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

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1answer
63 views

full wave rectifier is not rectifying the wave properly

the following rectifier does not create a wave that is rectified evenly. according to the books this should work when using a centre-tap transformer. scales : (Y = 10ms/div) & (X = 5V / div) ...
0
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2answers
26 views

Determining the inital phase of a waveform

How could I determine the initial phase of the following sinusoids with these parameters only ? from what I can see , I know that B is leading C since the crest is behind the Y axis .. Therefore , ...
0
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1answer
49 views

Triangular Wave Current input to a capactior, Voltage Response?

I am simulating a cap. When i give a triangular current input to a capacitor, I see an increase in voltage for both rising and falling side of current signal. why is this happening? For a rising ramp ...
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2answers
55 views

High-current capable, high precision sine wave

I'm actually asking 2 questions - one about sine wave generation and another about high rate / precision voltage measurement. I'm working on a project where we have to generate a sine wave on top of ...
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5answers
478 views

What is the best way to get a sine wave from a square wave?

I have square waves of different frequencies (1KHz to 20KHz), and I need to convert them to a sine wave of the corresponding fundamental frequency. A RC ladder Low-pass filter was the first thing ...
0
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0answers
90 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 ...
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2answers
43 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
votes
2answers
125 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
73 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
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1answer
54 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
174 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
223 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
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1answer
76 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 ...
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votes
2answers
44 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
vote
1answer
125 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 ...
1
vote
1answer
71 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
204 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, ...
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5answers
402 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
164 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
232 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
161 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
89 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 ...
1
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0answers
70 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
132 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
129 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 ...
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1answer
83 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
171 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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3answers
230 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
159 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
77 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
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1answer
210 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
73 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
289 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
40 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
73 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
202 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
165 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
145 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
3answers
396 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
66 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
254 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
617 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
219 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
306 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
5k 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
139 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
436 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
120 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
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1answer
207 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
110 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 ...