Radar systems and technologies have long been synonymous with military applications. Starting with World War II, as vehicles and weapons began their march toward greater sophistication, requirements for radar systems have followed suit. With their capabilities to “see” targets from a distance, and even to detect targets that were meant to remain invisible, radar has long been an invaluable part of the battlefield—and more importantly, as a means of maintaining order so that there is no battlefield.
Radar technology has evolved into many different forms of systems, from basic continuous-wave (CW) systems to more complex systems with different lengths of pulses and modulation formats. In most cases, military radar systems are attempting to detect and identify targets that are not supposed to be detected, such as missiles and enemy aircraft. But radar technology has grown a great deal over the years, and is increasingly used in non-military applications for detecting such things as weather patterns and vehicle speeds on interstate highways.
With regard to the latter, radar has been used by law enforcement professionals since the 1950s for vehicle speed detection. Ironically—following the behavior practiced by military forces when using electronic countermeasures (ECM) systems to detect and thwart enemy radar, electronic-warfare (EW), and other military electronic systems—civilians now purchase radar detectors for their vehicles to help locate police radar sources. And, as a form of counter-countermeasure, police radar systems often employ a “POP” operating mode by which radar signals are transmitted intermittently, so that civilian radar detectors cannot get a fix on the police radar.
In the hospital, the use of radar systems is growing quickly for medical purposes—specifically, for noncontact monitoring and measuring of vital signs. Radar technology detects the movements of key organs, such as the lungs and heart. Applying radar technology to medical purposes is nothing new: Initial medical radar systems involved CW signals, but more recent systems have been designed to use pulsed signals as in advanced military radar systems.
The pulses provided more capabilities, such as measurements of organ movements, as well as the range or distance of those movements. Patients needn’t be concerned over potential electromagnetic (EM) damage from these radar signals, since short, extremely low amplitude pulses are used in medical radar systems.
Non-military uses for radar technology continue to expand. Vehicular radar systems, for example, are now employing 77-GHz with Doppler techniques for such functions as adaptive cruise control and pre-crash collision-avoidance warnings. As leading semiconductor suppliers develop more affordable millimeter-wave devices at such high frequencies, radar developers can offer competitive prices that spread these radar-based products to the masses.
Military users depend more on radar with each new conflict and advance in weaponry. But they are no longer alone, as civilian and industrial users continue to appreciate the benefits of this versatile technology.