An air cooling system using an axial flow fan is generally applied in an electronic cabinet on shipboard. However, cases that apply a water cooling system or a mixture of water cooling and an air cooling system are gradually increased by applying the high-performance SBC (Single Board Computer) or DSP (Digital Signal Process), which has a high heating value. In this study, a structure borne noise reduction design for an electronic cabinet that applied a mixture of air and water cooling system was performed. First, the cooling system design was performed using a numerical analysis to secure a thermal stability, and then an electronic cabinet was produced. Next, considering the cooling performance, the reduction design for structure borne noise that causes an underwater radiated noise was performed using the experimental approach. The electronic cabinet, which has a thermal stability and meets the structure borne noise specifications, was finally developed.

Recently, with the development of the IT industry, technology for satellite communication network systems using multichannel, high-capacity data is getting increasingly popular. Especially in the field of defense, experts emphasize the necessity for research and development (R&D) to improve communication quality in order to facilitate Network-Centric Warfare (NCW) and increase mission efficiency through the use of satellite communication network systems. High power is required for the implementation of this technology, and its quality is greatly affected by Passive InterModulation Distortion (PIMD). In order to improve PIMD levels, the leakage characteristics of the system were analyzed with knowledge of the strong influence of the state of the flange joint that has been confirmed by years of experience and previous studies. In this paper, we analyzed various problems from the mechanical point of view in order to improve the radio frequency (RF) performance by minimizing PIMD in the X band, which is used for the satellite communication. Based on our findings, we propose the flange shape to achieve the test result of -150 dBm, which is an improvement from the existing PIM performance and reference level.