By John Oncea, Editor
The future of RF test and measurement hinges on software and hardware innovation. Digital signal processing advancements enable complex analysis, while speed and accuracy improvements are achieved through these innovations.
Wat: You have been weighed.
Roland: You have been measured.
Kate: And you have absolutely ...
Chaucer: Been found wanting.
William: Welcome to the New World. God save you, if it is right that He should do so.
So, it’s tested and measured we’re looking at here, not weighed and measured. But I’m not apologizing for the lede – I’m going to take any opportunity that comes my way to remember the brilliance that is A Knight’s Tale.
But we’re not here to talk about movies. We’re here to look at the latest innovations in testing and measurement in the RF industry. But first, a recap.
And So, Without Further Gilding The Lily And With No More Ado, I Give To You, The Past
“RF test and measurement equipment is necessary for the design, test, manufacture, and debug of radio frequency devices,” writes our friends at Rohde & Schwarz. “Every device that uses RF, from TV and radios to Wi-Fi, cell phones, GPS, etc. was created using RF test and measurement instruments.”
Some of the most common test and measurement solutions for the RF industry are:
- Spectrum analyzer: This instrument displays power versus frequency and measures RF presence and strength. Additionally, it can demodulate various signals.
- Signal generators: Used to create the different types of RF signals needed to design and test RF devices, particularly receivers, signal generators can be simple, unmodulated signals, or complex modulated signals like those used in most wireless communications. A signal generator allows the user to control all the parameters of the signals it generates, including power, frequency, and modulation.
- Network analyzers: To ensure the proper functioning and performance of the entire system, it is essential to have accurate, reliable, and repeatable methods to measure the individual components. Testing the networks involves injecting RF into one of the ports and simultaneously measuring the reflection of RF from that port as well as the amount of RF that comes out of the other ports. Additionally, the delay introduced by the network and any changes in other characteristics of the injected signal are measured.
- Power sensors: A simple instrument, power sensors are used in RF to measure power levels. Their primary function is to report the power as a numerical value, such as 10.92 dBm. Although not as sophisticated as other instruments, they are widely used in RF labs and are easy to find.
A handful of other devices are shielded enclosures, power amplifiers, load, GTEM cells, and antennas, all of which are available to the RF industry. The specific solution that is best for a particular application will depend on the specific needs of the application.
When considering RF test equipment, it is tempting to concentrate on specifications such as insertion loss, frequency range, or VSWR, without acknowledging that a complex testing scheme usually involves integrating multiple pieces of equipment from multiple manufacturers, writes another friend, JFW Industries.
“For multiple devices to work seamlessly together in an automated test flow, designers and engineers must also consider the interface that would be used to drive the testing equipment,” advises JFW. Unfortunately, the software interface is often overlooked despite the critical role it plays in putting together a test system.
“It’s not enough for a piece of equipment to work well in isolation,” JFW writes. “In a production environment, it must interact with and take commands from other modules, and in a laboratory setting, it must work seamlessly with multiple hosts. Understanding some of the potential interface barriers and how to remove them is an important first step before evaluating any piece of test equipment.”
The test and measurement solutions we’ve mentioned here are the present – let’s take a look at what the future might hold.
Change Your Stars And Live A Better Life Than I Have
The growth of the RF industry is being driven by the increasing demand for wireless devices and the need to ensure that these devices meet the required performance standards. The RF test and measurement industry is also being driven by the development of new technologies to keep pace.
Some of the most promising future technologies for RF testing and measurement include:
- 5G and beyond: The rollout of 5G and beyond networks will require new testing and measurement technologies to ensure that devices meet the performance requirements of these new networks. These technologies will need to be able to measure data rates, latency, and other performance metrics in real time.
- AI and machine learning: AI and machine learning can be used to automate many of the tasks involved in RF testing and measurement. This can free engineers to focus on more complex tasks, and it also can help to improve the accuracy and efficiency of testing.
- Internet of Things (IoT): The growing number of IoT devices will create a new demand for RF testing and measurement technologies. These technologies will need to be able to measure the performance of IoT devices in a variety of environments, and they also will need to be able to secure IoT devices from unauthorized access.
- Wearable devices: Wearable devices are becoming increasingly popular, and they require specialized RF testing and measurement technologies. These technologies will need to be able to measure the performance of wearable devices in a variety of environments, and they also will need to be able to ensure that wearable devices are safe for users.
NIST CTL’s Radio Frequency (RF) Technology Division is responsible for developing theory, metrology, and standards for the technologies driving the future of wireless communications. “Our work spans on-chip measurements of the transistors that generate wireless signals, the testing of free-field signals and the antennas that send and receive them, and the characterization of the integrated circuits that receive and process signals,” NIST notes. “We tackle fundamental RF measurement problems applicable to a wide array of industry and government players and contribute to three of CTL’s major programs: Spectrum Sharing, Next-Generation 5G Wireless, and Fundamental Metrology for Communications.”
NIST is also wrestling with the challenge of ensuring that wireless systems of all sorts can operate in increasingly crowded, complex RF environments – a function of inexorable wireless demand growth. But there are also concerted efforts – in particular with spectrum sharing – to squeeze more users into the same spectrum bands.
“For decades, we have been developing new theories, new algorithms, new software, and new hardware to advance the metrological state-of-the-art for the U.S. wireless industry,” writes NIST. “We continue to invent new ways to accomplish this mission, including the world’s first robotic-arm antenna testing system, our electro-optic sampling system for on-chip metrology, our quantum field probe for antenna testing, and the new NIST Broadband Interoperability Test Bed (NBIT), among others. As our long-standing collaborations with the wireless industry identify new focus areas for our unique capabilities, this list will continue to grow.”
As the demand for faster, more accurate, and reliable measurements increases, the future of RF test and measurement automation will be driven by innovation in both software and hardware. The advancements in digital signal processing will enable more sophisticated analysis and interpretation of measurements, while new levels of speed and accuracy will be achieved through these innovations.