Search results
Results from the WOW.Com Content Network
Frequency agility is the ability of a radar system to quickly shift its operating frequency to account for atmospheric effects, jamming, mutual interference with friendly sources, or to make it more difficult to locate the radar broadcaster through radio direction finding.
Range ambiguity occurs when the time taken for an echo to return from a target is greater than the pulse repetition period (T); if the interval between transmitted pulses is 1000 microseconds, and the return-time of a pulse from a distant target is 1200 microseconds, the apparent distance of the target is only 200 microseconds.
Sensitivity time control (STC), also known as swept-gain control, is a system used to attenuate the very strong signals returned from nearby ground clutter targets in the first few range gates of a radar receiver. Without this attenuation, the receiver would routinely saturate due to the strong signals. This is used in air traffic control ...
Dynamic Frequency Selection (DFS) is a channel allocation scheme specified for wireless LANs, commonly known as Wi-Fi. It is designed to prevent electromagnetic interference by avoiding co-channel operation with systems that predated Wi-Fi, such as military radar , satellite communication , and weather radar , and also to provide on aggregate a ...
The PRF is normally much lower than the frequency. For instance, a typical World War II radar like the Type 7 GCI radar had a basic carrier frequency of 209 MHz (209 million cycles per second) and a PRF of 300 or 500 pulses per second. A related measure is the pulse width, the amount of time the transmitter is turned on during each pulse.
Dynamic range (abbreviated DR, DNR, [1] or DYR [2]) is the ratio between the largest and smallest measurable values of a specific quantity. It is often used in the context of signals, like sound and light.
A reconfigurable antenna is an antenna capable of modifying its frequency and radiation properties dynamically, in a controlled and reversible manner. [2] In order to provide a dynamic response, reconfigurable antennas integrate an inner mechanism (such as RF switches, varactors, mechanical actuators or tunable materials) that enable the intentional redistribution of the RF currents over the ...
A sensitivity guarantees that the distance from the critical point to the Nyquist curve is always greater than and the Nyquist curve of the loop transfer function is always outside a circle around the critical point + with the radius , known as the sensitivity circle.