Short for Radio-Frequency. Frequencies at which radiation (intentional or not) plays a role. Typically associated with wireless communications, but also relevant for high-speed PCB design.

learn more… | top users | synonyms (1)

0
votes
1answer
32 views

If I connected N numbers of amplifiers each have X gain 'dB“ and Y power ”dBm", how to calculate total gain and power?

sorry for bad description, I am a beginner. my question is just for knowledge and I did not test anything. If I connect for example 3 amplifier , each one has 60 dB gain and 15 dBm power. can we ...
-1
votes
0answers
34 views

Can't transmit a BPSK modulated signal

I'm currently working on a BPSK transmitter and receiver. The problem is I don't know what I am missing and can't transmit/receive a data. My supply is 12v and -12v. So I'm trying to send a varying ...
0
votes
0answers
18 views

How to modulate RF signal using LabView? [duplicate]

I am using Acousto-Optic Modulator (AOM) in my experiment to modulate laser light using controlled modulations in phase and intensity of RF signal being fed into the AOM. I want to know what program ...
0
votes
0answers
27 views

Using a LabView interface, how do I control phase and intensity fluctuations in the RF electrical signal being fed to an AOM? [on hold]

I am performing a Quantum Optics experiment where at one part I need to have a control over the fluctuations in the phase and intensity of the RF signal. This control then via an AOM provides me with ...
0
votes
0answers
30 views

PCB specifications for 2.4 GHZ RF Board

I am designing an RF module with a PCB trace antenna. I'm wondering what PCB specifications will have a significant effect on the quality of the RF Signal. Is there a prefered laminate and immersion? ...
2
votes
1answer
59 views

Rogowski Coil High Frequency Limit

I'd like to do some experiments involving high frequency (1.296GHz to be exact) that involve an 50ohm inductor that has minimal RF losses. The obvious candidate is to drive a Rogowski coil (driven as ...
2
votes
1answer
80 views

Are the stock transistor models in LTspice accurate at RF?

Just checking, I'm doing some experimenting of small signal RF design in LTspice.
0
votes
1answer
37 views

Modifying an amp evaluation board to bias the coax?

I'm normally a software guy, but a recent project requires me to dip my toe in the ocean of electrical engineering. I'm trying to (cheaply) capture GPS signals to process in software, and I have an ...
0
votes
0answers
28 views

Measuring RF Noise of Electric Train

I live near an old electric trolley, and I've noticed that it apparently interferes with RF signals. In particular: I notice that when I drive next to the line my satellite radio drops out. My ...
1
vote
1answer
49 views

Why is my guitar amplifier acting like a radio when I touch the volume knob?

I just bought an acoustic/electric mandolin (Ibanez M511SE-DVS) that I decided to test out with the only guitar amp that I have (a Baja BG-10). It works fine, but I noticed that when I have my finger ...
1
vote
1answer
31 views

Comparator input interfacing

I need to digitize a weak (-10 dBm) 1-20 MHz signal with a comparator. The output of the preceding stage is 50 ohm. The comparator I'm using is the LT1715. It's input trip point is ± 5 mV and the ...
1
vote
2answers
40 views

Passive Filter Negative Insertion Loss

Can someone please explain to me how a passive filter could possibly have a negative insertion loss? In the attached picture, this can be seen in the C or D curves where the insertion loss dips below ...
0
votes
0answers
25 views

Agilent N9330B for Antenna development?

We are considering buying an Agilent N9330B for using to match the antenna on our product. The antenna is a PCB etched design on the board. Our frequency range is GSM and 3G so about 800 to 2100 MHz. ...
0
votes
3answers
62 views

Waterproofing a GPS antena

I need to use this GPS antenna on a model boat. As a result of placement, it will be submerged periodically (though I don't expect it to work while submerged), and damp often. What can I encase it in ...
0
votes
0answers
62 views

433MHz quarter-wave length antenna: Longer is better?

I am trying to conduct an RF project using some cheap modules: link here My problem is that even though most blogs and Google searches for these modules use a quarter-wave length antenna (roughly ...
0
votes
0answers
36 views

Experiment using wifi frequency(Wisee) - SDR is the best equipment?

I'm going to do an experiment using Wifi frequency (2~5 Ghz). I need some equipment to generate and receive this 2~5Ghz frequency. I'm currently quite new to this field (RF) - currently majoring in ...
4
votes
2answers
121 views

Can't understand Frequency and Bandwidth [duplicate]

I just don't get it. How bandwidth is the factor that the data rate and the capacity are based on? Let's say we're using Amplitude Modulation. The main factor here is the ability to change the ...
0
votes
1answer
111 views

Length of a 40MHz antenna

A few days ago I had the brilliant idea of replacing the ugly antenna of a 40MHz car remote control with an extendable one. Now the range decreased from 50 meters to 3-4m. I don't know exactly what I ...
1
vote
0answers
37 views

How to measure RF receiver

I am trying to check how electric devices such as Sunroof could affect the remote key performance range (meter) for cars. I am thinking of measuring relative antenna gain of RF receiver of one test ...
1
vote
1answer
62 views

Estimating Path Loss from Measured 2.4Ghz/Wlan Signal Strength to get Distance

I want to estimate distances between Wlan Routers based on the RSS (received signal strength) indoors. Im fully aware that I only will get rough estimates. For that I studied some radio propagation ...
3
votes
1answer
94 views

Multiple nrf24l01, shared power, ripple/interference, DSO screenshot provided

I've got this circuit with 3x atmega328 & nrf24l01+ running off shared power supply, either 2x AA battery or 3v3 reg. It acts as a repeater, and depending on the origin of the message and the ...
0
votes
0answers
30 views

How would I go about analyzing this SDR-captured 300mhz AM radio signal?

I am attempting to reverse engineer the signal from a 300 mhz garage signal as a learning experience rather than an exercise in efficiency.My intent is to purchase a 300 mhz broadcaster IC and connect ...
-2
votes
1answer
34 views

My Rf reciever circuit on battery ,but not with a rectified xformer output as source

I just made a Rf circuit that turns on and off a relay depending on the transmitter's message The circuit is working fine when i connect it to a 9v battery. But i cant get the circuit to work with ...
2
votes
2answers
62 views

Balanced line impedance matching

Is there a way to convert a 100Ω balanced connection to a 200Ω balanced connection without using two baluns? I have a 2.4GHz baseband that I want to attach to a front end, but the baseband ...
0
votes
0answers
31 views

Fixed Frequency Synthesis with PLL

I'd like to design a downconverter with a fixed local oscillator frequency ~2GHz with fairly good stability. I understand that the best way to do this is a PLL with a fixed crystal oscillator and a ...
1
vote
3answers
88 views

How to chose an IF, or how bad is zero-IF really?

In a superheterodyne receiver, what must one consider in order to chose an intermediate frequency? Specifically, I'm working on a radio telescope project. It is basically a superheterodyne receiver ...
0
votes
1answer
37 views

How to determine antenna noise power?

For a 1.4 GHz radio telescope project I'm working on, I need to know the power level of noise an outdoor dipole antenna will be outputting in order to determine the amount of amplification needed. ...
3
votes
1answer
85 views

Analyzing this RF circuit

I'm trying to analyze this RF circuit: This circuit is designed for about 915 MHz operation. I'd be happy in fact understanding this smaller section of the circuit: I have been trying to find ...
1
vote
1answer
44 views

Exchanging packets over an nRF24L01+

I have two nRF24L01+ chips each attached to a Bus Pirate. I'm trying to write some code to test exchanging packets between them, at first entirely on my laptop before I eventually move out to an AVR ...
0
votes
1answer
41 views

Impedance line matching and component value matching

I have the following circuit for the SIM900's antenna connection, using the A10393 antenna from digikey: In closer look: First of all my knowledge on RF design is not great. My questions now are ...
1
vote
1answer
80 views

RF load (terminator) at the end of RF attenuator

Do I need to install RF terminator at the end of RF attenuator? Let's say that max power output for RM port is 50W and I'm using 100W 50dB attenuator. What if I was using 50W 40dB attenuator? Is there ...
0
votes
2answers
196 views

2.4 GHz versus 434 MHz transceiver for home automation

I am working on a project that uses an Arduino Uno R3 and will have one receiver and one transmitter. I'm going to use this for home automation within my home in India. I want to know which ...
2
votes
1answer
59 views

Is RF Transformer Impedance Significantly Affected by Wire Size?

I'm building a Softrock Ensemble III HF Receiver. The online instructions are pretty good, but have a few remnants from an earlier version that no longer apply. So, despite the discussion about the ...
0
votes
1answer
44 views

S-parameter measurement of a 3-port splitter

I am looking for possible ways to measure s-parameters of a 3-port power splitter (1 input and 2 outputs). It is similar in concept to a wilkinson, but also provides matching and none of the ports are ...
0
votes
1answer
36 views

Piezoelectric Transducer, effect of voltage amplitude vs frequency of pulsing signal?

I am not an expert in piezoelectric transducers used for ultrasound applications so I am looking for some insight into the matter. To extract the greatest amount of acoustic energy from the ...
1
vote
1answer
33 views

Reduce Interference in Wireless Mesh Network

I am playing with the idea of mesh network path finding. The goal is that each node can find the most efficient path through other node to a hub. One way I could approach it is by flooding the ...
0
votes
1answer
58 views

Parsing .s2p data through an automation script to plot graphs of the various s-parameters

Need to find a way to quickly decipher and plot s-parameters for tons of .s2p files in a short period of time. In specific, I need to plot the angle of the s-parameters versus frequency and then the ...
0
votes
1answer
89 views

Two-stage amplifier

This is my first time designing a circuit by myself :) The input of this circuit is the output jack of my MP3 Player. The output of this circuit is 4-Ohm loud speaker (sometimes I connect 8-Ohm ...
0
votes
1answer
48 views

How do multiple users connected to a wireless router receive their signals?

In other words how does a wireless router with multiple users work? I know that routers use electromagnetic waves radio waves, but how does information get sent to the user it is intended to? and if ...
0
votes
0answers
18 views

reflection and transmission coefficients when not given information of second medium

I need help with only part (A). I am stuck on this question, i have to find transmission coefficient and reflection coeeficient. I don't know how to get this, I don't have any information from the ...
1
vote
2answers
113 views

Using attenuators to damp reflections on transmission line?

I have a 3m long transmission line that transmits a 100ns bipolar square pulse every 200us. At the beginning of the coax cable is a pulsing circuit board, that generates the waveform, then it sends ...
0
votes
0answers
33 views

WS-RX-02 Receiver Range in Arduino

I have been preparing the receiver using WS-RX-02 receiver and arduino Uno R3 board. My connections are as follows. 3 GND PINS on RECEIVE UNITS are Connected to GND of ARDUINO 2 VCC PINS on RECEIVER ...
0
votes
1answer
36 views

Any Way of Converting Several 2-Port S-Parameters Measurement to 4-Port S-Parameters

I have a bi-driectional coupler and attenuator (att) in which I would like to capture its s-parameters: So I measured 2-port s-parameters between ports 1 & 2, 1 & 3, 1 & 4, 2 & 3, 2 ...
1
vote
1answer
109 views

Would you help me understand this simple circuit?

I have three questions: Is it common emitter or common collector (emitter follower) or something else? How do you recognize it? What is the function/usage of R1 and C1? Are they for biasing the ...
0
votes
1answer
83 views

What is the purpose of the following configuration of diodes on an RF line?

I've been told that these are disconnect diodes. However, I am unsure as to what purpose they serve. They are used on the line that sends a signal to a piezoelectric, the return signal from the ...
0
votes
1answer
45 views

XBee Power Consumption, RX Current and TX Peak Current

I'm trying to find out the max power consumption for an XBee Series 2 2mW module so as to pick out a suitable power supply for the system. The docs state that it has a TX Peak Current of 40 mA and RX ...
2
votes
2answers
57 views

Multipath fading in mobile radio systems

Here is the problem that left me thinking: "In a mobile radio system (e.g., cell phones), there is one type of degradation that can be modeled easily with sinusoids. This is the case of multipath ...
1
vote
2answers
42 views

Reading S2P Files - What Does Each Column Represent

I'm having a hard time reading s2p files. For an example say that I am measuring the parameters of a 2-port network (port 1 and port 2). What do each columns represent? I can tell that the first ...
1
vote
1answer
51 views

Is it possible to use a XBee module to controll a quadcopter? [closed]

I'm thinking to design my own quadcopter and wondered if it's possible to use a XBee module to control the drone? The reason I'm thinking about an XBee module is because I want to be able to plug it ...
1
vote
3answers
72 views

Simulate RF transmission lines at Low frequencies

I would like to simulate RF transmission lines in how they propagate, and how impedance mismatches at the end of the transmission line cause reflections and power transfer does not work. It would be ...