Birth Certificate
It all started in a cold Saturday night of February 2013 when Youssef Touil (prog) contacted Benjamin Vernoux (TitanMKD) about an idea that will become the core of the AIRSPY R2 and Mini SDR receivers. An old IRC log from that magic era.
Session Start: Sat Feb 16 21:53:25 2013
Session Ident: TitanMKD
[21:53] [prog] bonsoir
[21:53] [prog] t’aurais quelques minutes đ
[21:54] [prog] on bloque sur un projet hardware et peut ĂȘtre que tu as une solution toute faite
[21:54] [prog] ou toute prĂȘte
–
[21:54] TitanMKD is Titan@*.fbx.proxad.net * Titan
[21:54] TitanMKD on #hackrf
[21:54] TitanMKD using holmes.freenode.net London, UK
[21:54] TitanMKD is logged in as TitanMKD
[21:54] TitanMKD End of /WHOIS list.
–
Session Close: Sat Feb 16 22:47:44 2013Session Start: Sat Feb 16 23:14:22 2013
Session Ident: TitanMKD
[23:14] Session Ident: TitanMKD (freenode, prog) (Titan@*.fbx.proxad.net)
[23:14] [TitanMKD] bonsoir
[23:14] [prog] hello
[23:15] [prog] tu parles bien français?
[23:15] [TitanMKD] je suis français
[23:15] [prog] on sait jamais
[23:16] [prog] sinon, il s’agit de streamer les donnĂ©es du STM32 depuis l’ADC vers l’USB
[23:16] [prog] entrée en mode réel (pas complexe)
[23:16] [TitanMKD] oui
[23:16] [prog] peut ĂȘtre aussi de la decimation
[23:17] [prog] la sortie devrait ĂȘtre aux alentours de 2msps
[23:17] [TitanMKD] tu veux dire valeur brute par valeur réel ?
[23:17] [prog] est ce qu’on peut faire ça avec le STM32 ?
[23:17] [prog] des samples de 16bit
[23:17] [prog] (short)
[23:17] [prog] mais pas en quadrature
[23:18] [prog] juste un ADC
[23:18] [TitanMKD] oui on peut tout Ă fait faire en temps rĂ©el des acquisitions avec transfert vers l’usb
[23:18] [prog] sans perte de samples?
[23:18] [prog] je t’explique je que j’essaie de faire
[23:19] [prog] tuner R820T -> ADC (4MSPS) -> qq chose -> USB -> PC
[23:19] [prog] le MCU va controler le R820T en I2C
[23:19] [TitanMKD] j’arrive sans problĂšme Ă faire ce genre de chose depuis du sampling SPI =] USART ] @3MSPS
[23:19] [prog] nickel
[23:20] [prog] ça devrait donner un joli rececepteur 24 – 1900 MHz pas cher
[23:20] [prog] si en plus on utilise un ADC 16 bit… c’est le pompon
[23:20] [prog] dans un premier temps, l’ADC integrĂ© fait l’affaire
[23:21] [TitanMKD] quel interĂȘt par rapport Ă une clĂ© usb genre Terratech qui coĂ»te 20euros et qui faits du 3.2MSPS en I/Q avec pratiquement le mĂȘme range ?
[23:21] [prog] -> le bit width
[23:21] [TitanMKD] sachant que l’I/Q c’est largement mieux qu’une valeur ADC raw
[23:22] [prog] ça permet d’avoir un bon dynamic range
[23:22] [prog] le tuner 820T a une sortie réelle (pas de quadrature)
[23:22] [prog] elle est samplée en quadrature par la puce RTL
[23:23] [prog] le problĂšme de ces clĂ©s c’est le dynamic range
[23:23] [prog] il est trop bas
[23:24] [TitanMKD] ok
[23:24] [TitanMKD] aprĂšs tu veux utiliser quel STM32 ?
[23:25] [prog] le M4F
[23:25] [prog] je pourrais mĂȘme faire toute la demodulation dedans
[23:26] [TitanMKD] tu veux dire le STM32F4 ?
[23:26] [TitanMKD] @168Mhz
[23:26] [prog] yes
[23:26] [TitanMKD] oui dans ce cas tu vas pouvoir faire pas mal de traitement avec
[23:26] [TitanMKD] le meilleur serait le LPC43xx pour ce genre de chose avec 2 MCU
[23:26] [prog] problĂšme: il me faut un setup initial sur lequel je me base.
And that was it. Starting from this simple architecture proposed by Youssef, Benjamin was quick to trim the fat from the HackRF firmware and derive a small test PCB from the HackRF hardware with the RF front-end contributed by Youssef. One of the main challenges Benjamin had to face was to stream the ADC samples continuously to the USB transceivers without or with minimal loss. This initial hardware was basically a data glue between the high speed ADC of the LPC4370 and the computer, where all the DSP processing happens. The raw samples from the ADC were converted into useful IQ data using Youssef’s novel high speed IQ generation algorithm, with the IQ output being readily usable by any SDR software. This also defines the final performance of the chain, especially by eliminating the DC offset, 1/F noise and IF images that plagued all the quadrature SDRs at the time. The algorithm design also included spur avoidance mechanisms and many candidate RF/IF configurations to achieve the best dynamic range and alias rejection for the different sample rates. For this purpose, a new driver for the Rafael Micro R820T was developed by Youssef in order to adapt its dynamic parameters to the rest of the SDR platform, and optimize the code to be included in the firmware. This work will be key in achieving a higher performance than the RTL-SDR dongles. It also resulted in the wide adoption of this tuner with back-ports in many applications, including RTL-SDR itself.
The Industrialization Phase
At this stage, Airspy had a working prototypeânot yet a fully developed product, but a highly functional and promising prototype. Youssef and Benjamin reached out to numerous OEMs, facing rejection after rejection. But then came a breakthrough: Itead Studio, a small and growing OEM company at the time, stepped forward with a proposal to industrialize the prototype into a fully-fledged product. Although the idea was risky and filled with uncertainty, Youssef managed to secure a favorable deal with Itead. They would handle the financing, production, distribution, and user support, while Youssef continued to oversee the technical side, particularly the SDR development. This partnership laid the backbone of a real productâmarking the transition from a prototype to a legitimate product ready for the market.
Innovation in Production and Testing
One of Youssef’s key innovations to streamline the production and testing process was the use of a HackRF radio. Traditionally, RF test equipment was expensive and required specialized knowledge, which could be a bottleneck in mass production. However, Youssef found an innovative and cost-effective solution by using the HackRF radio to generate RF test signals. These signals were then injected into the unit under test (UUT), providing an efficient method to simulate real-world conditions.
To complement this, Youssef developed a specialized SDR program to perform complex mathematical calculations, which helped assess the performance of each unit. This program allowed for the automatic validation or rejection of units based on their test results. The innovative testing system achieved 99.9% conformity, which was an exceptional result for mass production, ensuring that only fully functional and well-calibrated units reached the market.
A Cornerstone of Airspy’s Reputation
This streamlined and cost-effective approach to quality control became one of the cornerstones of Airspy’s reputation for high-quality and reliable products. It not only ensured the viability of the project but also helped the company scale up production without compromising on product standards. The use of non-RF savvy personnel to operate the testing system was a significant achievement, as it allowed for efficiency and scalability in production. Airspyâs ability to maintain rigorous quality control using inexpensive equipment and automated processes played a crucial role in the companyâs success, proving that high-quality products could be delivered at scale even with minimal specialized resources.
Identity
Now that we have a real product, we need a market and an identity. Here’s the funny story of how it was born.
[20:01] [TitanMKD] on peut mettre un logo aussi
[20:01] [TitanMKD] en bitmap jpeux l’intĂ©grer
[20:01] [prog] c’est l’idĂ©e
[20:01] [prog] un joli diĂšze đ
[20:01] [TitanMKD] haha
[20:01] [TitanMKD] lpcsdr# ?
[20:01] [prog] trop long
[20:01] [TitanMKD] lpc#
[20:02] [prog] on n’a pas le droit
[20:02] [TitanMKD] lpcshark#
[20:02] [prog] il faut qq chose qui inspire l’Ă©coute đ
[20:03] [TitanMKD] oula
[20:03] [TitanMKD] HydraSDR# đ
[20:05] [prog] airspy
[20:05] [prog] qq chose comme ça
[20:05] [TitanMKD] ha oui
[20:06] [prog] sympa non?
[20:06] [TitanMKD] sans le mot sdr alors
[20:06] [TitanMKD] ou sharp đ
[20:06] [TitanMKD] AirSpy
[20:07] [prog] donc
[20:08] [prog] le logo: AIRSPY en maj, avec une police sympa
The AIRSPY))) logo was born. Now how to sell it?
Enter SDR#
The easiest path to success for all SDRs is their first letter. It’s all about software. SDR# (SDRSharp) by Youssef (prog) was a key factor in Airspyâs success because it provided a high-performance, user-friendly software ecosystem that fully utilized Airspy’s hardware capabilities. This was unheard of at the time. Hereâs how SDR# contributed to the great success of the Airspy platform:
1. Optimized Software for Airspyâs Hardware
SDR# was designed with highly optimized DSP algorithms, ensuring that Airspy could deliver superior signal processing compared to competing SDRs. The software tweaked the Airspyâs internal to improve the dynamic range and offer lower sample rates with higher performance, making it the best companion for the hardware.
2. Seamless Integration & Performance Boost
Unlike generic SDR software, SDR# had native support for Airspy, reducing latency and maximizing efficiency.
The decision to offload DSP to the PC (instead of running it on the microcontroller) allowed for much more powerful demodulation, filtering, and noise reduction.
3. A Well-Designed, Extensible Platform
The plugin system enabled users to extend SDR# with new features, making it a long-term, adaptable solution for Airspy users.
The graphical layering system in SDR# made signal visualization more intuitive, improving user experience.
4. Market Differentiation & Adoption
SDR#’s ease of use and superior performance compared to alternatives like GNU Radio or HDSDR helped establish Airspy as a premium SDR solution.
The combination of Airspy + SDR# was a turnkey solution, removing the complexity that often discouraged newcomers from using SDRs.
5. Community & Ecosystem Growth
SDR# had an established user base, meaning Airspy immediately had a strong community of users and developers.
Continuous software updates ensured Airspy remained relevant and outperformed competing SDRs over time.
In sort, an established platform like SDR# was the last missing ingredient for the Airspy success. The rest is history.
More on the HF+ series in the next episode!