Digital-electronics 简明教程

Types of Signals

在电子工程中，用于传输数据或信息的电气量，例如电压或电流或电磁波，称为 signal 。

In electronics engineering, an electrical quantity like voltage or current or electromagnetic wave that is used for transmission of data or information is called a signal.

信号被认为是任何数据通信或处理系统的核心，例如互联网。信号指示电子硬件组件执行某项任务，例如将信息从一点传送到另一点。

Signals are considered the heart of any data communication or processing system like the Internet. Signals instruct the electronics hardware components to perform a certain task such as convey the information from one point to another.

除了电压、电流或电磁信号外，我们还有 optical signals ，其中信息以光的形式表示和传输。

Apart from voltage, current or electromagnetic signals, we also have optical signals, where the information is represented and transmitted in the form of light.

本章将解释信号的概念以及电子工程中使用的不同类型的信号。

This chapter will explain the concept of signal and different types of signals used in electronics engineering.

What is a Signal?

具有将信息从一点传输到另一点的能力的物理量称为 signal 。信号的一些常见 examples 包括电压、电流、电磁波、光信号等。

A physical quantity that has capability to transmit information from one point to another is called a signal. Some common examples of signals include voltage, current, electromagnetic wave, optical signals, etc.

信号是任何电子处理或通信系统的支柱。它们可以通过各种类型的通信信道传输，如电线、空间（电磁波）、光纤等。

Signals are the backbone of any electronic processing or communication system. These can be transmitted through various types of communication channels like wires, space (electromagnetic waves), optical fibers, etc.

Properties of Signal

在电子学中，信号具有以下重要特性−

In electronics, a signal is characterized by the following important properties −

  1. Magnitude − The intensity or maximum value of a signal is termed as its magnitude.

  2. Frequency − The number of oscillations per second is called frequency of the signal.

  3. Time period − The time taken to complete one oscillation is called the time period of the signal.

Types of Signals

在电子学中，主要使用两种类型的信号，它们是 −

In electronics, there are mainly two types of signals used, they are −

  1. Analog Signals

  2. Digital Signals

让我们详细讨论这两种类型的信号。

Let us discuss these two types of signals in detail.

What is an Analog Signal?

一种在给定范围内具有连续值的电子信号称为模拟信号。模拟信号表示为时间的连续函数。它们表示为连续变化电流或电压的波形。

A type of electronic signal that has continuous values within a given range is called an analog signal. Analog signals are expressed as the continuous functions of time. They are represented as the waveforms of continuously varying current or voltage.

模拟信号的 Example 包括语音、速度、压力、温度等。

Example of analog signals are voice, speed, pressure, temperature, etc.

digital electronics analog signal

模拟信号的一个重要特征是它们在每个时间点都具有一个确定的值，称为 instantaneous value of the signal 。

An important characteristic of analog signals is that they have a definite value at every instant of time, known as instantaneous value of the signal.

模拟信号具有平滑的波形，因为它们在幅度和时间上都是连续的。这意味着，它们在时间上的表示没有中断。

Analog signals have smooth waveforms as they are continuous in both amplitude and time. That meant, there is no interruptions in their representation over time.

Properties of Analog Signal

以下是模拟信号的主要特性：

The following are main properties of analog signals −

  1. Analog signals are continuous signals in both amplitude and time.

  2. Analog signals have a certain value or magnitude at any given instant of time.

  3. Analog signals have infinite resolution.

  4. Analog signals are best suited for representing the real-world phenomena.

  5. Analog signals are represented by the continuously varying smooth waveforms.

What is a Digital Signal?

digital signal 是一种电子信号，它具有表示信息的一组有限的离散值。

A digital signal is a type of electronic signal that has a finite set of discrete values representing information.

digital signal

数字信号也称为二进制信号，因为它们使用二进制 0 或 1 来表示信号的状态。其中，二进制 0 表示信号的关或低状态，而二进制 1 表示信号的开或高状态。

Digital signals are also called binary signals, as they use binary 0 or 1 to represent the state of a signal. Where, the binary 0 represents the off or low state of the signal, while the binary 1 represents the on or high state of the signal.

因此，数字信号表示为时间的非连续函数。

Thus, digital signals are expressed as discontinuous functions of time.

Properties of Digital Signal

以下是数字信号的一些主要特征：

The following are some key characteristics of digital signals −

  1. Digital signals have discrete or discontinuous values in terms of both amplitude and time.

  2. Digital signals do not have values defined between any two distinct instants of time.

  3. Digital signals are represented using binary system by sampling the values of the signals at specific time instants.

  4. Digital signals represent information in the form of a sequence of binary 0s and 1s.

  5. Digital signals have a finite resolution.

  6. Digital signals are capable to perform logical operations.

  7. Digital signals are more efficient and reliable when it comes to storage and transmission.

Difference between Analog and Digital Signals

现在，我们讨论一下模拟信号和数字信号之间的重要差异 -

Let us now discuss the important differences between analog and digital signals −

Key

Analog Signals

Digital Signals

Representation

Analog signals are represented as continuous functions or waveforms of time.

Digital signals are represented as discrete functions of time.

Nature

Analog signals are continuous as they have infinite values within a specified range.

Digital signals are discontinuous as they have distinct values sampled at specific time instants.

Resolution

Analog signals have infinite resolution.

Digital signals have a finite resolution.

Accuracy

Analog signals are more accurate.

Digital signals are relatively less accurate.

Storage

Analog signals are difficult to store.

Digital signals are efficient to store.

Noise immunity

Analog signals are less immune to noise.

Digital signals have high immunity against noise.

Examples

Voice signals, temperature, speed, etc.

Data transmitted over internet, computer generated signals, etc.

Applications of Signals

模拟信号和数字信号都广泛应用于电子领域。以下是信号的一些关键应用 -

Both analog and digital signals are widely used in the field of electronics. The following are some key applications of signals −

  1. Signals are used for storage and transmission of information.

  2. Signals are used in control systems to regulate their behavior.

  3. Signals are also used in measurement of physical quantities like temperature, pressure, speed, sound, light, and more.

  4. Signals are used in computing systems for data processing, etc.

Conclusion

在电子工程中，信号是一个系统的最重要的元素。信号只不过是电压、电流、电磁波、光脉冲等物理量，用于传达从一点到另一点的信息。

In electronics engineering, signals are most significant elements of a system. Signals are nothing but physical quantities like voltage, current, electromagnetic waves, light pulses, etc. used to convey information from one point to another.

在本章中，我们介绍了不同类型的信号及其属性。在下一章中，我们将介绍逻辑电平和脉冲波形的概念。

In this chapter, we covered different types of signals and their properties. In the next chapter, we will cover the concept of logic levels and pulse waveform.