ASR Antenna System Quadruple Rotary Joint Assembly Type FAA/Srds-108-31-4d

摘要

The development of a Quadruple Rotary Joint Assembly for the FA-5144 ASR Antenna System is described. The assembly includes an S-band High Power Channel and three L-band Channels. The principle attribute of the S-band Channel is its high power handling capability and low VSWR. This channel was subjected to a high power test and breakdown occurred at 1.375 megawatts with no pressure, and at 2.71 megawatts maximum with 15 psi pressure. The VSWR measured over the band on each unit is less than 1.135. The three L-band Channels were subjected to a high power test and no breakdown occurred up to 100 KW with no pressure. The specified requirement is 25 KW maximum with no pressure. The three L-band Channels tested to a maximum VSWR of 1.2. A 67 db minimum to 86 db maximum isolation between channels was obtained compared to 60 db maximum cross coupling specified between joints. WOW is less than = .05 over each frequency range throughout the 360 degree rotation. The insertion loss of all channels varied from .07 db minimum to .3 db maximum. Insertion loss was kept to a minimum by the use of silver-graphite bushings to provide effective r-f short circuiting and mechanical centering. (Author)