One of the fastest-growing, most attractive markets in the next few years is for low-power wireless modules, and with good reason. The Internet of Things (IoT) and associated sensor-based connectivity means this market—already growing in strong double digits this year, with similar growth anticipated over the next few years—indicates that vendors who can mix digital, analog, and RF in a single module or IC will have large opportunities with entirely new customer bases and applications.
According to a recent report, “Low-Power Wireless Modules Report – World, 2013,” from the Information Technology service of IHS, worldwide revenue for these modules will reach $1.40 billion this year, up a robust 14 percent from $1.23 billion in 2013. Lee Ratliff, principal analyst for connectivity at IHS, noted that the modules are very popular in low-volume applications because they reduce the high non-recurring development expenses associated with radio frequency (RF) design, verification and certification. Ratliff added, "they also find favor in devices that ship in millions of units, because they simplify manufacturing and increase flexibility. A single module design, for instance, can be reused across multiple product SKUs, easing the headache of supporting numerous unique RF designs while reducing supply chain complexity and risk."
While the vendors of these modules (primarily for the IEEE 802.11.x Wi-Fi standard) and associated ICs are the obvious potential winners, they will face the usual pressures of low margins, declining ASPs (average selling prices), and very tough competition that all such markets encounter. As a result, among suppliers there will be winners, losers, and those in the difficult middle who are just "getting by."
But one group in the wireless module ecosystem should see both high growth and high margins, yet not face the relentless volume-driven cost pressures that IC and module vendors endure. The vendors of sophisticated test and measurement (T&M) units are gearing up to support wireless modules and WLANs (wireless local area networks) with instrumentation that meets the unique technical and regulatory needs of this emerging market.
Why is the WLAN market so attractive to the T&M community? Most of the OEMs who are embedding these wireless modules have little or no RF experience or equipment, yet the end-products have a complex regulatory hurdle: FCC compliance for sale in the US and similar but different regulations in other regions. One aspect of compliance is to verify that the product does not cause interference or have unwanted emissions. Note that this says nothing about the product's reliability, actual performance, or quality. Pass the certification process and you are good to go to market; fail and it's anything from a trivial fix to major re-spin. Either way, a full re-test is needed.
Getting that FCC (or equivalent) certification is neither easy nor trivial even when using a "canned" module that is itself certified. The reason is that once that module is embedded in the final product, the complete assembly of the final product must be tested and qualified as well. Selecting and embedding a module is only one step in the process.
Subtle issues of PC board layout, antenna placement, module-to-antenna routing, and system interactions can result in the final product not meeting the certification requirements. The reality for OEMs is this: using a certified module does not guarantee the end-product will meet stringent regulatory requirements—although it is a good start. Thus, being able to perform in-house pre-compliance testing is a very good idea for all but the bravest, most foolish, or most experienced OEMs.
Even when a tested and certified module is used, countless subtle problems can occur due to hardware/software issues (courtesy Tektronix).
Formal certification, which is mandated prior to sale, must be done at a special lab equipped with a carefully defined test set-up, and that can cost between $5,000 and $10,000 per day (not including travel expenses and logistics headaches). Thus, instrumentation that can let OEMs do a full range of pre-compliance checks at their own test bench and site is a comparative bargain, if it lets them find where and by how much their product falls short among the hundreds of complex compliance tests.
Equally important, these new test instruments do not just give pass/fail grades; they also help the design team debug subtle problems that inevitably arise even when using a standard, certified module. The result is that the design team can both debug the product and go to final costly compliance tests with a very high degree of confidence.
Tektronix announced the first WLAN-specific test and certification unit and tools in late 2013, with the MDO4000B oscilloscope/spectrum analyzer ($12,400), which supports a full range of tests and analysis for all IEEE 802.11.n standards. The unit is much more than just two separate instruments conveniently housed in one box, with a shared user interface.
The Tektronix MDO4000B plus associated SignalVu-PC Vector Signal Analysis (VSA) software package is a combined oscilloscope/spectrum analyzer unit.
Instead, it internally links the time-domain capture of the oscilloscope with the frequency-domain analysis of the spectrum. By doing so, it lets the design team investigate and solve problems, including the very frustrating ones that might cause certification rejection: when a glitch occurring at wake-up in the product's clock timing or even in the humble power-supply rail (both best seen in the time domain) causes spurious signals and out-of-band emissions (visible in the frequency domain).
By using the time-domain oscilloscope as a trigger for frequency-domain spectrum analyzer, engineers can capture hard-to-find transient events.
To provide complete WLAN pre-compliance insight, Tektronix also introduced the companion SignalVu-PC Vector Signal Analysis (VSA) software package, which runs on a user's PC and links to the MDO4000B unit in real time. This package runs a complete suite of compliance tests including all required "masks" (there are thousands of these in the formal process), analyzes the resulting data, and identifies areas of likely non-compliance.
Other high-end T&M vendors are also seeing the growth opportunity in reaching out to novice designers of products with wireless capability based on modules with embedded RF circutry. In many cases, since the potential customers for these instruments have little or no experienced in RF design or debug, they may not even know what they need or how to approach the problems and regulations.
These OEMs may assume they'll just buy a wireless module, drop it into their product, and will have it ready and certified for market with minimal effort of their own. Yet they also face a stumbling block of the complexity of any RF integration effort, no matter how simple it may seem, plus regulatory compliance that they need to get through. The cost and time of going directly to a compliance certification facility, without doing any pre-compliance assessment on their own, is their major concern—and that's assuming they don’t have subtle integration problems.
Units such as the one from Tektronix address the well-defined needs of this new user community, which are very different from the traditional highly sophisticated ones (mil/aero, for example) that design and build their own unique RF-based products, with a long BOM of advanced components. While there will certainly be competition in providing this instrumentation, the barriers to entry are quite high, and the customary "race to the ASP bottom" trajectory associated with ICs is absent.