Questions tagged [analog]

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2
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2answers
40 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
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1answer
48 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
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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)?
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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
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1answer
157 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 ...
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0answers
45 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-...
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2answers
139 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
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1answer
60 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
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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
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1answer
56 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
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1answer
87 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
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1answer
150 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
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1answer
720 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?
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1answer
52 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 ...
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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
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1answer
49 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
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1answer
76 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
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1answer
293 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
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1answer
254 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
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1answer
50 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
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1answer
334 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
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1answer
93 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
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2answers
137 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
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1answer
129 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
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1answer
58 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 ...
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0answers
93 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
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1answer
172 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
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1answer
341 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
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1answer
165 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 ...
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5answers
120 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
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1answer
588 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
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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
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1answer
934 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
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2answers
311 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
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3answers
442 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
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1answer
111 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
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2answers
144 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? ...
62
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4answers
20k 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
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0answers
98 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
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1answer
213 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
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1answer
545 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
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3answers
461 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
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1answer
91 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 ...
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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
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4answers
368 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
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3answers
811 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
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1answer
452 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 ...
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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?
0
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1answer
196 views

How is multiplexing on FM signals performed? [closed]

How does multiplexing differ from FM signals to AM signals. If both FM and AM shift the message signal in frequency, then is there a difference between multiplexing for FM or AM signal?
0
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1answer
213 views

Given a noise-free channel with limited bandwidth, why is the channel capacity infinite? [duplicate]

In the Shannon Hartley theorem, if N = 0 but B is limited, the theorem tells us that C is infinite. Why is this intuitively true? If bandwidth is limited, I can only post so many pulses per second ...