# Questions tagged [rf-electronics]

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### Attenuation along microstrip

I just wanted to know why signal attenuation decreases with length across a micro strip transmission line. Isn't it meant to decrease but experiments show otherwise.
24 views

### Mathematical Modelling of Wireless Power Transfer in Biological Tissue

I am trying to develop a mathematical model which describes wireless power transfer through layers of biological tissue, with power being transferred from an external transmitting antenna to a ...
1 vote
28 views

### 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?
1 vote
42 views

### 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?
42 views

### 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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1 vote
62 views

### 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 ...
• 133
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### Building drone transceiver module with 2 recievers onboard to switch gates ON/OFF to turn motors On/Off

I'm looking for any resource that can help me build a radio (no infrared) controlled circuit with two receivers onboard a drone. The purpose of this circuit is for research and education. Whenever ...
31 views

### 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 ...
• 350
19 views

### T/R switch IC - HMC784AMS8GE IC does not work properly

I want to use a T/R switch IC to select the filters. So I made a small board test HMC784AMS8GE IC like the schematic below: The input (IN1) is the sine signal. But when I test, both OUT1 & OUT2 ...
1 vote
119 views

### 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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1 vote
61 views

### 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?
1 vote
44 views

### 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: ...
1 vote
46 views

### 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 ...
• 111
78 views

### 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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1 vote
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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 ...
42 views

### 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 ...
• 101
45 views

### Find electronics in wilderness; or, "I dropped my cell phone in the woods!"

Imagine I was working in the woods and dropped my cell phone somewhere in a large area where it is now hidden beneath dense vegetation. By calling it I confirm that either it has powered off or its ...
• 1,785
31 views

### 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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1k views

### 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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1 vote
40 views

### 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 ...
1 vote
614 views

### 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, ...
1 vote
39 views

### 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 ...
• 11
31 views

### 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 ...
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1 vote
40 views

### 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, ...
110 views

### 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 ...
1 vote
431 views

### 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 ...
1 vote
6k views

### 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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78 views

### 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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1 vote
109 views

### 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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1 vote
182 views

### 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 ...
• 161
1 vote
29 views

### 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 ...
• 161
55 views

### 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 ...
• 161
1 vote
22 views

### 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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1 vote
62 views

### 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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1k views

### 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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1 vote
75 views

### 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?
382 views

### 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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1 vote
68 views

### 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 ...
• 275
73 views

### 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 ...
383 views

### 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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594 views

### 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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131 views

### 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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456 views

### 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, ...
• 385
242 views

### 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 ...
• 385
98 views

### 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 ...
• 141
281 views

### 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 ...
• 143
16k views

### 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 ...
• 115
512 views

### 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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