红外遥控系统毕业论文外文文献翻译

Infrared Remote Control System

Abstract

Red outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique,drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos etc.characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage.Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application.

The purpose that design this system is transmit customer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish customer’s operation demand.

Keywords:Infrare dray；Code；Decoding；LM386；Redoutside transceiver

1 Introduction

1.1 research the background and significance

Infrared Data Communication Technology is the world wide use of a wireless connection technology, by the many hardware and software platforms supported. Is a data through electrical pulses and infrared optical pulse switch between the wireless data transceiver technology.

Infrared transceiver products with low cost, small, fast transmission rate, the point-to-point transmission security, not subject to electromagnetic interference and other characteristics that can be achieved between the different products, rapid, convenient and safe exchange and transmission, In short distance wireless transmission have a very distinct advantage.

Infrared transceiver products in the portable product of a great role. At present, the world's 150 million piece of equipment used infrared technology in electronic products and industrial equipment. medical equipment and other fields widely used. For example, 95% of the notebook computers on the installation of infrared transceiver interface the majority of the cell phone is also the allocation of infrared transceiver interface. With the exchange of quantitative data, infrared data communications will enable cell phone data transmission more convenient. With infrared data transmission technology matures, perfect, low costs, Infrared Transceiver in short distance communications will be more widely applied.

This chapter first describes the infrared transceiver IC design issues to the background and significance. then briefed the infrared data communications technology features and applications, and infrared transceiver product characteristics, domestic and international situation and development trend of the last under infrared remote transceiver system in practical application to establish a task of design orientation.

1.2 Infrared Remote ControlTransceiver System

Infrared remote control system is divided into single-channel and multi-channel remote control. Only a command signal transmission channel, called single-channel remote control system; with more than two instructions signal transmission channel known as a multi-channel remote control system. Relatively simple single-channel remote control, in general, only a launcher directive Key receivers and only one circuit implementation. While in the receiving circuit to add more stable memory circuits that can be activated commands to launch a number of key, so that the receiver circuit multistable memory circuit repeatedly to change the state, to realize many of the functional control, But such a state of change is the order. If we are to achieve an arbitrary control, resort to the use of multi-channel remote control system. Multi-channel remote control can be realized by the object of arbitrary multi-function remote control. As for the choice of several routes and what control methods, according to the actual situation (such as object, operational requirements and cost accounting, etc.) to decide. General infrared remote transceiver system by infrared remote control transmitter signal coding, infrared remote control signal receivers and decoders (or decoder chip MCU) and the external circuit consisting of three parts. Signal transmitter remote control code used to generate pulses of infrared emission-driven output infrared remote control signal, receiver completion of the remote control signal amplification and detection, plastic and demodulation encoding pulse. Infrared remote control coded pulse is going to obtain a continuous serial binary code, and for most of the infrared transceiver system, This serial code as micro-controller of the remote control input signals from the internal CPU completion of the remote control instruction decoder, on the other infrared remote control transceivers, the designers of electronic products, The internal micro-controller of the remote control decoder directive is not accessible.

Therefore, people are using infrared encoder / decoder chip and microcontroller developed various generic infrared remote transceiver system, In various equipment infrared signals between the transceiver.

Remote transceiver system generally transmitters and receivers is composed of two parts. Launchers from the general direction keys, coded instructions circuit modulation circuit, driving circuit, firing circuit of several parts. When pressed a key, the directive coding circuit, in the corresponding instructions encoded signal, the encoder signal to the carrier modulation, Driven by the power amplifier circuit after circuit fired from the field after firing instructions coded modulation signals. General receiver by the receiving circuit, the amplifier circuit, demodulation circuits, instruction decoder circuit, driving circuit, circuit implementation of several parts. Receiving Circuit will launch vehicles have been coded modulation signal receiving instructions from, and to enlarge evacuation demodulation circuit. Demodulation circuit will have the coding modulation signal demodulation, namely, reduction of signal coding. The instruction decoder to the encoder signal decoding, Driven by the final circuit to drive the implementation of various instructions circuit to control the operation.

1.3 infrared remote control transceiver product profiles 1.3.1 infrared remote control transceiver product structure and type

Currently infrared transceiver in accordance with the mode of transmission rate and can be divided into four categories : Serial mode, the highest rate of 115.2 Kbps; medium-speed model : the highest rate of 0.567 Mbps and 1.152Mbps; High-speed mode : The maximum rate of 16 Mbps.

Also according to the size chip power consumption can be divided into low-power consumption and standard two categories, low-power type normally used 3 V power supply, transmission distance closer to about 0 - 30cm, which is commonly used standard 5V power supply, transmission distance away at least 1m

above.

1.3.2 infrared remote control transmitters of the status quo at home and abroad

Infrared communication technology in the development stage and there are several infrared communication standards, between different standards for infrared equipment can not infrared communication. To have all the infrared equipment to interoperability in 1993 by more than 20 large manufacturers initiated the establishment of an Infrared Data Association (IRDA) unified the infrared communication standards , which is currently widely used in infrared data communication protocols and standards, also known as the IRDA standard.

Since 1993 IRDA since the establishment of the Infrared Data Association members have developed to more than 150. IRDA standards of the industry has been widely recognized and supported. Has been developed with the infrared communications equipment have been as many as 100 species. IR module, installed capacity has reached 150 million sets. Although there is also a short distance wireless Bluetooth technology, But in infrared communication technology low cost and broad compatibility advantages, Infrared data communication in the future will still be a very long time inherent short-range wireless data communications fields play an important role.

1.3.3 Infrared Transceiver product development trend

In various infrared transceiver products, although the transmission rate, transmission distance and other characteristics, But infrared transceiver products has been towards improving the transmission rate, increase the transmission distance and lower power consumption, expanding launch reception angle of development. In particular, as the technology development and maturity, the means of transmission is moving in the direction of point-to-multipoint. Therefore infrared remote control transceiver products have broader prospects for development.

2 Infrared communication of knowledge

2.1 infrared ray foundation knowledge

2.1.1 infrared outlined

Infrared is actually a kind of electromagnetic wave. From the analysis of various natural component of the electromagnetic wave reflected spectrum is :-ray, x-ray, ultraviolet, visible, infrared, microwave and radio wave. From the viewpoint of form, and they did not seem to, but if the wavelength in descending order, and we will find him all the only visible light spectrum of the entire 0.38 μm - 0.76μm so long little area, and adjacent to the visible light and infrared (including the far infrared, mid-infrared and near infrared foreign) accounts for the spec trum of 0.76 μm - 1000μm of a major. Which micron wavelength range also includes UV, visible, near infrared, mid-infrared and far-infrared, microwave.

From the above analysis shows that infrared is a very rich spectrum resources, it currently has in production, life, military, medical, and other aspects have been widely used, such as infrared heating, medical infrared, infrared communication, infrared camera, infrared remote control, and so on. Infrared remote control is the many applications of infrared part of the current household appliances widely used in TV remote control, VCR remote control, VCD remote control, high-fidelity audio remote control, are used infra-red remote control, It allows the control of these appliances have become very easy.

2.1.2 infrared properties

Infrared lies between visible light and microwave a wave, it is with certain clinical characteristics of the wave. In the near-infrared, visible light and its adjacent, it is visible in certain characteristics, such as straight-line transmission, reflection, refraction, scattering, diffraction, can be certain

objects and can be absorbed through the lens of their focusing. In the far-infrared region, owing to its neighboring microwave, it has some characteristics of microwave, If a strong penetrating power and can run through some opaque substances. Since in any object, natural profession, regardless of whether its own luminescence (referring to visible light), as long as the temperature is above absolute zero (-273 °C), moment will be kept around to infrared radiation. Only higher temperature of objects strong infrared radiation, low-temperature objects infrared radiation weaker. Therefore infrared feature is the greatest common in nature, it is called thermal radiation called thermal radiation. Infrared cameras, infrared night market pyroelectric infrared detectors and some other missiles aiming at is the use of this characteristic of infrared work.

Infrared and visible light compared to another characteristic of a variety of colors. As the longest wavelength of visible light is a wavelength of the shortest times (780 nm-380 nm), So is called an octave. And infrared wavelength is the longest shortest wavelength of a times, and the longest wavelength infrared is the shortest wavelength of 10 times, that is, 10 octave. Therefore, if visible light can be expressed as seven colors, infrared may performance 70 colors, showing the rich colors. Infrared smoke through the good performance, which is also one of its features.

Because not visible to the infrared, it has little effect on the environment. By the wave infrared rays than the long wavelength radio waves, infrared remote control will not affect the nearby radio equipment. Another wavelength of less than 1.5μm near infrared light, transparent atmosphere in the visible light transmission characteristics much better than, because it close to the visible edge of the red light, linear transmission, reflection, refraction and absorption material and the physical characteristics very similar to visible light. Therefore, it can be used with similar visible focusing lens and other optical

devices. Because infrared remote control is not as remote as the radio through the barrier to control the object's ability to control, so in the design of household appliances infra-red remote control, wireless remote control as unnecessary, each set (transmitters and receivers) have different frequency or remote coding (Otherwise, wall will control or interference with neighbors household appliances), all similar products in the infrared remote control, The same can control the frequency or coding, and no remote control signal "drop." This universal infrared remote control provides a great convenience. Infrared to visible light, is very subtle and confidentiality, therefore, the security, Alert and other security devices have been widely used. Infrared remote control is simple in structure and easy, low-cost, anti-interference capability, high reliability are a number of advantages, is a close-up remote control, especially in indoor remote control optimized manner.

2.1.3 infrared diode characteristics

Infrared is not visible, people here are not aware of. Electronic technology is used infrared light emitting diode (also known as the IR emission diode) to generate infrared. Infrared remote control transceiver is using near-infrared transmission control instructions 0.76μm wavelength of ~ 1. 5μm. Near-infrared remote control as a light source, because there infrared light emitting diodes and infrared receiving device (photodiode. Transistor and PV) and the luminescence peak wavelength of light by the general 0.8μm ~ 0. 94μm. in the near-infrared band, both of the spectrum is the coincidence to a good match, access to higher transmission efficiency and higher reliability. Commonly used infrared diode, and its shape is similar LED light emitting diodes, Its basic circuit shown in figure 2 -2. The triode plans for the switch, when the base added a driving signal, Transistor saturated conduction infrared LED D is also Wizard Lin k, issued infrared (near infrared about 0.93 μm). D.

The pressure drop of about 1.4 V and the current general for 10-20mA. To adapt to the working voltage of the D loop resistance often as a series of infrared diode current limit resistance.

When the circuit diagram of the infrared emission control corresponding to the controlled device, the control of the distance and D is proportional to the transmitting power. In order to increase the distance of infrared control, infrared diode D should work on the pulse state that work is the lifeblood of current. Because pulse light (optical modulation) the effective transmission distance and pulse is proportional to the peak current, only maximize peak current Ip, will increase the infrared distance. Ip increase is a way to reduce the pulse duty cycle, that is compressed pulse width τ some TV infrared remote control, its infrared luminescence of the pulse duty cycle of about 1/4-1/3; Some electrical products infrared remote control, its duty cycle of 1 / 10. Decreasing pulse duty cycle also enable low-power infrared LED distance of the greatly increased. Common infrared light emitting diodes, power is divided into small power (1 mW - 10mW). Chinese power (20mW - 50mW) and power (50mW - 100mW more) three categories. Use different power infrared LED, the allocation should be driven by the corresponding power control. Figure 2 -2 by the reflected infrared light-emitting diodes to make produce optical modulation, Drivers only need to add the control of a certain frequency pulse voltage.

Infrared transmitter and receiver in the way the two kinds of straight, and the second is reflective. Luminescence pointed straight pipe and tube receiver placed in a relatively controlled and fired on the two ends, a certain distance away from the middle; Reflective means luminescent tube and pipe parallel with the receiving peacetime, without always receiving tube light, luminescence only in possession of the infrared light reflected from

encountered, the receiving tube received from the reflected infrared before work.

2.2 infrared communication basic tenets

2.2.1 infrared communication Principle

Communication is the use of infrared wavelength of 900 nm-infrared waves from 1000 to serve as an information carrier, through infrared technology between the two close communication and confidentiality of information transmitted. Infrared communication system structure include : part launcher, channel, the receiver part.

Launcher source letter issued after the binary signal from the high-frequency modulated infrared LED sent, receiving device regard the reception of high-frequency signals from the infrared receiver tube after receiving further demodulation photoelectric conversion of the original information of a mass communication lose way. Afterwards the former Information received after receiving part of the drive circuit connected to the expected completion of the various functions. To which the modulation coding style pulse width modulation (by changing the pulse width modulated signal PWM) and pulse modulation time (through change the pulse train interval time between the modulation signal PPM) two.

2.2.2 infrared communication system elements

(1) Launches : Currently there is a infrared wireless digital communications system sources of information including voice, data, images. Its methods of work for the launch of the receiver can be divided into different layout LOS way (Light-of-Sight , intracardiac way), diffuse (diffuse) mode. LOS way directional, it has good channel characteristics such advantages, but the existence of a "shadow" effect. difficult to achieve roaming function. Roaming means the main features of non-directional, and easy to implement

roaming function, but its channel quality is better sometimes LOS way. Transmission of signals required for a few of (the sampling was quantified), the general need for baseband modulation, transmission, modulation, sometimes signal source coding, the above-driven signals from photoelectric converter complete optical signal transmission. Infrared wireless digital communications system and its scope of work-for-fired power distribution, the quality of the communication. While using various methods to improve optical transmitter power, the other using spatial diversity, holographic films and so on so diffuse light for the launch of space optical power evenly distributed.

(2) Channel : infrared wireless digital communication channel refers to the transmitters and receivers in the space between. Due to natural light and artificial light sources such as light signals in the context of intervention, and the source - Electrical Equipment, The optical noise and disturbances, infrared wireless digital communications in some occasions, poor quality, At this point needed to channel coding. Infrared wireless communication system, the optical signal reflection, light scattering and background noise and interference effects, Infrared wireless digital channel presence multi-path interference and noise, This is to improve the quality and access for high-speed applications should be addressed. Infrared wireless digital communication channel often used by the major optical components, optical filter, condenser, their role is : plastic, filter, depending on the field transformation, the band division, the lens can be used as launch-ray focusing, the use of optical filters filter out stray light, the use of optical lenses to expand the field of view receiver, able to make use of optical components for the link frequency division multiplexing, etc.. Infrared wireless communication channel optical noise : the natural noise (sunlight) and anthropogenic interference (fluorescent lighting). can be modulated by the transmission technology such as filters and adding to be addressed.

(3) receivers : Channel optical signal from the optical receiver partially photoelectric conversion, In order to remove noise and intersymbol interference and other functions. Infrared wireless digital communications system receiver include optical receiver parts and follow-up sampling, filtering, judgment, quantity, balanced and decoding part. Infrared wireless optical receiver often used amplifier, and called for large-bandwidth, high gain, low noise and low noise, frequency response and channel impulse response matched. To be suppressed by low-frequency noise and human disturbance needs a band-pass filter. To obtain large optical receiver scope and instantaneous field of view, often using spherical optical lens.

2.2.3 infrared communications feature

Wireless communications are a lot of ways, some using infrared communication with the following characteristics :

? The high frequency, wave length, and fired the energy concentrated space propagation attenuation coefficient can ensure the effective signal transmission;

? infrared is the invisible li ght, strong confidentiality and use it as an information carrier. device when there is no visual pollution, it does no harm to the human body;

? dissemination without limitation, and there is no question of frequency interference with radio-wave pattern, not on the spectrum resources to the relevant authorities for the application and registration, easy to implement;

? has a good point, when the transmission equipment and infrared receiver ports line up straight, deviation of not more than about 15 degrees when infrared devices running the best effect;

? through infrared or not bypassed and objects, data transmission, optical path can not be blocked;

? currently produce and receive infrared signals in the technology is relatively mature, components small size, low cost production of simple, easy to produce and modulation advantages.

2.3 infrared communication code based on the knowledge

Usually, infrared remote control transmitters will signal (pulse binary code) modulation at 38 KHz carrier, After buffer amplified sent to the infrared light-emitting diodes, infrared signals into firing away. Pulse binary code in a variety of formats. One of the most commonly used code is PWM (pulse width modulation code) and the PPM code (Pulse Code Modulation). The former said in a pulse width, pulse indicated 0. The latter pulse width, but the width of code-not the same, the codes represent a bit - and the digits represent narrow 0.

Remote coding pulse signal (PPM code as an example) are usually guided by the code, the system code, the anti-code system, a feature code, functional anti-code signal components. Guide the code name for the initial code, by the width of 9 ms and the margin width of 4.5 ms to the low-level components (different remote control systems in the low-level high width of a certain distinction), remote coding used to mark the beginning of pulsed signals. System identification code is also called code, which used to indicate the type of remote control system, in order to distinguish other remote-control system, prevent the remote control system malfunction. Functional code is also called scripts, which represents the corresponding control functions, Receiver of the micro-controller functions under the numerical code to complete the various functions operating. Anti-code system and function codes are anti-system code and the functional code against code Anti-code can be joined to the receiver synchronization transmission process leads to errors. In order to improve performance and reduce interference power consumption, The remote control will be coded pulse frequency of 38 KHz (for the cycle of 26.3 ms) of the carrier signal pulse reshuffle system (PAM), and then sent

to the buffer amplified infrared LED, the remote control signal transmitter away.

Address code and data codes are composed of different pulse width expressed that the two narrow pulse "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."

Is the first part of a group a group of code, each code synchronization between separated. The plan is to enlarge the second half of a group code : a code from 12 AD (the address code plus data code For example, eight address code plus four data code), each with two AD-Pulse's : Pulse said the two "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."

Realize fired at each fired at least four groups code, PT2272 only twice in a row to detect the same address code plus data code data will be the code "1" is driven The data should be output to drive margin and VT terminal for synchronous serial.

红外遥控系统

摘要

红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术，被众多的硬件和软件平台所支持。红外收发器产品具有成本低，小型化，传输速率快，点对点安全传输，不受电磁干扰等特点，可以实现信息在不同产品之间快速、方便、安全地交换与传送，在短距离无线传输方面拥有十分明显的优势。红外遥控收发系统的设计在具有很高的实用价值，目前红外收发器产品在可携式产品中的应用潜力很大。全世界约有1亿5千万台设备采用红外技术，在电子产品和工业设备、医疗设备等领域广泛使用。绝大多数笔记本电脑和手机都配置红外收发器接口。随着红外数据传输技术更加成熟、成本下降，红外收发器在短距离通讯领域必将得到更广泛的应用。

本系统的设计目的是用红外线作为传输媒质来传输用户的操作信息并由接收电路解调出原始信号，主要用到编码芯片和解码芯片对信号进行调制与解调，其中编码芯片用的是台湾生产的PT2262，解码芯片是PT2272。主要工作原理是：利用编码键盘可以为PT2262提供的输入信息，PT2262对输入的信息进行编码并加载到38KHZ的载波上并调制红外发射二极管并辐射到空间，然后再由接收系统接收到发射的信号并解调出原始信息，由PT2272对原信号进行解码以驱动相应的电路完成用户的操作要求。

关键字：红外线；编码；解码；LM386；红外收发器。

1 绪论

1．1 课题研究的背景及意义

红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术，被众多的硬件和软件平台所支持。是一种通过数据电脉冲和红外光脉冲之间的相互转换实现无线的数据收发的技术。

红外收发器产品具有成本低，小型化，传输速率快，点对点安全传输，不受电磁干扰等特点，可以实现信息在不同产品之间快速、方便、安全地交换与传送，在短距离无线传输方面拥有十分明显的优势。

红外收发器产品在可携式产品中的应用作用很大。目前，全世界有1亿5千万台设备采用红外技术，在电子产品和工业设备、医疗设备等领域广泛使用。比如有95％的笔记本电脑就安装了红外收发器接口,现在绝大多数手机上也配置红外收发器接口。而且随着交换的数据量变大，红外数据通讯将使手机的数据传输越来越方便。随着红外数据传输技术越来越成熟、完善、成本更低廉，红外收发器在短距离通讯领域必将得到更广泛的应用。

本章首先阐述了红外收发集成电路设计课题的背景和意义，然后简要介绍了红外数据通讯技术的特点和应用领域，以及红外收发器产品的特点、国内外现状和发展趋势，最后根据红外遥控收发系统的实际应用性确立了课题的设计定位。

1．2 红外遥控收发系统简介

红外遥控系统分为单通道遥控和多通道遥控。只有一个指令信号传送通道的称为单通道遥控系统;具有两个以上指令信号传送通道的称为多通道遥控系统。单通道遥控比较简单 ,一般来说 ,发射器仅有一个指令键 ,接收器也只有一个执行电路。虽然在接收电路中加入多稳态记忆电路 ,可以根据按动发射器指令键的次数 ,使接收电路中的多稳态记忆电路的状态多次改变 ,实现多项功能控制 ,但是这种状态的改变是顺序进行的。如果要实现一项任意控制 ,就要采用多通道遥控系统。多通道遥控可以实现对被控对象的任意多功能遥控。至于选用几个通道及何种控制方式 ,要根据实际情况(如被控对

象、操作要求及成本核算等)来决定。一般的红外遥控收发系统是由红外遥控信号编码发送器、红外遥控信号接收器和解码器（解码芯片或单片机）及其外围电路等三部分构成的。信号发送器用来产生遥控编码脉冲，驱动红外发射管输出红外遥控信号，接收器完成对遥控信号的放大、检波、整形并解调出编码脉冲。红外遥控编码脉冲是一组组连续的串行二进制码，对于一般的红外收发系统，此串行码作为微控制器的遥控输入信号，由其内部CPU完成对遥控指令的解码，对其他各种红外遥控收发电子产品的设计者来说，上述的微控制器内部解码出的遥控指令是不便于利用的。因此，人们利用红外编/解码芯片及单片机研制出多种通用红外遥控收发系统，在各种设备之间进行红外信号的收发。

遥控收发系统一般由发射器和接收器两部分组成。发射器一般由指令键、指令编码电路、调制电路、驱动电路、发射电路等几部分组成。当按下某键时 ,指令编码电路,产生相应的指令编码信号 ,编码指令信号对载波进行调制 ,再由驱动电路进行功率放大之后由发射电路向外发射经过调制的指令编码信号。接收器一般由接收电路、放大电路、解调电路、指令译码电路、驱动电路、执行电路等几部分组成。接收电路将发射器发射的已调制的编码指令信号接收下来 ,并进行放大后送解调电路。解调电路将已调制的编码信号解调下来 ,即还原为编码信号。指令译码器将编码指令信号进行译码 ,最后由驱动电路来驱动执行电路实现各种指令的操作控制。

1．3 红外遥控收发器产品概况

1.3.1红外遥控收发器产品的结构和类型

目前红外收发器按照工作模式和传输速率可分为四类：串行模式，最高速率为115.2Kbps；中速模式：最高速率为0.567Mbps和1.152Mbps；高速模式：最高速率为16Mbps。

另外按芯片功耗大小又可以分为低功耗型和标准型两类，低功耗型通常使用3V电源，传输距离较近，约0-30cm，标准型通常使用5V电源，传输距离较远最少1m以上。

1.3.2红外遥控收发器的国内外现状

在红外通信技术发展的早期，存在好几个红外通信标准，不同标准之间红外设备不能进行红外通信。为了使各种红外设备能够互联互通，1993年由20多个大厂商发起成立了红外数据协会（IRDA）统一了红外通信的标准，这就是目前被广泛使用的红外数据通信协议及规范，也称为IRDA标准。

自1993年IRDA成立至今，红外数据协会的会员已经发展到150多个，IRDA 标准已经获得了业界广泛认同和支持。已经开发出来的具备红外通讯能力的设备已经有一百多种之多，红外模块的年装机量已经达到一亿五千万套。尽管现在有了同样是近距离无线通讯的蓝牙技术，但以红外通讯技术低廉的成本和广泛的兼容性的优势，红外数据通讯仍旧会在将来很长一段时间内在短距离的无线数据通讯领域扮演重要角色。

由IRDA协会的资料表明，国外公司的红外收发器产品起步较早，已经形成了红外收发器的配套生产产业链。由以下部分组成：Sharp等公司主要提供红外发光二极管和光敏二极管；Agilent等公司主要设计制作红外收发芯片；Infineon等公司主要从事红外收发器封装；IBM、Microsoft等公司则推出红外数据收发器驱动程序和红外通信软件。其中如Agilent等公司还具有生产红外收发器系列产品的能力，而HP、IBM等大公司则专门为自己公司产品配备红外收发器。

在中国台湾地区也形成了一批红外收发产品的生产厂家和公司，但在大陆地区只有一些器件销售公司在做这些国际公司和台湾公司的代理，缺乏具有自主产权的该类产品。

1.3.3红外收发器产品的发展趋势

在各种红外收发器产品中，虽然传输速率、传输距离等特性不同，但红外收发器产品一直朝着提高传输速率，增加传输距离，降低功耗，扩大发射接收角度等方面发展。特别是随着技术发展和成熟，传输方式正朝着点对多点方向发展。因此红外遥控收发器产品还有更加宽广的发展前景。

2 红外通信的基础知识

2．1红外线基础知识

2.1.1红外线概述

红外线实质上是一种电磁波。从分析自然界中各种电磁波组成的波可知，波谱是由：射线，ｘ射线、紫外线、可见光、红外线、微波和无线波组成的。从形式上看，它们之间似乎没有关系，但如果按照他们的波长依次排列，就会发现和我们形影不离的可见光只占了整个波谱中0.38μm-0.76μm长的这么一点儿范围，而和可见光相邻的红外线（包括远红外线、中红外线和近红外线外）却占了波谱中0.76μm-1000μm的一大段。其中微米波长范围内又包括了紫外光、可见光、近红外、中红外、远红外、微波。

从上述分析可知，红外线是一种十分丰富的波谱资源，目前它己在生产、生活、军事、医疗等多方面得到了广泛的应用，例如红外线加热、红外线医疗期间、红外线通信、红外线摄像、红外线遥控等。红外线遥控只是红外线众多应用中的一部分，目前在家用电器中广泛应用的彩电遥控器、录像机遥控器、 VCD遥控器、高保真音响遥控器等，都采用了红外线遥控，它使这些家用电器的控制变得十分简单方便。

2.1.2红外线的特性

红外线是介于可见光和微波之间的一种电磁波，因此它具有相临波的某些特性。在近红外区，它和可见光相邻，因此具有可见光的某些特性，如直线传播、反射、折射、散射、衍射、可被某些物体吸收以及可以通过透镜将其聚焦等。在远红外区，由于它邻近微波区，因此它具有微波的某些特性，如较强的穿透能力和能贯穿某些不透明物质等。在自不论任何物体，然界中，也不论其本身是否发光（指可见光）只要其温度高于绝对零度（-273℃），都会一刻不停地向周围辐射红外线。只不过是温度较高的物体辐射的红外线较强，温度低的物体辐射的红外线较弱。因此红外线的最大特点是普遍存在于自然界中，又叫做热辐射线简称热辐射。红外线摄像、红外线夜市、热释电红外探测以及某些导弹的瞄准等就是利用红外线的这一特性工作的。

红外线和可见光相比的另一个特点是，色彩丰富多样。由于可见光的最长波长是最短波长的1倍（780nm-380nm），所以也叫作一个倍频程。而红外线的最长波长是最短波长的1倍，而红外线的最长波长是最短波长的10倍，即有10个倍频程。因此如果可见光能表现为7种颜色，则红外线便可能表现70种颜色，显示了丰富的色彩。红外线透过烟雾的性能好，这是它的又一个特点。

由于红外线为不可见光 ,因此对环境影响很小。再由红外光波的波长远小于无线电波的波长 ,所以红外线遥控不会影响邻近的无线电设备。另外波长小于 1.5μm 的近红外光 ,在透明大气中的传输特性要比可见光好得多 ,而且由于它靠近可见光的红光边缘 ,其直线传播、反射、折射和被物质吸收等物理特性与可见光非常相似。因此 ,它可以使用与可见光类似的聚焦透镜等光学装置。由于红外线遥控不具有像无线电遥控那样穿过障碍物去控制被控制对象的能力 ,所以 ,在设计家用电器的红外线遥控器时 ,不必要像无线电遥控那样 ,每一套(发射器和接收器)要有不同的遥控频率或编码(否则 ,就会隔墙控制或干扰邻居的家用电器) ,所有同类产品的红外线遥控器 ,可以有相同的遥控频率或编码 ,而不会出现遥控信号“串门”的情况。这对于普及红外线遥控提供了极大的方便。红外线为不可见光线 ,具有很强的隐蔽性和保密性 ,因此 ,在防盗、警戒等安全保卫装置中也得到了广泛地应用。红外线遥控具有结构简单、制作方便、成本低廉、抗干扰能力强、工作可靠性高等一系列优点 ,是近距离遥控、特别是室内遥控的优选遥控方式。

2.1.3红外发光二极管的特性

红外线是不可见光，人眼是觉察不到的。电子技术中是用红外发光二极管（又称红外发射二极管）来产生红外线。红外遥控收发是利用近红外光传送遥控指令的波长为 0.76μm～1. 5μm。用近红外光作为遥控光源 ,是因为目前红外发光二极管与红外接收器件(光敏二极管、三极管及光电池) 的发光与受光峰值波长一般为 0.8μm～0. 94μm ,在近红外光波段内 ,二者的光谱正好重合 ,能够很好地匹配 ,可获得较高的传输效率及较高的可靠性。

常用的红外发光二极管，其外形和发光二极管LED相似，它的基本工作电