Questions tagged [rf-electronics]
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53
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How to calculate permittivity for higher frequencies?
In many books the permittivity of a material is only listed as dielectric constant for one or a couple of frequencies. 1 kHz is used often (for example in the Plastics Technology Handbook, 4th ed, ...
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What is Byte Alignment Time in radio communication?
According to this paper, which deals with time synchronization in wireless networks, this kind of delay occurs, however I do not understand its explanation. The paper says the reciever (radio) has to ...
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Are there any differences between using nylon or ABS for RF electronic cases?
I want to contain a very small PCB (roughly a square centimetre) in a casing. For demonstration purposes I want to 3D print a couple of those casings as well.
The most obvious method available would ...
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Building RF power meter
I want to build power meter for wifi signals. One way to do it is to use a diode to rectify AC signal and amplify that before measuring. But are there diodes which work at such high frequency? Also, ...
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Measuring the distance to an object with RF resonance
Assume I put an RF antenna in front of an object (typically the face of someone sitting in a chair, so able to move about +/- 10cm in all directions) at a typical distance of 1m. If I consider the ...
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A material to insulate a container so that water inside the container is not affected by microwaves?
I'm running an experiment and I need to have a container filled with water. The container will be placed inside a microwave oven, but I need to minimize any effect the microwaves will have on the ...
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Frequency dependence of electromagnetic shield metal
I know that the effectiveness of metals used for electromagnetic shields heavily depends on the used frequency or frequency range.
I could not find a resource in the web (tables or graphs) that give ...
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How much current is this phone drawing?
I know the current should be higher than 0.67 mA, because I know phones use current in the order of 1A. Also the charger is able to support up to 1A, it doesn't make sense that the charger would have ...
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Methods of finding the angle to an object
I'm working on a project that needs a system that can determine approximate angle of an object related to it. I have anchor position (multiple anchors, but fairly close ~ 1m of each other). And object ...
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3
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Effect of magnetic field on electronic components
Are electronic components like diodes,transistors, micro-controllers, microprocessors, wireless transceivers etc are damaged by strong static or dynamic magnetic fields? If yes, at what strength the ...
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A 40MHz oscillator in usb wifi adapter
I disassembled a usb wifi adapter. I was surprised to see a 40MHz oscillator, when wifi works at 2.4GHz. How the output of the oscillator is scaled to the required frequency?
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Evaluating bonding integrity of piezoceramic transducer
Currently I am working on a Structural Health Monitoring system utilizing piezoceramic transducers. The proof of concepts have worked very well. But we are in the process of working small scale ...
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Detection of weak signal by satellites
An animal's blood pressure and/or body movements can be used to generate a few mW of electrical energy. Can an RF transmitter which radiates 1 mW be detected by receivers (without any parabolic ...
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Low bandwidth electronic filter
Is it possible, under current technology, to have an electronic filter in the microwave range (100 MHz to 300 GHz) with very low bandwidth , say 100 to 1000 Hz?
If yes, then what is the basic ...
- 21
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Is there any hardware to use in GPR applications? [closed]
I want to make a radar system which needs to send EM wave and receive the reflected wave from the ground.
I am looking for a ready to use RF signal processing hardware but can't be sure which is ...
- 141
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579
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How to design a 915 MHz waveguide circulator?
I would like to design a waveguide circulator. I tried to design one but, my attempt was not successful. My design used a cylindrical cavity with ferrite as region. I then connected 3 waveguides in ...
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Will the water in a gold fish bowl signficantly abosorb Bluetooth or WiFi if transciever is at bottom of bowl?
Using WiFi or bluetooth frequencies 5.8GHz and 2.4-2.485GHz respectively, I want to place a hermetically sealed circuit at the bottom of a gold fish bowl, and want to know if the water will ...
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Electronic component datasheet handling
What is $V_{IH}$ and $V_{IL}$ in datasheets? I found High-level input voltage and Low-level input voltage on the datasheet?
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Can Schotkky diodes rectify signals of GHz frequency? [closed]
Switching speed of PN diode is limited by reverse recovery time. Can Schotkky diodes rectify signals of GHz frequency? If yes, which ones?
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Are there diodes which can switch at multiple GHz speed? [closed]
Are there diodes which can switch at multiple GHz speed? Most of them are limited up to few hundreds of MHz.
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Can a signal below -176 dbm be decoded?
Can a signal below -176 dbm, which is 1.6 db below thermal noise at room temperature, be decoded irrespective of the modulation type?
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Electrical Engineering/Telecommunications/Power Amplifiers VSWR and harmonics
How does VSWR at a power amplifier output affect the level of harmonics? and is there any textbook or paper which addresses this issue?
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Why is the tv playing if the carrier frequencies in our RF project appear unsupported?
My group made an RCA video/audio to RF modulator for a school project. The video is a NTSC composite video signal. Here is a clip of our tv receiving the output of the project on NTSC channel 2:
...
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Why channel 1, 6 and 11 are best for Wifi communication 802.11n?
In 802.11n 2.4Ghz, the spectrum is varied from 2400Mhz to 2500Mhz and consists of 13 (or 14) channels, each channel having 20Mhz band width.
When I search google for best channel, all websites say 1,...
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609
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Two GPS receivers on one antenna?
Has anyone tried to do this?
I have two GPS receivers, and when they are near each other, they calculate different positions.
The difference is about 5-10 meters, but in reality it is several ...
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Trying to understand Nathan Stubblefields 1898 American Patent #600,457
I find this solenoid to be intensely interesting. It has a number of unique properties:
The coil wire is made from dissimilar metals so that the voltage is internally produced in the coil.
The ...
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0
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78
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IP2, IP4 relationship with P1 dB of an amplifier
It is well known that the difference between IP3 and P1 dB of an amplifier can be derived and results in a theoretical 9.6 dB difference. Can a similar relationship be derived for IP2 and IP4?
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Upper frequency limit of transmission line
How would I determine the upper frequency limit of a transmission line from these plots? I plotted these in matlab after being given some RLCG values. About all I can seem to understand from these ...
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Methods for External Antenna Detection - RF systems
I’m designing an RF device that should be able to use multiples sets of antennae, one a low-gain internal PCB antenna and the other an external high gain antenna attached via an SMA connector.
I’d ...
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Swapping transmitter and receiver locations
Pardon me if this is a silly question, because I don't quite study RF.
Let's say I have a set of transmitter (radio + antenna) and a set of receiver (radio + antenna), at location A and B ...
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What are the strengths and limitations of the antenna design of the Montjuïc Communications Tower?
The Montjuïc antenna is an interesting design for an antenna. I presume the design is principally an antenna, but perhaps it is not? If the ring + mast is an antenna, how does the ring work to ...
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Can an antenna damage an iPhone?
I am currently attending a radio technology course. We continuously work on radio sets that are sometimes used as manpacks by the Army. In order to learn how to operate them we work in close proximity ...
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Faraday cage to reduce EMI in audio amplifier
western United States.
Problem / Question
The bad power in my house is somehow producing EMI in my audio equipment. Will a simple Faraday cage help? (Using an aluminum metal screen)
If not that, ...
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Gap between the two frequencies in FSK
Frequency shift keying uses at least two different frequencies. How much should be the difference between the two frequencies so that the receiver reads the signal properly reliably? Is there any ...
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What types of oil reservoirs are applicable to radio/microwave heating and advantageous to SAGD?
I am doing a project looking into the advantages of radio/microwave heating of oil reservoirs. I've seen research indicating that RF/Microwave heating can be used for environments such as shallow, ...
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How to simulate Ground Penetrating Radar system?
We have a project which requires Ground Penetrating Radar(GPR). We got a student license of NI AWR software and Ansys HFSS (high frequency structural simulator). Are those the correct software for ...
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Are there any negative aspects to using baseband frequencies in radar systems?
Is there any application or circuit design for RF radar systems to use directly the transmitter frequency for the receiver side.
From what I've seen, a mixer is always used to get the frequency ...
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Generating electromagnetic signal using CPU clock [closed]
Laptops have processors running on few GHz clock. Is there a way to generate electromagnetic signals in that range using some software or coding? Say generating 2.4 GHz signal if the CPU runs at 3 GHz....
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A naïve question about computer chips
Is it true that computer chips "float" inside of the computers ? Can someone give me references(books, articles, papers...) about that fact ?
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Can a wireless signal of sufficiently high energy damage a wireless transceiver?
A wi-fi router works at 2.4GHz. Can a wireless signal of 2.4 GHz or any other frequency, of sufficiently high energy, damage the device?
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Can a piece of conductor be made invisible to radar by overdamping?
To my understanding every conductor reemits a bit of electromagnetic waves induced in it by radiation.
If theres a way in an antenna one could create a wave of opposite phase to the incident one so ...
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Pathway for drone racing
How can I build a v shaped pathway for drones? It would be a sort of racing path and there would be multiple drones flying over the pathway at the same time.
The race would be a relay race. So there ...
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Should we use ELF or ULF for very deep metal detection and which specific frequency?
We are trying to design a metal mineral deposit detection system using low frequency radio waves. I am not sure on the physics of why the ultra low frequency electromagnetic radiation can penetrate ...
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How is RF data encoded in WAV files?
I have tried recording RF data using several different software packages: SDR Console, SDR# and HDSDR. They all seem to produce WAV files. When I open the HDSDR file in Mathematica, it says the file ...
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How far can my FM transmitter signal reach?
I have a working FM transmitter on a raspberry pi2. I'm running my FM raido at 103.3MHz, and the antenna that I connected to the GPIO4 is a 70cm copper wire.
More data:(checked with a multimeter ...
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Tunable phase delay for RF modulation
I've been trying to understand if there's a way to create two RF signals at the same frequency with a fixed, tunable phase delay. The goal is for one to trigger an RF-modulated laser and the other an ...
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CMOS AC-to-DC Converter Design
I am trying to analytically model the power conversion efficiency of an AC-to-DC power converter circuit (see Figure 1). In this design, the drain-source voltage of each MOS device can be expressed as ...
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S-Parameters and Received Power for Implant Antenna
I am simulating an implant antenna using the Ansys HFSS EM simulation tool - the simulation setup looks something like this, with a transmitting (TX) antenna of transmit power $P_{TX}$ and transmit ...
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Wireless Power Transfer Modelling
I am trying to develop an analytical model for RF wireless power transfer from an external antenna to an implant antenna, embedded inside layers of lossy tissue.
The external antenna will be ...
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Calculating the doppler shift between a satellite receiver and ground station transmitter with python
I'm trying to write a python script calculate the doppler shift that occurs between a satellite receiver and ground station transmitter. Below are the examples that I've been following . What I don't ...
