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  1. #1
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    Anti-jamming antennas

    Hi,

    Ive read some articles about anti-jamming GNSS antennas. Some antennas are said to resist jamming signal of 50V/m while others have 15dB J/S ratio. Well, both seem to be the specification describing the anti-jamming capability. Can they be compared somehow?

    Senmeis

    •   Alt19th November 2017, 07:23

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    Re: anti-jamming antennas

    I presume they can be compared by putting in the received GNSS field strength.



    •   Alt19th November 2017, 18:22

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    Re: anti-jamming antennas

    Quote Originally Posted by FvM View Post
    I presume they can be compared by putting in the received GNSS field strength.
    Do you mean this comparison makes sense only if the input GNSS power is given?

    Senmeis



    •   Alt24th November 2017, 13:47

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    Re: Anti-jamming antennas

    Input power varies according to antenna, the primary unit of received signal strength is power density or field strength, both are related by impedance of free space. The field strength probably varies with satellite elevation angle.

    A typical GPS receive field strength is in a V/m range, e.g. 2 V/m corresponds to -135 dBm with 0 dBi antenna gain.

    You can refer to an R&S application note for the calculation https://cdn.rohde-schwarz.com/pws/dl..._Estimator.pdf



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