High Power Waveguide Combiners for SSPA

Earlier this year, MEGA’s high power waveguide combiners were utilized in a 300kW solid state RF power amplifier (SSPA) system at 500MHz. The project for the NSLS-II Synchrotron at Brookhaven National Laboratory (BNL), completed by Ampegon, utililzed a MEGA waveguide combiner to supply 320kW RF into the synchrotron ring.

About the High Power Waveguide Combiner

MEGA designed and manufactured the WR1800 power combiner / splitter, for use within the 500 MHz amplifier. The following technical specifications apply to the MEGA combiner design:

Frequency:	500 + 10 MHz
Power:	4x Inputs @ 80 kW, 320 kW Output (WR1800)
VSWR:	<1.18:1 (all 6″ ports terminated 50 Ohm)
Power Split:	-6.02 + 0.1 dB, + 3 Deg Phase
Insertion Loss:	<0.12 dB
Isolation:	8 dB min
Material:	Aluminum Waveguide Body, Copper/Brass Coax Inners
Interface:	WR1800 CPRF
Wall Thickness:	0.19 in. (4.826 mm)
Weight:	108 lbs (49 kg)

The combiner is of the non-isolating style. Mega has developed these style combiners in several waveguide sizes, for a range of other markets, including industrial and medical. The high-power waveguide combiner was highlighted in an article from Ampegon earlier this year, in which they discussed their solid-state RF amplifiers.

The following text is a quoted article, credited to Ampegon, who delivered the final product.

Ampegon Solid-State 500MHz RF Amplifiers Commisioned at BNL

March 26th, 2021

Ampegon engineers completed the installation and commissioning of a 300kW solid-state 500MHz RF amplifier system for the NSLS-II Synchrotron at Brookhaven National Laboratory (BNL), in New York State, USA.

The NSLS-II synchrotron accelerates a beam of electrons to almost light-speed to create various wavelengths of x-rays useful for scientific research at a host of experimental stations. It has been powered by 2x 320kW klystron amplifiers, providing 500MHz RF into accelerating cavities in the synchrotron ring since 2013. The RF provides an accelerating gradient within the cavities and keeps the electrons in the beam at the correct relativistic speed.

As part of a recent multi-year upgrade program, BNL contracted Ampegon to provide a third RF amplifier, but this time utilizing a fully solid-state topology. In this form, the amplifier consists of 4x 80kW amplifier stacks, each using a cavity combiner to combine the outputs of 64x dual RF amplifier modules. These four stacks are further combined using a BNL/Mega Industries combiner to supply 320kW RF into the synchrotron ring.

Ampegon RF Engineer, Bodo Fritsche, completed the project alongside BNL staff and was present as the system first ran at full power: “As far as we know, this is the biggest 500MHz Solid State System in the world. Taking the system up to over 300kW output, knowing that this was the first time this power was reached with solid-state technology at this frequency, was incredibly exciting. To achieve 350kW briefly without an issue exceeded all expectations!”

To learn more about Ampegon’s Solid-State RF Power Amplifiers, click here.

If you wish to access Ampegeon’s original article, please click here.

About Mega Industries

Mega Industries has a longstanding history of supplying a wide variety of high-power devices and sub-assemblies to many of the world’s leading universities and laboratories. For decades, we’ve supplied various microwave and RF components to further critical scientific research.

Recently, we expanded our product offerings to the scientific sector, with the creation of Microwave Techniques, following our 2020 merger with Ferrite Microwave Technologies (FMT). As a result, we now have a joint offering of legacy FMT and MEGA components, including: circulators, isolators, loads, windows, assemblies, and beyond.