Tagged Questions

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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1answer
35 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
62 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
73 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 ...
28
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
72 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
161 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
67 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
73 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
77 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
35 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
102 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
122 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
143 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
126 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
80 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
39 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 ...
1
vote
1answer
56 views

Scale/offset wave

I have a wave profile stored in a micro-controller that I want to scale and shift with two input arguments. Is it possible to fix an 'absolute' scale (max/min = 1.02 for e.g.) and have an offset that ...
1
vote
2answers
282 views

Full-wave rectified sine wave representation?

Let us suppose I have an input voltage \$V=V_0 \sin(\omega t)\$ connected to a full-wave rectifier bridge which changes the voltage to \$V=V_0|\sin(\omega t)|\$. Now, if I want to work out the voltage ...
0
votes
3answers
127 views

What defines a frequency in electronics?

As Hertz is defined as one cycle per second, what are the requirements of an electric wave to have a certain frequency? What I mean is more lucid in a picture. The black wave has a frequency of about ...
1
vote
2answers
153 views

A new form of modulation? [closed]

On the Wiki site re: Amplitude Modulation, see: http://en.wikipedia.org/wiki/Amplitude_modulation -it states, "It is assumed that \$\omega_m \ << \omega_c\$," ...which means that the ...
0
votes
1answer
291 views

which one is better for smoothing a sine wave: Low pass filters or a serially connected inductor?

Smoothing a sine wave is my main concern in this question. I have a sine wave made by DDS that in higher frequencies shows some steps. Normally in every electronic class it is heard that the best ...
1
vote
1answer
1k views

How to make sawtooth wave from square or triangular wave?

I know it is easy to convert a square wave to a triangular wave by an integrator. I know also that they can be made out of Harmonics but I don't know how to make a sawtooth wave form. Having a ...
0
votes
1answer
922 views

How do I save a waveform from ModelSim for later opening/viewing

If I save the waveform, it is saved as a .do file in ModelSim/QuestaSim. This does not help as later I will have to run the simulation to get the wave back anyway! What I am looking for is means by ...
2
votes
2answers
231 views

Why a wave does not enter a cable? Understanding TDR (Time Domain Reflectometry)

I have been doing some TDR (Time Domain Reflectometry) measures which involves sending gaussian pulses through a cable and measuring the s11 (reflection) parameter. In this measure, I could see that ...
1
vote
1answer
131 views

Reflection coefficient VS frequency

I was trying to look for the answer of what I think it should be quite a simple question but I haven't found any nice answer (at least any that has convinced me). Here it is: Through a cable ...
0
votes
3answers
258 views

Amplify .7Vpp square wave to 5Vpp square wave buffered to go over a 15-50 foot cable

I've got a sensor that outputs a .7Vpp square wave at 36kHz-60kHz. I need to take that square wave and amplify it to 5Vpp, as close to 0V to 5V rails as possible. Then I need to send that signal ...
2
votes
2answers
620 views

Square Wave Amplifier - 5VDC -> 13VDC

I want to have a square wave that goes from 0 VDC to 5VDC go through some sort of amplifier and that amplification takes that same wave ( at a frequency of 1200Hz but could also be adjusted later ) ...
5
votes
2answers
433 views

How to generate 30Hz sine wave?

I'm building a voice ring modulator. Part of it involves a 30Hz carrier sine wave to modulate the voice with. Since I'm trying to build a portable device it will be DC powered, and since a function ...
0
votes
1answer
139 views

is it possible to load a transversal wave with a longitudinal wave

like in communication engineering for sending information what we do, we take a high frequency carrier and modulate it with the message signal so can we do the same thing like take a high frequency ...
0
votes
1answer
117 views

12 volt DC to 12 volt AC sine wave inverters for 10 watt and 22 watt pumps

I have two 12 volt AC small water pumps that I want to run on 12 volt DC (solar). One pump is rated 6 watts (max ~10 watts) and the other pump is rated 16 watts (max ~22 watts). Since I need to ...
-4
votes
1answer
326 views

What kind of waves can penetrate walls/floors and cause tingling, headache, nausea, etc? [closed]

What types of waves would be able to penetrate walls and floors and at high frequency or intensity would cause symptoms like tingling or burning skin, headache, nausea, and heart palpitations? I know ...
1
vote
0answers
66 views

Waves and Antenns

What is meant when someone says that a wave is linear and reciprocal, and also what is meant by antennas are linear, bilateral and passive
1
vote
5answers
5k views

How to Generate a square, sine, and triangle wave with DC input

I want to make a simple synthesizer as a start to audio electronics. I want to start with a simple square, triangle, and sine, which the user can vary the pitch. Is there a simple circuit to do ...
3
votes
1answer
618 views

How to apply the Barkhausen criterion in order to know if a system will oscillate?

How to analyze or apply the Barkhausen criterion for oscillation of the astable multivibrator below? The criterion talks about the magnitude of the products in a loop must be equal to 1 (ideally) ...
6
votes
5answers
800 views

Suggestion to electrically disable a Faraday Cage

My plan is to ultimately develop an Autonomous Faraday Cage. The project seems very straight forward; however, I am unsure on how to effectively control the cage (turn on and off). I have constructed ...
2
votes
1answer
326 views

Dump verilog array in gtkwave

Is there a way to dump the memory in verilog using vcd dump? Since now i have written this: ...
1
vote
3answers
349 views

Wobble Bass LFO circuit with Op Amps

I am trying to build a LFO circuit that produces a wobble bass effect. My overall plan is using an Op Amp to create the LFO and another Op Amp to create the low pass filter. How should I connect ...
2
votes
3answers
876 views

Trying to understand range and frequency of an RFID reader

I am trying to understand how range of communication between RFID reader and tag is related to frequency and power. So if I increase frequency, the range will be shorter or larger? why? (I need to ...
3
votes
3answers
2k views

How does an swr meter directional coupler work?

How does the directional coupler in an swr meter work? How are the forward and reflected waves separated out from the standing wave on the feeder? I would like an answer in terms of sine (or cosine) ...
1
vote
2answers
321 views

How to create a square wave signal with 120MHz

What is a cheap way to generate a square wave with a frequency of 120MHz. I've been thinking of the following solutions: * Use a Raspberry Pi, then use a timer or something from that board * Use an ...
1
vote
1answer
313 views

Calculating what frequencies a dielectric can be considered perfect

I have a problem that is likely going to be on my E&M final this semester that my classmates and I can not figure out how to solve. The question is At what frequencies can Earth be considered ...
1
vote
1answer
113 views

Antenna that can be used for large range of frequences?

Is there an antenna or device that can be used for WiFi, NFC, bluetooth, GSM for use with a frequency counter to measure the frequency of the waves?
-1
votes
1answer
130 views

Determing the Phase Angle of the following code: [closed]

I'm trying to determine the phase of xx after the code is run. You shouldn't need to actually run it to determine it however, as it is unclear on the graph. The two phases present appear to be (-3*j) ...
1
vote
2answers
1k views

Measure AC Sine Wave amplitude with ADC

I have created an AC sine way using a wien-bridge network. I would like to measure the peak to peak voltage of this wave using my microcontrollers ADC. I cannot just use this wave as an input to my ...
3
votes
1answer
235 views

Oscilloscope acquisition frequency

I have an FPGA design and the FPGA design has a signal called start which is always high. Here is how it works. I use the computer to send data over RS232 to FPGA, the start signal drops for a cycle ...
18
votes
7answers
9k views

What exactly are harmonics and how do they “appear”?

From reading so many sources online, I still cannot grasp why a different waveforms have harmonics. For example: when designing a silly amplitude modulation (AM) circuit that puts a square wave from ...
-2
votes
2answers
294 views

Transformation of Sin wave

I was impressed by your solution of my previous problem. So, I think you may help me with this image I have made huge circuit with OpAmps and couple of active and passive components, but I suppose ...
5
votes
3answers
1k views

How to get half frequency square wave from sin wave?

The task is to get such wave: I can get square wave from sin wave, but I have no idea how to make it half-frequency. Have some advices?
2
votes
2answers
2k views

Error caused by Scope or Function Generator?

This question may not be valid, please excuse my ignorance. I am having difficulty measuring a decent square wave at 500kHZ. The image below shows a 4 volt CMOS output with a frequency of 500kHz ...