팜테크(FAMTECH)

[FFT] Window Function 이란? (시간, 주파수, 윈도우 함수) 본문

기초이론/동해석(진동,Vibration)

[FFT] Window Function 이란? (시간, 주파수, 윈도우 함수)

FAMTECH 2022. 10. 28. 11:55

 

목차

     

    "관련제품 문의는 로고 클릭 또는 공지사항의 연락처를 통해 하실 수 있습니다."

     

     

    원문>>

    https://vru.vibrationresearch.com/lesson/tables-of-window-function-details/

     

    Window Function (윈도우 함수)란? 사용 목적

     

     

    신호 처리(Signal Processing)에서 FFT(Fast Fourier Transform)은 신호를 빠르게 주파수 변환을 해줘서 주파수(Frequency)에서의 특성을 실시간 확인가능하게 해줍니다. 

     

    FFT 변환을 위해서 시간 프레임(Time Frame)으로 잘라내서 처리를 하게 됩니다. 패스트 푸리에 변환은 프레임으로 자른 신호를 분석하다 보니 프레임의 양 끝에 불연속(Discontinuity)성이 발생하게 됩니다. 이 불연속성은 주파수 스펙트럼에서 노이즈(Noise) 처럼 동작하게 됩니다. 이러한 노이즈 현상을 Spectral Leakage(주파수 리키지)라고 부릅니다. 

     

    이러한 노이즈 제거를 위해 위 그림과 같이 윈도우 함수를 사용해서 불연속(Discontinuity)을 줄여줍니다. 

     

    하지만 윈도우 함수를 사용해서 강제적으로 불연속(Discontinuity)을 줄이다 보니 원 주파수 신호에서 왜곡이 발생하게 됩니다. 

     

     

     

     

     

    Window Function (윈도우 함수) 종류와 특징#1

     

    • Main Lobe Width

    Main Lobe Width 는 윈도우 함수 응답 곡선에서 메인 Lobe의 -3dB 위치의 너비입니다. 너비값이 커질수록 노이즈 성분이 포함되어 주파수 왜곡이 발생합니다. 

     

     

    • Side Lobe Height

    Side Lobe는 Main lobe 이 외의 원치 않는 주파수 영역의 응답으로 Height이 낮을 수록 노이즈 차단 능력이 좋습니다.

     

     

     

    • Side Lobe Roll-off Rate

    Side Lobe가 떨어지는 정도로 Rate 값이 높을 수록 노이즈 차단 능력이 좋습니다. 

     

     

     

    • Equivalent Noise Bandwidth(ENBW)

    Noise 를 통과시키는 대역폭으로 출력 노이즈 파워를 계산할 때 사용합니다. 예를 들어 화이트 노이즈 PSD가 P인 노이즈가 윈도우를 통과했을 때 전체 노이즈 파워는 P x ENBW로 계산됩니다. 

     

     

     

     

     

     

     

     

    Window Function (윈도우 함수) 종류와 특징#2

     

    Function Name: Blackman
    Use: All-purpose window function

    DESCRIPTION
    Wide main lobe, but a good roll-off rate

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 12π/N
    SLH: -58.2336 dB
    SLRR: -18 dB/octave
    ENBW: 1.7272
    SIMILAR WINDOWS: Hamming, Hanning

     

     

    Function Name: Hamming
    Use: All-purpose window function

    DESCRIPTION
    Sinusoidal shape, wide main lobe reduces frequency resolution. Has the best selectivity for larger signals.

    Time Domain (Left) & Frequency Domain (Right)

    MLW:   8π/N
    SLH:   -43.7547 dB
    SLRR:  -6 dB/octave
    ENBW:  1.3631
    SIMILAR WINDOWS:  Blackman, Hanning

     

    Function Name: Hanning
    Use: All-purpose window function

    DESCRIPTION
    Sinusoidal shape, delivers good frequency resolution and reduced spectral leakage. A safe choice when no function has a clear advantage.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   8π/N
    SLH:   -31.5565 dB
    SLRR:   -18 dB/octave
    ENBW:   1.5
    SIMILAR WINDOWS: Hamming, Blackman

     

    Function Name: Lanczos
    Use: Interpolation and re-sampling advantages

    DESCRIPTION
    Narrow main lobe, but only moderate attenuation. Derived from the main lobe of a sine function.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   6.5π/N
    SLH:   -26.5935 dB
    SLRR:   -12 dB/octave
    ENBW:   1.2994
    SIMILAR WINDOWS:   None

     

    Function Name: Parzen
    Use: Density estimation, machine learning, pattern classification

    DESCRIPTION
    Best side lobe roll-off rate but gains this at the cost of a wide main lobe and relatively high side lobes for its ENBW

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   16π/N
    SLH:   -53.0459 dB
    SLRR:   -24 dB/octave
    ENBW:   1.9175
    SIMILAR WINDOWS:   None

     

    Function Name: Bartlett

    DESCRIPTION
    A simple triangular window, with narrow main lobe and high side lobes

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   8π/N
    SLH:   -26.5269 dB
    SLRR:   -12 dB/octave
    ENBW:   1.333
    SIMILAR WINDOWS:  Rectangular, Trapezoidal

     

    Function Name: Trapezoidal
    Use: Bat chirp analysis, transients

    DESCRIPTION
    A variation of the rectangular window, with narrow main lobe and high side lobes

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   4.125π/N
    SLH:   -13.4122dB
    SLRR:   -6dB/octave
    ENBW:   1.0212
    SIMILAR WINDOWS:  Rectangular, Bartlett

     

    Function Name: Rectangular
    Use: Periodic signals that are perfectly spaced or for signals shorter than the length of the window

    DESCRIPTION
    Simple box waveform, typically results in leakage due to discontinuities

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 4π/N
    SLH: -13.3239 dB
    SLRR: -6 dB/octave
    ENBW: 1
    SIMILAR WINDOWS: Trapezoidal, Bartlett

     

     

     

    Function Name: Kaiser 1
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   4.25π/N
    SLH:   -14.7171 dB
    SLRR:   -6 dB/octave
    ENBW:   1.0046
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 2
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   4.75π/N
    SLH:   -18.6075 dB
    SLRR:   -6 dB/octave
    ENBW:   1.0472
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

    Function Name: Kaiser 3
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   5.5π/N
    SLH:   -28.4232 dB
    SLRR:   -6 dB/octave
    ENBW:   1.366
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

    Function Name: Kaiser 4

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   6.5π/N
    SLH:   -30.1532dB
    SLRR:   -6dB/octave
    ENBW:   1.2467
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 5
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   7.5π/N
    SLH:   -36.8982 dB
    SLRR:   -6 dB/octave
    ENBW:   1.359
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

    Function Name: Kaiser 6
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   8.625π/N
    SLH:   -44.0897 dB
    SLRR:   -6 dB/octave
    ENBW:   1.4668
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

     

    Function Name: Kaiser 7
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height.  Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW:   9.75π/N
    SLH:   -55.9526 dB
    SLRR:   -6 dB/octave
    ENBW:   1.569
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

     

    Function Name: Kaiser 8
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height.  Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 11π/N
    SLH: -59.0503 dB
    SLRR: -6 dB/octave
    ENBW: 1.657
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 9
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height.  Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 12.125π/N
    SLH: -66.7879 dB
    SLRR: -6 dB/octave
    ENBW: 1.7576
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 10
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 13.625π/N
    SLH: -78.8358dB
    SLRR: -6 dB/octave
    ENBW: 1.8451
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 11
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height.  Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 14.625π/N
    SLH: -89.6442 dB
    SLRR: -6 dB/octave
    ENBW: 1.9288
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

    Function Name: Kaiser 12
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 15.75π/N
    SLH: -90.6277 dB
    SLRR: -6 dB/octave
    ENBW: 2.0092
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Kaiser 13

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 17π/N
    SLH: -109.6578 dB
    SLRR: -6 dB/octave
    ENBW: 2.0865
    SIMILAR WINDOWS:  Chebyshev, Saramaki

     

    Function Name: Kaiser 14
    Use: Modular window function, all-purpose window

    DESCRIPTION
    Balances amplitude accuracy, side lobe distance, and side lobe height. Increasing the coefficients results in a wider main lobe and more attenuation on the side lobes.

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 18.25π/N
    SLH: -118.4404dB
    SLRR: -6dB/octave
    ENBW: 2.1611
    SIMILAR WINDOWS: Chebyshev, Saramaki

     

    Function Name: Chebyshev 40
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 7π/N
    SLH: -40.1168dB
    SLRR: 0dB/octave
    ENBW: 1.4563
    SIMILAR WINDOWS: Kaiser, Saramaki

     

     

     

    Function Name: Chebyshev 50
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level. Flat side lobes. The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 8.75π/N
    SLH: -50.1403 dB
    SLRR: 0 dB/octave
    ENBW: 1.4109
    SIMILAR WINDOWS:  Kaiser, Saramaki

     

    Function Name: Chebyshev 60
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 9.875π/N
    SLH: -60.245 dB
    SLRR: 0 dB/octave
    ENBW: 1.5187
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 70
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 11.375π/N
    SLH: -70.168 dB
    SLRR: 0 dB/octave
    ENBW: 1.6333
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 80
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level. Flat side lobes. The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 12.75π/N
    SLH: -80.3373 dB
    SLRR: 0 dB/octave
    ENBW: 1.7418
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 90
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 14.5π/N
    SLH: -90.3681 dB
    SLRR: 0 dB/octave
    ENBW: 1.844
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 100
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 15.625π/N
    SLH: -100.1973dB
    SLRR: 0dB/octave
    ENBW: 1.9409
    SIMILAR WINDOWS:  Kaiser, Saramaki

     

    Function Name: Chebyshev 110
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 17.125π/N
    SLH: -110.5814dB
    SLRR: 0dB/octave
    ENBW: 2.0332
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 120
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 18.875π/N
    SLH: -120.2028dB
    SLRR: 0dB/octave
    ENBW: 2.1214
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 130
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level. Flat side lobes. The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 20π/N
    SLH: -130.2188dB
    SLRR: 0dB/octave
    ENBW: 2.2062
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Chebyshev 140
    Use: Modular window function

    DESCRIPTION
    Provides minimum main lobe width for a specified side lobe level.  Flat side lobes.  The variable parameter implicitly controls the height of the side lobes (e.g., 40 – > -40 db).

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 21.5π/N
    SLH: -140.4674 dB
    SLRR: 0 dB/octave
    ENBW: 2.2878
    SIMILAR WINDOWS: Kaiser, Saramaki

     

    Function Name: Saramaki 1
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB. β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 4π/N
    SLH: -13.3227dB
    SLRR: -6dB/octave
    ENBW: 1.002
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 1.5
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB. β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 6π/N
    SLH: -31.5163 dB
    SLRR: -6 dB/octave
    ENBW: 1.1923
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 2
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB. β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 8π/N
    SLH: -44.542 dB
    SLRR: -6 dB/octave
    ENBW: 1.4076
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 2.5
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB.  β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 10π/N
    SLH: -52.9516 dB
    SLRR: -6 dB/octave
    ENBW: 1.589
    SIMILAR WINDOWS:  Kaiser, Chebyshev

     

    Function Name: Saramaki 3
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB.  β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 12π/N
    SLH: -65.9015 dB
    SLRR: -6 dB/octave
    ENBW: 1.7477
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 3.5
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB.  β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 14π/N
    SLH: -86.0196 dB
    SLRR: -6 dB/octave
    ENBW: 1.891
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 4
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB. β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 16π/N
    SLH: -98.9664 dB
    SLRR: -6 dB/octave
    ENBW: 2.0228
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 4.5
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB.  β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 18π/N
    SLH: -114.0496 dB
    SLRR: -6 dB/octave
    ENBW: 2.1457
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Saramaki 5
    Use: Modular window function

    DESCRIPTION
    Provides minimum side lobe height for a specified main lobe width, while maintaining a roll-off rate. Beta determines the distance of the first null from the main lobe peak. S determines the side lobe level with respect to the main lobe peak in dB. β = -0.0389S + 0.4509

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 20π/N
    SLH: -122.2238 dB
    SLRR: -6 dB/octave
    ENBW: 2.2614
    SIMILAR WINDOWS: Kaiser, Chebyshev

     

    Function Name: Flat Top
    Use: Amplitude resolution, when it is more important to find the exact amplitude, rather than the exact frequency, of the signal

    DESCRIPTION
    Delivers the most accurate amplitude resolution

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 20π/N
    SLH: -69.0129dB
    SLRR: -6dB/octave
    ENBW: 3.7703
    SIMILAR WINDOWS: None

     

    Function Name: Exponential
    Use: Impact testing and burst random excitation

    DESCRIPTION
    Very narrow main lobe, consistent but poor attenuation

    Time Domain (Left) & Frequency Domain (Right)

    CHARACTERISTICS
    MLW: 8.875π/N
    SLH: -15.4337dB
    SLRR: -6dB/octave
    ENBW: 1.4414
    SIMILAR WINDOWS: None

     

     

     

     

     

     

    Window Function (윈도우 함수) 통합 비교(Time Domain Graphs)

     

     

    Window Function (윈도우 함수) 통합 비교(Frequency Domain Graphs)

     

     

     

     

     

     

     

     

    저작자표시 비영리 변경금지

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