Solid-state upgrade for the COBRA JUDY S-band phased array radar

COBRA JUDY S-band is a phased-array data collection radar permanently mounted aboard the USNS Observation Island (Figure 1). Designed in 1976 and first made operational in 1981, the transmitter hardware has become difficult to support and, in some cases, obsolete. In December 2004, Diversified Technologies, Inc. (DTI) was awarded a contract to upgrade the transmitter with solid-state technology. Conventional tube-type radar modulators upgraded with switching power supplies and high voltage modulators demonstrate improved performance and significantly extended lifetimes. Employing solid-state technology in high voltage transmitters is cost-effective, improves reliability, and delivers better protection to the RF amplifier than conventional transmitter designs. In this paper, DTI will present an overview of the CJS transmitter design, key technical drivers, and a summary of progress thorough installation of the transmitter in early 2006.