Sam Benzacar of Anatech Electronics, an RF and microwave filter company, has
published his October 2023 newsletter that features his short op−ed entitled
"The Resurgence of the Traveling-Wave Tube." In it, Sam demonstrates an
impressive knowledge of the state of the TWT industry. As is always the case
with technology, the desire for greater functionality, lower cost, higher
reliability, and small size and weight drive the research and development for
fulfilling the need. Sometimes ideas are borne of fantastic fictional accounts
of future scenarios, but most often it is the need to break through the barriers
of existing science to achieve a goal. As the old saying goes, necessity is the
mother of invention. Being a frequent surveyor of tech news sites, I read
occasionally of TWT products and research, but I do not recall seeing where the
efficiencies have nearly doubled over previous designs, so that was a surprise.
Incremental advances in TWT research does not receive the same amount of print
space as, say, photovoltaic semiconductors, which produce headlines whenever
scientists manage to squeeze another 0.1% efficiency in the conversion of
sunlight to electricity (in a laboratory environment). Per Sam's piece, the
surging demand for traveling-wave tubes is being driven by the inability of
semiconductors to provide power levels required for unique applications. Another
motivation, per Sam, is somewhat shocking, and could reasonably be avoided if
not for insane politicians. Read on for a great synopsis on the state of TWTs.
A Word from Sam Benzacar - The Resurgence of the Traveling-Wave
By Sam Benzacar
Readers of this column know what traveling wave tubes (TWTs) are and many assume
that they're no match for semiconductor solutions, primarily GaN-on-SiC MMICs, that
continue to permeate more applications yearly. But dig deeper, and you'll find that
the market for TWTs is actually increasing, so why is a device conceived 80 years
ago still viable today?
First, in 1986, President Reagan ordered NASA to focus on its core activities
and hand off the rest to private industry, saying "NASA will keep America on the
leading edge of change, and the private sector will take over from there." Now,
the SpaceX Starlink constellation accounts for 5700 of the 7700 or so communications
and other satellites around the Earth, all launched by the company itself. Others,
like Amazon's Project Kuiper, will follow in the next few years. Although satellites
in low Earth orbit (LEO) use solid-state (typically GaN) RF power amplifiers, those
in geostationary orbit are much further away, and only TWTs can generate enough
RF power to span the distance.
Another (unfortunate) factor driving TWT demand is Russia's war on Ukraine, which
is depleting the resources of the U.S. and Europe that must be replaced as quickly
as possible. This trickles down to TWTs and TWT amplifiers (TWTAs) that are extensively
used in systems ranging from EW to radar and electronic countermeasures.
TWT technology development hasn't been stagnant, either, with their overall performance
and efficiency increasing dramatically. Even small increases in efficiency have
a positive impact on reducing the size, weight, and power required by a platform.
While satellites are the most obvious platforms to benefit, almost every commercial
or defense platform also stands to gain. Fifteen years ago, TWT efficiency was about
20%, but today it's twice that and increasing.
The Department of Defense and satellite broadband providers are also interested
in using higher frequencies. DoD needs to develop EW and electronic countermeasures
systems to address new threats high in the millimeter-wave region, and satellite
companies need the massive bandwidth available there when current bands as high
as Ka−band are no longer enough to provide greater capacity.
As a result, an enormous amount of R&D is being conducted to advance the
TWT state of the art to meet the requirements of systems operating at much higher
frequencies, even up to W−band and E−band. Several start-up companies, such as Teraphysics,
are developing fabrication techniques like those of semiconductor processes to make
TWT components at scale. That's a complete departure from the labor-intensive ways
TWTs have always been made.
In short, despite the incursion of GaN technology, TWTs are likely to continue
their development for many years to come.
World's More Sensitive Radio Telescope
A team of researchers has
developed a 'SMART box' to power the world's largest radio telescope, the Square
Kilometer Array (SKA) low-frequency telescope, a network of radio dishes currently
under construction in Western Australia. The Power and Signal Distribution (PaSD)
SMART boxes (Small Modular Aggregation RFoF Trunk) provide electrical power to the
SKA-Low telescope's 131,072 antennas. The team had to source special very-low-noise
devices that emit minimal interference and are wrapped in a specially designed case
to prevent stray radio waves from escaping. The SKA will be the world's largest
and most sensitive radio telescope, capable of detecting faint signals from the
Boston Launches First 5G Broadcast
The first 5G broadcast
channel in the U.S. has begun operation in Boston, launched by low-power TV station
WWOO-LD. The broadcast is the result of efforts from LPTVBA and XGen Network and
is being conducted under an experimental license from the FCC. 5G broadcast is a
"one-to-many” solution that simultaneously sends content and data to many mobile
devices. 5G broadcasting can also push alerts to mass targets in less than a second,
which will be needed to rapidly send messages to the public when traditional uses
overwhelm nearby transmitters.
Global EW Market Booming
A report from Fortune Business
Insights values the global electronic warfare market at $15 billion in 2022. It
expects it to grow to $16.65 billion this year and $31 billion by 2030, an annual
increase of 9.4%. The market's growth can be attributed to the increasing geopolitical
tensions and regional conflicts. These factors have led to a greater need to adopt
advanced warfare methods. In addition, the report says the cognitive EW market,
valued at $308 million last year in 2022, will reach $1.7 billion this year and
expand at a rate of 19.2% until 2032.
Microwaves are Helping Recycle Plastic
Mitsui Chemicals and Microwave
Chemical are continuing a project designed to commercialize microwave technology
for plastic waste chemical recycling. The project aims to directly produce raw monomers
from traditionally difficult-to-recycle plastics, such as automotive polypropylene
and molding compounds used in bathtubs. The firms use Microwave Chemical's "PlaWave"
microwave-based plastic degradation technology to break down the plastics into raw
monomers. They say it is more efficient than the conventional approach that first
converts the waste into oil.
Anatech Electronics Introduces a New Line of Suspended
Stripline and Waveguide Type RF Filters
Check out Our Filter Products
Cavity Band Pass Filters
LC Band Pass Filters Cavity Bandstop/Notch Filter
About Anatech Electronics
Anatech Electronics, Inc. (AEI) specializes in the design and manufacture of
standard and custom RF and microwave filters and other passive components and subsystems
employed in commercial, industrial, and aerospace and applications. Products are
available from an operating frequency range of 10 kHz to 30 GHz and include cavity,
ceramic, crystal, LC, and surface acoustic wave (SAW), as well as power combiners/dividers,
duplexers and diplexers, directional couplers, terminations, attenuators, circulators,
EMI filters, and lightning arrestors. The company's custom products and capabilities
are available at www.anatechelectronics.com.
Anatech Electronics, Inc.
70 Outwater Lane
Garfield, NJ 07026
Posted October 17, 2023