Two key areas of electronics are driving the development
of new test and measurement (T&M)
instruments—high-speed serial buses and wireless
test. Both require very high-frequency capability
as well as the ability to support the many standards that
are being developed.
CIRCUITS AND PACKETS
There is a movement in digital design, from parallel bus structures
to serial buses at microwave frequencies, with the growing
set of T&M applications aimed at the protocol layers in
communication systems. Due to the finite propagation skew
of trace lengths on a printed-circuit board (PCB), digital bus
design must change from a parallel structure to a serial structure
with embedded clocks.
This has a wide set of implications as digital design enters
the microwave range. Jitter replaces setup-and-hold times as
the most critical timing parameter of digital systems, with
equivalent measurement needs. PCB traces are microwave
transmission lines, requiring S-parameter measurements and
simulations that are common in the RF domain. These trends
have large T&M implications.
On the protocol side, there’s more and more value added
to network elements and cell phones in the communication
protocol layers of these devices. This will be even more so as
the network and devices transition from the circuit-switched
world to the packet-switched world. Since half of all T&M
focuses on the communications industry, this is an important
test trend.
COMPETING COMPLEXITY
3GPP Long Term Evolution (LTE) and WiMAX are competing
trend examples in the wireless communications market.
They share common ground with regard to technology contributions
from multiple-input/multiple-output (MIMO) and
orthogonal frequency-division multiple access (OFDMA).
MIMO, a capacity-enhancing, multi-antenna technology
that’s an important component of both Mobile WiMAX and
LTE, improves spectral efficiency by allowing more bits/hertz
to be transmitted in a given bandwidth. OFDMA, on the other
hand, employs the orthogonal frequency-division multiplexing
(OFDM) modulation scheme in an innovative way so RF
spectrum can be allocated more effectively to more users.
In both cases, the addition of MIMO and OFDMA functionality
to the LTE and WiMAX standards results in complex,
demanding signals that must be not only accurately created,
but also rigorously analyzed. WiMAX and LTE, though
differing in their current development and deployment cycles,
are demanding rapid and accurate test solutions to meet their
global market windows for wireless.
3G HOTSPOTS
Femtocells can be seen as home basestations, like a Wi-Fi basestation,
which connect to a broadband Internet service. As an
alternative for hotspots for Wi-Fi, femtocells can be hotspots
for 3G mobile phones.
In many ways, femtocells can be considered lower-power
versions of basestations, and they could be developed the same
way as a basestation for the physical layer or the RF portion.
The challenge for femtocells is all about their ability to manage
the network and interface to the thousands of cells that could
be deployed while dealing with other test challenges like verifying
location, synchronization, and security.
GETTING SMALLER
Chip counts are decreasing as the industry moves toward its
goals, which aren’t necessarily achieved yet, of delivering a
single-chip radio that will conserve space and power consumption.
This makes test points and test modes critical. Designers
no longer always have signals readily available in the form
needed to test.
Asia will continue to fuel much of the anticipated growth
in the electronic manufacturing services industry with increasing
usage of high-speed differential signaling with shrinking
components and rising node counts. The key challenge for
electronic manufacturing test (EMT) will be figuring out how
to meet both business and technology demands that can help
manufacturers gain faster and better test access and defects
coverage, while at the same time providing better return on
invested capital for the customer.
WHAT’S NEXT?
Although these are just a few of the many challenging test
trends facing the electronics industry today, it is an exciting
time to create and deliver test. The test solutions’ requirements
are often multiple years ahead of actual market delivery, and
there is a constantly evolving set of standards driving each area
of interest, as new and better technologies are being discovered
in the electronics industry.