Low-profile high-sensitivity sub-array module with HTS filters for an active phased array antenna

We have developed a low-profile high-sensitivity sub-array module for an active phased array antenna. By using this sub-array module, a low noise receiving antenna can be easily available for wireless applications such as radar systems, communication systems, and so on. In this paper, we describe the new 16 elements S-band multichannel receiving sub-array module using high-temperature superconducting (HTS) filters as a key component for an active phased array antenna. Each receiving channel correspond to an antenna element consists of a HTS filter, a low noise amplifier (LNA), and interface circuits. In the sub-array module, 16 channel circuits are contained within a 200 mm×240 mm×30 mm vacuum chamber and cooled by a small cooler to 77 K. By using HTS filters and the cooler, feed-line loss and internal noise can be substantially reduced. Therefore, high sensitivity for an active phased array antenna can be realized. Additionally, radio wave interferences can be suppressed effectively by sharp frequency selectivity of the HTS filter with high-Q factor.