Antenna-on-Package Design Simplifies mmWave Sensing in Buildings and Factories

Traditional sensing technologies have been used to solve challenging problems such as people counting, motion detection, industrial area scanning, and robotics to detect objects and avoid collisions.

As more industrial applications move toward automation, sensing becomes critical for generating and processing a variety of data, allowing systems to become autonomous and make real-time decisions. Texas Instruments' (TI) highly integrated millimeter-wave (mmWave) radar sensors can process a large amount of data internally, enabling edge intelligence.

TI mmWave sensors work in a variety of environments and lighting conditions, both indoors and outdoors. These extremely durable sensors can be mounted directly behind a plastic housing without the need for external lenses, openings or additional microstrip antennas, which enables this technology to accurately sense in many buildings and factories. TI's 60 GHz frequency modulated continuous wave (FMCW) mmWave technology provides open mmWave sensing for most industrial applications around the world. To make industrial sensing simpler, small package antenna sensors enable form factors that have never been possible before.

Antenna-on-package sensor design

In radio frequency (RF) sensor-based systems, antenna design is as important as sensor selection. Antenna configuration determines the maximum target detection range, maximum field of view (FoV), and resolution, which are important for many applications. With just a single sensor and the right antenna configuration, industrial systems can cover a wide area for target detection. Traditionally, millimeter wave antennas using Rogers materials have been designed on printed circuit boards (PCBs) to provide high-precision sensing.

While very effective, this does require RF expertise to design and manufacture the antenna to go with the sensor.

Comparison of a 60 GHz 55 mm × 55 mm TI mmWave evaluation board with an external antenna (a) and a new 22 mm × 23 mm evaluation board design featuring a TI mmWave antenna-on-package sensor (b).

The new package antenna (AoP) design greatly simplifies board manufacturing and system design, making it very easy for engineers with less RF expertise to integrate TI mmWave sensors into their systems. Compared with standard TI 60-GHz sensors, package antenna sensors can reduce board area by 40%, and compared with other radar technologies, board area can be reduced by 75%. The figure above shows the possible size reduction when going from a traditional 60 GHz mmWave sensor to a 60 GHz mmWave package antenna sensor.

Key benefits of using TI mmWave antenna-on-package sensors include:

Reduce system and manufacturing costs and complexity, and accelerate time to market.

- Uses simpler, cheaper FR4 design with flexibility to produce anywhere in the world.

- In-house design and development of sensor solutions requires minimal RF expertise.

 Compact appearance.

- Suitable for industrial markets where smaller sensor area is required.

 Zero circuit board wiring loss, making it more efficient.

- Longer detection range performance.

Industrial 3D sensing using TI mmWave sensors with antenna-on-package design

Millimeter wave sensors need to capture position and precision data from their environment. Key data sets include the distance of the target relative to the sensor and the target's velocity. To enhance the collection of useful data, the 3D sensing system should also be able to detect the height of the object and filter out ground clutter. This maximizes the sensor's accuracy and measurement performance.

The wide field of view configuration of the antenna of the packaged antenna sensor provides a 130-degree viewing angle both horizontally and vertically. Whether the sensor is mounted on the ceiling or on the side, true 3D sensing can be achieved. This antenna configuration and the small size of TI mmWave packaged antenna sensors make radar sensing available almost anywhere in building automation, factory automation, smart homes, personal electronics and industrial systems.

Robotics: Avoiding collisions at a large scale

When industrial robots work next to people, they are designed to move slowly. In order to quickly detect and avoid possible collisions, manufacturers of robotic arms and autonomous robots need to implement a higher level of environmental perception and redundancy analysis performance in robotic systems, which can define safe or dangerous areas through 3D sensing functions.

TI mmWave packaged antenna sensors support a variety of robotic applications, as shown in the figure below. The wide field of view can cover a wider range around the robot to avoid collisions on the factory floor. The small form factor makes it easy to install in smaller robotic designs, such as cleaning robots.

TI mmWave antenna-on-package sensors enable a variety of robotic automation in factories and homes.

In addition to 3D object detection for robotics applications, the AoP sensor design addresses three key challenges in factory automation:

 Single sensor with wide coverage: The package antenna design can detect targets with a 130-degree field of view, achieving wider area coverage, from which multiple moving targets or personnel can be detected, thus better event management in robotic applications. This in turn reduces the number of sensors used for area scanning and reduces the overall system cost.

 Small form factor: The smaller form factor of AoP sensors means they can fit into smaller housings, which is important for sleek, small autonomous robotic designs such as automated guided vehicles, conveyor robots, and small robotic arms in factories for sensing and collision avoidance.

Faster time to market: Without the need for expensive PCB substrates and RF expertise, the APS-P simplified the design and manufacturing process, enabling in-house design and faster time to market.

Occupancy Detection: Simplified Sensing for Wall and Ceiling Mounts

Sensing solutions in building automation typically involve detecting and understanding the occupancy of a room or area of ​​interest in a commercial or residential building. In addition to the benefits of motion sensitivity, location accuracy and privacy brought by TI mmWave technology, the antenna-on-package design brings additional value to the building automation market.

Building automation sensing applications using TI mmWave sensors include elderly monitoring and air conditioning.

TI mmWave AOP sensors feature a wide field of view and a small form factor, bringing installation and design flexibility to unique building automation sensing applications such as elderly monitoring and air conditioning, as shown in the figure above.

Solution complexity can be an incredible barrier to entry for sensing technology in building automation. Antenna-on-package sensors simplify and accelerate the design process, allowing engineers in building automation applications to focus on the differentiated software for detecting and identifying people.

The antenna configuration of the AoP sensor makes it suitable for both wall-mounted and ceiling-mounted installations. In building automation, this wide field of view provides installation flexibility, allowing the sensor to be installed near power and data wiring in commercial buildings, or integrated with existing automation systems to reduce installation costs and the number of installed systems. The AoP sensor has the ability to fit into smaller housings, and the smaller form factor enables cleaner industrial designs, helping to clear the visual ceiling clutter or "ceiling acne" common with sensing installations in today's commercial buildings.

Automatic doors: Position- and speed-based operation in tight spaces

Smart sensors play a key role in automatic door applications by providing safe, economical and energy-efficient solutions. In addition to the advantages of TI mmWave sensors, packaged antenna design brings more advantages for designers and manufacturers who do not necessarily have RF expertise in antenna design. The ease of integration of packaged antenna sensors allows them to focus on making doors smarter instead of investing resources in sensor development. Due to the wide field of view, one sensor is able to cover the entire area of ​​interest of a specific door.

The A/P design solves the common problem of “blind spots” where typical door sensor detection areas may not reach, eliminating the need for multiple sensors in the system.

Example of a building and warehouse automation entrance system enabled by TI mmWave antenna-on-package sensors.

Using the AoP design can be handy for counting people in a turnstile to avoid overcrowding or determining the height of an obstacle blocking a garage door, fitting seamlessly into tight spaces where larger sensor modules are not feasible. The AoP sensor's small form factor allows for seamless integration into entry systems while still covering a wide field of view for easy door operation, as shown in the image above.

TI's unique mmWave sensor

Combined with the existing advantages of TI mmWave technology, building and factory designers can take automation and intelligence to a new level through packaged antenna sensor design. These packaged antenna sensors have a wide field of view, a smaller form factor and a simplified design, allowing industrial system designers to quickly and easily integrate mmWave technology into existing designs and new applications.

Click here to view a reference design using TI mmWave sensors to achieve a solution with these advantages.

author:

Prajakta Desai

Industrial Radar Product Marketing Manager, Texas Instruments

Keegan Garcia

Industrial Radar Product Marketing Manager, Texas Instruments

Osamah Ahmad

Industrial Radar Product Marketing Manager, Texas Instruments