COSI Transmit – Open source soft- and hardware transmission system for traditional and rotating MR


Open source software and hardware project of a transmitter and RF amplifier for traditional and rotating magnetic resonance imaging


Blücher Christian1, Han Haopeng1, Hoffmann Werner1, Seemann Reiner2, Seifert Frank2, Niendorf Thoralf1,3,4, Hasselwander Christopher5, Grissom William5, Winter Lukas2

Estimated cost

~1000€ (SDR)

~2000€ (RF power amplifier)


CERN OHL v1.2, prototype

The spectrometer or software defined radio is capable of producing arbitrary shaped RF-pulses, un-/blanking the RFPA, recording acquired data and controlling a rotating
gradient field. Pulse length, amplitude, readout-length and –delay can be chosen freely.

The RFPA successfully amplied rect- and sinc-pulses generated by the spectrometer. A signal amplitude of 500mV at the input leads to an output voltage level of 200V which corresponds to a total gain factor of 52dB and a power level of 800W in a 50Ω system. The RFPA shows good linearity for the investigated frequency range f=1.8-54MHz (B =0.042-1.27T) with a maximum power output of around 1kW peak power.
The whole system occupies a volume of around (50x30x35)cm3.


Blücher C, Han H, Hoffmann W, Seemann R, Seifert F, Niendorf T, and Winter L, “COSI Transmit: Open Source Soft- and Hardware Transmission System for traditional and rotating MR”, Proc ISMRM, 2017, #184


1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany

2Physikalich-Technische Bundesanstalt (PTB), Berlin, Germany

3Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité medical faculty and the MDC-Berlin

4MRI.TOOLS GmbH, Berlin, Germany

5Vanderbilt University, Tennessee, USA