by Kailash Narayanan, Vice President and General Manager, Wireless Test Group, Keysight Technologies, Inc.
MPD: How effective do you believe operation at millimeter wavelengths will be for meeting the challenges of 5G?
We have stated numerous times that realizing the vision of 5G will require many technologies and mmWave is just one of them. If you think about the original vision: Amazingly Fast, Great Service in a Crowd, Best Experience Follows You, Super Real-Time and Reliable Communications, as well as Ubiquitous Things Communicating, you can see where mmWave will make a difference and also where other technologies are required. mmWave will contribute to the Amazingly Fast part given wide bandwidths enabling very high data-rates. It can also enable, to some degree, Great Service in a Crowd given the high level of directivity possible and hence, opportunities for spatial multiplexing. It can enable parts of Best Experience Follows You by providing that experience in places where mmWave makes the biggest difference (indoor situations, shorter path-length), and it can even help with low latency by eliminating the need for data-compression—eliminating the time it takes for such processing. Those designing and implementing mmWave systems will need to address multiple challenges like appropriate coverage, addressing indoor/outdoor issues, the complexities of mobility in a highly directional transmission scheme, and the economics of implementing an expensive technology in mainstream commercial communications. These challenges can and will be overcome with advancements in the standard, innovations in transceiver and antenna design, and the experience that the early implementers are receiving in making these systems work.
MPD: If you sell to the defense sector, what do you believe are the major challenges for RF and microwave technology in serving DoD’s needs?
As is true with the broader test and measurement industry, obsolesces of hardware in existing test solutions and long-term support strategy are some of the major challenges in selling into the defense sector. The DoD looks for test solutions that can last for 20, 30, or more years with the ability to service them until the end of life. Today, technology is accelerating so rapidly as the commercial market longevity of test solutions is typically much less than 20 years.
Another major challenge is defense sector customers require Keysight to provide the necessary tools to develop the systems needed to address mounting threats. So, we must supply equipment to emulate and analyze these systems in advance—before they are operational. This requires Keysight to be at the very leading edge of technology.
Although throwing boundless amounts of money at a challenge may be a solution, the DoD no longer has this luxury. Solutions to the challenges that face the defense sector require a creative mix of the most advanced technology available, as well as an element of frugality. The very capable hardware Keysight has available also requires a complex set of software to enable functionality out of the box; although some systems are utilized for decades, time is of the essence to address the constant stream of emerging threats. Utilization of COTS (Commercial off the Shelf) and its functional blocks change the entire supply chain for the defense industry, but it is a trend to accelerate innovations while keeping costs down. Leveraging 5G technology for defense sector needs is a great example of COTS utilization.
MPD: What RF and microwave technologies will have the greatest impact in the next few years?
We see innovation across the ecosystem and it is very exciting. Thinking about the largest industries taking advantage of RF and microwave, it is not too difficult to see where the biggest differences will be made. In no particular order: mmWave and directive radio transmission—5G means a move of this technology to mainstream commercial wireless systems will change the face of how we think about high data-rate communications. This is applicable not just in 5G, but also in satellite communications, which are in the midst of a sea of change given private investment in large-constellation LEO systems for communications. Even 3GPP will specify non-terrestrial network communications in the next release, so the separation of satellite and terrestrial becomes blurred. Another key technology is MIMO. MIMO systems for RF have been effective in Wi-Fi starting with the first practical implementations in 802.11n. MIMO has been part of cellular mobile radio since 3G, but practical limitations have left much to be desired in the benefits of this complex technology. In 5G, multi-user Massive MIMO systems, especially for FR1 frequencies above 2.5GHz, have begun to show significant capacity and link-budget benefits by being very effective at real spatial multiplexing. I have spoken with many experts and they insist that Massive MIMO is not just nice to have, but a “must” for the new NR FR1 bands above 3GHz. Many operators have already deployed and are fully leveraging extensive MIMO systems. Perhaps one last huge impact example is the work in higher frequency and higher efficiency electronics in all semiconductor material types. Silicon is seen as showing significant promise for mmWave and is used extensively in the high-speed signal processing systems for 5G baseband. GaAs will continue to be a stalwart for efficient FEMs and its pervasive use will help to drive costs down. The same is true of GaN —the band-gap of which makes for much more efficient RF amplifiers. The growing use of GaN will also drive more innovation into that technology to eliminate some of GaN’s drawbacks (cost, linearity at lower power levels, noise, etc.). I have seen experiments using SiGe at frequencies above 200GHz. Of course InP, in all of its variants, will get more attention for mainstream use as more development takes place. Wireless communications will drive more and more innovation into all these technologies and many others in the coming years.
MPD: In addition to 5G and IoT, what commercial markets will be the most important for the industry in 2020?
5G and IoT are large markets and will continue to be a source of excellent business opportunities for the industry; add the satellite industry (mentioned above), and automotive (radar, imaging, sensing—all to aid driving and navigation). I think a subtle important part of the RF and Microwave market is high-speed digital systems. The data rates that are now required for inter-system communications (on chip, on board, on chassis, between chassis) mean the digital designer also has to be an RF engineer and a data-comms’ engineer. DDR memory technology now has regular channel sounding for the memory bus to equalize the nonlinearities of this “communication channel” and ensure the highest possible data transfer. Inter-chip and interboard communication demands are now in the 100GB/s territory with no end in sight for increase of data rate. So, these “digital transceivers” on either end of a “digital bus” or “digital serial line” are microwave equipment challenges microwave engineers understand, plus a few that microwave engineers have rarely addressed (for example, how many RF engineers completely understand a PAM4 eye diagram?).
MPD: Is your company having trouble in finding new microwave engineers?
Microwave engineering does not appear to have the cache’ of artificial intelligence, graphene, or quantum computing. The challenge we have as an industry is not just to find the engineers, but to “make” them. The explosion of wireless communications combined with the other opportunities described above means there is no lack of opportunity for the technically minded who want to take up Maxwell’s Equations and Smith Charts.