Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [frequency-modulation]

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Simple detection of a transient FM frequency shift

I have an application with a 2D array of inductive sensors for position detection of an object on a plane. I have experimented with inductance to digital converters (https://www.ti.com/product/LDC1314), which work very well on a small scale…
learnvst
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Why does the frequency deviation of a FM wave have different definitions?

Source 1 defines the modulation index in the expression for FM as follows: As per the expression for frequency modulated wave, isn't the frequency deviation same as Modulation index 'M'? "The max value for the quantity inside bracket…
Divya K.S
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LoRa - Frequency Shift Chirp Modulation - chips in a symbol

I am trying to create a form of FSCM (frequency shift chirp modulation) based on LoRa principle just to learn from it and to obtain a deeper understanding. What I do not get: why is (or must be?) the bandwidth equal to the chip rate. If my spreading…
Mart
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What does 'rotating vector addition' mean in this context, and how does it generate AM and FM?

I am currently learning about wave modulation. In communication theory, it is said that 'rotating vector addition' generates AM (amplitude modulation) and FM (frequency modulation). What does 'rotating vector addition' mean in this context, and how…
The Pointer
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How phase is modulated according to our message signal?

My question: let message signal m(t) be sin(w1t).For frequency modulation (instantaneous phase deviation=phi(t)) d[phi(t)]/dt=kf m(t) so i get that at 90° or π/2 frequency will be max because the amplitude of sinw1t is max. So same results should be…
user305532
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Need help with signal modulation

To capture a mammalian cell, I need to have a constant 4MHz AC signal (coming from a function generator) while sweeping the frequency from the vector network analyzer (VNA) 9kHz to 9GHz to read the scattering parameters. Mammalian cells usually can…
Ferrofluid
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What is a modulated optical sensor?

I was told to try out a modulated optical sensor as a better and more "robust" option than the usual (unmodulated) optical sensors, saying the modulated ones are less subject to interference. Conceptually, I don't know what that means or why that…
KMC
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