The upper mmWave frequencies bands above approximately 100 GHz are the focus of regulatory bodies like the FCC in the U.S. and CEPT in Europe, which are laying the regulatory foundation to enable new innovative applications like 6G communications and industrial radio determination. To address these new applications, 2π-LABS has developed 2πSENSE, a 126 to 182 GHz ultra-wideband (UWB) frequency-modulated continuous wave (FMCW) radar platform.
2πSENSE was designed to be a versatile tool to support the complete product life cycle, beginning with scientific research to industrial applications, from material characterization and non-destructive testing to radar imaging. The sensor is available in two versions—one for lab use, with an easy to set up USB interface and a robust, waterproof sensor for industrial use, with an Ethernet interface. The industrial version is well-suited for fielding applications where short time-to-market is important.
The 2πSENSE radar sensors bridge the gap between lab-grade vector network analyzers (VNAs) and industrial distance measurement devices based on radar. For the first time, a sensor enables using measurement grade mmWave spectral characterization in rugged industrial environments. The sensor can be configured with either a WR6.5 flange or a dielectric lens antenna (see Figure 1). With a versatile application programming interface (API) and raw data access enable extracting the wideband frequency response of targets, achieving VNA-like S-parameter measurements from a small, portable and ruggedized sensor.
Figure 1 The 2πSENSE radar is available with a dielectric lens antenna (left) or WR6.5 waveguide flange (right).
Figure 2 Three channel SiGe MMIC (a) and integrated front-end using an SIW PCB split-block construction (b).
2πSENSE TECHNOLOGY
Figure 3 Block diagram of the radar sensor configured with a single Tx and Rx.
2π-LABS has developed a custom D-Band radar MMIC, which serves as the foundation for its innovative radar products. Designed on Infineon’s B11HFC SiGe process (see Figure 2a), the MMIC covers 126 to 182 GHz—56 GHz bandwidth—and has three channels: one transmit (Tx) and two receive (Rx). The MMIC is then embedded in a mmWave sensor module using a substrate integrated waveguide (SIW) PCB split-block technology (see Figure 2b). The sensor can be configured with an embedded ortho-mode transducer for dual-polarization receive or, alternatively, a single center transceiver and two additional receive channels for angle estimation applications. A functional block diagram of the sensor in a single Tx/Rx configuration is shown in Figure 3.
The sensor’s clock network achieves exceptional frequency stability for very low jitter measurements (see Figure 4) and fast FMCW operation, sweeping the 56 GHz bandwidth in 1 ms. It uses a stable ±100 ppb long-term stability frequency reference and can be locked to Sync-E frequency sources (e.g., global navigation satellite clock sources) for calibration. The sensors include a versatile external trigger with a programmable trigger subsystem, designed to meet the needs of complex applications. The 56 GHz spectral modulation bandwidth makes it possible to measure the transmission and reflection or absorption behavior of a significantly larger portion of the spectrum compared to currently available industrial radar sensors (see Figure 5).
Figure 4 Measured jitter over 10 minutes (a) and associated histogram (b) with a waveguide short connected to the sensor.
Figure 5 Measured IF of a 1 m distant target showing the sensor’s bandwidth and 80 dB dynamic range.
2π-LABS provides an API in Python, which provides access to all the important radar parameters via an SCPI command set, the same protocol used by many VNAs. The documentation includes example scripts for the most common tasks, which are expanding from a growing community of users.
APPLICATIONS
For distance measurements, 2πSENSE radars achieve a target range resolution of just a few millimeters and range accuracies in the single-digit micron range, with short-term jitter an order-of-magnitude lower. The power of these capabilities becomes evident in wideband “radarlytic” applications like spectral mmWave characterization. Many innovative and sophisticated applications become possible because of the bandwidth, stability and VNA-like frequency response characterization packaged in a small form factor.
The first applications demonstrated have been contactless thickness measurements of dielectric materials for plastic extrusion and multi-layer composites with built-in material characterization features. Other interesting applications are monitoring dielectric material parameters: contactless detection of material type, permittivity, thickness, moisture content and coating in glass, polymer—even food production. With the capability to precisely measure complex permittivity, dielectric liquids, foams or polymers can be monitored in line for effective permittivity and losses. Using the data with production optimization algorithms can enhance production quality assurance in many complex applications.
2πSENSE devices cover the complete product development cycle, from early-stage lab experiments for proof-of-concept verification using the USB-powered scientific version to industrial deployment using the configuration with OPC-UA interfaces and power-over-Ethernet capability. As the regulatory bodies lay the foundation to enable new innovative applications, 2π-LABS is advocating regulations that allow harmonized and compliant use of the sensors.
2π-LABS GmbH
Bochum, Germany
www.2pi-labs.com