1 / 7

The story of Knee Frequency

The story of Knee Frequency. Ruxin Xie 11.05.2013. Why it’s called Knee frequency. Knee Frequency?. Knee Frequency?. Knee Frequency?. Definition of the Knee frequency. Note: Pulse shape hardly matters K = 0.35 is typically used K = 0.5 for conservative approximation

maxine
Download Presentation

The story of Knee Frequency

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The story of Knee Frequency Ruxin Xie 11.05.2013

  2. Why it’s called Knee frequency Knee Frequency? Knee Frequency? Knee Frequency?

  3. Definition of the Knee frequency • Note: • Pulse shape hardly matters • K = 0.35 is typically used • K = 0.5 for conservative approximation • Imprecise measurement • Advantage: • Simply defined based on rise time • Easy benchmark of frequency effect

  4. How to calculate the Knee frequency Amplitude (Linear scale) 90% Amplitude (Linear scale) 50% 10% FFT Time E(t) = A0exp() E(𝜔) = A1exp() Set E(𝜔) = 0.5, 𝜔 = Since 𝜎 = Tr10%-90% /1.69, 𝜔 = 2𝜋f f = 0.32/ Tr10%-90% Set E(t) = 10%, t10% = 𝜎 E(t) = 90%, t90% = 𝜎 Tr10%-90% = | t90% -t10% | = 1.69𝜎 Frequency (Hz)

  5. Simulation Results Assume Square wave signal, Tr10%-90% = 1ns, T = 10ns, Duty Cycle = 50% fknee = 0.32/ Tr10%-90% = 0.32/1ns = 0.32 GHz

  6. Simulation Results K = 0.27 K = 0.32 K = 0.5

  7. Thank you! Questions?

More Related