The development of a solid state transceiver for an active element ground based L-Band phased array radar

In the late 1960’s and early 1970’s advances in silicon bipolar technology demonstrated the potential for solid-state active element phased arrays. To gain the solid-state advantages of rapid start, high reliability and lower life cycle cost a program called Camel was initiated to build an L-Band array radar. The transmit/receive module was to be developed at Texas Instruments. The architecture of the power amplifier and the low noise receiver sharing a common phase shifter at the input and a ferrite circulator at the output with digital control of the switching and the phase shifter persists in transceiver modules today. This presentation will describe the technical choices made in these early efforts and the difficulties and surprises that these early solid-state microwave engineers faced. Based on the Camel program a program for a large ground based active element L-Band array was initiated but subsequently terminated.