Questions tagged [radiation]

While rare, this tag should be used for questions pertaining to using electronic devices (passive or active) in an ionizing radiation environment. This could be space, medical facilities or physics labs. Defense or military related questions are probably classified.

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45 views

How to calculate maximum effective radiated power in any direction for Galtronics small cell site

Answer Calculations from PE commissioned by AT&T: the GQ2410-06621 antenna does have 10 total input ports, however, our analysis of the AT&T DAS node includes only the frequencies and power ...
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1answer
28 views

FDTD simulation for beginners using matlab

My previous posts are as follows: 1.Mitigation of dead zones when applying circular polarized antenna 2.Standing waves modes inside a cavity resonator 3.Visual understanding of EM fields within a ...
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1answer
59 views

Multimode cavity resonator

From my previous posts Insight into cavity resonators, Visual understanding of EM fields within a rectangular metal container I have slowly gained a better insight into cavity resonators and thereof. ...
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1answer
37 views

Antenna's resistance: meaning and evaluation

When I studied elementary antenna's theory, I saw that the resistance (for simplicity let's consider only the resistive terms) of an antenna Ra is made of: 1) a parasitic resistance Rl, which causes ...
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2answers
331 views

Insight into cavity resonators

Modes of a waveguide As shown in the link above, they show how these modes work for various values of m, n, and p. However, where is the antenna/ source of radiation placed within the cavity? From ...
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2answers
239 views

Visual understanding of EM fields within a rectangular metal container

I have the following scenario setup inside a rectangular metal container. The container size is 12.03m by 2.39m by 1.84m (lxbxh). Additionally, inside the container I have placed 4 antennas equally ...
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1answer
60 views

Mitigation of dead zones when applying circular polarized antenna

I would like to know if I used a circular polarized (RHCP) antenna inside a metal container as show in the configuration below will it reduce the dead zones, as compared to a linear polarized antenna? ...
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1answer
53 views

Detecting radiation - Looking for ideas

I have to detect a small radiation from this tags and I´m looking for some ideas how I can do this with some kind of small electronic circuit (or lecture to read how to do it) - not with a Geiger-...
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1answer
53 views

Long term health effects of a gsm modem [closed]

We all use internet through our mobile phones hence gsm infrastructure. I know the radiation exposure is higher than wifi. That's why I preffer wifi over mobile whereever i can. However I'm currently ...
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0answers
76 views

PIN Photodiode gamma detection amplifier circuit - rectangular wave output

I've been working on a project recently, where I need to build a device which detects gamma radiation and can be used for gamma spectroscopy. I've done some research and found many interesting ways of ...
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2answers
203 views

Am I exposed to high levels of radiation at my job? [closed]

I made this post because I have a safety concern about my job as medical device tester. I was reading the user manual of the equipment I work with and found the next warning: “Per FCC regulations, ...
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3answers
106 views

Non-ionizing radiation [closed]

This is out there - But hear me out. There is a new device on the market that promotes baby sleep by playing white noise. The speaker is directly under the baby’s head while sleeping (separated by ...
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2answers
4k views

Why do radiation hardened IC packages often have long leads?

What purpose do long leads serve?
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0answers
45 views

Radiation Source placement and waveguide parameters for Horn Antenna

I am designing ("arranging", actually) a horn antenna for a 77-81 GHz Radar. My module has a patch antenna which can't be placed inside the waveguide for some reasons. After the patch antenna, we have ...
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3answers
230 views

Physics of Dirty Electricity? [closed]

I've been reading about "dirty electricity" lately and while I know there's much controversy whether it causes adverse health effects this question is not about that subject. I'm simply trying to ...
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2answers
177 views

Microwave starts working when door opens - how dangerous is it?

I've just rented a house that came with an equipped kitchen, and I've found that the microwave has a rather weird behavior - opening the doors seems to trigger it to start working, which the owners ...
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1answer
75 views

Reflection of Electric field in open-circuited transmission line

Consider a parallel-wire or parallel-plate or coaxial transmission line, carrying TEM wave, which we model as E,H,V,I, each having a forward(+) and backward(-) wave. In terms of V,I, we define ...
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2answers
87 views

Photodiode Output measurement

I'm using Hamamatshu s8559 photodiode to convert x-rays into it's respective energy. I'm using a 10 bit ADC converter. The problem I'm facing is I have no relationship between the Photo-current ...
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6answers
4k views

Can antennas be viewed as light sources?

Clearly antennas are nothing but a device to radiate the electrical energy through electromagnetic waves. Since visible light is also simply a certain range of frequencies, isn't it more easier to ...
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1answer
127 views

Ability of a 100km power transmission line to radiate 50Hz EM waves?

This is about confusion of relating antenna radiation theory to power lines. Assuming a straight 100km or even longer possible power transmisson line with 50Hz frequency. What can be said about the ...
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1answer
134 views

Are headphones with EMF measurement of 10,000 milligauss harmful to me?

I used a EMF detector app on my phone and measured the EMF output on my wired headphones. It measured around 10,000 milligauss on one part of both ear cups. Since wearing these headphones on my head ...
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1answer
218 views

Can a magnet cause a microwave oven to unsafely radiate energy?

I've already successfully warped the colors on a large old CRT Television by setting unshielded speakers on top of it. If I understand correctly, this was due to the deviation of the electro-magnetic (...
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2answers
528 views

Does an electrical outlet radiate EM waves? [closed]

Please consider all cases even with a tiny values. If plug two separated wires to each terminal of electrical outlet, like shown, will it radiate em waves? ...
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2answers
671 views

What is the acceptable margin for radiated emission on an European CE device

One of our prototype (IOT gateway) has completed the emission test (EMC) but we have a margin on two particular frequencies, just wondering what is the acceptable margin for CE device in Europe ? I ...
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1answer
140 views

Calculate radiation power of an antenna in respect to a given antenna radiation pattern and a given angle

I work on a program that simulates the wave propagation of high frequency electromagnetic waves (2.4 or 5 GHz Bands) in 3D. I use a ray launching approach, where the emitted rays approximate the ...
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3answers
412 views

PCB design - signal loops

I've read about loops that a PCB designer should avoid them "mostly about ground loops" but i think I've read also about power. so in this case, is this wrong: ???
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5answers
336 views

Short-range radar and LIDAR, how do they work?

I was wondering how does short-range radar and LIDAR work? Considering the speed of light, the receiver sampling rate would need to be extraordinarily high to detect short-range distances(sub 1-2 feet)...
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3answers
149 views

Radiation Effects on Electronics

I'm developing a magnetic field sensing kit for a project. The kit contains sensors (specifically an accelerometer, a gyroscope, and a magnetometer) that will detect and measure magnetic fields, and ...
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1answer
98 views

How to build EMF radiation protection [closed]

I've recently started to use my laptop more and more on my lap and I'm worried about exposire to radiation emmited by the laptop. I keep it at a distance of about 10cm but still... I was wondering if ...
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1answer
69 views

Slayer Exciter Interfering With Voltage Measuremnet With Multimeter

I've built myself a slayer exciter and I am trying to measure the output voltage. I've created a coil with approximately 10 turns and soldered a bridge rectifier to the ends of the coil so I can ...
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2answers
1k views

What is a “half latch” in an FPGA?

In a paper about radiation hard FPGAs I came across this sentence: "Another concern regarding Virtex devices is half latches. Half latches are sometimes used within these devices for internal ...
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1answer
1k views

How do I calculate the length of a transmission line?

A quick translation: Generator has \$Z_g = 50\Omega\$ and 12 V. The line is loaded with an unknown RL. We observe we have a maximum of 8 V at 250 MHz and a minimum at 500 MHz. Solution: Asks for the ...
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0answers
542 views

Photodiode OP-AMP circuit for UV light radiation

The project: The aim is to be able to use the photodiode to detect plasma (radiation in the UV light spectrum). The photodiode suggested for this application is the BPX65 and I currently have access ...
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2answers
179 views

Slayer Exciter Health Hazards

I recently made a slayer exciter which produces arcs about 1-2 inches long. It also makes any electronic device near it go mad (it froze my iphone 6S when I was recording the arcs). What radiation is ...
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1answer
89 views

electricity substation radiation measurements [closed]

I live next to an electricity substation and want to contact the operator/owner to ask for details about the station itself. What measurements should I ask them for?
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1answer
151 views

How to determine power from emitted light using a photodiode?

I have a project that involves detecting blue light (400nm-490nm) from Cherenkov radiation to find the power that is being generated by the reactor. I understand the photodiode will give me a leakage ...
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2answers
213 views

Recapturing side and back lobe radiation from a directional antenna

When you look at the radiation pattern for a directional antenna, you see a major lobe where the greatest concentration of radiation is found and side and back lobes that have much less concentrated ...
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2answers
11k views

how much power is radiated by cell towers?

I want to know how much power is radiated by cell towers of GSM (1.8 Ghz), 3G (2.1 Ghz), 4G (2.6 Ghz) ? I want links to references if exist.
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2answers
154 views

Largest spectrum image sensor and processing its entire spectrum image

I was developing a digital system to process raw images stemming from an image sensor but I would like to deal with "universal" (as possible) spectrum image sensors with no filter. I know that for ...
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2answers
588 views

What size of hole do microwaves eventually pass through?

I've been searching high and low across the internet and haven't found an answer for this. I have a microwave I got from a friend who wants me to repair it (he REALLY does not want a new one). It had ...
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0answers
87 views

Geiger-Mueller Tube Question

this is a question about GM-tubes. I have read about radioactive stuff and also constructed a few geiger counter kits. But here is my question: The unit "bequerel" defines how many disintegrations ...
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2answers
1k views

Formula for Field Strength

According to this document on page 3, the formula for Field strength is stated as follows: I can't find reference to this formula elsewhere and was wondering if someone can verify this is correct, in ...
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1answer
74 views

Simulate in Puma-EM given radiation pattern

Is it possible to simulate the EM field in Puma-EM if the radiation pattern is supplied instead of a 3D model of the antenna? Is there other (free) simulation software that can do this? I need to ...
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1answer
157 views

Radiation susceptibility test circuit

I am looking to set up a test jig to test radiation susceptibility. This is to do a small in house test to check if my board is susceptible to radiation. The tests frequencies are the standard test ...
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2answers
510 views

What is the most widely accepted EMF exposure limit?

I know that there isn't a specific answer to this and different countries have different guidelines in regard to this. There are a couple cell-phone towers in my vicinity (one of which is some 15-20 ...
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1answer
174 views

Why am I getting signs of high RF radiation, while the desktop computer turns off?

The desktop computer doesn't have any Wi-Fi accessories. The keyboard and the mouse are wired. But even when the computer and the LCD monitor are turned off (while the power plugs are still connected)...
4
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1answer
302 views

Skew planar wheel antenna - is it circularly polarised or not?

'Skew planar wheel' antennas are popular for uhf. They are often described as circularly polarised, but I don't see how they would be. Are they instead just a mixed polarisation omnidirectional ...
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2answers
114 views

strange results from transmitter radiation calculation

This table was taken from:http://www.emfwise.com/distance.php At that site a formula: Power Density = P/4Πr2 was used in order to calculate the power density(mW/m2) according to the distance from ...
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2answers
4k views

Are chicken bits left in space-qualified ICs?

A chicken bit "is a bit on a chip that can be used by the designer to disable one of the features of the chip if it proves faulty or negatively impacts performance." Would space-qualified logic ...
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2answers
213 views

Could a customs x-ray corrupt sram data?

Could a customs x-ray corrupt sram data? Programming RTC on one side of the world, then transporting to the other side has worked fine in the past. The majority of a recent batch all had corrupted ...