The ZeptoSDR is a software defined radio solution comprised of the Xilinx Zynq-based Zedboard, and Nutaq’s Radio420X. It provides developers with a low cost, table top solution to use the Zynq System on Chip, while utilizing a high performance, tunable, auto-calibrated radio solution.

Related post: GNU Radio embedded on an ARM-based SoC FPGA for portable SDR designs

Video Transcript:

Hi. My name is Jean-Benoit Larouche, and today I am going to talk to you about ZeptoSDR, which is the latest product of the Nutaq product line.

So what is the ZeptoSDR? Basically, it’s made of two pieces, which is a well-known Zedboard and an FMC radio card developed by Nutaq, which is our famous FMC Radio420X, which includes one TX path and one RX path.

This FMC radio card covers from 0.3 GHz up to 3.8 GHz, with a baseband modulation bandwidth user selectable from 1.5 MHz up to 28 MHz of bandwidth.

This FMC radio comes also with very nice features, like auto-calibration of the DC offset and IQ balance and also user controllable LNAs (low noise amplifiers) for automatic gain control  applications.

So what about the Zedboard? Everyone knows and that’s a secret for everybody that the Zedboad is made of an ARM processor, in which we have Linux OS, and here connected to the FMC card and to our IOs you have an FPGA, which is a Artix-7.

So what is the main differentiator of the ZeptoSDR compared to the other Zedboard solutions? Basically, it comes at first from our FMC radio hardware, which is a very nice FMC radio transceiver on top of a FMC radio card. But it also comes through what we call BSDK, which stands for Board Software Development Kit, which means that we are providing HDL drivers but also C drivers for the ARM or the host PC that we will have later on, and it comes also with different designs, documentation of all these cores, which means that, for example, to control the radio, we have here the actual, I’ll call it the IP Core, but it is the actual radio IP core, which enables you to plug your I&Q signal and receive on TX, whatever the way you want to, directly to your custom logic here.

So this is the first piece of software so you don’t have to do any hardware interfacing. You simply plug and play your in and out signal directly to your custom logic.

The other important piece of software is that we are providing what we call RTDEx drivers, both in FPGA and the ARM processor. What is the RTDEx? RTDEx stands for real-time data exchange, which is basically on all our systems, our multi-processor data transfer protocol.

So using this IP core on both systems enables bidirectional data exchange between the ARM and the FPGA. But it also enables, on the Zedboard, a transition through the gigabit Ethernet interface to a host computer. So it does enable at first to do hardware-in-the-loop co-simulation using our board, using that RTDEx interface.

Let’s say we have an application here, let’s call it “app”, which receives the RTDEx. So it enables very easily the client’s new hardware-in-the-loop co-simulation using that interface. It’s bidirectional for sure. That app, since we’re providing drivers either over Linux or Windows, it can be either over Linux or Windows.

But on top of this, to suit a growing community of open source users, we are the first to provide with our Zedboard based platform what we call the GNU Radio plugin. What does that mean? That means that directly from your actual GNU Radio flow graph here, we are providing blocks for the RTDEx interface, but also I’ll call it “radio”. We will have here your GNU Radio flow graph, and inside it you’ll have the actual GNU Radio plugin for this specific IP code, provided by us, which enables you to match your actual algorithms to these blocks for real-time data exchange, not only in the loop co-simulation, but also to configure and play with the radio in real time, always through that gigabit Ethernet interface.

When you’re satisfied with that kind of simulation, we do not stop there. We are providing, and we are again the first to provide that right now in the market, the actual GNU Radio embedded plugin, which means that when you want to get closer to an actually similar application and battery powered application, you can actually remove the card and move your GNU Radio application into the ARM processor here, and afterward, again using the same GNU Radio plugin, exchange data in and out of the laptop and have a complete tabletop, standalone working waveform development system.

So the sum of all these features makes the ZeptoSDR a very attractive solution and a low cost one. The other advantage of it is that when your proof of concept has been done and if the budget is actually permitted, afterward you can move to our higher end system, which is PicoSDR, effortlessly because all these RTDEx interface drivers, which are mainly where the clients most struggle, all these IP cores are the same as on the actual PicoSDR system. So that means that the transition of your application is very effortless.

Thank you. This was simply a quick overview and introduction of this product, which is ZeptoSDR. If you want more information, don’t forget to check our website at, and to have more information regarding the GNU Radio plugin, the FMC radio, or the ZeptoSDR itself, and even the PicoSDR, you can check our blog at