May refer to an electromagnetic wave (such as a radio wave) or the PCB manufacturing process of wave soldering.

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0
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0answers
66 views

Bandpass filter for square waves

I'm an embedded software person rather than an electronics person, so please excuse me if this is an idiot or otherwise inappropriate question. We have an encoded square wave in, need to filter it ...
0
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2answers
37 views

Medical Ultrasonography Phased Array Beamforming

Medical ultrasonography equipment images the interior of the body by reflecting ultrasonic sound waves off of discontinuities between internal tissues / organs. I did some reading about this ...
-1
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2answers
110 views

Ways to voltage shift a wave down to ground

Say I have a wave signal that is always above ground, that is, the signal is positively clamped to the ground. (EDIT: from an input of a helpful user, I now know this should be called "negatively ...
-6
votes
2answers
63 views

How electromagnetic waves works, how they are created and how thay transform to electric signal? [closed]

Few days I am trying to learn more about electromagnetic waves, induction, electromagnetic spectrum... And how it's connected. Here is what I understand now: There is a lot of electromagnetic waves ...
1
vote
1answer
48 views

Digital potentiometer as INA129 gain

I'm working on a waveform generator for which I'm using the DDS AD9833 chip to generate sine signals and triangular signals. I'm trying to amplify these waves since the AD9833 output is 600mVpp and I ...
-2
votes
1answer
91 views

How to calculate R and C for AM Demodulation envelope detection?

How can I calculate the value of \$R\$ and \$C\$ for an AM envelope detection circuit. Knowing that the carrier wave is \$20\mathrm{KHz}\$, \$1\mathrm{Vpp}\$ sine wave, and the message signal is a ...
0
votes
1answer
152 views

Designing audio player - low-pass filter, DAC

I'm building audio (wave) player on some microcontroller. I will have external 16-bit DAC and I wonder if that's enough? I mean, is low-pass filter really needed? (I know what it does and why you ...
1
vote
1answer
67 views

Convert PWM to 3-level voltage

I want to convert a generated PWM by a microcontroller to a 3-level voltage. [] the maximum output voltage range is between -5 to 5 or -10 to 10 volts. Another point that may well be considered is ...
0
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0answers
77 views

Is there any way to inspect small holes (in micron scale) inside a PCB non-destructively?

I have PCBs with two layers of copper at top and bottom. PCBs with low quality have holes between top layer copper and epoxy. The holes are in near circle shape with 20 - 70 micrometres of diameter ...
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2answers
39 views

How to solve Power Density Function?

How to solve this problem: A radio receiver needs $$ 1 \textrm{ nW/}\textrm{m}^2 $$ of power density function, how far away from a 1-watt point source will it continue to work?
1
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1answer
117 views

Why do we not use both E and B fields for a receiving antenna?

An antenna is an electrical device which converts electric power into radio waves and vice versa we all know this. In transmission, a radio transmitter supplies an electric current oscillating at ...
0
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0answers
41 views

Wave Digital Filter (Basic)

DOWN wave is the reflection, am I right? And is D considered as reflection-free (rf) in dtyeh's illustration? Because the root of the tree is D, there should not be rf on D and since there is no rf ...
0
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1answer
66 views

“Drawing” signals with antenna

Can you produce max waves, adding them, creating massive spikes like it showed in this video with water, but with multi antennas. Can you do this with electromagnetic wave in air with some complex ...
2
votes
1answer
137 views

Square generator 1KHz to 1MHz with 1KHz precision

I would like to make a square wave generator which will output a signal with amplitude X voltages and frequency between 1KHz to 1MHz, with the precision of 1KHz (for example: 785kHz, 926kHz, 999kHz, ...
0
votes
5answers
194 views

Wavelength in real life

How to understand term wavelength of radio wave in real life. What this column 'Wavelength range' means to us in real life? I theoretically understand what it is (distance between two successive ...
6
votes
1answer
157 views

Why does EM radiation travel much further than the magnetic field of an equivalent power electromagnet?

If both fall of as 1/r^2 from the source then why can radio waves travel around the world and still be picked up easily at the right frequency but the field from a powerful electromagnet can not?
2
votes
1answer
163 views

How tuning of particular FM signal is done?

I have a transistor radio which has facility to play FM radio channels between 88MHz to 108MHz frequencies. Now,consider a situation ,there are five FM stations which I can hear in my city ...
2
votes
2answers
145 views

What are values of fundamental frequency and the harmonics for the below signal g(t)?

We know that a Fourier series formula for any signal $s(t)$ is given as $$\frac {a_0} 2 + \sum \limits _{m=1} ^\infty (a_m \cos \frac {2 \pi m t} T + b_m \sin \frac {2 \pi m t} T)$$ Here,as we see ...
2
votes
3answers
86 views

Fundamental property of an EM wave

Imagine there's an electromagnetic wave propagating in vacuum with a frequency \$f\$ and wavelength \$\lambda\$. Its speed is \$c\approx3\cdot10^8{{m}\over{s}}=f\cdot\lambda\$. Now, the wave has to ...
0
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0answers
63 views

What do we mean when we say that a quantity is phase wrapped?

I have asked a question here in researchgate and I'm looking forward to get the answer. I thought it might be helpful to post the question here in an electrical engineering Q&A site. please inform ...
1
vote
0answers
69 views

perfect square wave cannot be played back

If I produce a square-wave by creating a sine wave first and then doing, if x >= 0 return 1, else return -1 this produces a "perfect" square wave(python code). Like this the audio signal cannot even ...
0
votes
1answer
88 views

permittivity and conductivity vs. attenuation [closed]

Is there any direct relationship between permittivity of a medium and attenuation of an EM wave? What about conductivity vs attenuation? edit: Ok for instance an EM wave traveling in sea water. I ...
0
votes
2answers
103 views

+5 to 0v square wave from a 12vdc supply

I need to build a simple 0 to +5v square wave from a 13vdc (automobile) supply. The frequency of the output needs to be based on a 1vac input signal. I believe it can be done with a handful of ...
1
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1answer
72 views

Confused regarding standing waves on transmission line

I am currently learning about transmission lines form an online book hosted by a website called “All About Circuits”. If anyone is interested, the particular chapter I am currently reading can be ...
1
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3answers
111 views

Dipole antenna VS. coil for RF transmission or recieving

Correct me if I am wrong, but all RF light waves are created via a changing electric and magnetic field. But when looking at all kinds of radios and RF circuits, this light wave is always made with a ...
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votes
3answers
170 views

Using half wave rectifier for low power applications

Im trying to make a low power application feeding it from a 9vAC, source, i have been reading that i can use a half wave instead of a full wave rectifier, i already did the circuit and been doing ...
0
votes
1answer
138 views

Triangle Wave Generation

What would be the best way to generate a triangle wave that can operate at 250kHz @ 4V peak-to-peak? I have tried the following circuit: However, the best I could obtain was a 4mV peak to peak ...
0
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2answers
73 views

Measuring the dampening sinusoidal wave of a simple LC Tank circuit?

I've been trying to do the simplest of things...measure the decaying sinusoidal wave of a LC Tank circuit on a breadboard. I've created an "inductor" out of a coil of copper wire I wrapped around a ...
1
vote
1answer
153 views

Get triangular wave on pspice

I designed a integrator op-amp on pspice. I want to get triangular waves for output and square waves for input. Input is OK, but I can't get triangular waves. What is wrong, should I use a second ...
2
votes
1answer
62 views

Measure propagation velocity through finite transmission line

I'm currently trying generate a wave in a circuit but am running into the issue of figuring out exactly how to measure the propagation velocity. The circuit diagram is below L1=L2=L3, C1=C2=C3, ...
-4
votes
1answer
220 views

How to encode and decode electromagnetic waves in binary? [closed]

If I am not wrong the electromagnetic waves can be produced by opening and closing an electric circuit. (Tell me if I am wrong) Let's say we want to send an electromagnetic wave that has the ...
1
vote
1answer
38 views

EM wave polarization check

I am trying to recall the quick way to check the EM polarization theoretically, I mean if I have a wave described as (ssume capital letters are vectorial fields) \begin{equation} \ E = E_o *exp(j* ...
0
votes
1answer
71 views

How deep can I bury a 1 MHz transmitter

So in designing a deep underground sensor network, my team wants to use a 1 MHz radio, but we cannot determine a way to model the soil, so as to calculate how deep i can bury a radio for showing proof ...
0
votes
1answer
131 views

Are all antennas traveling wave antennas?

I've been reading a lot about traveling and standing waves, and I am right now reading about traveling wave antennas, to my understanding ALL antennas should be traveling wave antennas, but this is ...
0
votes
1answer
137 views

sine, triangle and square wave generator?

I have little experience regarding wave generating circuits. I am aware that there are various circuits that are able to create signals but i would like to know if there is a circuit that can output ...
0
votes
2answers
129 views

Amplitude of an AM wave

A message signal is modulated on a carrier wave of amplitude \$50V\$ using amplitude modulation. The modulation index is given as \$50\%\$. Find the amplitude of the AM wave. I was able to ...
2
votes
2answers
352 views

Why does a metal sheet block all noise, but not when wrapped around a cable?

If I place a flat sheet of aluminum foil between a near-field probe and a noisy wire, the sheet completely blocks the noise. However, if that sheet is then wrapped around the wire, it seems to have no ...
0
votes
1answer
58 views

Detect incidence angle with an antenna array

Having an antenna array, how can we determine incidence angle of an incoming signal. I know it is related to the phase of the signal in each antenna but I only found information about how to send a ...
0
votes
2answers
213 views

Change AC signal frequency without changing the voltage

I have a non constant -/+1 Volts to -/+7 Volts AC audio signal. I want to design a device that takes this input signal, doubles the frequency, without changing the voltage. So, the output voltage is ...
1
vote
3answers
490 views

Generation of triangle wave at 15KHz frequency

I want to generate a triangle wave with peak value 5V. I am using a 555 timer to generate square wave pulse of frequency 15KHz. Then I passes this square wave through a active integrator ( A opamp ...
0
votes
2answers
186 views

square wave generator on 20MHz

I need a circuit that generates rectangular waves. It shouldn't be lo-hi-lo-hi, but a random sequence of lo-hi-hi-hi-lo-lo is needed. It also has to oscillate like that, at at least 20MHz. I don't ...
3
votes
3answers
281 views

What is the wrong with this simple sine wave generator circuit?

I've designed this circuit myself aiming to generate sine wave at the collector of the transistor, but I doesn't work. the current at the collector is DC. Is it a simulator error or the design is ...
16
votes
12answers
4k views

Do we know what a radio wave looks like?

In precalculus class we are learning about sin/cos/tan/cot/sec/csc and their amplitude, periods and phases shifts. I've studied electronics on and off for about a year. I would like to know if we ...
1
vote
1answer
110 views

Trying to understand directivity of an ultrasonic sensor

I am trying to understand this plot of directivity from the following link: http://www.nicera.co.jp/pro/ut/pdf/T4010B4(ENG).pdf How do I read this plot? I can say that at 0 degree , the energy ...
1
vote
4answers
265 views

Calculating wavelength of sine wave

I am looking for formula and easy explanation for calculating the wavelength of a sine wave. So far I have not been able to calculate the example I want to do as I could not understand the resources ...
0
votes
2answers
107 views

Sketching Sine Wave in Matlab

I am working with matlab in college and I need to generate sine wave whcih represents signal going through a wire. But its not clear to me what t equals to and how can I multiply \$y\$ by \$t\$ this ...
0
votes
1answer
175 views

How to use a graph of a wavefunction (psi) to create an approximate graph for potential (U)?

I don't understand how the top graph was used to approximate the bottom graph, could someone please explain to me what was going on? I know that in regions 1, 3, 5, 7, there is no oscillation and ...
2
votes
1answer
94 views

Finding the Power developed by the Nominal Frequency in FM

Question The sinusoidal signal \$f(t) = \cos(2 \pi f_m t)\$ is applied to the input of an FM system. The corresponding modulation signal output for \$f_m = 1kHz\$, is $$Q(t)=100 \cos(2 ...
2
votes
2answers
161 views

How wireless communication works?

When an AC signal is transmitted through a conductor, direction of flow of electrons is continuously alternated. In wireless communication signal is transmitted through air, in this case which ...
30
votes
5answers
6k views

Can I turn Radio waves into light?

Wikipedia says that the frequency of light is 300 THz. I've made a radio waves transmitter that transmits about 100 MHz. If I increase the frequency of the transmitter to 300 THz, will the antenna ...