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

learn more… | top users | synonyms

6
votes
1answer
73 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?
1
vote
1answer
68 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 ...
0
votes
2answers
99 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
73 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
votes
0answers
41 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
46 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
39 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
63 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
vote
1answer
50 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 ...
0
votes
2answers
31 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 ...
0
votes
3answers
62 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
61 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
votes
2answers
59 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
65 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
34 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, ...
-3
votes
1answer
75 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
30 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
0answers
29 views

Square wave oscillator (up to 5kHz) from -40V to -10V (approximately)

I want to test a depletion mode TFT which has a turn on gate voltage of about -35V and consequently I want to show that this TFT can be used as an inverter and find the maximum frequency at which it ...
0
votes
1answer
64 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
56 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
88 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
105 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
304 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
44 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
94 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
259 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
123 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
242 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
3k 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
53 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
123 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
79 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
0answers
50 views

Continuous Wave with flip-flops

What I'm going for is imagine 6 LED outputs, every other one on. (Off first) What I need to have happen is after I toggle on the 1 input to 1, it sets off a chain reaction, like a wave, where every ...
0
votes
1answer
82 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
72 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 ...
0
votes
2answers
124 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 ...
29
votes
5answers
5k 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 ...
1
vote
1answer
271 views

Why do LCD Screens ripple through cameras?

I noticed that when taking pictures of an LCD screen (thank you, laziness to print), that while I look at the LCD screen through the cell phone camera, the screen has both 1) Ripples and 2) Moving ...
1
vote
4answers
448 views

How do you remove negative voltage from a sin, triangle or square wave?

I need square wave without negative voltage. Considering a source which produces square wave (could be function generator or from other circuits) has no ability or I don’t have the control required ...
0
votes
0answers
69 views

Very high speed counter (2GHZ) [duplicate]

I'm trying to build a high speed counter to measure the time delay between two radio waves . I'm thinking of using a MC100EP016A counter which works at a maximum frequency of 1.4 GHz but I cannot find ...
2
votes
2answers
262 views

What phenomena does “Coherence Bandwidth”?

Could anyone please provide a simple explanation of what Coherence Bandwidth means, and how is that related to Delay Spread. I read some articles but they don't help me to form the relation between ...
4
votes
3answers
2k views

What will I see in oscilloscope when attempting to analyze Bluetooth or Wi-Fi signals?

I would like to know what will show up if I put bluetooth or wifi carrier signal (2.4GHz family) in a say 50MHz oscilloscope? Am I going to see something like a rectangular block? And the only ...
1
vote
1answer
133 views

XR2206 Amplification problem

I'm generating a clean sine wave signal of about 4V of amplitude from the IC XR2206 and I need to amplify the signal to about 10V of amplitude, I'm using the following amplifier: Still, on the ...
2
votes
0answers
55 views

Plane wave causing TE mode in waveguide

I've been struggling with a problem given to us during a exercise-session of waveguides. First part of the exercise was calculating the electric field inside of a waveguide in the form of 2 parallel ...
0
votes
1answer
188 views

Solving the RMS of waveform

I was asked to find the form factor of this voltage wave: But before getting the form factor, I should know the RMS value and the average value of the waveform. Knowing that the ...
2
votes
3answers
131 views

Voltage and Current along a Wire

In this question I am referring to this article. At first I was looking for a physical explanation of the fact that energy or the signal, respectively, travels much faster through a wire than the ...
2
votes
2answers
272 views

+/- 60V Sawtooth/Triangle/Sine Wave

I'm trying to create a power supply for biasing a Langmuir probe. It needs to run some sort of predictable wave (I need to compute an I-V curve for a plasma, so I need to vary the voltage in a ...
-3
votes
1answer
214 views

Down converting square wave

I'm making some experiences with relaxation oscillators using 74 series. I'm trying to down convert to square wave but I get confused. Let's say I have 50khz square wave frquency generated with a ...
0
votes
1answer
81 views

Help Understanding an Autonomous rectifier

Could anyone tell me how does the circuit below work ? It's a autonomous rectifier. Taking the signal between the two output resistors gives a full-wave rectification, and taking it at the output of ...
0
votes
0answers
48 views

Applying Transmission Line Theory To Plane Waves

I'm working on a project for my E&M class. Our goal is to use transmission line theory to design a "stealth" dielectric layer for some sort of aircraft. I can assume the radar wave is incident ...