radio frequency

  1. S

    RF DRIVER

    I'm looking for someone with experience in fpga design to construct a rf logic pulsing circuit to send digital signals via shortwave antenna. It's an inductance matching signal type from tuned coil to tuned coil.
  2. K

    27MHz carrier signal using a oscillator chip or with few transistors alone

    I am trying to generate a 27MHz carrier signal to transmit it through a loop antenna, I referred many circuits couldn't able to find the one I need. can anyone guide me on generating it using a few simple transistors or using an oscillator chip with a 3v cell battery? The thing is my design is...
  3. N

    Microwave frequencies emitter circuit

    Hello, For my project I need to build a variable frequency emitter, with a frequency between 100MHz and 3500Mhz. I saw some simple RF circuits on the Internet but I don't think they can reach such high frequencies. Here is a circuit I've found : I don't need to transfer any information, so...
  4. O

    RF 50 Ohms Dummy Load PCB Design (High Frequency Ground Plane)

    Hi I am a rookie on both RF and PCB design and I am currently trying to do a 50 Ohm 11 Watts Dummy Load project for 100MHz-1GHz. My calculations are done for the load but I have some questions about designing the PCB. I am trying to do it as a microstrip line and as a simple structure of the...
  5. Circuit wanted: Antenna Current lead or lagging Antenna Voltage?

    I need a circuit which will produce a DC level proportional to the jX term at the feedpoint of an antenna. The frequency range is 1 to 20MHz. The circuit should work with RF levels from ~10W to 1000W. The antenna impedance range: 5<R<500, -500<jX<500 Ohms. I am building an Arduino-based...
  6. D

    Building a FM transmitter

    Hi, I am planning to build a FM transmitter for my school project. There are a lot of designs available on the internet and I simply don't know which to choose. I decided to choose a simple one from the cryptomuseum webpage. Its circuit is shown below. I am new to RF design. Please forgive my...
  7. I

    Frequency Response Heterojunction Bipolar Transistor

    I have a project, first i need to find a circuit to Analyse/study the Frequency Response of Heterojunction Bipolar Transistor. Then simulate that circuit on SPICE (i'am using Orcad Cadence). Can someone help me finding a circuit as mentioned above???, I'm having difficulties finding one. Any...
  8. Making a replacement cable for a HP 8445B spectrum analyzer preselector

    Hello All, Lately, I have been working on building a replacement for a somewhat rare cable assembly for communicating between a HP 141T/8555A/8552 mainframe spectrum analyzer and a HP 8445B "Automatic Preselector" add-on box, and I thought I would document my work here for others to follow. A...
  9. S

    Using MMIC RF chip

    Hi all, Having played around with my new DVBT dongle I kind of like the idea of decoding ADSB signals. This is all fine and well but since I am not that close to an airport I see limited traffic. So the next logical step would be to get a LNA between my antenna and dongle, the not so logical...
  10. K

    RF circuit with HT12E and HT12D

    Hi, I have made a simple RF circuit with HT12E and HT12D. My problem is that when I press any switch on the transmitter and cut power to the transmitter by holding push switch, the receiver end is still showing a LED output. I want it to go to the default state of all LEDs off whenever...
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