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Modern racons are frequency-agile; they have a wide-band receiver that detects the incoming radar pulse, tunes the transmitter and responds with a 25 microsecond long signal within 700 nanoseconds . Older racons operate in a slow sweep mode, in which the transponder sweeps across the X-band over 1 or 2 minutes.
The frequency response is characterized by the magnitude, typically in decibels (dB) or as a generic amplitude of the dependent variable, and the phase, in radians or degrees, measured against frequency, in radian/s, Hertz (Hz) or as a fraction of the sampling frequency.
Graph showing mechanical resonance in a mechanical oscillatory system. Mechanical resonance is the tendency of a mechanical system to respond at greater amplitude when the frequency of its oscillations matches the system's natural frequency of vibration (its resonance frequency or resonant frequency) closer than it does other frequencies.
When an FuG 25a responded on its 168 MHz frequency, the signal was received by the antenna system from an AI Mk. IV radar , which originally operated at 212 MHz. By comparing the strength of the signal on different antennas the direction to the target could be determined.
In the physics of coupled oscillators, antiresonance, by analogy with resonance, is a pronounced minimum in the amplitude of an oscillator at a particular frequency, accompanied by a large, abrupt shift in its oscillation phase. Such frequencies are known as the system 's antiresonant frequencies, and at these frequencies the oscillation ...
Image response (or more correctly, image response rejection ratio, or IMRR) is a measure of performance of a radio receiver that operates on the superheterodyne principle. [1] In such a radio receiver, a local oscillator (LO) is used to heterodyne or "beat" against the incoming radio frequency (RF), generating sum and difference frequencies .
Ultra low frequency: ULF — 3–30 kHz 100–10 km: Very low frequency: VLF — 30–300 kHz 10–1 km: Low frequency: LF — 300 kHz – 3 MHz 1 km – 100 m: Medium frequency: MF — 3–30 MHz 100–10 m: High frequency: HF: HF: 30–300 MHz 10–1 m: Very high frequency: VHF: VHF: 300 MHz – 3 GHz 1 m – 100 mm: Ultra high frequency: UHF ...
The RIAA curve. RIAA equalization is a form of pre-emphasis on recording and de-emphasis on playback. A recording is made with the low frequencies reduced and the high frequencies boosted, and on playback, the opposite occurs. The net result is a flat frequency response, but with attenuation of high-frequency noise such as hiss and clicks that ...
A response spectrum is a plot of the peak or steady-state response (displacement, velocity or acceleration) of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock.
Resonators may be both electromagnetic and acoustic. Coupling coefficients together with resonant frequencies and external quality factors of resonators are the generalized parameters of filters. In order to adjust the frequency response of the filter it is sufficient to optimize only these generalized parameters.