How to build a wireless antenna for a satellite dish - PBP Community Forum
Welcome to PC & Home Electronics Forum!
A great place for help and reviews on computers, home electronics, cell phones, software and much more!

• » Computer Software Help
• » Computer Hardware Help
• » Home Electronics Help and Advice
• » Consumer Reviews

We are a friendly community for PCs, home electronic enthusiasts. Our community is here when you need help.
Don't hesitate to join us now and discover just what so many people are talking about!

YES! I want to register for free right now!
Results 1 to 5 of 5

Thread: How to build a wireless antenna for a satellite dish

  1. #1
    Administrator PBP Administrator Rank Tetris Champion, Chopper Challenge Champion, Wordex Champion Rumas's Avatar
    Join Date
    Dec 2006
    Posts
    1,220
    Rep Power
    10
    Computer Details
    Rumas's Computer Specs:
    CPU:
    AMD FX-8350 4.0GHz Eight-Core
    Mainboard:
    ASUS SABERTOOTH 990FX R2.0
    RAM:
    16GB of Corsair CMZ16GX3M2A1866C9
    HDD:
    2x 2TG WD raided, WD 120GB SSD
    Graphics:
    2x NVIDIA GeForce GTX 560 Ti 1GB GDDR5
    Sound:
    On-board audio
    OS:
    Windows 7 Ultimate, XP, Linux

    Default How to build a wireless antenna for a satellite dish

    Biquad Antenna Construction
    (first published September 2002)

    This page details the construction of a biquad antenna. The biquad antenna is easy to build, and provides a reliable 11dBi gain, with a fairly wide beamwidth.

    Use the photos of the biquad below.

    Parts Required:
    • 123x123mm square section of blank PCB
    • 50mm length of 1/2" copper pipe
    • short length of CNT-400 or LMR-400 low loss coax (~300mm long)
    • 250mm of 2.5mm2 copper wire (approx 1.5mm diameter)
    • N connector
    Note that you don't have to use blank PCB for the reflector. You can use any material that's electrically conductive, can be electrically connected to the coax braid, and will reflect microwaves (ie, any metal plate will do fine).
    I've also heard of people using CDROM as the reflector, as the foil on it will certainly reflect microwaves.

    Reflector
    Cut a square piece of blank printed circuit board, 123x123mm.

    Note that a size of 123x123mm is recommended if your using the biquad as a stand-alone antenna, while 110x110 is optimal if using it as a feed for a large dish.
    Also attaching some lips to the two sides of the reflector is recommended, to reduce radiation from the rear lobes.

    Use some steel wool to remove any tarnish and polish it up. Cleaning the copper in this way will make it easier to solder.



    blank printed circuit board
    Cut a 50mm section of copper pipe, and file both ends smooth. Using some sandpaper and/or some files, polish up the copper pipe (including the inside of the copper pipe, to ensure a good connection with the coax braid).



    the dimensions of the copper pipe
    Cut a notch into one end of the copper pipe, removing approx 2mm from half the circumference.



    a short secion of copper pipe, notched at one end
    Drill a hole in the centre of the blank PCB so that the copper pipe is a tight fit in the hole. I found a reamer to be very useful for enlarging the hole to the correct size.



    making a hole in the centre
    Insert the copper pipe into the hole, with the notched end on the copper side of the blank PCB. The copper pipe should be protruding approx 16mm through the hole, measured on the copper side of the PCB.



    insert the copper pipe into the reflector
    Solder the copper pipe to the PCB, to ensure a good physical and electrical connection.



    solder the copper pipe to the PCB
    Quite a bit of heat is needed, due to the thickness of the copper pipe, and an electrical soldering iron probably won't be able to deliver sufficent heat. I found a small gas torch works quite well.


    Making the Element
    The element is made from a length of copper wire, bent into the appropriate shape.

    Note that the length of each "side" should be as close to 30.5mm as possible (measured from the centre of the copper wire to the centre of the copper wire), which is a quarter of a wavelength at 2.4GHz



    the shape and dimensions of the element
    I had some offcuts of electrical power cable lying around, and found that 2.5mm2 power cable had a diameter of approx 1.6mm - a little bigger than the 1.2mm that Trevor Marshall specifies, but didn't think it would make a significant difference to the performance of the biquad.



    recycling power cable offcuts
    Remove the insulation, measure and cut a 244mm length the copper wire, and straighten it as best as you can.



    straighten the wire
    Measure the mid-point of the wire, and make a 90 degree bend. The bend should be quite sharp and pronounced.



    90 degree bend
    Measure the midpoints of each half, and make two more 90 degree bends in the wire, so that it looks like that shown in the photo below.



    another two bends
    Once again, measure the midpoints of each section, and make some more 90 degree bends, resulting in what is shown below.



    bend it some more...
    Do the same to the other side, resulting in the biquad shape.



    make it symetrical...
    Clean up all your bends, and ensure each side of the element is as straight as possible, and as close to 30.5mm as possible.
    Note that you may need to trim a small amount off each end of the wire to achieve this.

    Assembly
    The element must now be attached to the reflector. Note that only the two "ends" of the copper wire are to be attached to the copper pipe - the centre of the copper wire must not touch the copper pipe (hence the notch which was cut into the end of the copper pipe.

    The copper wire element should be approximately 15mm away from the reflector. Testing antenna performance while varying the spacing between the copper wire element and the rear reflector indicates that a spacing of approx 15mm provides the lowest SWR.



    the element soldered onto the copper pipe
    Strip approx 30mm of the outer sheath from the end of the coax.



    strip the outer sheath
    Fold the braid back over the outer sheath, and trim the centre conductor, so that about 4mm is protruding.



    fold the braid back, trim the centre conductor
    Insert the braid into the copper pipe, so that the end of the centre conductor lines up with the extreme end of the copper pipe, and solder the centre of the element to it, ensuring the centre of the element is not in contact with the copper pipe. Refer to some of the additional photos below for details.



    solder the centre conductor to the element


    another view
    Note that the feed between the rear reflector and the biquad element needs to be shielded. Using coax to feed the biquad element directly, and positioning the coax inside the copper tube achieves this.
    Use of bare conductors as a feed between the reflector and biquad element results in a radiating feed, which will have a detrimental effect on the biquad's performance.

    I used a coax crimper to crimp the end of the copper pipe onto the coax. This ensures that the coax would not move inside the copper pipe.



    the copper pipe crimped onto the coax


    the completed biquad
    Now terminate the other end of the coax with an N connector.

    If desired, you can add spacers at each end of the element, to ensure the element doesn't move in relation to the reflector.

    If you intend to mount the biquad outside, I'd recommend you place it into a weather-proof enclosure, to prevent corrosion, and to prevent water ingress into the coax.
    Numerous people have used small tuppaware containers successfully.

    This can be achieved by drilling a hole in one side of the container, and pass the coax tail through the hole, leaving the biquad itself inside the container. Seal up the hole for the coax with some silicone, and your biquad should be protected against the elements.



    another view of the completed biquad

    Testing
    Some very rough initial testing using the biquad as a feed on a 24dBi Conifer dish looks very promising.

    I also managed to get a marginal link to a 180 degree waveguide on an access point 10km away, using only the biquad by itself, connected to a 30mW RoamAbout wireless card.

    Some more detailed testing with multiple antennas, including the biquad shown above, indicates the biquad has a gain of approx 11-12dBi.

    A friend has access to some antenna test equipment, and performed some tests on the biquad featured on this page.
    The azimuth plot (ie, radiation pattern) of the biquad is shown below, and shows a 3dB beamwidth of about 50 degrees.



    azimuth plot of the biquad
    Variations
    A number of people have suggested the spacing between the element and the rear reflector should be a 1/4 wavelength (ie, 30.5mm) instead of 15mm. However, test results indicate the SWR of the biquad is minimised when the spacing is about 15-17mm. Increasing the spacing to 30.5mm increases the SWR significantly, thus reducing the efficiency of the biquad.

    Usage
    When using a biquad to establish a link to another wireless device, you should ensure the polarisation of the biquad is the same as the antenna you are connecting to. Similarily, if establishing a link with two biquads, ensure they are both oriented for the same polarisation.
    Failing to match the polarisation will result in significant signal loss.



    vertically polarised
    horizontally polarised
    Changing the polarisation is just a matter of rotating the entire biquad antenna by 90 degrees.

    The biquad antenna is not particularly directional, but has a fairly wide beamwidth.
    The 3dB beamwidth for a biquad (without side lips) is typically about 40-50 degrees, thus making it ideal for any applications where you want fairly wide coverage.

    The relatively wide beamwidth also makes a biquad very suitable for war-driving and stumbling, allowing you to pick up signals without having to align the antenna directly with the signal source.

    While a directional antenna, such as a Conifer dish (3dB beamwidth of a 24dBi Conifer dish is approx 7 degrees), is better suited for point-to-point links, the narrow beamwidth of a Conifer dish requires more precision when aligning the antennas (the narrower the beamwidth, the less susceptible it will be to interferance from other sources). An antenna with a wider beamwidth, such as a biquad, doesn't require the same precision for alignment, thus making it easier to get a link working.


    Please, DO NOT PM admins/mods for personal support. Keep posts here in the Forums instead and we all learn.

    Any questions you have will get a good answer as long as you have followed the forum rules and shown you have tried to help yourself. Your questions are clear and contain as much relevant info as possible, especially error messages and solutions you have tried.


    5 ways you can make PreferredByPete.com Better!

    Read the site RULES

  2. #2
    Administrator PBP Administrator Rank Tetris Champion, Chopper Challenge Champion, Wordex Champion Rumas's Avatar
    Join Date
    Dec 2006
    Posts
    1,220
    Rep Power
    10
    Computer Details
    Rumas's Computer Specs:
    CPU:
    AMD FX-8350 4.0GHz Eight-Core
    Mainboard:
    ASUS SABERTOOTH 990FX R2.0
    RAM:
    16GB of Corsair CMZ16GX3M2A1866C9
    HDD:
    2x 2TG WD raided, WD 120GB SSD
    Graphics:
    2x NVIDIA GeForce GTX 560 Ti 1GB GDDR5
    Sound:
    On-board audio
    OS:
    Windows 7 Ultimate, XP, Linux

    Default Re: How to build a wirless antenna with satellite dish

    Double Biquad Antenna

    This page contains details on building a double biquad antenna with approx 13dBi gain.

    Background
    Having experimented with a number of biquad antennas I have found them to be relatively easy to contruct, reliable, and good performers, with about 11 dBi gain.

    A number of websites showed a variation of the biquad, with the reflector being double the size, and with the element having twice as many sections.

    I decided to make a double biquad, to see how the gain compared to that of a biquad.

    Construction
    I made a double biquad using exactly the same construction techniques as described in the first post, except the rear reflector is 110x220mm, and the element is double the size.


    double biquad
    Note that the element wires do not touch where they cross over, but are separated with a gap of approx 1-2mm.

    To provide some more robustness, and to ensure the element doesn't move, I added some spaces at each end of the element.
    The spacers are made from a small section cut from a hollow reticulation riser, and attached to the reflector and element using a small wire tie. Measure and cut the spacers to be 14.5mm long, as this should result in the element being the correct 15mm from the reflector.


    parts required for the spacers
    Drill two small holes in the reflector, in line with each end of the element. The holes must be large enough to allow the wire tie to pass through them.


    two holes in the reflector for the cable tie
    The spacers are attached by passing the wire tie through one of the holes in the reflector, through the tube, looped around the element, and then passed through the tube again, and through the other hole in the reflector.


    spacer installed
    The spacers will ensure the posititioning of the element relative to the reflector will not change, and also means the antenna is less likely to be damaged while in transit or while being handled.


    detail of spacer
    Note that you can make spacers out of any non-metallic material, providing it does not absorb microwaves.

    As with the biquad antenna, if you intend to use one of these outdoors, I'd recommend you place it into a weather-proof enclosure, to prevent corrosion, and to prevent water ingress into the coax.


    completed double biquad
    Testing
    To determine the difference in gain between a biquad and the double biquad, some tests were performed, with the signal, noise and SNR recorded.

    antenna SNR
    (dB) signal
    (dBm) noise
    (dBm) biquad 43 -58 -101 double biquad 45 -56 -101
    The test results indicate that the gain of the double biquad is approx 2dBi higher than that of the biquad, which is a significant improvement (as 3dBi is a doubling of signal).

    As the biquad has a gain of 11-12dBi, this means the double biquad has a gain of 13-14dBi, so it's a pretty good performer for something that's relatively easy to build.

    These results are similar to those obtained by other people who have made double biquads.


    Please, DO NOT PM admins/mods for personal support. Keep posts here in the Forums instead and we all learn.

    Any questions you have will get a good answer as long as you have followed the forum rules and shown you have tried to help yourself. Your questions are clear and contain as much relevant info as possible, especially error messages and solutions you have tried.


    5 ways you can make PreferredByPete.com Better!

    Read the site RULES

  3. #3
    Administrator PBP Administrator Rank Tetris Champion, Chopper Challenge Champion, Wordex Champion Rumas's Avatar
    Join Date
    Dec 2006
    Posts
    1,220
    Rep Power
    10
    Computer Details
    Rumas's Computer Specs:
    CPU:
    AMD FX-8350 4.0GHz Eight-Core
    Mainboard:
    ASUS SABERTOOTH 990FX R2.0
    RAM:
    16GB of Corsair CMZ16GX3M2A1866C9
    HDD:
    2x 2TG WD raided, WD 120GB SSD
    Graphics:
    2x NVIDIA GeForce GTX 560 Ti 1GB GDDR5
    Sound:
    On-board audio
    OS:
    Windows 7 Ultimate, XP, Linux

    Default Re: How to build a wireless antenna for a satellite dish

    Here is a ton more info on Biquad Antenna's. I would like to see what anybody does with this info. Post your results, pictures if possible.

    10 Euro dish with biquad feeder satellite dish, biquad antenna.

    2.4 GHz quad double quad design is basically 4 double quad antennas phased together such that the signal from each antenna is added. The overall gain of this antenna is approaching 16dB, just under four times that of a single double quad

    2.4GHz Cubic Quad Antenna how to make a 2.4GHz Cubic Quad Antenna

    Bauanleitung für eine Bi-Quad Antenne für 2,4 Ghz W-LAN Anwendungen in German

    Bicircle calculator included

    BiQuad 802.11b Antenna 11dBi, wide band the characteristic impedance of a biquad antenna is 50 Ohm, 802.11b BiQuad feed for Primestar dish

    Biquad USB Adapter IEEE802.11b/g WLAN Biquad USB Adapter IEEE802.11b/g part of biquad

    Wifi antenne bouw pagina in Dutch

    Biquad analysis Biquad analysis, 3D Radiation pattern, Gain, Radiator height, Reflector lips height, Wire radius, Impact of lips on SWR, Double biquad, SWR

    Bi-Quad AntennaBi-Quad AntennaBi-Quad Antenna How-To: Build a WiFi biquad antenna

    Bi-Quad Antenna How-To: Build a WiFi biquad dish antenna

    Bi-Quad Antenna 2.4 GHz 802.11b/g Bi-Quad Antenna

    Biquad Antenna Building a biquad antenna for wireless 802.11b

    Biquad Antenna pdf file

    Biquad Antenna Double Biquad Antenna This page contains details on building a double biquad antenna with approx 13dBi gain

    Biquad Antenna Construction Biquad Antenna Construction

    Biquad Antenna Construction WiFi Client Construction biquad antenna construction to establish a small WiFi LAN

    Biquad Antenna with parabola ConstructionBiquad antenna met Wifi USB Adapter (D) Biquad antenna met Wifi USB Adapter (D)

    BI-QUAD ALS DISHFEEDBiquad cantenna Biquad cantenna design

    Biquad dish antenna WiFi biquad dish antenna

    Biquad dish antenna How To Build a WiFi biquad dish antenna

    Beam antennas Beam antennas, Beam antenna design

    Biquad antenna construction Biquad antenna construction, How to make a 802.11b BiQuad Antenna for WiFi

    Biquad antenna construction Biquad antenna construction, How to make a 802.11b BiQuad Antenna for WiFi, wireless networking info

    Biquad antenna construction Biquad Sector antenna for 2.4 GHz / 802.11b / WiFi / WLAN

    BiQuad antenna 11dBi, wide band. Wireless networking systems using the 802.11b standard operate in the 2.4GHz ISM band. Other services, including microwave ovens, medical equipment, and cordless phones also operate in the ISM band. The IEEE 802.11b standard defines how WLAN networking will be configured, and how interference can be minimized from the other services operating at the same frequencies

    Biquad sector antenna for 2.4 GHz / 802.11b / WiFi / WLAN, This sector antenna was made from a piece of thick copper wire formed into a "bowtie" shape (the biquad - with sides 32 millimetres) and soldered to a round N-type connector. The N connector was then screwed into a steel disc about the size of a CD (Compact Disc)

    Biquad Wifi antenneBuilding a biquad antenna for wireless 802.11b Building a biquad antenna for wireless 802.11b

    Double Biquad Antenna

    Double Biquad Antenna Double Biquad Antenna design

    Double Biquad Antenna Double Biquad Antenna design, pdf file

    WLAN Biloop Antenna Biloop antenna with Wifi USB Adapter
    Last edited by Rumas; October 10th, 2007 at 05:59 PM.


    Please, DO NOT PM admins/mods for personal support. Keep posts here in the Forums instead and we all learn.

    Any questions you have will get a good answer as long as you have followed the forum rules and shown you have tried to help yourself. Your questions are clear and contain as much relevant info as possible, especially error messages and solutions you have tried.


    5 ways you can make PreferredByPete.com Better!

    Read the site RULES

  4. #4
    Administrator PBP Administrator Rank Tetris Champion, Chopper Challenge Champion, Wordex Champion Rumas's Avatar
    Join Date
    Dec 2006
    Posts
    1,220
    Rep Power
    10
    Computer Details
    Rumas's Computer Specs:
    CPU:
    AMD FX-8350 4.0GHz Eight-Core
    Mainboard:
    ASUS SABERTOOTH 990FX R2.0
    RAM:
    16GB of Corsair CMZ16GX3M2A1866C9
    HDD:
    2x 2TG WD raided, WD 120GB SSD
    Graphics:
    2x NVIDIA GeForce GTX 560 Ti 1GB GDDR5
    Sound:
    On-board audio
    OS:
    Windows 7 Ultimate, XP, Linux

    Default Re: How to build a wireless antenna for a satellite dish

    Just thought I would add this:

    Here are the lists of metals in order of greatest conductivity in Pauling scale.

    Electrical Conductivity

    Gold - 2.54
    Lead - 2.33
    Platinum - 2.28
    Mercury - 2.00
    Tin - 1.96
    Silver - 1.93
    Nickel - 1.91
    Silicon - 1.90
    Copper - 1.90
    Cobalt - 1.88
    Iron - 1.83
    Zinc - 1.65
    Aluminum - 1.61
    Titanium - 1.54


    Please, DO NOT PM admins/mods for personal support. Keep posts here in the Forums instead and we all learn.

    Any questions you have will get a good answer as long as you have followed the forum rules and shown you have tried to help yourself. Your questions are clear and contain as much relevant info as possible, especially error messages and solutions you have tried.


    5 ways you can make PreferredByPete.com Better!

    Read the site RULES

  5. #5
    Administrator PBP Administrator Rank Tetris Champion, Chopper Challenge Champion, Wordex Champion Rumas's Avatar
    Join Date
    Dec 2006
    Posts
    1,220
    Rep Power
    10
    Computer Details
    Rumas's Computer Specs:
    CPU:
    AMD FX-8350 4.0GHz Eight-Core
    Mainboard:
    ASUS SABERTOOTH 990FX R2.0
    RAM:
    16GB of Corsair CMZ16GX3M2A1866C9
    HDD:
    2x 2TG WD raided, WD 120GB SSD
    Graphics:
    2x NVIDIA GeForce GTX 560 Ti 1GB GDDR5
    Sound:
    On-board audio
    OS:
    Windows 7 Ultimate, XP, Linux

    Default Re: How to build a wireless antenna for a satellite dish

    Some dBm info:

    dBm = log10 (mW)*10
    mW =10^(dBm/10)


    40 dBm 10.00 watts
    36 dBm 4.00 watts (Maximum ERP allowed by FCC in U.S.)
    30 dBm 1.00 watts
    27 dBm 500 milliwatts
    26 dBm 400 milliwatts
    25 dBm 320 milliwatts
    24 dBm 250 milliwatts
    23 dBm 200 milliwatts (Typical output from WLAN devices at 915MHz)
    22 dBm 160 milliwatts
    21 dBm 130 milliwatts
    20 dBm 100 milliwatts (Maximum ERP allowed by E.T.S.I. In Europe)
    15 dBm 32 milliwatts
    10 dBm 10 milliwatts
    5 dBm 3.2 milliwatts
    4 dBm 2.5 milliwatts
    3 dBm 2.0 milliwatts
    2 dBm 1.6 milliwatts
    1 dBm 1.3 milliwatts
    0 dBm 1.0 milliwatts
    1- dBm 0.79 milliwatts
    5- dBm 0.32 milliwatts
    10- dBm 0.1 milliwatts
    20- dBm 0.01 milliwatts
    30- dBm 0.001 milliwatts
    40- dBm 0.0001 milliwatts
    50- dBm 0.00001 milliwatts
    60- dBm 0.000001 milliwatts
    70- dBm 0.0000001 milliwatts
    80- dBm 0.00000001 milliwatts


    Please, DO NOT PM admins/mods for personal support. Keep posts here in the Forums instead and we all learn.

    Any questions you have will get a good answer as long as you have followed the forum rules and shown you have tried to help yourself. Your questions are clear and contain as much relevant info as possible, especially error messages and solutions you have tried.


    5 ways you can make PreferredByPete.com Better!

    Read the site RULES

Similar Threads

  1. Replies: 0
    Last Post: September 24th, 2009, 06:19 PM
  2. Satellite Antenna Transponder Listings (All sats)
    By CASPER in forum General FTA Discussions
    Replies: 0
    Last Post: February 15th, 2009, 06:57 PM
  3. [Help!] Antenna Settings Twin and Dual LNB's with Dish 21 switches
    By srameram in forum CaptiveWorks Discussions
    Replies: 0
    Last Post: October 22nd, 2008, 08:32 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •