Questions tagged [analog]
The analog tag has no usage guidance.
87
questions
0
votes
1answer
22 views
Time delay of LPF to exponential decay amplitude input
How can one calculate the time delay a Low Pass analog filter adds from steady state when the amplitude of the input signal decays exponentially?
19
votes
3answers
3k views
What sampling frequency should I use if Nyquist is not available?
I have the following homework question that confuses me:
We have an audio emitter that can emit two signals:
It either emits a sine wave at 23 kHz or it emits a sine wave at 25 kHz.
The receiver has ...
2
votes
2answers
42 views
Amplitude and phase compensation of analog filter
My analog filter perform much needed antialiasing and input protection. Unfortunately, the filter adds undesired changes in the gain/phase across frequency. For example, here is an example of ...
3
votes
1answer
60 views
Different formulations of Chebyshev II resulting in different poles?
I am currently trying to implement a C++ program to calculate digital filter coefficients using a Chebyshev Type II filter design technique. The text I am using to understand the theory of the ...
0
votes
1answer
30 views
Is there a separate word for the time domain when working with digital signals?
Typically the phrase "time domain" implies an analog signal x(t), but I've also seen it referring to a digital signal x[n]. Is there any phrase that refers to x[n], but not x(t)?
1
vote
0answers
33 views
Simulating Effects of Sampling after Butterworth Filter
Is there anyway to simulate the effects of sampling an analog signal with Python/MATLAB? I am trying to show what happens to the frequency domain (magnitude and phase) of the analog signal after it ...
0
votes
1answer
167 views
Band limited discrete signals division
If I take two analog, band limited signals $ x(t) $ and $ y(t) $ with non-zero $y(t)$ I can define the division:
$$
z(t) = \frac{x(t)}{y(t)}
$$
In general $z(t)$ may have a very wide bandwidth, also ...
0
votes
0answers
46 views
Analogue Filters (Picking the right filter!)
I'm new to Analogue and I'm trying to find the Ideal filter for the following specifications:
$0.1\ \rm dB$ ripple
Cutoff Frequency $F_c = 80\ \rm{kHz}$
An attenuation of $40\ \rm dB$ at the stop-...
1
vote
2answers
200 views
Fractional Bandwidth of a Gaussian Amplitude Modulated Signal
a gaussian modulated sinusoidal signal may be expressed as
$$x(t)=A\cdot e^{(j2\pi ft)}\cdot e^{\left[-\frac{1}{2\sigma^{2}}\cdot(t-t_{0})^{2}\right]}$$
Let's consider the case in which the gaussian ...
1
vote
1answer
76 views
Combining Analog Video Signals for Diversity Receiver System
The system I want to build takes an analog video from two receivers (that are receiving from the same transmitter) and then combines the signals using equal gain combining (or maximal gain combining ...
0
votes
1answer
42 views
Modulate Bipolar(?) signal
I want to modulate this signal if possible with an Arduino, but have no idea what circuit can help me here. Let's ignore the timing and the measurements from the image for a moment, my problem is more ...
3
votes
1answer
58 views
Why is a bandpass filtered analog PM signal still PM and not AM
I know, that in theory a sinusoidally phase modulated (PM) signal with an expression like $\Re(e^{\mathrm{j}k\sin(\omega_s t)} \cdot e^{\mathrm{j}\omega_ct})$ with the signal frequency $\omega_s$, the ...
0
votes
1answer
97 views
why don't we use Broadband technology to transmit digital signals ,and use Baseband technology to transmit analog signals? [closed]
I learn the Broadband technology and baseband technology in this website: https://www.computernetworkingnotes.com/networking-tutorials/differences-between-baseband-and-broadband-explained.html
...
1
vote
1answer
159 views
Are there analog re-configurable filters?
I know that we can build a chip (or circuit) or use FPGA to have re-configurable digital filters. But how about analog filters, can we have re-configurable analog filters?
thanks
0
votes
1answer
889 views
Analog Square Root Raised Cosine Filter
I am wondering if it is possible to realize an analog square root raised cosine filter.
Any idea about how to do that with Matlab?
0
votes
1answer
53 views
How to convert between function forms of single frequency signals
I have an equation x(t) = (3+4j)*e^(j*8*pi*t)+(3-4j)*e^(-j*8*pi*t) and am trying to convert between this and shifted sines and cosines. I'm attempting mash this through euler's formula and got a 10 ...
0
votes
0answers
37 views
Is this PSK or FSK
I am analysing a captured 433.92MHz signal sampled at 2MHz:
If we zoom in:
I am thinking this is PSK? Am I wrong?
Thanks
0
votes
1answer
56 views
Obtaining a high sample rate digital approximation to an analog filter from lower frequency measurements
Consider a set of dense, but generally irregularly-spaced frequency response measurements of some real low-pass analog filter. Denote the maximum frequency for which a frequency response measurement ...
2
votes
1answer
81 views
phase response of an analog filter
I am trying to understand the relation between phase response of an analog filter and its influence on the quality of a signal with PSK modulation.
For example I want to design a BPF for HF ...
1
vote
1answer
306 views
When calculating SNR, is noise included in signal?
Given a signal $x(t) = s(t) + n(t)$ where $s(t)$ is the desired signal voltage and $n(t)$ is the noise, should the signal to noise ratio of this signal be 20log(xrms/nrms) or 20log(srms/nrms)? i.e., ...
0
votes
1answer
308 views
Binary and Quadrature Phase Shift Keying [duplicate]
I was learning Modulation Techniques and was on the topic Phase Shift Keying (PSK). As far as I have understood,
In Binary PSK we encode a single bit on a one signal element and we differentiate ...
0
votes
1answer
58 views
The phase of signal when it passes a frequency divider?
When we used the microwave frequency divider, such like: RF Bay FBS-N-14 or analog dividers in wiki.
The input signal is $\cos(\omega t+\phi)$, and the output signal is $\cos(\frac{1}{2}\omega t+\...
3
votes
1answer
367 views
Compensating the Group Delay of an Analog Filter using DSP
I am having a problem in my current project where I need to measure different biological signals (like ECG) simultaneously.
As the instrumentation hardware is developed by different people over time, ...
3
votes
1answer
98 views
analog-to-discrete-to-analog system sampling problem
This is not a homework problem, I am solving practice problems for my exam.
Consider the analog-to-discrete-to-analog system shown in figure 1. The CT signal $x_a(t)$
is sampled at a frequency of $...
0
votes
2answers
145 views
Is it possible to just remove the noisy part of signal?
Is there a way to scan through a signal and remove the parts that don't look "normal". This would mean using more advanced then a simple pass band filter, but something that can look at a period in ...
2
votes
1answer
140 views
Signals sampling
I have a simple question, but sadly I'm kind of "noob" in signals theory.
A signal having 4 harmonics at the following frequencies: 1 kHz, 2 kHz, 3.5kHz and 4.2 kHz.
(How can a signal have harmonics "...
1
vote
1answer
59 views
How do I add more resolution / taps to an analog -> digital filter?
(I am trying to create an IIR audio filter that adds reverb to an initial sample)
Say I designed an analog filter to model acoustic attenuation based on the following mathematical model:
$$
I = I_0 ...
1
vote
0answers
94 views
Digital or analogue filtering?
I'm trying to self learn the art of signal processing whilst moving through my third year pure maths degree.
Sorry if my terminology is incorrect however I hope I am understandable!
I am looking at ...
0
votes
1answer
186 views
Is it possible to encrypt an audio wave? NFL Example
In the NFL, quarterbacks receive playcalls from coaches over their helmet's wireless interface.
Someone mentioned how occasionally, these radios will pick up interference from airplanes, and that ...
0
votes
1answer
361 views
OFDM RF signal waveform
From the Wikipedia article:
"An inverse FFT is computed on each set of symbols, giving a set of complex time-domain samples. These samples are then quadrature-mixed to passband in the standard way. ...
0
votes
1answer
173 views
confusion between frequency and amplitude in digital to analog and vice versa conversion
bandwidth is defined as the difference between the highest frequency and lowest frequency.
amplitude is the distance between the, let's call it a crest and a trough, in a wave.
cycle is the time per ...
0
votes
5answers
126 views
How Can Telecommunication System Know Which Part Is Signal and Which Is Noise? [closed]
When signal is received how can receiver know which part of received signal is signal and which part is noise??
3
votes
1answer
615 views
Proof-of-concept for active noise cancellation to block consistent low-frequency HVAC noise transmission
Background
We live in a multi-unit building where each unit's HVAC system/closet is located directly across a party-wall from the neighboring unit's bedroom, and adjacent to a shared external curtain ...
2
votes
1answer
2k views
How to simulate analog VU meter response to audio?
I'd like to simulate the movement of an analog VU meter dial as shown below and often found on stereos and other music monitoring equipment.
I just learned through this article by Rod Elliot (ESP) ...
-1
votes
1answer
993 views
Amplitude ranges for different bit-depths
In Python, I am using the library Soundfile (which uses the library libsndfile) for digital sound processing. I am working with different sound files coming from different internet databases, and ...
0
votes
2answers
321 views
Analog vs digital
If there are means to process all signals after they have been captured and digitilized, why are we still designing ICs to do analog signal processing? For any giving case, can not we just digitilize ...
0
votes
3answers
471 views
How to calculate the frequency response of LTI system based on measured impedance
I have an analog circuit containing unknown resistance, capacitance, and inductance. I have measured its complex impedance across the frequency range of interest. Is there an equation that will allow ...
-1
votes
1answer
112 views
Can I apply CWT on a digital signal?
First, I am so sorry for my dumb and stupid question, I am very beginner with signals.
Say that I have an ultrasonic sensor cabled to an ADC (Analog to Digital Converter).
The ADC converts the analog ...
0
votes
2answers
153 views
Analog Integrator Sampling Rate
What would be the effective sampling rate of an op amp analog integrator (such as the one described here ) taking in a rapidly varying signal be? Ie what time resolution would such an integrator have? ...
63
votes
4answers
21k views
Why is TV static noise always black and white?
Most modern day Cathode Ray Tube (CRT) televisions manufactured after the 1960s (after the introduction of NTSC and PAL standards) supported the circuit-based decoding of colored signals. It is well ...
1
vote
0answers
106 views
Processing digital sound in Audiokit to sound like the 1960's
I am looking to imitate 70's analog equipments sound. I was wondering is there a way to create tape saturation / distortion inside Audiokit? I want to add that and randomized tape crackles and ...
1
vote
1answer
226 views
AM modulated signal not centered at carrier frequency [closed]
I am trying to modulate the signal bl_msg_time (this is a speech signal) using DSB-SC modulation however the signal doesn't appear centered at the carrier frequency....
2
votes
1answer
569 views
Plotting the discrete time signal
Consider the following analog signal
$$x(t) = 2 \sin(100\pi t)$$
The signal $x(t)$ is sampled with a sampling rate $F_s=50\textrm{Hz}$. Determine the discrete time signal. Plot the discrete time ...
4
votes
3answers
495 views
Going from digital to analog filters
I've been learning about digital signal processing for some time, and I understand the principles in the digital world, as well as the conversion of continuous filters in the s-domain to digital ...
0
votes
1answer
96 views
Separate Complicated Signal into Exponential Components
This morning, I asked a similar question about separating simple signals - with constant frequency - into exponential components. User @AndreasH suggested that a hilbert transform can do this as ...
1
vote
2answers
3k views
Relation between Normal Phase Shift of a wave and Phase Modulation
I am little confused with the Phase Modulation and the phase of a sine wave. I get the phase modulated wave from the google images as below:
Phase modulation has the form:
$$PM(t)=A_c \cos\big(2\pi ...
1
vote
4answers
395 views
Signal and Space/Time
I have been reading a couple of definitions on signal such as:
Any quantity measurable through time over space or any higher
dimension can be taken as a signal.
And this,
In the physical ...
1
vote
3answers
839 views
Applying Nyquist theorem to digital vs. analog audio quality
I had a recent conversation with a friend about analog vs. digital recordings. He shared his opinion that music recorded by analog techniques is of superior sound quality to music recorded by digital ...
1
vote
1answer
474 views
Two-sided impulse response and its inverse in real life
Dear StackExchange gurus,
I would like to pose this question from a practical standpoint rather than a theoretical one, although perhaps some context in the latter might come useful.
Real-life ...
0
votes
1answer
40 views
What is full AM used for?
What are some applications where full AM is used nowadays? Is it used at all considering the fact that it is less power-efficient than, say, AM with suppressed carrier?
