Radar

• FENN, TEMME, DELANEY, AND COURTNEY

The Development of Phased-Array Radar Technology

The Development of Phased-Array Radar Technology
Alan J. Fenn, Donald H. Temme, William P. Delaney, and William E. Courtney
s Lincoln Laboratory has been involved in the development of phased-array radar technology since the late 1950s. Radar research activities have included theoretical analysis,application studies, hardware design, device fabrication, and system testing. Early phased-array research was centered on improving the national capability in phased-array radars. The Laboratory has developed several test-bed phased arrays, which have been used to demonstrate and evaluate components, beamforming techniques, calibration, and testing methodologies. The Laboratory has also contributedsignificantly in the area of phased-array antenna radiating elements, phase-shifter technology, solid-state transmit-andreceive modules, and monolithic microwave integrated circuit (MMIC) technology. A number of developmental phased-array radar systems have resulted from this research, as discussed in other articles in this issue. A wide variety of processing techniques and system components have alsobeen developed. This article provides an overview of more than forty years of this phased-array radar research activity.

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     was certainly not new when Lincoln Laboratory’s phasedarray radar development began around 1958. Early radio transmitters and the early World War II radars used multiple radiating elements to achieve desired antenna radiation patterns. TheArmy’s “bed spring” array, which first bounced radar signals off the moon in the mid-1940s, is an example of an early array radar. A new initiative in the 1950s led to the use of rapid electronic phasing of the individual array antenna elements to steer the radar beam with the flexibility and speed of electronics rather than with much slower and less flexible mechanical steering. Many industrialfirms, government laboratories, and academic institutions were involved in developing methods for electronic beam steering. In fact, this research area in the 1950s could be characterized as “one thousand ways to steer a radar beam.” Bert Fowler has written an entertaining recollection of many of these efforts from the 1950s to the present [1]. Many skeptics at that time believed a workable andaffordable array radar with thousands of array elements, all working in tightly orchestrated phase coherence, would not be built for a very long time. In retrospect, both the enthusiasts and the skeptics were right. The dream of electronic beam movement was achievable, but it has taken a long time to achieve the dream, and it is not yet fully realized—we still need to reduce the cost ofphased-array radars. We are certainly encouraged, however, by the progress in modern solid state phased arrays. The Beginning Lincoln Laboratory started working on phased-array radar development projects around 1958 in the Special Radars group of the Radio Physics division. The initial application was satellite surveillance, and the level of national interest in this work was very high after the SovietUnion’s launch of the first artificial earth satellite—Sputnik I—in 1957. The Laboratory had played a key role in the development of the Millstone Hill radar under the leadership of Herbert G.
VOLUME 12, NUMBER 2, 2000 LINCOLN LABORATORY JOURNAL

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• FENN, TEMME, DELANEY, AND COURTNEY

The Development of Phased-Array Radar Technology

Weiss, a radar visionary. At that time, the MillstoneHill radar was one of the few radar instruments in the world with satellite detection and tracking capability. Weiss, along with others in the U.S. Air Force, foresaw that the United States would soon need the capability to detect all satellites passing over its territory. The volume of radar surveillance needed to accomplish this task was clearly enormous, which meant that radars of great power,...