State-of-the-art wireless and computing technologies are demanding greater innovation when it comes to test & measurement, as Sebastian Richter explains to New Electronics.

It seems that, today, advanced technology is increasingly spreading into every aspect of life. Wireless technologies are delivering essential services through our phones, every second of the day and connecting the IoT and smart technologies we use to control our homes and monitor our health and fitness. We are also expecting 5G to have huge implications for consumer services, industrial controls, enterprise digital transformation, and improving road safety.

However, if we look only a little further into the future quantum computing could have an even more profound influence over every aspect of our lives.

These are important trends that present challenges on many levels. Of course, those that involve taking precision measurements and dealing with difficult noise and interference issues are especially interesting to companies working in the area of test and measurement.

Wireless coexistence

With our personal devices and IoT sensors all around us, we are in an environment saturated with LPWAN, Bluetooth, ZigBee, Wi-Fi, and cellular wireless connections. As this growing number of RF technologies reaches into every space of life around the globe, coexistence between the various systems becomes even more important and at the same time more difficult to ensure.

The ability for various systems to transmit and receive their signals without interference, even when they are active at the same time, can only be tested during development or during pre-compliance testing in a realistic test environment. That means that the test equipment must be designed for the transmission technologies concerned.

Wireless transmissions need to be tested over the air interface and it is important to test under realistic conditions. At Rohde & Schwarz, for example, we have placed a great emphasis on this, and have developed wireless testers that are capable of testing cellular and non-cellular signals simultaneously, including Bluetooth LE.

On the other hand, with conducted transmissions, an instrument such as an oscilloscope needs to recognise all of the transmission technologies concerned and decode them in real time. It is convenient if the user can see at a glance which event in the signal led to a faulty bus protocol transfer.

However, the test setup can noticeably influence the result when making cable or PCB measurements, however, this influence can be removed using computational de-embedding. At Rohde & Schwarz, we have worked with leading semiconductor and cable manufacturers to develop a suitable algorithm for vector signal analysers. Moreover, our new high-performance oscilloscopes, the R&S RTP, provide real-time de-embedding, allowing the trigger system to directly access the de-embedded signal. All trigger types are supported up to the maximum bandwidth of 16 GHz. For troubleshooting on signal lines, there is also an option for transmission and reflection measurements in the time domain.

Test and Measurement sensitivity

Another factor that presents major test and measurement challenges is the trend towards ever-lower supply voltages, and hence tighter voltage tolerances, for the latest integrated components.

While end users see the benefits in terms of smaller, lighter products and longer battery life, those of us concerned with testing need effective ways to reliably measure extremely low voltages. We also need to be able to measure nanoamp currents in all operating modes and estimate the impact of power-saving modes in order to optimize devices with ultra-low power consumption.

Another issue is that fast digital signals and other disturbance sources can be coupled into the DC supply voltage network. Low-noise oscilloscopes with bandwidths in the GHz range are therefore required. They must also have high vertical input sensitivity in combination with a broadband 1:1 power rail probe, and a high update rate is needed to reliably capture rare events. R&S RTP oscilloscopes acquire up to 750,000 waveforms per second, allowing developers to quickly and accurately characterise power supplies.

Quantum computing is happening now

While 5G and the IoT continue to grab headlines, and while we begin to understand the impact of technologies such as AI, quantum computing is potentially even more disruptive.

With today’s major computing and web giants in the game, as well as various younger, specialised companies, quantum computers are already in the cloud. You can sign up right now for an account and start dabbling. This has massive implications for the way we will live in a future that could be closer than any of us quite realises.

Our current state of the art computers (quantum computing articles are already calling them classical computers), although fantastic, remain essentially simple binary machines. In contrast, a quantum bit, or qubit, can have many more than two states. This allows quantum computers to work on complex problems and ultimately deliver results far more quickly and efficiently than a conventional computer.

While quantum computers are not expected to replace today’s computers, rather they will enable us to tackle challenges that have hitherto been impossible.

Putting quantum in the cloud will provide affordable access for scientific and commercial applications, just as you can rent AI applications in the cloud, right now, to do complex workloads and pay for the service according to the number of computer cycles used.

Cloud AI enables hospitals, for example, to identify genetic disorders in newborn babies within minutes for just a few pounds – rather than several days at the cost of half a million.

Cloud services like these are transforming healthcare, and cloud quantum computing could do the same in fields such as materials science, financial services, cryptography, and others. Simulating a caffeine molecule, for example, is incredibly difficult to do with a classical computer, demanding over 100 years of processing time. A quantum computer can complete the task in a matter of seconds.

Cryptographic calculations are likely to be another of the quantum computer’s talents. Its ability to accelerate brute force decryption is breath-taking as much as it is a massive concern for privacy and security. A quantum computer could theoretically mine every token in the Bitcoin system almost instantaneously, for example, while our current computing is projected to take until 2140 to mine the last Bitcoin.

Above: The R&S RTP164 oscilloscope with the RT-2M160 test probe

Low-noise design

A great deal of development must happen before all this becomes reality, and test & measurement specialist have a key role to play here.

Because of the nature of the technology, with each bit having multiple potential states, noise is a key concern. As the computer operates, the error rate increases and eventually reaches to a level that interferes with the results. Extending this effective operating time period, as well as increasing the number of qubits in the machine, have to be the major goals for builders of quantum computers right now.

Slowing the rising error rate is dependent on minimising sources of noise. The equipment is cryogenically cooled to near absolute zero, for example, to cut thermal noise to lowest level possible. Also, extremely pure and clean RF sources are needed. At Rohde & Schwarz we are currently working with academic partners to meet the challenge using our ultra-low-noise R&S SGS100A RF sources.

To address this market companies in the test & measurement space have to support many different partners, but it is truly exciting to be working alongside the development of this potentially game-changing technology.

Author details: Sebastian Richter is Vice President Market Segment Industry, Components, Research and Universities, Rohde & Schwarz