Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Search results

  1. J

    Crosspol is not at boresight

    I have an S band antenna for satellite communications and when I check the copol pattern from a LHCP satellite (XTAR-EUR in my case) everything is cool. When I switch it to RHCP with a coaxial switch to check for crosspol I get double crosspol nulls at sides of the signal and couldn't...
  2. J

    Eb/No to BER formula for QPSK

    Hi, I am trying to find the formula for the BER vs Eb/No curves but I only see the curves themselves as 10^-6 BER is about 10.5 Eb/No what is the formula to get these results?
  3. J

    [SOLVED] Polarizer axial ratio

    Hi. I'm trying to design a Ka band Tapered corrugated polarizer. I somewhat was able to keep phase difference stable but the S parameters differ alot. What i was trying to ask when I search the papers they only use the phase difference between the ports for axial ratio calculation but not the...
  4. J

    Spectrum Analyzer weird results from LNA

    Hi.I have designed an LNA for S-band between 2.2-2.4 GHz bands. The thing is when i test it i see this weird stuff on Spectrum analyzer like some 50 MHz signal is getting mixed in.I couldnt really work out a reason. can you give me a clue why it might be doing this ? You can see my marker is at...
  5. J

    Semi-rigid vs flexible cable for antenna feed

    I designed an antenna feed that is capable of monopulse tracking.What I wanted to ask was which cable is better to use for both monopulse and antenna feed cable.I would like to use flexible cable t-flex 405 for ease of use but I also think the phase stability is critical for tracking accuracy...
  6. J

    Horn Antenna to coax pin feed

    Hi. I've designed a waveguide to coax adaptor for an S band feed horn. The thing is when I was designing the conductor that goes into the waveguide I didn't check available product length and took Pasternack's PE4099(Candlestick SMA connector) as base for conductor and ptfe dimensions . Now I...
  7. J

    S11 smith chart contour too big

    Hi. I designed an S band LNA and fabricated it but there is a little problem. S11 and S22 of the circuit is nowhere near the simulation Here is the both measurement and simulation results. What could be the problem here ?
  8. J

    [SOLVED] LDO tps7a4701 not working as intended.

    Hi. For my LNA design I was using tps7a4701 as a regulator to supply DC voltage to circuit. I designed the pcb according to datasheet and used any-out option and it should give 4V all times. Now i get a variable output at the output of LDO. when i give Vin=3V, ı get Vout=3V and this goes all the...
  9. J

    Voltage drop at second stage LNA

    Hell everyone. I've been designing a 3-stage LNA for 2.4 GHz and today I tested the LNA but for some reason when I connect the LNA to voltage source it voltage supply drops from 4V(correct value) to 2.7V. Then i used seperate voltage sources for 3 seperate stages and it seems the second stage...
  10. J

    Using Invar material in Septum Polarizer and Feed

    Hi. For a project i had to design a septum polarizer. But they wanted it to work from +55C to -30C. If i hit these limits my crosspol drops below 30 dB if i use Aluminium.So I found this Invar which is %64 iron and %36 Nickel and has a very low thermal expension coefficient.Here is the Link...
  11. J

    TE21 monopulse coupler

    How does it work? I found a paper(https://ieeexplore.ieee.org/document/7068002/) and a company that explains it vaguely(https://docs.wixstatic.com/ugd/bdfa9d_4c310c25fbaa4b29a3e545ce45656ab3.pdf) but is there any book or formula you can point how we get the signals and how do we seperate the...
  12. J

    Contacting Rotary Joint Design

    Hi. I need to design a contacting rotary joint from DC to 18 GHz but i don't know how. I tought of a slip ring but when I think about it, a ring would act like a rat race coupler depending on the frequency.So i might get nothing from the recieve port. It will have sma connection and 2 channels...
  13. J

    [SOLVED] Relation between Frequency and bit rate.

    I know the relation between bps and Hz as a formula but i can't imagine how the data is sent. Say I have a basic psk modulation and i want to send data from a satellite down to earth for tv. They allot me 50 MHz bandwidth. How do I send my data over this 50 MHz bandwidth between 12000 MHz and...
  14. J

    Biasing with parallel (series LC) at input

    Hi.İ've been working on LNA design but I needed to connect one series, one parallel capacitance at the input of transistor. Is it ok for me to use series LC instead of only C for parallel Capacitance If I use an inductor to stop RF leaking to ground over capacitance ?
  15. J

    Ce3512k2 CEL RF Transistor non linear model.

    I found this transistor for X band LNA but i couldn't get non-linear model of the transistor. Contacted to CEL costumer service but still not a reply after 2 months. Is there anyone who used this transistor and have the non-linear parameters ?
  16. J

    NF of a LNA in AWR EM simulation

    Hi. I am designing an LNA on AWR. When I run the simulation without EM_Extract I get 0.47 dB NF. When I run it with EM on and X,Y cell size= 1 mm I get around 0.53 dB NF. When I decrease the X,Y cell size to 0.1mm it gives 0.61 dB NF. My question is which one I should consider as more...
  17. J

    [SOLVED] Importance of Unconditional Stability in LNA design.

    I'm trying to design a LNA in S band for 2.4 GHz Wlan applications , Input VSWR<1.5(probably antenna will be matched to 75 ohms) , NF<0.5 , S21=50dB. I will cascade 3 or 4 transistors for S21. I was able to get 0.45 NF for the first transistor on AWR but the transistor is unstable after 4...
  18. J

    [SOLVED] 2.3 GHz lna design parameter vs netlist

    2.3 GHz lna design sparameter vs netlist Hi. I am trying to design an LNA at 2.3 ghz with infineon's BFP 740 ultra low noise transistors. On their page there is an axamle at the same frequency. When i use sparamets i get 0.18 db NF but when i use netlist with the same matching circuit I get...

Part and Inventory Search