Change folder location and add note
PinkR1ver
7
content/.trash/research_plan_MayToJuly.md
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|||||||
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---
|
||||||
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title: 科研计划 5月 - 7月
|
||||||
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tags:
|
||||||
|
- plan
|
||||||
|
date: 2024-04-29
|
||||||
|
---
|
||||||
|
|
||||||
@ -20,7 +20,7 @@ date: 2024-02-28
|
|||||||
|
|
||||||
* [Physics](physics/physics_MOC.md)
|
* [Physics](physics/physics_MOC.md)
|
||||||
|
|
||||||
* [Signal Processing](signal_processing/signal_processing_MOC.md)
|
* [Signal Processing](signal/signal_processing/signal_processing_MOC.md)
|
||||||
|
|
||||||
* [Data Science](data_sci/data_sci_MOC.md)
|
* [Data Science](data_sci/data_sci_MOC.md)
|
||||||
|
|
||||||
|
|||||||
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26
content/computer_sci/multiThread_and_multiProcess/basic.md
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|
|||||||
|
---
|
||||||
|
title: What's Multi-Thread and Multi-Process Coding
|
||||||
|
tags:
|
||||||
|
- multi-code
|
||||||
|
- advanced
|
||||||
|
- code-design
|
||||||
|
date: 2024-04-26
|
||||||
|
---
|
||||||
|
|
||||||
|
|
||||||
|
# Introduction
|
||||||
|
|
||||||
|
|
||||||
|
## Thread vs. Process
|
||||||
|
|
||||||
|
### Overview
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
### Process
|
||||||
|
|
||||||
|
|
||||||
|
# Reference
|
||||||
|
|
||||||
|
* https://ycc.idv.tw/multithread-multiprocess-gil.html
|
||||||
|
* [https://www.youtube.com/watch?v=4rLW7zg21gI⭐⭐⭐](https://www.youtube.com/watch?v=4rLW7zg21gI)
|
||||||
BIN
content/plan/research_plan/科研计划Main Thread.xmind
Normal file
@ -56,7 +56,7 @@ Diodes:
|
|||||||
|
|
||||||
In this article, [Circularly Polarized Ultra-Wideband Radar System for Vital Signs Monitoring](https://ieeexplore.ieee.org/document/6491501), it uses AD9959 DDS to control UWB pulse repetition frequency (PRF). This DDS has the capability to generate sinusoids up to 250MHz at 0.1-Hz frequency tuning resolution. The DDS has four channels, one for transmitting pulse, one for storing reference pulse from receiver.
|
In this article, [Circularly Polarized Ultra-Wideband Radar System for Vital Signs Monitoring](https://ieeexplore.ieee.org/document/6491501), it uses AD9959 DDS to control UWB pulse repetition frequency (PRF). This DDS has the capability to generate sinusoids up to 250MHz at 0.1-Hz frequency tuning resolution. The DDS has four channels, one for transmitting pulse, one for storing reference pulse from receiver.
|
||||||
|
|
||||||
The outputs from the DDS, the sinusoids will be amplified by [op-amps](signal_processing/device_and_components/op_amp.md)(Texas Instruments Incorporated OPA699, in this article). After amplifying, the signal will be fed to [step recovery diode](signal_processing/device_and_components/SRD.md)(SRD).
|
The outputs from the DDS, the sinusoids will be amplified by [op-amps](signal/signal_processing/device_and_components/op_amp.md)(Texas Instruments Incorporated OPA699, in this article). After amplifying, the signal will be fed to [step recovery diode](signal/signal_processing/device_and_components/SRD.md)(SRD).
|
||||||
|
|
||||||
The **cascaded shunt mode SRD** with **decreasing lifetime method** of pulse generation produces high amplitude pulses of 3 $V_{p-p}$ at low PRFs (megahertz range), thus the pulse generator can directly drive the antenna subsystem saving the need for expensive broadband power amplifiers
|
The **cascaded shunt mode SRD** with **decreasing lifetime method** of pulse generation produces high amplitude pulses of 3 $V_{p-p}$ at low PRFs (megahertz range), thus the pulse generator can directly drive the antenna subsystem saving the need for expensive broadband power amplifiers
|
||||||
|
|
||||||
|
|||||||
@ -56,7 +56,7 @@ Diodes:
|
|||||||
|
|
||||||
In this article, [Circularly Polarized Ultra-Wideband Radar System for Vital Signs Monitoring](https://ieeexplore.ieee.org/document/6491501), it uses AD9959 DDS to control UWB pulse repetition frequency (PRF). This DDS has the capability to generate sinusoids up to 250MHz at 0.1-Hz frequency tuning resolution. The DDS has four channels, one for transmitting pulse, one for storing reference pulse from receiver.
|
In this article, [Circularly Polarized Ultra-Wideband Radar System for Vital Signs Monitoring](https://ieeexplore.ieee.org/document/6491501), it uses AD9959 DDS to control UWB pulse repetition frequency (PRF). This DDS has the capability to generate sinusoids up to 250MHz at 0.1-Hz frequency tuning resolution. The DDS has four channels, one for transmitting pulse, one for storing reference pulse from receiver.
|
||||||
|
|
||||||
The outputs from the DDS, the sinusoids will be amplified by [op-amps](signal_processing/device_and_components/op_amp.md)(Texas Instruments Incorporated OPA699, in this article). After amplifying, the signal will be fed to [step recovery diode](signal_processing/device_and_components/SRD.md)(SRD).
|
The outputs from the DDS, the sinusoids will be amplified by [op-amps](signal/signal_processing/device_and_components/op_amp.md)(Texas Instruments Incorporated OPA699, in this article). After amplifying, the signal will be fed to [step recovery diode](signal/signal_processing/device_and_components/SRD.md)(SRD).
|
||||||
|
|
||||||
The **cascaded shunt mode SRD** with **decreasing lifetime method** of pulse generation produces high amplitude pulses of 3 $V_{p-p}$ at low PRFs (megahertz range), thus the pulse generator can directly drive the antenna subsystem saving the need for expensive broadband power amplifiers
|
The **cascaded shunt mode SRD** with **decreasing lifetime method** of pulse generation produces high amplitude pulses of 3 $V_{p-p}$ at low PRFs (megahertz range), thus the pulse generator can directly drive the antenna subsystem saving the need for expensive broadband power amplifiers
|
||||||
|
|
||||||
|
|||||||
@ -20,7 +20,7 @@ $$
|
|||||||
H(\mu)(t) = \frac{1}{\pi} \text{p.v.} \int_{\infty}^{\infty} \frac{\mu(t)}{t-\tau}d\tau
|
H(\mu)(t) = \frac{1}{\pi} \text{p.v.} \int_{\infty}^{\infty} \frac{\mu(t)}{t-\tau}d\tau
|
||||||
$$
|
$$
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
```MATLAB
|
```MATLAB
|
||||||
analytical = hilbert(signal)
|
analytical = hilbert(signal)
|
||||||
|
|||||||
9
content/signal/hardware/frequency_mixer.md
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|
|||||||
|
---
|
||||||
|
title: Frequency Mixer
|
||||||
|
tags:
|
||||||
|
- hardware
|
||||||
|
- basic
|
||||||
|
- ciruit
|
||||||
|
- ciruit-componets
|
||||||
|
date: 2024-04-28
|
||||||
|
---
|
||||||
|
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@ -20,11 +20,11 @@ EMD is similar to Fourier Transform (FT). FT assumes our signal is periodic and
|
|||||||
|
|
||||||
## Overview
|
## Overview
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
## Flow Chart
|
## Flow Chart
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
## Step by Step
|
## Step by Step
|
||||||
|
|
||||||
@ -47,7 +47,7 @@ Input $x(t)$,
|
|||||||
* Residuum signal is just a constant, monotonic, or just have 1 extremum
|
* Residuum signal is just a constant, monotonic, or just have 1 extremum
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
## Hilbert Spectral Analysis (HSA)
|
## Hilbert Spectral Analysis (HSA)
|
||||||
@ -56,11 +56,11 @@ Input $x(t)$,
|
|||||||
|
|
||||||
To see:
|
To see:
|
||||||
|
|
||||||
[Instantaneous Frequency⭐](signal_processing/basic_knowledge/instantaneous_frequency.md)
|
[Instantaneous Frequency⭐](signal/signal_processing/basic_knowledge/instantaneous_frequency.md)
|
||||||
|
|
||||||
### HSA after EMD
|
### HSA after EMD
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
得到这些IMF之后，我们的信号$x(t)$可以表达为，
|
得到这些IMF之后，我们的信号$x(t)$可以表达为，
|
||||||
|
|
||||||
@ -11,25 +11,25 @@ date: 2024-04-23
|
|||||||
|
|
||||||
# Intro
|
# Intro
|
||||||
|
|
||||||
集合经验模态分解（Ensemble Empirical Mode Decomposition, EEMD）是一种改进的[EMD](signal_processing/algorithm/EMD/basic.md)方法，它通过引入白噪声来解决EMD中的**模态混叠问题**。
|
集合经验模态分解（Ensemble Empirical Mode Decomposition, EEMD）是一种改进的[EMD](signal/signal_processing/algorithm/EMD/basic.md)方法，它通过引入白噪声来解决EMD中的**模态混叠问题**。
|
||||||
|
|
||||||
|
|
||||||
模态混叠是指在分解过程中，不同时间尺度的信号成分错误地混合在一起，导致分解结果不准确。
|
模态混叠是指在分解过程中，不同时间尺度的信号成分错误地混合在一起，导致分解结果不准确。
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
上述figure就是一个很好的例子，连续低频正弦信号上叠加了间歇性高频震动的调制信号，因为间歇性高频震动的调制信号干扰了Maximum点的选择，使得局部极值在很短的时间间隔发生多次跳变，进而使得我们的IMF并不准确，不同时间尺度的信号成分错误地混合在一起。
|
上述figure就是一个很好的例子，连续低频正弦信号上叠加了间歇性高频震动的调制信号，因为间歇性高频震动的调制信号干扰了Maximum点的选择，使得局部极值在很短的时间间隔发生多次跳变，进而使得我们的IMF并不准确，不同时间尺度的信号成分错误地混合在一起。
|
||||||
|
|
||||||
以下我们也通过我们写的EMD做了示范：
|
以下我们也通过我们写的EMD做了示范：
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
很明显，在IMF1，发生了混叠
|
很明显，在IMF1，发生了混叠
|
||||||
|
|
||||||
@ -190,11 +190,11 @@ def EEMD(signal, max_imf = 10, tolerance = 0.01, iterations = 10):
|
|||||||
|
|
||||||
通过EEMD，结果如下：
|
通过EEMD，结果如下：
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
EEMD的前几个IMF将高频噪声和白噪声过滤，在IMF7显示了信号原有的模态
|
EEMD的前几个IMF将高频噪声和白噪声过滤，在IMF7显示了信号原有的模态
|
||||||
# Reference
|
# Reference
|
||||||
@ -0,0 +1,8 @@
|
|||||||
|
---
|
||||||
|
title: Power spectral density estimation
|
||||||
|
tags:
|
||||||
|
- signal-processing
|
||||||
|
- statistics
|
||||||
|
date: 2023-11-30
|
||||||
|
---
|
||||||
|
[Power spectral density estimation](signal/signal_processing/basic_knowledge/concept/Spectral_density.md)(PSDE, or SDE)，功率谱估计是随机信号处理的重要研究内容之一
|
||||||
|
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|
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|
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@ -31,9 +31,9 @@ cov(X, Y) & = \frac{\sum(x-\overline{x})(y-\overline{y})}{n-1} \\
|
|||||||
\end{split}
|
\end{split}
|
||||||
\end{equation}
|
\end{equation}
|
||||||
$$
|
$$
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Covariance is hard to **interpret** because it is sensitive to the **scale**
|
Covariance is hard to **interpret** because it is sensitive to the **scale**
|
||||||
@ -43,7 +43,7 @@ To solve the scale effect, here's the correlation:
|
|||||||
|
|
||||||
## Correlation
|
## Correlation
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
We can quantify the strength of the relationship with correlation (**Pearson’s correlation**)
|
We can quantify the strength of the relationship with correlation (**Pearson’s correlation**)
|
||||||
@ -61,13 +61,13 @@ $corr(X, Y)$ is between -1 to 1
|
|||||||
> NOTE: When we’re talking about correlation, we’re only talking about using **straight line**
|
> NOTE: When we’re talking about correlation, we’re only talking about using **straight line**
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
For correlation, we usually use **p-value** to **quantify the confidence** of the straight line relationship. **The more samll p-value, the more confident we say they are straight line relationship**; Like the figure:
|
For correlation, we usually use **p-value** to **quantify the confidence** of the straight line relationship. **The more samll p-value, the more confident we say they are straight line relationship**; Like the figure:
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
About P-value, you have better know what's [significance test](math/Statistics/significance_test/whats_the_significance_test.md)
|
About P-value, you have better know what's [significance test](math/Statistics/significance_test/whats_the_significance_test.md)
|
||||||
@ -221,7 +221,7 @@ $$
|
|||||||
# Application
|
# Application
|
||||||
|
|
||||||
|
|
||||||
* [Period Detection by Autocorrelation](signal_processing/algorithm/advanced_statistic/autocorrelation/period_detection.md)
|
* [Period Detection by Autocorrelation](signal/signal_processing/algorithm/advanced_statistic/autocorrelation/period_detection.md)
|
||||||
# Reference
|
# Reference
|
||||||
|
|
||||||
* https://pinkr1ver.notion.site/Autocorrelation-Analysis-Power-Spectral-Density-330755770347472989062c6b31f18a21?pvs=4
|
* https://pinkr1ver.notion.site/Autocorrelation-Analysis-Power-Spectral-Density-330755770347472989062c6b31f18a21?pvs=4
|
||||||
@ -10,4 +10,4 @@ date: 2024-03-18
|
|||||||
# Method
|
# Method
|
||||||
|
|
||||||
* [DTW(Dynamic Time Warping)](computer_sci/deep_learning_and_machine_learning/Trick/DTW.md)
|
* [DTW(Dynamic Time Warping)](computer_sci/deep_learning_and_machine_learning/Trick/DTW.md)
|
||||||
* [Manhattan Distance](signal_processing/algorithm/curve_similarity/manhattan_distance.md)
|
* [Manhattan Distance](signal/signal_processing/algorithm/curve_similarity/manhattan_distance.md)
|
||||||
|
Before Width: | Height: | Size: 148 KiB After Width: | Height: | Size: 148 KiB |
|
Before Width: | Height: | Size: 21 KiB After Width: | Height: | Size: 21 KiB |
|
Before Width: | Height: | Size: 593 KiB After Width: | Height: | Size: 593 KiB |
@ -9,7 +9,7 @@ date: 2024-01-12
|
|||||||
|
|
||||||
# Introduction
|
# Introduction
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
# Envelope Explanation
|
# Envelope Explanation
|
||||||
## Envelope and Fine Structure
|
## Envelope and Fine Structure
|
||||||
@ -36,7 +36,7 @@ date: 2024-01-12
|
|||||||
|
|
||||||
早期关于包络和瞬时相位的研究都是基于笛卡尔坐标系x-y
|
早期关于包络和瞬时相位的研究都是基于笛卡尔坐标系x-y
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
有关系：
|
有关系：
|
||||||
$$
|
$$
|
||||||
@ -73,7 +73,7 @@ $$
|
|||||||
H(\mu)(t) = \frac{1}{\pi} \text{p.v.} \int_{\infty}^{\infty} \frac{\mu(t)}{t-\tau}d\tau
|
H(\mu)(t) = \frac{1}{\pi} \text{p.v.} \int_{\infty}^{\infty} \frac{\mu(t)}{t-\tau}d\tau
|
||||||
$$
|
$$
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
The Hilbert transform is given by the [Cauchy principal value](math/real_analysis/cauchy_principal_value.md) of the convolution with the function $1/(\pi t)$.
|
The Hilbert transform is given by the [Cauchy principal value](math/real_analysis/cauchy_principal_value.md) of the convolution with the function $1/(\pi t)$.
|
||||||
|
Before Width: | Height: | Size: 164 KiB After Width: | Height: | Size: 164 KiB |
|
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@ -54,7 +54,7 @@ T_{n+1}(x) & = 2xT_n(x)-T_{n-1}(x)
|
|||||||
\end{split}
|
\end{split}
|
||||||
\end{equation}
|
\end{equation}
|
||||||
$$
|
$$
|
||||||
|
|
||||||
#### 第二类切比雪夫多项式
|
#### 第二类切比雪夫多项式
|
||||||
|
|
||||||
$$
|
$$
|
||||||
@ -67,7 +67,7 @@ U_{n+1}(x) & = 2xU_n(x) - U_{n-1}(x)
|
|||||||
\end{equation}
|
\end{equation}
|
||||||
$$
|
$$
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
### 正交性
|
### 正交性
|
||||||
|
|
||||||
@ -7,13 +7,13 @@ date: 2023-11-30
|
|||||||
---
|
---
|
||||||
# Almost Fourier Transform
|
# Almost Fourier Transform
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
It is important to see there are 2 different frequencies here:
|
It is important to see there are 2 different frequencies here:
|
||||||
1. The frequency of the original signal
|
1. The frequency of the original signal
|
||||||
2. The frequency with which the **little rotating vector winds around the circle**
|
2. The frequency with which the **little rotating vector winds around the circle**
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Different patterns appear as we wind up this graph, but it is clear that the x-coordinate for the center of mass is important when the winding frequency is 3; The same number as the original signal
|
Different patterns appear as we wind up this graph, but it is clear that the x-coordinate for the center of mass is important when the winding frequency is 3; The same number as the original signal
|
||||||
|
|
||||||
@ -28,7 +28,7 @@ $$
|
|||||||
因为在Fourier transform中，convention way是顺时针旋转，所以使用$e^{-2\pi ift}$，那如何衡量center of mass呢，如下图：
|
因为在Fourier transform中，convention way是顺时针旋转，所以使用$e^{-2\pi ift}$，那如何衡量center of mass呢，如下图：
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
$$
|
$$
|
||||||
@ -43,7 +43,7 @@ $$
|
|||||||
|
|
||||||
这个就是Almost Fourier Transform, 但是实际情况上，Fourier transform倾向于得到scaled center mass，越长的time，旋转越多圈，其Fourier transform也会成倍放大
|
这个就是Almost Fourier Transform, 但是实际情况上，Fourier transform倾向于得到scaled center mass，越长的time，旋转越多圈，其Fourier transform也会成倍放大
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
# Fourier Transform (FT)
|
# Fourier Transform (FT)
|
||||||
@ -118,7 +118,7 @@ $$
|
|||||||
|
|
||||||
## 复数形式推导
|
## 复数形式推导
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
## 三角函数推导
|
## 三角函数推导
|
||||||
@ -184,7 +184,7 @@ $$
|
|||||||
|
|
||||||
**For $X[k]$, it means a $\cos$ wine like this:**
|
**For $X[k]$, it means a $\cos$ wine like this:**
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
# Fast Fourier transform(FFT)
|
# Fast Fourier transform(FFT)
|
||||||
|
|
||||||
|
Before Width: | Height: | Size: 1.1 MiB After Width: | Height: | Size: 1.1 MiB |
|
Before Width: | Height: | Size: 790 KiB After Width: | Height: | Size: 790 KiB |
|
Before Width: | Height: | Size: 481 KiB After Width: | Height: | Size: 481 KiB |
|
Before Width: | Height: | Size: 132 KiB After Width: | Height: | Size: 132 KiB |
|
Before Width: | Height: | Size: 1.9 MiB After Width: | Height: | Size: 1.9 MiB |
|
Before Width: | Height: | Size: 368 KiB After Width: | Height: | Size: 368 KiB |
|
Before Width: | Height: | Size: 53 KiB After Width: | Height: | Size: 53 KiB |
|
Before Width: | Height: | Size: 314 KiB After Width: | Height: | Size: 314 KiB |
|
Before Width: | Height: | Size: 1.4 MiB After Width: | Height: | Size: 1.4 MiB |
|
Before Width: | Height: | Size: 1.4 MiB After Width: | Height: | Size: 1.4 MiB |
@ -33,7 +33,7 @@ $$
|
|||||||
平稳信号具有Ergodicity，即各态历经，即多样本**集合平均**和单一样本**时间平均**相同
|
平稳信号具有Ergodicity，即各态历经，即多样本**集合平均**和单一样本**时间平均**相同
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
$$
|
$$
|
||||||
\mu_x=E\{x(n)\}=\lim_{M\rightarrow\infty}\frac{1}{2M+1}\sum_{n=-M}^Mx(n)
|
\mu_x=E\{x(n)\}=\lim_{M\rightarrow\infty}\frac{1}{2M+1}\sum_{n=-M}^Mx(n)
|
||||||
@ -70,7 +70,7 @@ $$
|
|||||||
|
|
||||||
对于拥有Ergodicity的信号，可以用时间平均代替集合平均，即
|
对于拥有Ergodicity的信号，可以用时间平均代替集合平均，即
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
$$
|
$$
|
||||||
@ -47,7 +47,7 @@ $$
|
|||||||
|
|
||||||
最后一个等式来自无穷几何级数，而等式仅在 $|0.5z^{−1}| < 1$ 时成立，可以以 z 为变量写成 $|z| > 0.5$。因此，收敛域为 $|z| > 0.5$。在这种情况下，收敛域为复平面“挖掉”原点为中心的半径为 0.5 的圆盘。
|
最后一个等式来自无穷几何级数，而等式仅在 $|0.5z^{−1}| < 1$ 时成立，可以以 z 为变量写成 $|z| > 0.5$。因此，收敛域为 $|z| > 0.5$。在这种情况下，收敛域为复平面“挖掉”原点为中心的半径为 0.5 的圆盘。
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
@ -28,4 +28,4 @@ date: 2023-11-02
|
|||||||
|
|
||||||
总之，阶跃恢复二极管（SRD）是一种特殊的二极管，它在高频、脉冲和微波应用中具有广泛的应用，因为它可以产生非常快速的电流和电压变化，适用于各种电子电路中的特殊应用。
|
总之，阶跃恢复二极管（SRD）是一种特殊的二极管，它在高频、脉冲和微波应用中具有广泛的应用，因为它可以产生非常快速的电流和电压变化，适用于各种电子电路中的特殊应用。
|
||||||
|
|
||||||
|
|
||||||
@ -18,7 +18,7 @@ About what is VNA: [VNA Research](research_career/UWB_about/report/VNA_research.
|
|||||||
|
|
||||||
1. Reference Calibration
|
1. Reference Calibration
|
||||||
|
|
||||||
基准校准是通过标准的开路、短路和负载器（Load）标准件来进行校准；因为这些标准件已经知道它们的[S参数](signal_processing/basic_knowledge/concept/scattering_parameters.md)响应，因此可以用来校准
|
基准校准是通过标准的开路、短路和负载器（Load）标准件来进行校准；因为这些标准件已经知道它们的[S参数](signal/signal_processing/basic_knowledge/concept/scattering_parameters.md)响应，因此可以用来校准
|
||||||
|
|
||||||
在LiteVNA产品中，
|
在LiteVNA产品中，
|
||||||
* 中间没有内针的为开路校准件
|
* 中间没有内针的为开路校准件
|
||||||
@ -49,24 +49,24 @@ About what is VNA: [VNA Research](research_career/UWB_about/report/VNA_research.
|
|||||||
|
|
||||||
### Verify Calibration
|
### Verify Calibration
|
||||||
|
|
||||||
可以使用[Smith Graph](signal_processing/basic_knowledge/concept/smith_graph.md)来验证我们的Calibration
|
可以使用[Smith Graph](signal/signal_processing/basic_knowledge/concept/smith_graph.md)来验证我们的Calibration
|
||||||
|
|
||||||
开路状态下，Smith Graph的标记点应该在电阻线的最右端，表明阻抗无限大，且表现出纯电阻性
|
开路状态下，Smith Graph的标记点应该在电阻线的最右端，表明阻抗无限大，且表现出纯电阻性
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
PORT1链接短路校准件，查看史密斯图标记点应该在史密斯图上电阻线的最左端(阻抗为0，并且表现纯电阻性)。
|
PORT1链接短路校准件，查看史密斯图标记点应该在史密斯图上电阻线的最左端(阻抗为0，并且表现纯电阻性)。
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
PORT1链接50欧姆校准件，查看史密斯图标记点应该在史密斯图上电阻线的中心(阻抗为50欧姆，并且表现纯电阻性)。
|
PORT1链接50欧姆校准件，查看史密斯图标记点应该在史密斯图上电阻线的中心(阻抗为50欧姆，并且表现纯电阻性)。
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
链接一根可以确认阻抗与谐振都正常的天线（可以把一根天线定位对照组并妥善保管），可以通过拨轮移动标记点至[驻波比](signal_processing/basic_knowledge/concept/SWR.md)最低点，并同步观察该频率在史密斯图上的点是否在正中心（或者无限接近中心）。同时可以看屏幕最上面的参数，如图显示，我的这条对照天线最好的驻波比为1.021，此时对应的频率2.455GHz，史密斯图中阻抗为50.72Ω+j748mΩ
|
链接一根可以确认阻抗与谐振都正常的天线（可以把一根天线定位对照组并妥善保管），可以通过拨轮移动标记点至[驻波比](signal/signal_processing/basic_knowledge/concept/SWR.md)最低点，并同步观察该频率在史密斯图上的点是否在正中心（或者无限接近中心）。同时可以看屏幕最上面的参数，如图显示，我的这条对照天线最好的驻波比为1.021，此时对应的频率2.455GHz，史密斯图中阻抗为50.72Ω+j748mΩ
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
###
|
###
|
||||||
|
|
||||||
|
Before Width: | Height: | Size: 16 KiB After Width: | Height: | Size: 16 KiB |
|
Before Width: | Height: | Size: 16 KiB After Width: | Height: | Size: 16 KiB |
|
Before Width: | Height: | Size: 16 KiB After Width: | Height: | Size: 16 KiB |
|
Before Width: | Height: | Size: 16 KiB After Width: | Height: | Size: 16 KiB |
|
Before Width: | Height: | Size: 18 KiB After Width: | Height: | Size: 18 KiB |
|
Before Width: | Height: | Size: 60 KiB After Width: | Height: | Size: 60 KiB |
|
Before Width: | Height: | Size: 228 KiB After Width: | Height: | Size: 228 KiB |
|
Before Width: | Height: | Size: 78 KiB After Width: | Height: | Size: 78 KiB |
|
Before Width: | Height: | Size: 68 KiB After Width: | Height: | Size: 68 KiB |
|
Before Width: | Height: | Size: 132 KiB After Width: | Height: | Size: 132 KiB |
|
Before Width: | Height: | Size: 40 KiB After Width: | Height: | Size: 40 KiB |
|
Before Width: | Height: | Size: 444 KiB After Width: | Height: | Size: 444 KiB |
|
Before Width: | Height: | Size: 100 KiB After Width: | Height: | Size: 100 KiB |
|
Before Width: | Height: | Size: 28 KiB After Width: | Height: | Size: 28 KiB |
|
Before Width: | Height: | Size: 48 KiB After Width: | Height: | Size: 48 KiB |
|
Before Width: | Height: | Size: 409 KiB After Width: | Height: | Size: 409 KiB |
|
Before Width: | Height: | Size: 750 KiB After Width: | Height: | Size: 750 KiB |
|
Before Width: | Height: | Size: 667 KiB After Width: | Height: | Size: 667 KiB |
|
Before Width: | Height: | Size: 725 KiB After Width: | Height: | Size: 725 KiB |
|
Before Width: | Height: | Size: 114 KiB After Width: | Height: | Size: 114 KiB |
|
Before Width: | Height: | Size: 109 KiB After Width: | Height: | Size: 109 KiB |
@ -8,7 +8,7 @@ date: 2023-12-05
|
|||||||
---
|
---
|
||||||
# Structure
|
# Structure
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
* Conductor is located at the center of the cable
|
* Conductor is located at the center of the cable
|
||||||
* Other layers is to protect
|
* Other layers is to protect
|
||||||
@ -79,7 +79,7 @@ date: 2023-12-05
|
|||||||
|
|
||||||
Chinese translation: 实心导体和绞合导体
|
Chinese translation: 实心导体和绞合导体
|
||||||
|
|
||||||
|
|
||||||
<center><strong>Solid Conductor is in left, Stranded Conductor is in right</strong></center>
|
<center><strong>Solid Conductor is in left, Stranded Conductor is in right</strong></center>
|
||||||
|
|
||||||
|
|
||||||
@ -100,7 +100,7 @@ Chinese translation: 实心导体和绞合导体
|
|||||||
> [!hint]
|
> [!hint]
|
||||||
> 根据前哥说的趋肤效应([Skin effect](https://zh.wikipedia.org/wiki/%E9%9B%86%E8%86%9A%E6%95%88%E6%87%89))，高频信号的电子喜欢在金属表面移动，因此实心导体可能已经被淘汰了。
|
> 根据前哥说的趋肤效应([Skin effect](https://zh.wikipedia.org/wiki/%E9%9B%86%E8%86%9A%E6%95%88%E6%87%89))，高频信号的电子喜欢在金属表面移动，因此实心导体可能已经被淘汰了。
|
||||||
>
|
>
|
||||||
> [skin effect note](signal_processing/device_and_components/cable/skin_effect.md)
|
> [skin effect note](signal/signal_processing/device_and_components/cable/skin_effect.md)
|
||||||
|
|
||||||
### Stranded Constructions
|
### Stranded Constructions
|
||||||
|
|
||||||
@ -111,9 +111,9 @@ Chinese translation: 实心导体和绞合导体
|
|||||||
|
|
||||||
#### Bunched Stranded Conductor
|
#### Bunched Stranded Conductor
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Bunched strands are simply gathered together without any specific arrangement.
|
Bunched strands are simply gathered together without any specific arrangement.
|
||||||
|
|
||||||
@ -121,7 +121,7 @@ Bunched strands are simply gathered together without any specific arrangement.
|
|||||||
|
|
||||||
#### Concentric Lay Stranded Conductor
|
#### Concentric Lay Stranded Conductor
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Concentric stranding (同心绞合)
|
Concentric stranding (同心绞合)
|
||||||
|
|
||||||
@ -146,17 +146,17 @@ In uni-lay stranding, every layer is twisted in the same direction.
|
|||||||
|
|
||||||
In a rope lay construction, the stranded conductors or strands are arranged in a spiral fashion to form a rope-like structure. This is a departure from the traditional uni-lay or multi-lay construction.
|
In a rope lay construction, the stranded conductors or strands are arranged in a spiral fashion to form a rope-like structure. This is a departure from the traditional uni-lay or multi-lay construction.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
# Cable Structure
|
# Cable Structure
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
1. **Standard Conductor（标准导体）：**
|
1. **Standard Conductor（标准导体）：**
|
||||||
|
|
||||||
@ -238,11 +238,11 @@ In a rope lay construction, the stranded conductors or strands are arranged in a
|
|||||||
|
|
||||||
# Letters on Cable
|
# Letters on Cable
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
## Size
|
## Size
|
||||||
|
|
||||||
* AWG - [American Wire Gauge](signal_processing/device_and_components/cable/AWG.md)
|
* AWG - [American Wire Gauge](signal/signal_processing/device_and_components/cable/AWG.md)
|
||||||
* $mm^2$ - Square millimeters
|
* $mm^2$ - Square millimeters
|
||||||
* MCM - Thousand Circular Mils
|
* MCM - Thousand Circular Mils
|
||||||
* KCMil - Thousand Circular Mils
|
* KCMil - Thousand Circular Mils
|
||||||
@ -272,7 +272,7 @@ In a rope lay construction, the stranded conductors or strands are arranged in a
|
|||||||
|
|
||||||
## Quality Control Certified
|
## Quality Control Certified
|
||||||
|
|
||||||
* [UL, TUV, ISO ... ...](signal_processing/device_and_components/quality_control_certified/qcc.md)
|
* [UL, TUV, ISO ... ...](signal/signal_processing/device_and_components/quality_control_certified/qcc.md)
|
||||||
|
|
||||||
# Cable Properties - Especially for RF circuit
|
# Cable Properties - Especially for RF circuit
|
||||||
|
|
||||||
@ -286,7 +286,7 @@ RF cables are quite different to audio cables. As in audio cables we can run cab
|
|||||||
* Frequency you're currently trying to transmit
|
* Frequency you're currently trying to transmit
|
||||||
* The length of the cable
|
* The length of the cable
|
||||||
|
|
||||||
RF circuits need to consider impedance matching, and the most likely to fluctuate in impedance is the cable. So the antenna cable we used for our radio systems is usually **[coax cable](signal_processing/device_and_components/cable/coax_cable.md) with a nice BNC connector**.
|
RF circuits need to consider impedance matching, and the most likely to fluctuate in impedance is the cable. So the antenna cable we used for our radio systems is usually **[coax cable](signal/signal_processing/device_and_components/cable/coax_cable.md) with a nice BNC connector**.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
@ -8,10 +8,10 @@ date: 2023-12-05
|
|||||||
---
|
---
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
A coaxial cable as a transmission line consisting of an inner conducting wire of radius A and an outer conducting sheath of radius B. The space between the two conductors is filled with a dielectric. The fields are entirely contained internally, so coaxial cables are completely protected from outside interference. However, they are difficult to fabricate, [unbalanced](signal_processing/device_and_components/cable/coax_cable_imbalance.md) and lossy over long distances, so their use is constrained to close range applications.
|
A coaxial cable as a transmission line consisting of an inner conducting wire of radius A and an outer conducting sheath of radius B. The space between the two conductors is filled with a dielectric. The fields are entirely contained internally, so coaxial cables are completely protected from outside interference. However, they are difficult to fabricate, [unbalanced](signal/signal_processing/device_and_components/cable/coax_cable_imbalance.md) and lossy over long distances, so their use is constrained to close range applications.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||