xSDR is a compact, single-sided M.2 software-defined radio designed for seamless integration into modern computing platforms. The “x” stands for extended; xSDR delivers extended bandwidth in the same minimal footprint as our previous model, uSDR. With 2x2 MIMO RX/TX channels, a wide 30 MHz–3.8 GHz tuning range, and up to 122.88 MSPS sampling and an updated FPGA, xSDR is a flexible platform for embedded RF, wireless research, signal intelligence, and rapid prototyping.

Designed to fit the M.2 2230 A+E-key form factor (30 mm × 22 mm), xSDR plugs directly into laptops, tablets, smartphones, and embedded computers. When paired with the wsdr.io web platform, it enables instant creation, control, and sharing of RF applications right from a browser, with no complex drivers or software setup required.

Small & Mighty

Traditional SDRs often force a trade-off between ease of use and performance. xSDR is designed to deliver both: serious RF capability in a form factor small enough to disappear into your system, paired with a modern, web-based software experience that dramatically reduces setup time and friction.

That’s why xSDR is ideal for work analyzing cellular communications (using open tools like BTS, eNodeB, or commercial ones like srsRAN or Amarisoft), embedded in edge computing devices where power and footprint are at a premium, or as a data link, connecting distant nodes using the web-based wsdr.io platform. Even in demanding scenarios like signals intelligence (SIGINT) or in industrial settings, xSDR is a fantastic solution.

Applications

Cellular Communication: Establish dedicated wireless networks by deploying BTS, eNodeB, or gNodeB systems using open-source platforms such as srsRAN and OsmoBTS.

Embedded: Develop compact, high-performance RF and frequency-analysis devices optimized for embedded and edge deployments.

Data Link: Build point-to-point or global communication channels using a browser-based or cloud-connected web platform (USB only).

Software Compatibility: Leverage a wide ecosystem of existing tools, including GNU Radio, srsRAN, and many others via SoapySDR.

Features & Specifications

• 2×2 MIMO RX / TX channels
• RF tuning range: 30 MHz – 3.8 GHz
• Sample rate:
  • 0.1 MSPS – 122.88 MSPS (SISO)
  • 0.1 MSOS - 80+ MSPS (MIMO)
• Channel bandwidth: 0.5 MHz – 90 MHz
• Host interface: M.2 2230 A+E key (USB 2.0, PCIe 2.0 ×2)
• FPGA: AMD Artix-7 XC7A50T
• GPIO: 12+2 pins 1.8V (pinout is the same as uSDR)
• RF Connectors: 4 x MHF4
• Clock stability: 0.5 PPM
• External clock synchronization:
  Synchronize multiple xSDR boards to build multi-channel and phase-coherent arrays (see xMASS SDR)
• Web-based SDR workflows with wsdr.io (USB adapter required)
• Adapters: All existing uSDR adapters are fully compatible with xSDR

xSDR Components

• RFIC: LMS7002M
• FPGA: AMD Artix-7 XC7A50T
• Crystal oscillator: NT2016SA-26.000000MHZ-NBG2
• Clock buffers: PL133-27GI, CDC3RL02
• USB 2.0 PHY: USB3330
• Temperature sensor: TMP114
• EEPROM: AT24CSW020
• RF Baluns: B0322J5050AHF + 3600BL14M050
• RF connectors: MHF4
• RF switches: BGS12P2L6

xSDR Block Diagram

Comparisons

¹ BTS, eNB or gNB via srsRAN, OsmoBTS, etc.

Adapter Compatibility (uSDR & xSDR)

xSDR shares the same physical connector ecosystem as uSDR and is fully compatible with all existing uSDR adapters.

When uSDR adapters are used with xSDR, the system exposes one receive and one transmit RF channel (1 RX + 1 TX). This applies to the development board, as well as to the USB and Mini PCIe adapters.

Note: Additional RF paths can be accessed by routing signals directly via MHF4-to-SMA cables.

As part of this campaign, we are also introducing a new M.2-to-PCIe breakout board, designed to provide improved integration options and expanded access for xSDR in desktop and embedded systems. This adapter has PCIe x4 host interface and JTAG connector exposed that makes it ideal for custorm firmware development.

Software

xSDR is compatible with established SDR tools such as GNU Radio, srsRAN, and SoapySDR. It also integrates seamlessly with the wsdr.io web platform, providing a streamlined environment for rapid RF solution development.

Users can build applications using a browser-based application builder or choose from ready-to-use apps, enabling effortless creation, deployment, and scaling of RF workflows, from spectrum analysis to complex wireless communication systems, including cloud-based setups via wsdr.io

Open Cellular with WSDR & NLnet

With support from NLnet Foundation we’re making cellular networks more accessible, open, and developer-friendly. The WSDR cellular network initiative focuses on lowering the barrier to building and experimenting with LTE and 5G systems, combining open-source software, web-based tools, and compact SDR hardware like xSDR, uSDR, and sSDR.

Documentation & Support

xSDR shares the same host software codebase as the uSDR platform, released under the MIT license. Universal support libraries and tools are hosted on our GitHub, enabling a smooth transition from uSDR to xSDR and xMASS with minimal software changes.

FPGA gateware is released under the CERN-OHL-P-2.0 license and is available on GitHub. Host libraries are released under the MIT license and are available on GitHub. Pre-built packages are hosted on Launchpad.

The xSDR schematic will be published after the campaign is completed. General information about features and installation can be found on our website.

Fulfillment & Logistics

After our production run is complete, we will package everything up and send it along to Crowd Supply’s fulfillment partner, Mouser Electronics, who will handle distribution to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.