  We propose a scheme of a universal block of broadband quantum memory
consisting of three ring microresonators forming a controllable frequency comb
and interacting with each other and with a common waveguide. We find the
optimal parameters of the microresonators showing the possibility of highly
efficient storage of light fields on this memory block and we demonstrate the
procedure for gluing several memory blocks for increasing spectral range of the
composite quantum memory while maintaining high efficiency.
