## 1 Introduction  
With the discovery of high-temperature (high-\(T_{c}\)) superconductivity [1], it became possible, in principle, to fabricate Josephson junctions (JJs) [2] with higher Josephson frequencies \(f_{\rm f}\) than those of low-\(T_{c}\) superconductor junctions. Due to small coherence lengths, even grain boundaries in high-\(T_{c}\) materials have the properties of weak links and JJs [3]. The most common high-\(T_{c}\) junctions are artificial bicrystal JJs formed by the coalescence of two misoriented high-\(T_{c}\) films [3]. The bicrystal junction consists of a structurally distorted interface in the middle and two adjacent layers of undistorted material with a reduced oxygen content and, accordingly, a depleted charge region [3]. Such a boundary is a potential barrier for the tunneling Cooper pairs and quasiparticles. Conventional bicrystal JJs are fabricated from two \(c\)-axes high-\(T_{c}\) films. They have characteristic voltages \(I_{c}R_{\rm n}\) up to 3 mV, which is significantly lower than the gap voltages \(2\Delta/\rm{e}\) for high-\(T_{c}\) materials. In these junctions, the dependence of the supercurrent \(I_{s}\) on the phase difference \(\varphi\) of the order parameters turned out to be close to sinusoidal, as in classical tunnel JJs. Moreover, the dynamics of such JJs is close to a simple resistively shunted junction (RSJ) model, where, along with the supercurrent \(I_{s}=I_{c}\rm{Sin}\varphi\), the quasiparticle current enters into the total current in the form of [PERSON]'s law: \(I_{q}=V/R_{\rm n}=(\hbar/2 eR_{\rm n})(\rm{d}\varphi/\rm{d}t)\)[4]. These circumstances played an important role when using JJs as frequency-selective detectors and served as a stimulus for intensive studies of spectroscopic applications of high-\(T_{c}\) JJs in a broad spectral range (see, for example, [5]). The further development of these works has already made possible several spectroscopic applications of high-\(T_{c}\) JJs. Among them are the following: the identification of liquids by their sub-THz reflection [6], the detection of broadband radiation from quasiparticle-injected nonequilibrium superconductors [7] and photoconductive antennas excited by femtosecond optical pulses [8], and the detection of 500 GHz radiation from a Bi\({}_{2}\)Sr\({}_{2}\)CaCu\({}_{2}\)O\({}_{8}\) intrinsic Josephson junction [9]. In high-energy physics, it was possible to substantiate and partially implement high-\(T_{c}\)\(J\)Js for spectral analysis of transition radiation from relativistic electron bunches in linear accelerators [10] and cyclotron electron emission from high-temperature plasma in tokamaks [11]. Previous studies of output sub-THz and THz radiation from commercial sources [12; 13; 14; 15; 16] with high-\(T_{c}\) JJs have paved the way for the spectral characterization of new THz sources based on quantum cascade lasers (QCLs) [17; 18]. Recently, using high-\(T_{c}\) JJs, subterahertz spectral lines have been found in the emission of free-running THz quantum cascade lasers (QCLs) due to difference-frequency generation (DFG) in the QCL active region [19]. Application of high-\(T_{c}\) JJs for the characterization of QCLs radiation looks very promising and competitive because these spectral measurements are in the frequency domain [18] and possess the potential to operate both in the sub-THz and THz ranges [17; 18; 19]. The latter circumstance is for verification in various configurations of high-\(T_{c}\) JJs with proper tuning of relevant parameters of the junctions. Previously, Josephson bicrystal junctions, consisting of two c-oriented YBa\({}_{2}\)Cu\({}_{3}\)O\({}_{7-x}\) thin-film electrodes, were mainly used for spectroscopic purposes [5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19]. The simple bicrystal junction, where the \(c\)-axis epitaxial films grow on each part of the bicrystal substrate, forms an artificial bicrystal boundary by the coalescence of two misoriented \(c\)-axis thin-film parts.