2.4Ghz Collinear

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by VK2XLX, Jul 26, 2009.

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  1. VK2XLX

    VK2XLX Ham Member QRZ Page

    HI All, I was wondering if somebody could point me in the right direction.

    I would like to design/build my own collinear mainly for the 2.4Ghz band but I wanted to design it myself rather than just build from a plan already on the web of which there are many.

    Is there a program for Collinear antenna calculation ?

    I am particularly interested in how the phasing coils are calculated, such as wire thickness, diameter & number of turns etc. The many designs I have seen simply skip all the information in regards to the coils & just give you the discrete dimensions & you have to take it for granted that they are correct.

    I didn't want use the 1/4 wave coaxial segments design. I would like to build something more like a mobile phone antenna look-a-like with phasing coils.

    Regards Glenn
     
  2. N7IFC

    N7IFC Ham Member QRZ Page

    Hi Glenn,

    Not sure about a program specifically for a collinear array, but I think most cell phones these days are using PCB stripline elements and some are using fractal folding to reduce the size even further. These techniques could certainly be used at 2.4GHz. The broad-band bi-quad element frequently used as a feed for microwave frequencies may be a good candidate in an array design. I would think that a 4-element bi-quad collinear for 2.4GHz would fit nicely on a single PCB with copper tracks for all the feed lines and elements. I know there are programs for designing strip line circuits for a given PCB dielectric and plating so hopefully something similar is available for your project.

    Bill

    Edit: It may be helpful to others to know what kind of radiation pattern you are after i.e. omni-directional, bi-directional or uni-directional and the gain you are shooting for...
     
    Last edited: Jul 26, 2009
  3. VK2XLX

    VK2XLX Ham Member QRZ Page

    Thanks for the reply Bill......

    Sorry I probably didn't make myself very clear, I just wanted to build a vertical omnidirectional antenna, in fact what I really wanted to try & understand was how the phasing coils on vertical collinear antenna's in general are calculated, such as the open coils you would see on a typical mobile phone glass mount antenna or a little magnetic base wifi antenna.

    I was wanting to know about the design formula's or a program that calculates the coils parameters for you based on the frequency you are working with.

    Regards Glenn
     
  4. N4AEQ

    N4AEQ Ham Member QRZ Page

    Try this link to make a vertical

    Google, W7LPN 2M/440 COLLINEAR - I have used this design for making a
    915mhz and 1800mhz antennas. These work great, I tried coax colinears but
    they have a big problem with the VP being different form the outer conductor to inner conductor. This antenna eliminates that problem and also makes use of larger outer conductor as the radiating element, sense the inner conductor
    dosent radiate it can be very small, smaller the better vs outside dia.
     
  5. AE5JU

    AE5JU Ham Member QRZ Page

    Do a search on Youtube, something along the lines of "wifi antenna" and you will find lots of videos.

    I've made some very long distance connections with a homebrew "cantenna".

    [​IMG]

    That little stub on the N-connector is 1.21" long, 1/4 wave at 2.4 ghz.

    [​IMG]

    [​IMG]

    [​IMG]

    Kept the lossy coax short, and used a long USB cable to the USB wireless adapter.

    [​IMG]

    The whole thing is mounted on a camera tripod.
     
    Last edited: Aug 15, 2009
  6. AE5JU

    AE5JU Ham Member QRZ Page

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