and other design considerations are made by the designer in setting up the IAM 350, wherein some IAM 350 are flexible and configurable. In the illustrated example, the MTM antenna structure 300 has several subarrays that are intended to direct the beam and form the desired radiation pattern.
Once an object is detected, the FoV-to-MTM mapping 360 identifies the portion of the FoV for the IAM 350 and maps that location to a specific MTM unit cell or subarray that will focus on and capture more information about the object. In some embodiments, the IAM 350 has access to various scenarios and may use detected information to predict future conditions on the road. For example, if the MTM antenna structure 300 detects a deer running across the road in an area having a known deer path, the IAM 350 may predict the direction of the deer, as well as anticipate other deer that may follow. The radiation beams from antenna structure 300 may sweep across the FoV, wherein the visual field of view and the antenna field of view are not necessarily the same. In this case, the antenna FoV may be a 2-D view, whereas objects are typically 3-D. Various systems and configurations enable 3-D object detection and classification through placement of transmit and receive antenna arrays and or combinations of multiple transmit to multiple receive structures.
As illustrated in
As a vehicle travels, there are different FoV snapshots or slices, such as from a near-field to a far-field slice. From the perspective of a vehicle there is a near-field FoV, a far-field FoV, and several mid-field FoVs, which may each be considered as a slice of information. The information may be stored according to angle of arrival, range to the target, velocity of the target, Doppler information from the received signal and so forth. In one embodiment, these are referred to as range-Doppler maps. Each slice corresponds to an instant in time as the car travels. The IAM 550 determines which type of beam is broadcast for each FoV as a function of many parameters, including, for example, the speed of the car and the speed of a detected object in relation to the car. The IAM 550 may determine that for specific conditions, the beams are meant to reach a specific FoV, such as where the car is moving slowly, the FoV 520 may be sufficient, but if the car is moving rapidly then there is a desire to reach more than just the FoV 520. Weather conditions will have an impact as well, such that if the car will take longer to react, stop or otherwise change the current driving conditions, then the IAM 550 may desire to reach the longest FoV to allow the car time to react. This may be utilized for snow or icy conditions, which dramatically impact how quickly a car may decelerate and/or halt.
In some embodiments, a nodal radar system may be positioned on a bill board placed along the road to detect objects traveling along the road. The bill board may have lighting, switched effects, messaging or other power-supplied effects. For power efficiency, the bill board is able to change to a static message that does not use these effects. In some embodiments, the bill board will be able to detect the type of vehicles traveling on a crowded highway and then post an ad that those drivers would like. For example, if there is a faster way to travel for electric vehicles, a bill board may detect times when that lane is empty or sparsely used, while the other lanes are jammed. In this case, the bill board may want to advertise electric vehicles. This ability for infrastructure, such as a stationery bill board, to understand what is happening in its vicinity may be enhanced by communicating with specific vehicles or broadcasting a message to all the vehicles. A communicative billboard may detect a specific driver via wireless signals with the car and may communicate via WiFi, Bluetooth, cellular or other communication method. Using an MTM antenna structure, these billboards are able to understand more about their environment.
A nodal radar may communicate with vehicles, buildings and other devices through a variety of communication protocols. As discussed above, WiFi and so forth may be used. In some embodiments, the radar provides a messaging protocol that is received at the vehicle, such as to direct a radiation beam to a specific target area of the vehicle. Such messaging may be used to initiate a communication or may be used to send a specific message, similar to Morse code or other coded signaling. The signaling may be made to a portion of a vehicle bumper, a metallic or reflective sticker on a vehicle, a mirror, headlamp and so forth.
There may be other sensors that work in collaboration with MTM antenna structures, where each has a special area of detection. In some embodiments a nodal radar system operates in coordination with other sensors, such as a camera sensor, infrastructure sensors, a laser or lidar sensor, vehicle operational sensors, user preference sensors, environmental sensors, a wireless communication module signal and so forth. In a vehicle these various sensors are combined and interpreted through a sensor fusion module that controls coordination of the information from sensors. An IAM may be designed to interface with a sensor fusion module. The camera, or visual, sensor is adapted for capture of objects, environments, and other elements in the FoV of the sensor. The laser sensor acts to identify objects, but its performance deteriorates with distance, weather and light inhibiting conditions. The addition of the MTM antenna sensor provides robust, consistent information when the other types of sensors do not.
Some other considerations for antenna applications, such as for radar antennas used in vehicles, include the antenna design, capabilities, and receiver and transmitter configurations. A typical electronic system with an antenna array consists of two or more antenna elements, beam forming network, and a receiver or transmitter. The beamforming network may consist of a Butler matrix or other antenna arrays combined with phase shifting elements. Many different antenna configurations can be utilized as an antenna element in the antenna array: simple dipole, monopole, printed patch design, Yagi antenna, and so forth. One of the primary goals for antennas mounted on/in the car is to achieve a compact and aesthetic design. Other goals relate to the type of communication signal used for the radar beam. One type of modulation used is Frequency Modulation Continuous Wave (FMCW), which is effective in radar applications, as radar does not need to pulse, but rather transmits continuously. FMCW is a continuous carrier modulated waveform that is transmitted as a continuous periodic function, such as sinusoid, sawtooth, triangular and so forth. The sweep time, or sweep period, Ts, is the time for transmission of one period of the waveform. The signal transmitted during one sweep period is referred to as a chirp. There is a difference in the frequency of the transmit and receive signals that is referred to as the beat frequency, bf. The range of the antenna, R, is the distance from the antenna to a detected object, and is a function of the sweep period, beat frequency, the speed of light, c, and the sweep bandwidth, Bs. A moving target induces a Doppler frequency shift that enables radar to detect the relative velocity of the target with respect to the antenna. The phase difference between the transmit and receive signals provides location information, while the frequency shift identifies a speed.
In the case of moving objects, the signal phase distortions may impact the performance of the antenna array. One way to offset such distortion is to use multiple subarrays at the Tx and Rx sides to filter out these impurities. Another way is to adjust the antenna calibration on-the-fly to reduce the phase distortion of moving objects.
Traditional phase shifting is used to control the beam of an antenna. Phased array antennas have multiple elements that are fed so as to have a variable phase or time-delay at each element and so that the beam scans from different angles. The multiple elements provide radiation patterns with lower sidelobes and enables careful beam shaping. The beam can be repositioned for more directed and efficient operation.
The present inventions provide an MTM antenna structure that provides phase shifting without the active elements required to change the phase, or in the traditional ways. The MTM antenna structures of various embodiments use the characteristics of the metamaterial shape and configuration to provide phase shift without the use of mechanical or electrical phase shifters.
The MTM antenna arrays of the present invention may be fed by a variety of configurations, such as a probe feed or a substrate integrated waveguide and so forth. In one example of an MTM antenna structure 1000, illustrated in
Another embodiment is illustrated in
Current technology presents a variety of sensors, such as for an automobile that may include various camera, laser, radar, temperature and other sensors. As shown in
Continuing with
Many types of sensors may be controlled by the sensor fusion controller 1210. These sensors may coordinate with each other to share information and consider the impact of one control action on another system. In one example, in a congested driving condition, a noise detection module (not shown) may identify that there are multiple radar signals that may interfere with your vehicle. This information may be used by IAM 1250 to adjust the beam size of the MTM antenna sensor 1202 so as to avoid these other signals and minimize interference.
An environmental sensor 1218 may detect that the weather is changing, and visibility is decreasing. In this situation, the sensor fusion controller 1210 may determine to configure the sensors to improve the ability of the vehicle to navigate these new conditions. The actions may include turning off camera or laser sensors or reducing the sampling rate of these visibility-based sensors. This effectively places reliance on the sensor(s) adapted for the current situation. In response, the IAM 1250 configures the MTM antenna sensor 1202 for these conditions as well. For example, the MTM antenna sensor 1202 may reduce the beam width to provide a more focused beam, and thus a finer sensing capability.
In some embodiments, the sensor fusion controller 1210 may send a direct control to the IAM 1250 based on historical conditions and controls. The sensor fusion controller 1210 may also use some of the sensors within system 1200 to act as feedback or calibration for the other sensors. In this way, an operational sensor 1214 may provide feedback to the IAM 1250 and/or the sensor fusion controller 1210 to create templates, patterns and control scenarios. These are based on successful actions or may be based on poor results, where the sensor fusion controller 1210 learns from past actions.
A variety of information is determined from the MTM antenna sensor 1202; such information may be a function of the modulation waveform and technique, the frequency, the chirp delay, the frequency change of the received signal and so forth. The specific radiation pattern used may be crafted to accomplish specific goals according to the application. The sensor fusion controller 1210 enables such control to optimize the system and reduce the processing required. For example, the MTM antenna sensor 1202 may be used to reduce the number of sensor and/or the active time of each sensor. In this way, some sensors may be disabled during certain conditions, and activated on a change in that condition.
The nodal radar system of
The present invention provides a nodal radar system that is configured for placement on a stationary or temporarily stationary location in an environment to complement and supplement information of individual vehicles, devices and so forth. The nodal radar system scans the environment, and may incorporate infrastructure information and data, to alert drivers and vehicles as to conditions. The nodal radar system is able to detect objects and actions within the environment.
In some embodiments, the nodal radar system communicates with other nodal radar units throughout the environment to gain and provide advance notice and warnings of activities, such as a speeding car. The nodal radar system may communicate through over the air, wireless systems, such as cellular, WiFi, Bluetooth and near field communication (NFC) methods. The nodal radar system acts as a complement to the sensor fusion within vehicles in the area. The nodal radar system may be part of a stationary sensor fusion module that includes camera, lidar, ultrasound and so forth, so as to be part of a smart city.
Claims
1. A method of operating a radar system, comprising:
- transmitting, via a radar unit of the radar system, a radio frequency (RF) beam in an environment of the radar system;
- controlling, via a feed distribution module, at least one subarray within the radar unit during the transmitting of the RF beam; and
- phase shifting, via a feed structure, the at least one subarray within the radar unit.
2. The method of claim 1, further comprising:
- adjusting a focus of the RF beam to a larger beam width to enable a faster scan of areas in the environment.
3. The method of claim 1, further comprising:
- adjusting a focus of the RF beam of the radar unit.
4. The method of claim 3, wherein adjusting the focus of the RF beam comprises changing a phase shift of the RF beam.
5. The method of claim 3, wherein adjusting the focus of the RF beam comprises controlling a reactance control means.
6. The method of claim 1, further comprising:
- detecting an object within the environment based on received signals from the environment; and
- sending a message to a vehicle based on the detecting.
7. The method of claim 6, further comprising:
- classifying the detected object based on the received signals.
8. The method of claim 1, further comprising:
- interpreting received signals in a reflected RF beam from the environment; and
- implementing one or more control actions based on the interpreted received signals.
9. The method of claim 1, wherein the radar system is fixed to an infrastructure and wherein the infrastructure is a building or a sign board.
10. A nodal radar system, comprising:
- a metamaterial radar unit configured to transmit radio frequency (RF) beams in an environment;
- a feed structure coupled to the metamaterial radar unit, the feed structure comprising a super element layer having conductive traces and non-conductive traces; and
- a metamaterial array control means configured to adjust reactance behavior of the metamaterial radar unit to change a phase of the RF beams.
11. The nodal radar system of claim 10, wherein the feed structure comprises a conductive layer having a plurality of discontinuities.
12. The nodal radar system of claim 11, wherein the feed structure further comprises a second conductive layer and a dielectric layer configured between the first and second conductive layers.
13. The nodal radar system of claim 12, wherein the feed structure further comprises a plurality of vias that are positioned from the first conductive layer to the second conductive layer through the dielectric layer.
14. The nodal radar system of claim 13, wherein the plurality of vias define a plurality of super elements within the feed structure.
15. A method of performing radar system operations, comprising:
- receiving radar signals via a plurality of sensors of a radar system within an environment;
- implementing one or more control actions based on the received radar signals;
- controlling one or more subarrays of a metamaterial antenna of the radar system via an intelligent antenna metamaterial (IAM) interface; and
- enabling, via the IAM interface, a communication with the metamaterial antenna.
16. The method of claim 15, further comprising:
- scanning a field of view of the radar system within the environment.
17. The method of claim 15, further comprising:
- interpreting the received radar signals;
- detecting an object based on the interpreting of the received radar signals; and
- sending a message to a vehicle after the detecting.
18. The method of claim 15, wherein the radar system is configured to collaborate with one or more radar systems within a network of radar systems.
19. The method of claim 15, further comprising:
- coordinating one or more operations of the plurality of sensors of the radar system.
20. The method of claim 15, wherein the radar system is fixed to an infrastructure and wherein the infrastructure is a building or a sign board.
Type: Application
Filed: Aug 20, 2021
Publication Date: Dec 9, 2021
Inventors: Maha Achour (Encinatas, CA), Tim Curley (San Carlos, CA), Matthew Harrison (Palo Alto, CA)
Application Number: 17/408,271