Sometimes complex problems require complex solutions. In today’s fast-moving world, where advanced wireless communications systems are at the forefront of technological development, the need for advanced testing systems is omnipresent. In everything from 6G development, to radar, or electronic warfare, there is a need for stress testing with real-world signals in real-world environments. While signal generators and simulators exist, sometimes the environment needs to exhibit elements that are both the expected and the unpredictable, making it challenging for engineers to make the products under test foolproof.
How can design engineers then recreate real-world environments to stress-test a prototype? How do they recreate the signals that would ready a product for the real world? With growing unpredictability in how and where a product will be used today, this challenge rests on the shoulders of arbitrary waveform generators (AWG), the Jack of all trades of the electronics world. Even more utilitarian are arbitrary waveform transceivers (AWT), a type of AWG that can both generate signals and receive the response.
But before seeing how AWGs and AWTs support engineers simulate an unpredictable environment, it is wise to take a look at the recent trends in wireless communications.
Emerging Trends in Wireless Communications
Taking time to assess the current or emerging trends in an industry helps prepare for the challenges that lay ahead. In that regard, areas such as Wi-Fi, 5G cellular, wireless sensing, drones, self-driving automotive, and even robots will evolve majorly in the coming years. The participating technologies and systems in these areas will also need to evolve to meet the rising demands.
According to Gartner, newer forms of wireless communications will power emerging technologies such as robots, drones, and self-driving cars. According to the 2019 study, wireless innovation will need a hands-on approach by technology leaders to study the landscape and anticipate what technologies, systems, and technical skills will be needed to cover the growing complexity. They should then prepare a roadmap and liaise with partners that are able to support them. It takes the example of technologies such as 5G cellular and millimeter-wave systems that will need superior skills to manage owing to their underdeveloped state. The study further lists down Wi-Fi, vehicle-to-everything (V2X) wireless, low-power wide-area (LPWA) network, and backscatter networking as a few of the top technologies that will emerge in the next three years.
Some of these technologies may either be clubbed with existing ones or see themselves influencing another tech. For example, the outgoing 5G standard (with the heralding of 6G in some countries) may improve the efficacy of Internet of Things (IoT).
Industrial automation has also recently warmed up to the idea of using wireless communications systems to complement remote maintenance. For example, cellular technologies like 4G and 5G are being used to monitor non-critical tasks at factories and assembly lines, thereby reducing the load on manual workforce and making it more efficient.
While such cellular standards, for instance, are iterations of their previous versions, there is also a need to improve the hardware that can withstand the scope of actually running the technology. This is where stress-testing and the need for arbitrary waveform generators come to play.
AWGs Simulate Real-World Environments
Radar Measurement, Part 2 – Emulating Radar Modes, and Angle of Arrival
If the equipment used in radar and electronic warfare require a certain level of resolution and precision during stress-testing, then the arbitrary waveform generators used for that purpose will need to deliver a better range of spectral bandwidth, for example, if not sufficiently. The waveform sampling rate, vertical resolution, and dynamic range all need to be beyond the noted limits of the applications being tested. One cannot depend on routine digital-to-analog converters (DAC) to test advanced equipment like radar that have extremely wide ranges or may want different forms of waveforms for the stress test. This is because, in an RF test environment, the sequences need to be altered and the waveforms (and their responses) recorded for future iterations, which may not be possible with routine signal generators. Even with some entry-level arbitrary waveform generators, this may be challenging due to shortcomings in the number of sequence steps that they can produce.
This turns the focus on advanced arbitrary waveform generators produced to be used across applications and ranges. For example, take the case of the Proteus arbitrary waveform transceivers (AWT), a cost-effective hybrid product and the world’s first such testing equipment by Tabor Electronics, that allows generating and receiving WLAN beacon signals at 2.4GHz. It can also be used all the way up to WiFi-6 frequency extension of 7.125GHz as demonstrated here. The four-channel Proteus P2584M can emulate four independent high-resolution target pulses and continuous waveforms that can be used to test artificial intelligence (AI) algorithms and radar modulation respectively. “The unique architecture of an AWT allows for wideband signal generation and analysis. The Proteus system uses the latest ADCs and DACs combined with a powerful FPGA that we can also utilize for further signal processing,” says Mark Elo, Tabor’s US regional sale manager.
AWGs are also capable of a variety of tasks that are essential for testing wireless communications technologies. Some of them are listed below:
- Combination of sequence steps to create complex pulses
- Waveform memory support to store waveform information for further iterations
- Modulation change (mimic Doppler radar and other obstacles, for instances)
- Branching and looping while generating waveforms
The ability can also be extended by manufacturers who can add or improve certain features. Tabor has implemented the following features in its Proteus series:
- Dual- or quad-channel 16-bit configuration (AWG, AWT)
- Integrated NCO for digital upconverting to microwave frequencies
- Real-time data streaming to FPGA
- Up to 16 GS waveform memory
- 9 GHz bandwidth
Available in PXIe module, desktop, or benchtop platforms, the Proteus AWT series aids in a range of wireless communications applications by providing modulated signals for stress-testing and iterative product designing. The entire series is available in dual, four, eight, and twelve channel 9 GS/s 16-bit configurations.
Using AWTs to Simplify Satellite Payload Testing
Wideband, Microwave, Arbitrary Waveform Transceivers for Satellite Payload Testing
The significance of arbitrary waveform transceivers in satellite payload testing comes from the fact that operators prefer to generate wideband, microwave carriers to test their transponders while also using the system as an RF receiver to measure the performance of the payload receiver. This is because detecting metrics like signal-to-noise ratio (SNR) and spurious-free dynamic range (SFDR) can be challenging, especially when the satellite frequencies are too wide for routine single-application simulators.
AWTs can act as the two-way systems that such testing needs, delivering arbitrary signals while also receiving RF signals to measure the response. In applications like this, AWT’s different modes of operation help extensively. For instance, the numerically-controlled oscillator (NCO) mode creates the output in a sinusoidal form for easier interpretation using regular equipment. Most AWTs have several modes such as direct, IQ, and streaming, further extending their range in testing applications.
Arbitrary waveform generators are already in wide use in the wireless communications industry to support the eclectic needs of technological development. Yet it is hybrid equipment like arbitrary waveform transceivers that are hogging the limelight thanks to their cost-effective mechanism to both generate and receive waveforms across applications such as radar, 6G, Wi-Fi, and Internet of Things.
With the reduction in the global digital divide, the need for safer and cheaper wireless technologies rises. And so does the need to test them before there are commercialized. It is manufacturers like Tabor Electronics that is leading the campaign as a testing and troubleshooting equipment manufacturer, providing design engineers the tools that they need to imitate real-world environments and produce real-time, fast-moving signals.