Knowledge Resources’ first RFSoC 

The team at Knowledge Resources GmbH (KR) completed the design of our first Xilinx (now AMD) RFSoC-based module in the fall of 2019. We entered the market with the KRM-4ZU27DR and released the updated version with RFSoC Gen3 parts shortly afterwards in 2020.

At the time, we did not have a specific market segment in mind and designed our RFSoM for broad appeal. Designing for an unknown market means that the aim was for maximum flexibility and enabling as many features of the underlying FPGA as possible. Here’s an overview of what we deemed important considerations.

But we wondered how our design decisions have held up. Did potential customers share our vision and order of importance? Looking back at more than half a decade of RFSoM design-ins and shipments has given us insights about which features have proved to be key enablers and, as a result, where our RFSoC modules are successfully deployed.

Multi Tile Synchronization (MTS)

The key feature of an RF-enabled FPGA module is the correctly implemented support for Multi Tile Synchronization (MTS) and Multi Module Synchronization (MMS). MTS and MMS are required to enable the RFSoM’s integration into multi-channel RF systems such as Radar, MiMo base stations or complex quantum compute control stacks.

MTS is reasonably straight forward to support. One must pay attention to:

  • length-matching of RF path
  • providing the proper clocking and Sysref signal
  • correctly designing the clocking tree and its initialization

In addition to the MTS of a single RFSoM, larger multi-module systems also require that coherent and phase aligned clocking is not only available to one RFSoC module, but to all instances in the system. As a result, the clock tree becomes more complex as the system grows in channels.

In these larger phased-array systems, the correct initialization and system-wide calibration depends on reliably knowing when all the RFSoCs are configured and available. Knowledge Resource’s RFSoC FPGA modules feature a unique housekeeping bus that ensures reliable power-up and synchronized configuration and initialization of large multi-module systems. Our customers rely on the fact that the KR RFSoMs provide both of these features (MTS/MMS and synchronized initialization), which ensures the successful deployment of our KRM-4 in Quantum control stacks, radar, and communications systems from day one.

KR RFSoMs in LEO space applications

Over time, clients adapted our RFSoMs for LEO space applications. One of the key enablers for space deployment is the robust mechanical concept supported by a top mounted heat-spreader and clamping mechanism. That robust design allows our COTS RFSoC modules to survive the acoustic, vibration, and massive acceleration stresses of a rocket launch.

The heat spreader and strategic top placement of power components also facilitate conduction cooling, which, coupled with a thermal radiator, is the only viable cooling method in the vacuum of space. The ECC RAM, select high-reliability mass storage devices, and a Board Management Controller (BMC) that can detect over-current conditions (caused by Single Event Latch-up, SEL) let our customers deploy our KRM-4 in LEO constellations. While the KRM-4 RFSoC module was not initially designed for space, almost four years of flight heritage and a growing list of multiple customer deployments speak for its suitability.

RFSoM Test and Measurement Applications 

Back on earth, Test and Measurement (T&M), as well as sensing applications, are also an excellent fit for our RFSoM. A favorite feature in that application space is the module’s dual PL attached DDR4 memory interface for high bandwidth sample capture or complex waveform playback.

Due to its dual PL interface, the KRM-4 RFSoC module features exceptionally high RAM bandwidth and on-SoM memory depth. The physical interface on the module is supplemented by our highly resource efficient memory controller IP core. At a quarter of the fabric-footprint of a Xilinix Memory Interface Generator (MIG) core, it reduces routing congestion and resource conflicts in high logic utilization designs.

Beyond your “typical” test and measurement application, the scientific community has also adopted our RFSoC modules in fields like radio astronomy. For example, the Metsähovi Radio Observatory deployed the KRM-4 in the world’s widest bandwidth radio telescope.

Another interesting design-in of the KRM-4 is the use in a quantum sensing application which tracks the slightest variability of earth’s gravity, or the upcoming deployment in CERN’s Large Hadron Collider upgrade. A low noise analog power stage and meticulous routing of the RF paths contribute to making our KRM-4 suitable for such scientific applications.

Expanding KR’s RFSoC Family

In summary, our six-year history with the KRM-4 RFSoC has shown that thanks to our design team’s careful consideration, the initial KRM-4 design has proven itself to be extremely versatile and well-suited to a wide range of applications. For areas where it was not a perfect fit, we released a 16-Channel RFSoM based on the ZU49DR and a DFE-enabled, compact module based on the ZU67DR. These modules have both been available since early 2024 and in their two years of existence, enabled many designs that required higher channel counts or small form factor.

What’s next for KR: Versal RFSoMs

Building on our proven technology and expertise, we will soon release a new RFSoM based on the AMD Versal RF family. Our first module is based on the VR1602 and VR1652, followed by the VR1902 and VR1952. Combined with our Versal VH1782-based HBM SoM, we can build highly capable wide-band spectrum monitoring, ELINT and SIGINT platforms.

Knowledge Resources is the only European SoM vendor that offers the full range of RFSoMs and in-house expertise to rapidly develop, build and deploy high performance intelligent RF systems. As always, all of our technology is developed, built, tested and supported by our highly capable in-house team of scientists, engineers and technicians.