# A Bunch of YBCO Josephson Generators for the Analysis of Resonant Cold-Electron Bolometers
## 3 Experimental Results
This system is a combination of the double-folded slot antennas designed to receive signals of various frequencies and is polarization sensitive. This antenna differs from the previous one by two things. First, the coplanar lines are connected in the middle of each slot for making the electromagnetic field distribution symmetric along the slot, and thus improving the radiation diagram of the antenna. Second, we use the central electrode in each slot for making narrower resonances of the receiving system. The coplanar line is also used to match the low impedance of the bolometers and the high impedance of the slot antenna. In addition, the length of the coplanar lines was adjusted to obtain the required operation frequency. Conductors are connected to the lumped capacitances, providing direct current or voltage bias of the CEB and connecting single antenna cells into a series or parallel array, respectively. Different from the two above described systems, the next analyzed receiver represents many-absorber detector with multiple dipole type antennas, intended for LSPE mission [33] with tens pW power range. The simulation results for this system have been recently presented in [34], and here we demonstrate the first measurement results of the first fabricated sample for the 210 GHz frequency range. This sample has 44 bow-tie dipole antennas for 210 GHz frequency range. These dipoles are connected in parallel for DC to further use this array with the SQUID readout. The length of a single dipole is 185 \(\upmu\)m, the wide end of a dipole petal is 60 \(\upmu\)m and its narrow end, located near the Cold-Electron Bolometer connection to the antenna, is 10 \(\upmu\)m. Another difference of the current design with the previous samples is the use of SINS structures with Andreev contact instead of typical SINIS structures. Unlike two other structures, this system has been designed to receive the signal from the side of antenna layer. However, preliminarily it has been measured with signal radiation through the substrate; see the notations with arrows in Figure 4. The corresponding curve of the CEB response is demonstrated in green with the main maximum at about 170 GHz. After the check that this sample is working and has a response, it has been bonded in another sample holder and in this case the radiation from the antenna side has been supplied. The corresponding curve of the CEB response is shown in red. In this case, one can observe the rather narrow bandwidth of the AFC in spite of the used array with bow-tie antennas with the main frequency around 210 GHz as planned, while the response is slightly smaller than in the case of radiation through the substrate. We, therefore, demonstrate the feasibility of the presented approach for the low-noise  
Figure 4: Frequency response of three resonant CEB structures, measured by YBCO Josephson generators. The photographs show the elemental structure of the studied samples. characterization of narrow-band receiving systems with Cold-Electron Bolometers using samples intended for various frequency and power ranges.