For the purpose of studing the microwave parameters of the thermonuclear plasma, radioastronomic applications, ets, the wide-band high-sensitive high-speed spectrum analyzers, radiometers, and receivers are required which operate in the frequency range of 50-300 GHz and higher. The existing techniques have a number of disadvantages. Thus, the high-speed heterodyne receivers are rather narrow-band ones, therefore, to cover the whole millimeter-wave band, complex multichannel systems should be designed. On the other hand, the wide-band Fourier spectrometers are very inertial and complex systems and have great losses in the long-wave portion of the millimeter-wave band. The wide-band high-sensitive spectroscopic technique has been proposed earlier [1,2]. This technique is based on ultra-wide band and very high sensitivity of the principle transformer, i.e. Josephson junctions. A series of experimenrs on the microwave signal spectral analyzis using Josephson junctions has been carried out earlier [1,2,3].