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RF Amplifier Usage Question

hawkeyethehacker

Hello All,

 

I am developing an extremely high frequency RF Transmitter solution and I am confused about the workings of RF Amplifiers.

At the moment I am specifically looking at this transmitter and this amplifier.

 

I have two questions:

 

  1. If I were to apply this in a custom PCB (where the transmitter takes Digital input, converting to an RF Signal, taking that output to the amplifier, which in turn puts it through to an antenna), are these the correct parts for the respective jobs?
  2. Is the output of the Transmitter and output of the Amplifier a co-axial type plug? If not, what is the correct type?
  • 0

    I'm only going to touch on the first part of your question(for now). The cc2591 is designed to work with the cc2500 series, an 8051 with integrated 2.4 GHz transceiver. take a close look at the data sheet for the cc2591, and look at the functional block diagram. this chip is not a complete transceiver, however it is suitable as a front end for a 2.4GHz radio system.

  • 0 in reply to sqkybeaver

    Okay. So, It would need another chip in conjunction with it just to transmit a signal through an amplifier which is just under 10Ghz? Please correct me if I am wrong.

  • 0 in reply to hawkeyethehacker

    If you are confused about the workings of RF amplifiers then you are not going to have any success "developing an extremely high frequency RF Transmitter solution". To do this you need RF design expertise (not just knowledge but actually to be good at it !) and suitable (and extremely expensive) test gear.)

     

    Your only hope is to buy a ready made and certified module - there are lots on the market.

     

    If you can explain what you are trying to do it may be possible to help by suggesting suitable parts.

     

    MK

  • 0 in reply to michaelkellett

    By the above I meant I was researching how it would work in a high frequency solution with the chips I had found, this is merely a learning project and not an actual project.

     

    If you have something wrong with people who are trying to figure out how even a minimal RF solution works, then to be honest, element14 is not the best place to ask questions because you will constantly be getting people who try to put you down due to lack of knowledge.

     

    tl;dr Research Question to learn about RF in general and the differences between low and high power frequencies in the technology.

  • 0 in reply to hawkeyethehacker

    @ Joshua, it's not  a matter of trying to put you down but save you from falling down a deep dark hole. Your original question was very much phrased to suggest that you were trying to build something specific.

     

    In the olden days people learned about RF mainly via amateur radio - this doesn't seem so popular or accessible now . You could start by looking at data sheets and app notes for the license exempt low power radio chips from TI, Microchip and Atmel. There is a lot of helpful material there. These parts will work at 455MHz or 900 ish MHz. These are still very high frequencies to start with and the theoretical design of circuits and board layouts very, very difficult. Most engineers use a combination of the theoretical and the empirical (which requires the fancy test gear). You can find some suggested board layouts in app notes an these will probably work if followed very carefully. You will get an idea of some of the issues involved in the design. (Try here to start with looking at TI stuff: Sub-1 GHz - Overview - TI.com)

     

    The highest frequencies at which I've done any paid work in RF (rather than digital which is different) is designing and testing aerials for Mifare which is ony 13.5MHz -  and that can get quite tricky. I've used modules that work at much higher frequencies but that doesn't count.

     

    MK

  • 0

    Hi Joshua,

     

    I will have to agree with most of the other comments here as well. The 2 devices just from their titles will not work as the Tx chip is 2.4GHz and the amplifier starts at 6GHz well above the 2.4GHz of the transmitter. Definitely a specialized area is PCB design too as there is a lot of stray capacitance's and Inductance's that are involved in this type of design.

     

    There are plenty of specialized module that can be purchases from places, one being mini-circuits and even on element14/Newark http://uk.farnell.com/jsp/search/browse.jsp?N=2031+203582&Ntk=gensearch&Ntt=rf+module&Ntx=mode+matchallpartial

     

    As a radio technician I too am learning as I progress through University to finer details of high frequencies in PCB design. I think there is a certain amount of secrecy in the question ie not divulging the idea but maybe more specifics are needed in what you are trying to accomplish.

     

    As far as the general questions, 2) coax connectors are an option but so are PCB design antenna which are also plausible. As long as you have the correct impedance matching (usually 50ohm ) it should work OK either way.

    The first question is mute point, you will need to use a different amplifier completely to work with the transmitter.

     

    Malcolm

  • 0 in reply to waelect

    OK, apologies for misunderstanding in the first place and I'll take this advice onboard.