As RFSoC based RF systems move towards distributed, multi board architectures, precise synchronization becomes increasingly important. Applications such as phased array radar, 5G massive MIMO and distributed sensing rely on a common frequency and timing reference for coordinated operation and signal coherence. However, maintaining synchronization across multiple boards, racks or remote locations using dedicated clock distribution becomes increasingly challenging.
Ethernet-based synchronization offers a scalable alternative. Synchronous Ethernet (SyncE) provides frequency synchronization, while IEEE 1588 Precision Time Protocol (PTP) enables time synchronization and phase alignment over existing Ethernet infrastructure. iWave offers advanced hardware platforms based on AMD Zynq UltraScale+ RFSoC devices, supporting the development of synchronized RF architectures. On its iWave AMD Zynq UltraScale+ RFSoC platform, iWave has validated SyncE frequency locking and PTP-based 1PPS alignment using a Microchip ZL30733 clock synthesizer, demonstrating the potential of Ethernet-based synchronization for multi-board RF systems for demanding applications.
How SyncE and PTP Complement Each Other:
Distributed RF systems require both frequency and time synchronization to maintain coordinated operation across multiple boards.
- Synchronous Ethernet (SyncE) provides frequency synchronization by recovering the clock from the Ethernet physical layer and distributing a stable frequency reference across devices.
- IEEE 1588 PTP provides time synchronization through timestamped packet exchanges between master and slave clocks, enabling alignment of their time reference
Together, SyncE and PTP deliver complementary frequency and time synchronization, providing a scalable solution for distributed multi-board RF systems
Hardware RFSoC Architecture for Multi-Board Synchronization:
SyncE and IEEE 1588 PTP provide complementary synchronization capabilities for distributed RFSoC systems. SyncE delivers a stable frequency reference through the Ethernet physical layer, while PTP enables time synchronization and phase alignment through packet-based communication.
In the implemented architecture, the slave recovered clock from master through ethernet and is routed to the slave’s Microchip ZL30733 clock synthesizer. DPLL lock status is monitored to validate frequency synchronization. PTP is implemented using standard Linux ptp4l, with the master and slave clocks exchanging timestamped packets over Ethernet
By combining both technologies, SyncE maintains frequency stability while PTP corrects timing differences between the master and slave clocks. This reduces dependence on packet-based frequency recovery and provides a scalable synchronization approach for multi-board RF systems.
Figure 1: Hardware Architecture of ZU67DR RFSoC-Based Multi-Board Synchronization Using SyncE and IEEE 1588 PTP
Frequency Synchronization (SyncE) and Why It Matters
- Frequency synchronization means every device runs its clock at the same rate. It does not mean every device agrees on what time it is.
- Consider two boards generating a 100 MHz clock. If one clock runs 5 Hz faster than the other, their timing drifts by 50 ns every second, reaching 180 µs in one hour.
- SyncE locks both boards to the same frequency, preventing continuous timing drift. But, PTP is required to align their time and phase
PTP Validation: 1PPS Synchronization with SyncE Support:
To validate PTP synchronization, the master and slave 1PPS outputs were connected simultaneously to a CRO. The captured waveforms were compared to observe their relative timing and phase alignment. SyncE acts on frequency and PTP acts on time. With SyncE, the slave’s ZL30733 DPLL locks to the clock recovered from the Ethernet link and reports lock status, so both boards run at the same frequency and the 1PPS offset no longer drifts. Without it, even a 5 Hz difference on a 100 MHz clock would move the edges apart by 50 ns every second. The fixed offset that remains is what PTP corrects, as shown in the captures below
Without PTP Synchronization: The captured waveforms show a relative timing offset between the master and slave 1PPS signals. The difference in their rising edge positions indicates the absence of precise time alignment between the two platforms
With PTP Synchronization: After enabling PTP, the master and slave 1PPS waveforms demonstrate improved rising-edge alignment, indicating more accurate timing synchronization across the RFSoC platforms.
This hardware validation demonstrates the ability of PTP to synchronize timing references across separate RFSoC platforms.
iWave RFSoC System on Module Portfolio
iWave RFSoC solutions are production ready platforms designed to accelerate RF system development and reduce time to market. Available in compact System on Module (SoM) designs, PCIe cards, development kits and ready to deploy VPX platforms, they offer flexible integration options for a wide range of high performance RF applications.
| Feature | iG-G42M | iG-G60M | iG-G79M |
|---|---|---|---|
| Products |  |  |  |
| Generation | Zynq™ UltraScale+™ RFSoC Gen1 / Gen2 / Gen3 | Zynq™ UltraScale+™ RFSoC Gen1 / Gen3 | Zynq™ UltraScale+™ RFSoC DFE |
| Device Variants | ZU49 / ZU39 / ZU29DR | ZU48 / ZU47 / ZU43 / ZU28 / ZU27 / ZU25DR | ZU67 / ZU65 / ZU64 / ZU63DR |
| Key Specifications |
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Enabling Synchronized RF Systems Across Key Industries:
Precise frequency and time synchronization are important for RF systems that require multiple platforms to work together. This solution can support various applications, including:
- Phased-Array Systems: Supports synchronized operation across multiple antenna panels.
- 5G and MIMO Networks: Enables frequency and timing alignment across radios and antenna arrays.
- Electronic Warfare and SIGINT: Supports synchronized signal detection across multiple sensors.
- Radio Astronomy: Enables coordinated data collection across distributed receivers.
- Test and Measurement: Supports synchronized measurements across multiple instruments.
Getting the timing right is key to building reliable RF systems. By combining SyncE and IEEE 1588 PTP, RFSoC platforms can keep multiple boards synchronized, ensuring better coordination of data acquisition, signal processing and RF operations.
With its production ready RFSoC portfolio, iWave offers flexible hardware platforms to support a wide range of applications, including radar, electronic warfare, SDR, 5G, instrumentation and scientific systems.
Planning your next RF design? Explore iWave’s RFSoC solutions and find the right platform to bring your ideas to life.
For more information, please write to mktg@iwave-global.com
