Transmission of a pulse through cylindrical waveguide

AGirlHasNoName
AGirlHasNoName Altair Community Member
edited July 2021 in Community Q&A

Hi,

I have modeled a cylindrical waveguide of radius, a = 38.1 mm. For this dimension, the first (TE11) and second (TM01) cut-off frequencies are at 2.3055 GHz and 3.0118 GHz, respectively. The model, has therefore, been simulated between 2.2 - 3.1 GHz.

I want to transmit a pulse through the structure, and obtain the near-field response at a specific distance from the waveguide. For this purpose, I used the analytical form of the time-domain signal (under consideration) and generated data points using MATLAB. These data points are used as the input time signal in POSTFEKO. Next, I tried observing the output response and obtained the following error message: "The simulated frequency range and signal bandwidth have insufficient overlap". The .cfx and .pfs files are attached here.

How can I observe the output response correctly?

 

-Thanks,

Bidisha

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Answers

  • Mel
    Mel Altair Community Member
    edited July 2021

    Have a look at the Section 3.13 "Guidelines for Defining a Time Signal" in the User Manual.

    Also note that you do not have to run Feko with a discrete frequency loop. You can use continuous frequency sampling and POSTFEKO will do frequency interpolation to obtain the full bandwidth's frequency response.

  • CJ_Reddy
    CJ_Reddy
    Altair Employee
    edited July 2021

    Bidisha - In addition to material in the user manual, you may also watch the webinar - 

    Time Domain Responses from Frequency Domain Results

    https://www.altair.com/resource/time-domain-responses-from-frequency-domain-results