I don't think you can really call them a knockoff. As far as I know, the HackRF has been designed as an opensource hardware[0], so I'd guess the designer intend

I don't think you can really call them a knockoff. As far as I know, the HackRF has been designed as an opensource hardware[0], so I'd guess the designer intended it to be built by different entities. [0] https://github.com/mossmann/hackrf/tree/master/hardware https://github.com/mossmann/hackrf/tree/master/hardware "This is a free hardware design; you can redistribute it and/or modify it under the terms of the GNU General Public License[..]"