## 1 Introduction  
Due to the ever-increasing requirements of communication systems, there is an increasing demand for systems in the millimeter wave range [1]. This range is also applicable to medicine, biology, astronomy, defense and materials technology [2; 3]. However, realization of high frequency communication systems in the THz range becomes extremely complex. Implementation of sources and detectors in this range is very complicated [4; 5]. Moreover, conventional communication techniques are incompatible with these high frequencies. On the other hand, photon energies are too low for adopting optical approaches. As a result, detection of millimeter wave radiation necessitates the development of new technologies of transmission and reception. Junctions in superconducting materials can be implemented by depositing a superconducting layer over a discontinuity in the material structure, such as in step-edge [6]. These junctions are known as Josephson junctions. A unique feature of superconducting junctions, which has important applications for detection of RF radiation, is the Shapiro steps. These current steps are the result of the modulation by RF radiation of the current flowing through the junction. They are observed when measuring the I-V (Current-Voltage) characteristics of the Josephson junction. The measurements of the Shapiro steps and the RF analysis are carried-out using simple Direct Current (DC) equipment [7]. As a result, the complexity and cost of detection systems for high frequency radiation are significantly reduced in comparison with common THz detection systems [2]. Thus, superconducting Josephson junctions are well suited to serve as detectors of millimeter wave radiation [7]. They provide a technique for measurement of intensity and frequency of high frequency signals, without resorting to complex electronics, such as high frequency spectrum analyzers [8; 9]. A major breakthrough in application of superconductivity was achieved with the discovery of High Temperature Superconductors (HTSC) materials, in which superconductivity can be obtained at higher temperatures, including liquid nitrogen temperatures. The first and most applicable family of HTSC materials are the YBCO [10]. The realization of high frequency Josephson junction detectors in HTSC, reduces drastically the intricacy of the detector systems. Inexpensive cryogenic systems, cooling down to liquid nitrogen temperature range, suffice for turning the material into a superconductor [11; 12]. A serious drawback of detection systems based on superconducting junctions is their low efficiency [13; 14]. This results in lower system sensitivity, higher electrical noise-equivalent-power (NEP), and lower coupled power voltage responsivity, \(\eta(V)\)[8; 9]. In addition, the performance of millimeter wave detector systems depends strongly on the exact structure and geometry of the antenna [3; 4]. The antenna must have a wide aperture and a high gain [15]. Another problem with detection systems based on HTSC Josephson junction is impedance mismatch between the junction and the antenna, due to the very low impedance of the junction (few Ohms) [8; 16; 17]. The impedance mismatch can be detrimental to the performance of the detector [18]. To reduce losses, the impedance of these two elements must be matched. Optimization of the interface between the detector and the antenna is essential. Moreover, detectors implemented in HTSC are more sensitive to the tolerances of production than those based on low temperature superconductors, due to the shorter coherence length at HTSC junctions [19]. In this paper, we present the analysis and implementation of a THz antenna system, combining a superconducting Josephson junction with a bow-tie antenna. Bow-tie antennas are the preferred architecture for the high performance of THz transmission and detection, with broadband, efficient radiation characteristics [20]. The size and the shape of these antennas make them ideal for interfacing with communication modules and detectors [21; 22].