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PCB 1090 MHz active antenna

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  • PCB 1090 MHz active antenna

    Hi All,

    For thoose who have long cable run between antenna and receiver, a new PCB active antenna design may be a good and cheap solution.
    This antenna base on the standard passive PCB antenna include on the same antenna PCB a LNA with a noise figure close to 1 db and haing a gain of 22 dB.
    It also incluse a SAW 30 MHz BW filter to reject (-35db) all GSM frequencies in the 900 MHz band.

    With such antenna, it is possible to use up to 35m of standard and cheap RG-58 coaxial cable without significant signal losses.
    More, the antenna is poswered through the coax cable with a Bias-Tee on a 5v USB port.

    Test shows coverage of 250 nM with a portable setup (tablet PC) and SDR dongle

    More info on this antenna here: http://f5ann.pagesperso-orange.fr/PC...nna/index.html

    Antenna is available here: http://h2204566.stratoserver.net/Sma...a-for-1090-mhz
    or here : http://www.shop-modesbeast.com/epage.../Products/1401

    F5ANN
    Attached Files

  • #2
    Hi F5ANN,

    I have already looked at the antenna on your own site and find it quite interesting. I have access to several very good locations but at these only existing coax feedlines can be used. They range from 35-70 meters in length. I would like to find a solution to be able to offer these locations to FR24 for rx placement and your antenna might enable this.

    Is the gain fixed or adjustable? 22 dB is a LOT of gain. On a couple of sites I have 35 m HFX2776 which attenuates approximately 6dB @ 1GHz. That would leave 16 dB gain at the recceiver, and I would expect a risk to saturate the Beast/radarcape/FR24 box. Any experience with this?

    Another complicating factor is that on some sites we would need to share the feedline with existing radio equipment, mostly in the VHF band. So I would need two diplexors with DC-pass on the 1 GHz ports , and with minimal losses on the VHF ports. Sourcing these commercially would cost a small fortune, but maybe you could help with a solution for that?

    /M
    F-ESDF1, F-ESGG1, F-ESGP1, F-ESNK1, F-ESNV2, F-ESNV3 F-ESSL4, F-LFMN3
    P-ESGR, P-ESIA, P-ESIB, P-ESGF
    mrmac (a) fastest.cc

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    • #3
      Originally posted by MrMac View Post
      Hi F5ANN,

      I have already looked at the antenna on your own site and find it quite interesting. I have access to several very good locations but at these only existing coax feedlines can be used. They range from 35-70 meters in length. I would like to find a solution to be able to offer these locations to FR24 for rx placement and your antenna might enable this.

      Is the gain fixed or adjustable? 22 dB is a LOT of gain. On a couple of sites I have 35 m HFX2776 which attenuates approximately 6dB @ 1GHz. That would leave 16 dB gain at the recceiver, and I would expect a risk to saturate the Beast/radarcape/FR24 box. Any experience with this?

      Another complicating factor is that on some sites we would need to share the feedline with existing radio equipment, mostly in the VHF band. So I would need two diplexors with DC-pass on the 1 GHz ports , and with minimal losses on the VHF ports. Sourcing these commercially would cost a small fortune, but maybe you could help with a solution for that?

      /M
      Hi there,

      F-WSSS1 uses an amp to his FR24 receiver which if i remember correctly is the AS-1090 preamp.

      As for me I use the KU LNA 1090 A TM amp over 7m westflex coax to my miniadsb receiver in the 2ch mode s beast... running with no problems for almost a year now. I did use it with the beast front end receiver before for a few hours no problems too it is just easier for me to use the miniadsb at the back.

      But then again you probably have more knowledge in this field then an amateur like me.
      Last edited by North Borneo Radar; 2014-03-26, 12:48. Reason: grammar

      Comment


      • #4
        Originally posted by MrMac View Post
        Hi F5ANN,

        I have already looked at the antenna on your own site and find it quite interesting. I have access to several very good locations but at these only existing coax feedlines can be used. They range from 35-70 meters in length. I would like to find a solution to be able to offer these locations to FR24 for rx placement and your antenna might enable this.

        Is the gain fixed or adjustable? 22 dB is a LOT of gain. On a couple of sites I have 35 m HFX2776 which attenuates approximately 6dB @ 1GHz. That would leave 16 dB gain at the recceiver, and I would expect a risk to saturate the Beast/radarcape/FR24 box. Any experience with this?

        Another complicating factor is that on some sites we would need to share the feedline with existing radio equipment, mostly in the VHF band. So I would need two diplexors with DC-pass on the 1 GHz ports , and with minimal losses on the VHF ports. Sourcing these commercially would cost a small fortune, but maybe you could help with a solution for that?

        /M
        Hi M,

        The active PCB antenna gain is not adjustable. But I don't think that it will be a problem with the Beast or Radarcape (Or FR24 receiver). It will be a problem with comparator based receiver like microAds-B or some SDR dongle due to the high gain of input tuner.
        The test I have performed here with the Beast and radarcape with a 3dB losses coax cable (10 m H155PE) to the active antenna have not shown any saturation problem and still have 225 nM radius coverage.

        For you second question on how to use the cable for VHF and Mode-S, you can try the solution of SAT/TV combiner. These device have one input with DC pass for SAT 950 to 2250 MHz which is ok for the mode-S access, and one input for terrestrial VHF TV 5 to 860 MHz with no DC pass which can be used for VHF air trafic. You need of coarse two device, one for coupling and one to separate the signals. You will have a small mismatch, as SAT devices are 75 ohms impedance and not 50 ohms as the Beast or the antenna. But the additional losses due to this mismatch will be very small ( less than 0.5 dB). Other coupling/de-coupling losses will be compensate by the high antenna gain. Such devices are very cheap.

        Regards
        F5ANN

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