5高频功放

高频功率放大器的工作原理高频功率放大器是一种电子器件，主要用于放大高频信号，并将其输出到负载上。

其工作原理基于电子管或晶体管的放大作用，在输入的高频信号上增加电压，从而实现信号放大的目的。

高频功率放大器广泛应用于无线电通信、雷达、卫星通信等领域。

最常用的高频功率放大器是基于晶体管的，其内部结构由多个不同功能的电路组成。

其中，收发信道通过变压器进行隔离，从而实现信号的单向传输。

在信号放大方面，晶体管的三个引脚分别为基极、集电极和发射极。

输入信号通过基极进入晶体管，集电极则是放大后的信号输出。

发射极则是提供功率的地方，通常在晶体管的大功率管中被找到。

高频功率放大器通常需要很高的驱动电压，它可以由直流电源提供。

晶体管的放大过程是通过电荷扩散和电场漂移来完成的。

在多数晶体管中，材料内部的电子浓度是不均匀的，因此电子在晶体中移动时会发生扩散。

此外，由于电场的存在，电子也会沿着电场方向移动，从而形成漂移的过程。

这两种运动将使得电子的浓度差异减小，最终导致电流被放大。

需要注意的是，在高频电路中，信号通常在不同的电阻、电容和电感之间进行传输，因此高频功率放大器要求不仅具有高放大倍数、低噪声等特点，还需要适应各种不同的阻抗，防止信号反射和损耗。

为了保证高频信号的传输质量，高频功率放大器通常采用多级级联的方式，以达到更高的放大倍数和更佳的工作效率。

总之，高频功率放大器是电子工程领域中极为重要的技术，其工作原理基于电子器件的放大作用。

通过不同级联和高数据速率的设计，高频功率放大器可以实现高精度的信号传输和处理，对无线电通讯、雷达、卫星通讯等领域具有举足轻重的作用。

高频功率放大器的基本原理(一)高频功率放大器的基本原理1. 什么是高频功率放大器高频功率放大器是一种用于增强高频信号幅度的电子设备。

它通常用于无线通信、雷达、高频电视和天线系统等领域。

高频功率放大器可以将低功率的高频信号放大到足够大的功率，以便传输和处理。

2. 高频功率放大器的工作原理高频功率放大器的工作原理可以简单分为三个步骤：放大输入信号、增加信号的功率和输出放大后的信号。

2.1 放大输入信号高频功率放大器的第一个任务是放大输入信号。

它通常使用晶体三极管（BJT）或场效应晶体管（FET）作为放大器的关键元件。

这些元件根据输入信号的幅度和频率变化进行放大操作。

2.2 增加信号的功率放大后的信号仍然可能是低功率的，因此高频功率放大器的下一个任务是增加信号的功率。

这一步骤通常通过使用功率放大器级联来实现。

级联多个放大器可以将信号功率从较低级别逐步增加到所需的功率级别。

2.3 输出信号在增加信号的功率之后，高频功率放大器将输出放大后的信号。

这个信号可以被用于进一步的处理或传输。

输出信号的幅度将取决于放大器的设计和配置。

3. 高频功率放大器的关键考虑因素在设计高频功率放大器时，需要考虑一些关键因素来确保性能和稳定性。

3.1 频率响应高频功率放大器应该能够在指定的频率范围内提供稳定的放大。

对于不同的应用，频率范围和响应要求会有所不同。

3.2 功率输出高频功率放大器应该能够提供足够的功率输出，以满足特定应用的需求。

功率输出的大小通常由设备和系统的要求来确定。

3.3 效率高频功率放大器的效率是指输入功率与输出功率之间的比率。

高效率的放大器能够最大限度地利用输入能量，减少能量浪费。

3.4 线性度高频功率放大器的线性度是指输出信号与输入信号之间的线性关系。

较好的线性度可以保持输入信号的准确度和完整性。

3.5 稳定性高频功率放大器的稳定性是指在各种工作条件下保持良好的性能。

它应该能够在不出现振荡或失真的情况下工作。

高频功率放大器简介
高频功率放大器，又称射频功率放大器，是一种能量转换器件，它将电源供给的直流能量转换成为高频交流输出。

高频功率放大器用于发射机的末级，作用是将高频已调波信号进行功率放大，以满足发送功率的要求，然后经过天线将其辐射到空间，保证在一定区域内的接收机可以接收到满意的信号电平，并且不干扰相邻信道的通信。

高频功率放大器是通信系统中发送装置的重要组件。

按其工作频带的宽窄划分为窄带高频功率放大器和宽带高频功率放大器两种，窄带高频功率放大器通常以具有选频滤波作用的选频电路作为输出回路，故又称为调谐功率放大器或谐振功率放大器；宽带高频功率放大器的输出电路则是传输线变压器或其他宽带匹配电路，因此又称为非调谐功率放大器。

高频功率放大器大多工作于丙类。

但丙类放大器的电流波形失真太大，因而只能用于采用调谐回路作为负载的谐振功率放大。

由于调谐回路具有滤波能力，回路电流与电压仍然极近于正弦波形，失真很小。

一、高频放大器的特点
1. 采用谐振网络作负载。

2. 一般工作在丙类或乙类状态。

3. 工作频率和相对通频带相差很大。

4. 技术指标要求输出功率大、效率高。

二、高频功率放大器的技术指标
主要技术指标有：输出功率、效率、功率增益、带宽和谐波抑制度（或信号失真度）等。

这几项指标要求是互相矛盾的，在设计放大器时应根据具体要求，突出一些指标，兼顾其他一些指标。

5w功放芯片5W功放芯片是一种功率放大器，用于电子设备中，为音频和视频提供强有力的放大功能。

这种芯片能够将低电压的信号进行放大，以达到更大的音量和更清晰的画面效果。

它在各种电子产品中得到广泛应用，如手机、电视、音响等。

下面将详细介绍5W功放芯片的特点和应用领域。

首先，5W功放芯片具有小体积、低功耗的特点。

由于采用了先进的半导体技术和优化的电路设计，5W功放芯片可以实现更高的功率放大，在体积上比传统的功放芯片要更小，同时功耗相对较低。

这使得5W功放芯片适用于那些空间有限和对电池续航能力要求较高的设备，如智能手机、便携式音箱等。

其次，5W功放芯片具有高性能的特点。

采用了多种先进的电路设计和信号处理技术，5W功放芯片能够提供更高的音频和视频质量。

它能够将信号放大到足够的功率，以使音乐更有动态感和层次感，视频更清晰锐利。

同时，5W功放芯片还具有良好的抗干扰能力，能够有效降低噪音和杂音的干扰，提升音质和图像的还原度。

此外，5W功放芯片还具有灵活的应用。

它可以根据不同的需求进行定制和配置，适应不同的音频和视频输出要求。

例如，在手机中，5W功放芯片可以用于驱动内置扬声器，提供更好的声音效果；在音响中，它可以用于驱动大功率的喇叭，提供更高的音量；在电视中，它可以用于驱动显示屏，提供更清晰的画面。

5W功放芯片的灵活性使得它可以广泛应用于各种电子设备中，提供更好的用户体验。

最后，5W功放芯片具有高可靠性和稳定性。

它经过严格的品质控制和稳定性测试，能够在不同的工作环境和温度条件下正常运行。

此外，5W功放芯片还具备过压、过流和短路保护功能，可以有效保护设备和芯片自身的安全。

这使得5W功放芯片可以长时间稳定地工作，无需频繁维修和更换。

总而言之，5W功放芯片是一种具有小体积、低功耗、高性能、灵活应用、高可靠性和稳定性的功率放大器。

它广泛应用于各种电子设备中，为音频和视频的放大提供强有力的支持。

随着科技的不断进步和应用需求的不断增加，5W功放芯片将进一步改进和提升，为用户带来更好的音视频体验。

第2章高频功率放大器第2章高频功率放大器2.1 谐振功率放大器基本工作原理2.2 丙类谐振功率放大器的工作状态分析2.3 谐振功率放大器的高频特性2.4 谐振功率放大器电路2.5 高效率高频功率放大器及功率合成技术第2章高频功率放大器一、工作状态分类A 类(甲类)、B 类(乙类)、C 类(丙类)等。

i i BEC tCu QA 类(甲类)：工作点Q 较高(I CQ 大)，信号360°内，管子均导通。

通角：θ＝180 °U CCR LR L′N 1∶N 2RBVCBu i第2章高频功率放大器甲类功放电路及交、直流负载线i Ct 0I C Q I C QI C Qu CE i Cu CEt00U CE QU CU CCQ直流负载线交流负载线i B1R L′－I CR B 为偏置电阻，决定Q 点的I CQ 及I BQ 。

变压器是理想的，则直流工作点电压U CEQ =U CC ，直流负载线为一垂直线，而交流负载线通过Q 点，其斜率为(-1/R ′L )第2章高频功率放大器CQCC C CQ CC TE I U dt t I I U TP ⋅=+=∫)sin (10ω1.电源功率P E2. 交流输出功率P LLC C C C C TL R U I U tdt I t U TP ′=⋅=⋅=∫22121sin sin 1ωωCC Cm U U =CQCm I I =CQCC CC E L I U I U P P 21==ηA 类放大器无信号时，效率为零，信号最强时最大效率只有50%。

这是A 类放大器的致命弱点，也是晶体管功率放大器极少采用A 类放大器的原因。

%50max =η一般: 20%~30%第2章高频功率放大器i C t 0i Cu BEQπ2π0u iV 1V 2V 0VD1VD 2I COi C1i C2U CCu o－U EER Li C1i C2B 类(乙类)：工作点Q 选在截止点，管子只有半周导通，另外半周截止。

RB-985MKII FIVE CHANNEL POWER AMPLIFIERAMPLIFICATEUR DE PUISSANCE À CINQ CANAUXFÜNFKANAL-ENDSTUFEAMPLIFICATORE DI POTENZA A CINQUE CANALIETAPA DE POTENCIA DE CINCO CANALESMULTI CHANNELPOWER AMPLIFIERRB-985 MKIIPROTECTIONF/L CTR F/RR/L R/RPOWEROwner’s ManualGuide d’utilisationBedienungsanleitungManuale di IstruzioniManual de InstruccionesWARNING:There are no user serviceable parts inside. Refer all servicing to qualified service personnel.WARNING:To reduce the risk of fire or electrical shock, do not expose the unit to moisture or water. Do not allow foreign objects to get into the enclosure. If the unit is exposed to moisture, or a foreign object gets into the enclosure, immediately disconnect the power cord from the wall. Take the unit to a qualified service person for in-spection and necessary repairs.Read all the instructions before connecting or operating the unit. Keep this manual so you can refer to these safety instructions.Heed all warnings and safety information in these instructions and on the product itself. Follow all operating instructions.Clean the unit only with a dry cloth or a vacuum cleaner.You must allow 10cm, or 4 inches, of unobstructed clearance around the unit.Do not place the unit on a bed, sofa, rug, or similar surface that could block theventilation slots. If the unit is placed in a bookcase or cabinet, there must besufficient clearance around the unit and ventilation of the cabinet to allowproper cooling.Keep the unit away from radiators, heat registers, stoves, or any otherappliance that produces heat.The unit must be connected to a power supply only of the type and voltagespecified on the rear panel of the unit.Connect the unit to the power outlet only with the supplied 2-pin polarizedpower supply cable or an exact equivalent. Do not modify the supplied cable inany way. Do not attempt to defeat grounding and/or polarization provisions. Thecable should be connected to a 2-pin polarized wall outlet, matching the wideblade of the plug to the wide slot of the receptacle. Do not use extension cords.Do not route the power cord where it will be crushed, pinched, bent at severeangles, exposed to heat, or damaged in any way. Pay particular attention to thepower cord at the plug and where it exits the back of the unit.The power cord should be unplugged from the wall outlet if the unit is to be leftunused for a long period of time.Immediately stop using the unit and have it inspected and/or serviced by aqualified service agency if:•The power supply cord or plug has been damaged.•Objects have fallen, or liquid has been spilled, into the unit.•The unit has been exposed to rain.•The unit shows signs of improper operation •Place the unit on a fixed, level surface strongenough to support its weight. Do not place theunit on a moveable cart that could tip over.FIVE CHANNEL POWER AMPLIFIER RB-985 MKII Figure 1:Controls and ConnectionsCommandes et prisesBedienelemente und AnschlüsseControlli e collegamentiControles y ConexionesFigure 2:Preamp Input and Speaker Output ConnectionsPrises d’entrée du préamplificateur et prises de sortie des enceintesAnschlußdiagramm (Cinch-Eingänge und Lautsprecher)Collegamenti di ingresso dal preamplificatore e delle uscite dei diffusori.Conexiones de la Señal de Entrada y Salidas a las Cajas AcústicasPREAMPLIFIER OR SIGNAL PROCESSOR○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○About Rotel A family whose passionate interest in music led them to manufac-ture high fidelity components of uncompromising quality founded Rotel over 30 years ago. Through the years that passion has re-mained undiminished and the family goal of providing exceptional value for audiophiles and music lovers, regardless of their budget,is shared by all Rotel employees.The engineers work as a close team, listening to, and fine tuning each new product until it reaches their exacting musical stan-dards. They are free to choose components from around theworld in order to make that product the best they can. You arelikely to find capacitors from the United Kingdom and Germany,semi conductors from Japan or the United States, while toroidalpower transformers are manufactured in Rotel’s own factory.Rotel’s reputation for excellence has been earned through hun-dreds of good reviews and awards from the most respected re-viewers in the industry, who listen to music every day. Theircomments keep the company true to its goal – the pursuit ofequipment that is musical, reliable and affordable.All of us at Rotel thank you for buying this product and hope it willbring you many hours of enjoyment.○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○About the THX Ultra ™ System THX is an exclusive set of standards and technologies establishedby the world-renowned film production company, Lucasfilms Ltd.THX grew from George Lucas' personal desire to make your expe-rience of the film soundtrack, in both movie theaters and in yourhome theater, as faithful as possible to what the director intended.Movie sound tracks are mixed in special movie theaters calleddubbing stages and are designed to be played back in movie the-aters with similar equipment and conditions. The soundtrack cre-ated for movie theaters is then transferred directly onto Laserdisc,VHS tape, DVD, etc., and is not changed for playback in a smallhome theater environment. THX engineers developed patentedtechnologies to accurately translate the sound from the movietheater environment into the home, correcting the tonal and spa-tial errors that occur.Before any home theater component can be THX Ultra certified, itmust incorporate the THX technologies and also pass a rigorousseries of quality and performance tests. Only then can a productfeature the THX Ultra logo, which is your guarantee that the HomeTheater products you purchase will give you superb performancefor many years to come.○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○Contents (circled numbers refer to illustration)About Rotel __________________________________________1About the THX Ultra™ System ________________________1Getting Started ______________________________________2A Few Precautions2Placement2Power and Control ___________________________________2Power Input 42Power Switch 1 and Power Indicator 22Protection Circuitry 32Input Signal Connection ______________________________3Input Signal Connection 53DB25 Connector Input 6Speaker Connection __________________________________3Speaker Selection 3Speaker Wire Selection 3Polarity and Phasing 3Speaker Connection 73Troubleshooting ______________________________________4Front Panel Power Indicator Is Not Lit 4Fuse Replacement 4No Sound 4Protection Indicator Is Lit 4Specifications _______________________________________25Lucasfilm and THX are trademarks of Lucasfilm Ltd.All rights reservedEnglish○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○Getting StartedThank you for purchasing the Rotel RB-985 MKII Power Amplifier.When used in a high-quality music or home theater system, it will provide years of musical enjoyment.The RB-985 MKII is a high-power, five-channel power amplifier,providing the highest level of audio performance. Discrete output devices, a massive power supply, premium components, andRotel’s Balanced Design ensure superb sound quality. High cur-rent capability allows the RB-985 MKII to drive the most demand-ing loudspeakers.Be aware that the RB-985 MKII is capable of high power levels, in excess of 100 watts per channel. Make sure that your speakerscan handle the power of the RB-985 MKII. If in doubt about yourspeakers, ask your authorized Rotel dealer for advice.The RB-985 MKII is straightforward in its installation and opera-tion. If you have experience with other stereo power amplifiers,you shouldn’t find anything perplexing. Connect some high-quality RCA cables to your preamp or signal processor and the RB-985MKII inputs, wire up your speakers, and enjoy.A Few PrecautionsPlease read this manual carefully. In addition to basic installation and operating instructions, it provides valuable information onsystem configuration, as well as general information that will help you get optimum performance from your system. Please contactyour authorized Rotel audio retailer for answers to any questionsyou might have. In addition, all of us at Rotel welcome your ques-tions and comments.Save the RB-985 MKII shipping carton and all enclosed packingmaterial for future use. Shipping or moving the RB-985 MKII inanything other than the original packing material may result in se-vere damage to your amplifier.Fill out and send in the owner’s registration card packed with theRB-985 MKII. Also be sure to keep the original sales receipt. It isyour best record of the date of purchase, which you will need inthe event warranty service is ever required.PlacementThe RB-985 MKII generates heat as part of its normal operation.The heat sinks and ventilation openings in the amplifier are de-signed to dissipate this heat. The ventilation slots in the top cover must be open. There should be 10 cm (4 inches) of clearancearound the chassis, and reasonable airflow through the installa-tion location, to prevent the amplifier from overheating.Likewise, remember the weight of the amplifier when you selectan installation location. Make sure that the shelf or cabinet cansupport its considerable bulk. Again, use common sense.○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○Power and ControlPower Input 4Because of its high power rating, the RB-985 MKII can draw con-siderable current. Therefore, it should be plugged directly into a 2-pin polarized wall outlet. Do not use an extension cord. A heavyduty multi-tap power outlet strip may be used if it (and the walloutlet) is rated to handle the current demanded by the RB-985MKII and all the other components connected to it.Be sure the power switch on the front panel of the RB-985 MKII is turned off (in the out position). Connect the supplied power cordto the power input receptacle on the back of the RB-985 MKII.Then, plug the other end of the power cord to the power outlet.Your RB-985 MKII is configured at the factory for the proper ACline voltage in the country where you purchased it (either 115volts AC or 230 volts AC with a line frequency of either 50 Hz or 60 Hz). The AC line configuration is noted on a decal on the backpanel.Note: Should you move your RB-985 MKII amplifier to anothercountry, it is possible to reconfigure your amplifier for use on adifferent line voltage. Do not attempt to perform this conversionyourself. Opening the enclosure of the RB-985 MKII exposes youto dangerous voltages. Consult a qualified service person or theRotel factory service department for information.If you are going to be away from home for an extended period oftime such as a month-long vacation, it is a sensible precaution tounplug your amplifier (as well as other audio and video compo-nents) while you are away.Power Switch 1 and Power Indicator 2The power switch is located on the front panel of your amplifier.To turn the amplifier on, push the switch in. The LED indicatorabove the switch will light, indicating that the amplifier is turnedon. To turn the amplifier off, push the button again and return it to the out position.Protection Circuitry 3The RB-985 MKII features a thermal protection circuit that pro-tects the amplifier against potential damage in the event of ex-treme or faulty operating conditions. Unlike many designs, theRB-985 MKII’s protection circuit is independent of the audio signal and has no impact on sonic performance. Instead, the protectioncircuit monitors the temperature of the output devices and shutsdown the amplifier if temperatures exceed safe limits.FIVE CHANNEL POWER AMPLIFIER RB-985 MKII○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○Speaker Connection Speaker Selection We recommend using loudspeakers with a nominal impedance of 4 ohms or higher with the RB-985 MKII. You should exercise some caution in driving multiple pairs of speakers in parallel configura-tion, because the effective impedance the amplifier sees is cut in half. For example, when driving two pair of 8 ohm speakers, the amplifier sees a 4 ohm load. When driving multiple speakers in parallel, it is recommended that you select speakers with a nomi-nal impedance of 8 ohms or higher. Speaker impedance ratings are less than precise. In practice, very few loudspeakers will present any problems for the RB-985 MKII. See your authorized Rotel dealer if you have any questions.Speaker Wire Selection Use insulated two-conductor stranded wire to connect the RB-985MKII to the speakers. The size and quality of the wire can have anaudible effect on the performance of the system. Standardspeaker wire will work, but can result in lower output or dimin-ished bass response, particularly over longer distances. In gen-eral, heavier wire will improve the sound. For best performance,you may want to consider special high-quality speaker cables.Your authorized Rotel dealer can help in the selection of appropri-ate cables for your system.Polarity and Phasing The polarity — the positive/negative orientation of the connec-tions — for every speaker and amplifier connection must be con-sistent so all the speakers will be in phase. If the polarity of one connection is mistakenly reversed, bass output will be very weak and stereo imaging degraded. All wire is marked so you can iden-tify the two conductors. There may be ribs or a stripe on the insu-lation of one conductor. The wire may have clear insulation with different color conductors (copper and silver). There may be po-larity indications printed on the insulation. Identify the positive and negative conductors and be consistent with every speaker and amplifier connection.Speaker Connection 7The RB-985 MKII has five pairs of color coded binding posts on the back panel. These connectors accept bare wire, connectorlugs, or dual banana type connectors (except in the European Community countries where their use is not permitted).The negative connectors for all the channels are black. The posi-tive connectors for the right front and surround speakers are red.The positive connectors for the left front and surround speakers are blue. The positive connector for the center speaker is green.Most likely, you will never see this protection circuitry in action.However, should a faulty condition arise, the amplifier will stop playing and an LED indicator on the front panel will light up.If this happens, turn the amplifier off, let it cool down for several minutes, and attempt to identify and correct the problem that caused the protection circuitry to engage. When you turn the am-plifier back on, the protection circuit will automatically reset and the indicator LED should go out.In most cases, the protection circuitry activates because of a fault condition such as shorted speaker wires, or inadequate ventila-tion leading to an overheating condition. In very rare cases, highly reactive or extremely low impedance speaker loads could cause the protection circuit to engage.If the protection circuitry triggers repeatedly and you are unable to isolate and correct the faulty condition, contact your Rotel au-dio retailer for assistance in troubleshooting.○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○Input Signal Connection 5[See Figure 2 for wiring illustration.]The RB-985 MKII has conventional RCA type input connectors, the type found on nearly all audio equipment.Note: Do not connect inputs to both the RCA and DB25 inputs.(See the following section.) Use one or the other.Note: To prevent loud noises that neither you nor your speakers will appreciate, make sure the amplifier is turned off when you make any signal connections.Use high quality audio interconnect cables. Connect the various outputs of your preamplifier or signal processor to the corre-sponding inputs of the RB-985 MKII . Check these connections carefully to be sure there are no incorrect connections.DB25 Connector Input 6The RB-985 MKII is also equiped with a DB25 type input. This input is typically only used in professionally-installed custom systems.The DB25 input duplicates the function of the five RCA inputs. For information regarding how to use this input, contact your nearest authorized Rotel service center.EnglishRoute the wire from the RB-985 MKII to the speakers. Give your-self enough slack so you can move the components enough to al-low access to the speaker connectors.If you are using dual banana plugs, connect them to the wires and then plug into the backs of the binding posts. The hexagonal thumbscrews of the binding posts should be screwed in all the way (clockwise).If you are using terminal lugs, connect them to the wires. If you are attaching bare wires directly to the binding posts, separate the wire conductors and strip back the insulation from the end of each conductor. Be careful not to cut into the wire strands. Un-screw (turn counterclockwise) the binding post hexagonal thumb-screws. Place the connector lug or wire around the binding post shaft. Turn the hexagonal thumbscrews clockwise to clamp the connector lug or wire firmly in place.Note: Be sure there are no loose wire strands that could touch adjacent wires or connectors.○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○TroubleshootingMost difficulties in audio systems are the result of poor or wrongconnections, or improper control settings. If you encounter prob-lems, isolate the area of the difficulty, check the control settings,determine the cause of the fault and make the necessarychanges. If you are unable to get sound from the RB-985 MKII, re-fer to the suggestions for the following conditions:Front Panel Power Indicator Is Not LitNo main power to the RB-985 MKII. Check the front panel powerswitch. Make sure that it is set to the on position. Check powerconnections at the amplifier and the outlet.Fuse ReplacementIf everything checks out correctly and you still cannot get the am-plifier to turn on, the internal power fuse may have blown. If youbelieve this has happened, contact your authorized Rotel dealerfor information on where to take your amplifier to get the fuse re-placed.No SoundIf the amp is getting power, but is producing no sound, check theProtection indicator on the front panel. If it is lit, see below. If not, check all of your connections and control settings on associatedcomponents.Protection Indicator Is LitThe front panel indicator lights when the RB-985 MKII protectioncircuits have shut off the amplifier. Typically, this occurs onlywhen the ventilation openings are blocked, when there is faultyspeaker wiring, or after a period of extreme use. Turn off the sys-tem and wait for the amp to cool. Then push the front panel power switch in and out to reset the protection devices. If the problem is not corrected or reoccurs, there is a problem with the system orthe amplifier itself.FIVE CHANNEL POWER AMPLIFIER RB-985 MKIIRB-985 MKIIFIVE CHANNEL POWER AMPLIFIERAMPLIFICATEUR DE PUISSANCE À CINQ CANAUXFÜNFKANAL-ENDSTUFEFINALE DI POTENZA MULTICANALEETAPA DE POTENCIA DE CINCO CANALESThe Rotel Co. Ltd.10-10 Shinsen-ChoShibuya-KuTokyo 150-0045JapanPhone: +81-3-5458-5325Fax: +81-3-5458-5310Rotel of America54 Concord StreetNorth Reading, MA 01864-2699USAPhone: +1 978-664-3820Fax: +1 978-664-4109Rotel EuropeMeadow RoadWorthing, West Sussex BN11 2RXEnglandPhone: +44 1903-524-813Fax: +44 1903-524-831Rotel DeutschlandKleine Heide 12D-33790 Halle/Westf.GermanyPhone: +49 5201-87170Fax: +49 5201-73370082 OMRB-985 MKII 033199。

高频功率放大器
高频功率放大器是指能够放大高频信号的功率的放大器。

在无线通信、雷达、医学诊断等领域，需要对高频信号进行放大，因此高频功率放大器具有重要的应用价值。

高频功率放大器通常采用半导体器件如晶体管、场效应管等作为放大元件。

不同的放大器结构和电路设计可以用于不同的频率范围和功率要求。

在设计高频功率放大器时，需要考虑以下几个关键因素：
1. 频率响应：要保证放大器在所需的频率范围内具有良好的增益和相位特性，以确保信号的准确放大。

2. 功率输出：放大器应能够提供所需的输出功率，以满足系统的功率要求。

3. 效率：高频功率放大器的效率越高，其在转换输入功率为输出功率时损耗的能量越少。

4. 线性度：在大功率输出时，要保持放大器的线性度，以避免失真和干扰。

5. 稳定性：放大器应具有良好的稳定性，以避免产生震荡或变换输出。

6. 抗干扰性：高频功率放大器应能够抵抗外部干扰，保持信号的纯净性。

高频功率放大器在无线通信系统中扮演着重要的角色，能够增强信号传输的距离和可靠性，提高信号的质量和覆盖范围。