In the next decade, the technology industry is set to undergo several major shifts. One key influence is the Internet of Things (IoT), which is changing the way information technology handles changes in the world around us. Sensors can relay real-time data to cloud servers that determine how best to respond, enabling services such as predictive maintenance, smart cities and health monitoring. 5G communications technology will not just help connect IoT devices to the cloud but enable services that rely on much higher data rates, such as virtual and augmented reality. Smarter cars will take advantage of 5G communications to build a better understanding of traffic flow while they sense the environment around them using millimetre-wave radar.
Although these technologies can seem quite disparate, they are driving research, development and test strategies in similar directions. For example, the need for energy efficiency is moving the focus in power electronics away from conventional silicon technologies to those based on wide-bandgap materials such as silicon carbide (SiC) and gallium nitride (GaN). Both support much faster switching than silicon. They also offer properties such as high temperature capability, particularly in the case of SiC, lending themselves to automotive applications. GaN also requires less cooling than silicon, making it suitable for use in smaller, dense radio units that offer features such as massive MIMO and beamforming.
Instruments and probes for high quality test and measurement
Instruments that can handle high voltages will be needed to measure the behaviour of wide-bandgap devices. In addition, there is a requirement for specialised test fixtures that are optimised for high-speed and high-power switching to support safe operation. The Keithley Model 8010 is an example that provides safe and easy connections for testing packaged high power devices up to 3000V and 100A as well as connections for Keithley’s Source Meter Units.
The improved properties of power semiconductors mean some of them generate extremely low leakage currents when switched off that are difficult to measure using standard probes because of noise. Triaxial cables provide a high-quality connection in combination with safety probes. Examples include the Model 4725 and 5342 cables from Pomona and the Keithley 7078-TRX-1.
Probing technology is equally important in other areas of test for IoT, 5G and automotive systems. Although the probes supplied as standard with an oscilloscope are often good for a range of applications, engineers need to use probes that make it easier to capture small signals or measure subtle changes in power consumption as they tune the energy profile of their IoT devices. The Pico Technology TA044 provides differential connections with high-voltage capability to measure not just common serial buses but power circuitry as well. The Tektronix TLP058 makes it easy to capture signals accurately from parallel buses and other interconnects. The eight probes can be connected in a group or to separate traces as each probe has its own ground connection.
Multiple and integrated RF test functions are critical
Radio Frequency (RF) performance is increasingly important across the board, whether in IoT sensor nodes, 5G-enabled systems or the radar subsystems used by advanced driver assistance systems (ADAS) in motor vehicles. As a result of the capabilities offered by 5G and improved short-range protocols, there is a need to track increased data communication and processing rates.
RF spectrum is becoming so crowded, especially in unlicensed bands, that designers are trying to squeeze as much data as they can into frequency bands. This creates the need for highly advanced modulation schemes or extensions into frequency bands above 10GHz. These trends increase the complexity of debugging and call for more advanced instruments to show the effects of channel distortion and interference on signal quality. Instrument vendors have responded by integrating multiple RF test functions into their products.
Instead of requiring engineers to deal with multiple separate instruments, such as signal generators, spectrum analysers and network analysers, vendors are integrating the function into combined units that make testing easier to perform. An example is the Rohde & Schwarz FPC1500. The integrated design makes it easier to test a wide range of RF designs, including those that do not produce an RF signal independently, such as amplifiers. Whereas standalone spectrum analysers cannot help with these circuits on their own, the tracking generator in the FPC1500 provides the necessary stimulus. For testing the processing capability of a transmitter, the instrument automates the task of modulation analysis from basic shift-keying schemes through optional support for Bluetooth Low Energy and the tyre pressure monitoring system (TPMS) protocols.
The FPC1500 can be upgraded through keycodes. This means users can gradually augment the instrument for more sophisticated measurements and extended bandwidth capacity without having to change the hardware. Other instruments in the FPC extend bandwidth out to millimetre-wave systems, such as automotive radar and the upper frequency bands of 5G, providing the ability to perform the vital phase-noise measurements these systems require.
Portable high-quality performance equipment for field operation
Due to the wide range of installation possibilities for IoT devices, there is an increasing requirement for portable high-performance test equipment that can be used easily in the field. Handheld spectrum analysers such as the Keysight N9340B provide the ability to detect spurious signals and track down interference problems. The narrow resolution bandwidth is as low as 30Hz to help identify clashes in the often-congested sub-1GHz unlicensed bands.
An alternative to a fully handheld device is the RSA306B USB-hosted spectrum analyser from Tektronix. This instrument can be used with a laptop for mobile or benchtop use, which in turn supports the use of advanced PC-based apps to simplify and automate the taking of complex measurements.
Even relatively low-end IoT devices incorporate multiple functions, ranging from local data processing to high-speed communication, however engineers have to be able to debug complex system-level issues. This puts a greater emphasis on ease of use and integration in test instruments across the board and not just in RF design. One example is the integration of signal generators into oscilloscopes. Another is the increasing integration between logic analysis and oscilloscope functions. The advantage of this integration, found in instruments such as the Multicomp Pro MP720013, is that users can easily see the alignment of related logic and analogue signals. For example, if a software loop is failing to respond correctly to changes in a sensor input, the alignment onscreen may show that critical deadlines are being missed or signals are not being latched by an analogue-to-digital converter correctly.
The Tektronix MDO3104 takes a different approach, integrating oscilloscope with spectrum analyser functions, which lets the user see how a system behaves in both the time and frequency domains. This can reveal issues that analysis in just one domain may miss.
Bringing it all together
Although the rise of the IoT, 5G and advanced automotive electronics markets are leading to rapid changes in technology, test equipment is keeping pace and not just in extensions to bandwidth specifications or signal resolution. The vendors are responding with higher levels of integration and software content to provide greater ease of use. However, no-one manufacturer can provide all the test equipment required. This is where the experience of a distribution partner, such as Farnell, is vital. The distributor can guide engineering teams to the instruments and probes that will make the biggest difference to project timescales and success. A wide range of support services are also offered including the provision of fast delivery to ensure there is no delay to a project when a test need arises. The testing environment around 5G, the IoT, power and automotive is becoming more complex, but the expertise of distribution helps smooth the path to effectively utilise these new technologies.
