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Subelement E: Antenna Systems- 5 Key Topics – 5 Exam Questions— Topic 41: Antenna to Display Interface

Question 8-41E3

Element 8 (RADAR)

What is the most common type of antenna position indicating device used in modern RADARs?

Explanation
Resolvers are the preferred choice for antenna position indication in modern RADARs due to their exceptional accuracy and reliability. These electromechanical transducers provide a continuous, highly precise analog output representing the sine and cosine of the shaft's angular position. This inherent sine/cosine output is ideally suited for digital conversion and processing, allowing sophisticated radar systems to accurately determine target azimuth and elevation with high precision. While synchro transmitters perform a similar function, resolvers offer superior precision and robustness, making them more common in demanding modern applications. Servo systems are the *control mechanism* that *uses* such indicating devices to move the antenna, rather than being the indicator itself. Step motors provide discrete positional control and are generally not used for continuous, high-accuracy angular *sensing* in high-performance radar antennas.

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