Whether a user wants to find a lost item or track inventory, real-time location services (RTLS) are useful and versatile features of new IoT designs. However, with more precise tracking comes more expensive and power-hungry electronics, which does not bode well with RTLS low-power tags and sensors.
A high-level depiction of RTLS applications in a hospital. Image used courtesy of Advantech
Out of the Netherlands, the Antenna Company has released a new family of ultra-wideband antennas the company claims can provide the best of both worlds: high precision and low power.
Two Variations of RTLS
RTLS can come in two different forms: precision-based RTLS and proximity-based RTLS.
As the name implies, precision-based RTLS is a technology that allows object tracking down to the exact location. This technique is employed either via Wi-Fi or ultra-wideband technologies, the latter of which operate in the 3.1–10.6 GHz range.
While providing higher accuracy, precision-based RTLS is limited because it requires a significant amount of infrastructure, cost, and power to achieve such high accuracy.
Proximity vs. precision (positioning) RTLS. Image used courtesy of McCoy Components
On the other hand, proximity-based solutions are less expensive, require less infrastructure, and are often lower power than RTLS. The drawback is that they are much less accurate, often only determining an object’s location within ~100 square feet.
Three RTLS Implementations
There are many implementations of RTLS for both precision- and proximity-based methods. Some of the techniques are as follows:
- Passive RFID: A receiver sends out a signal, and once it is received, a passive RFID tag responds. This is a low-power, low-range solution.
- Bluetooth-based: Tags communicate with receivers via BLE. This method offers sensor data and position data, which is very inexpensive; however, the low range of Bluetooth protocols can be limiting.
- Ultra-wideband: Small tags transmit ultra-wideband signals (3.1–10.6 GHz), which send pulsed signals to beacons. These beacons measure the time it takes the signal to travel to calculate its location. While this method is the most accurate solution, it can be very expensive.
Innovation From the Antenna Company
The Antenna Company’s new family of UWB antennas is aiming to ease the development of ultra-wideband RTLS. The new antenna family integrates into Qorvo’s DW3000 transceiver IC, which is a so-called simple and affordable solution.
According to Antenna Company, designing these new ICs (the DW3xxx family) was essential to achieve high-precision RTLS for low-power sensors, anchors, and tags. Since these antennas operate on the 6.5 GHz and 8 GHz UWB channels, they are omnidirectional and are said to enable a location accuracy of 10 cm in real-time.
Block diagram of the DWM3000. Image used courtesy of Qorvo
While the exact power numbers are not made explicit in the datasheet, its design implications seem to be for low-power, battery-operated devices. The devices seem easy to integrate into a number of embedded designs, attachable either as a surface mount device, an SMA connector, or a micro-coax cable.
While the demand for high-precision RTLS is on the rise, ultra-wideband has been held back because of its high cost and high power consumption. The Antenna Company has expressed confidence in possible resolutions to these setbacks with its new antenna family and the associated transceiver module from Qorvo.