[en] Gyroamplifiers are very promising sources of coherent, phase-controlled, powerful electromagnetic radiation for driving future particle accelerators. At a given wavelength the interaction space in gyroamplifiers is much larger that that for klystrons. Therefore, gyroamplifiers usually operate at short wavelengths where the problem of miniaturization of the interaction space is, for conventional klystrons, extremely severe. Two years ago the operation of relativistic gyroklystrons in a 10 GHz frequency range was successfully demonstrated. The next step in the gyroamplifier development is directed towards improvement of electronic efficiency, enhancement of radiated power and an increase in operating frequency. The authors present some concepts of relativistic gyroamplifiers aimed at improving these output parameters