共查询到17条相似文献,搜索用时 78 毫秒
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主要以300 W调频广播发射为例,阐述了发射机、音频处理器、发射机自动监测仪、音频幅度监测仪、监听系统和稳压电源的工作原理,并介绍了调频发射机的发射系统方案与建设. 相似文献
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本文介绍新型调频发射机音频指标数字化自动测试系统的总体思路,着重阐述其工作原理,详细说明如何用谐波分析法测量调频发射机音频指标,并简要介绍硬件的主要组成部分。 相似文献
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陈士久 《卫星电视与宽带多媒体》2021,(4):40-42
新型固态调频发射机是一种将音频信号进行信道调制、功放放大然后通过天馈系统辐射的工作设备,目前广泛应用于我国各级广播电视台和传播中心。本人从事多年广播电视发射的工作,在此以本中心调频发射机为例,从调频发射机的系统组成、激励器和功放的工作原理介绍方面入手,浅析固态调频发射机的日常故障现象、成因、以及处理方法。 相似文献
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调频发射机数字激励器的特点就是其全程运用数字化处理控制技术,例如:DSS技术产生调制载波,同时利用DSP技术来处理音频信号,输出信号的稳定性与准确性更高.本文首先讲解了调频发射机数字激励器的工作原理,然后介绍了调频发射机数字激励器常见的一些故障以及处理故障的方法. 相似文献
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一种小型通信系统的设计 总被引:1,自引:0,他引:1
介绍了一种小型通信系统的设计方法及其工作原理。系统中的发射机单元采用调频方式实现音频信号的调制而接收机单元对调频信号进行解调,恢复出原始的音频信号。 相似文献
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论述了调频发射机音频总控数字化改造后的系统组成以及自动切换的方式,并介绍了音频总控系统的网管监测以及应用。 相似文献
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近年来在科学快速发展的带动下,我国调频广播取得了较快的发展.调频广播是高频振荡的频率伴随着音频信号的幅度而变化的一种广播技术,具有较强的抗干扰性、不失真、设备利用率高,覆盖范围有限制等特点.调频发射机作为调频广播的发射设备,在不间断的运行过程中极易出现故障,从而影响正常的广播播出.因此需要针对调频发射机的特点入手,对调频发射机的维护工作进行具体阐述,保证调频发射机的正常工作,确保播出的质量. 相似文献
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引信一般用一次性化学电池做能源,电池在高旋转和大冲击过载条件下激活发电,为了对电池在负载条件下的输出电压与输出噪声进行测试,往往需要在高速离心机上对电池进行动态监测,这就需要非接触动态测量系统。采用FM/FM体制的遥测系统来实现电池的动态测试,其特点是实时性好、抗干扰能力强、配置和操作灵活。调制器采用多路副载频调制方法,副载频解调采用集成锁相环路来实现,系统采用S频段晶控发射机,发射天线采用S频段片状微带天线,其体积小、重量轻。接收系统采用S频段点频接收机实现。系统标定、数据处理及结果输出等均由计算机来完成,对样机经现场考核和测试证明该系统工作正常,具有很好的实用性。 相似文献
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《Solid-State Circuits, IEEE Journal of》1976,11(6):817-825
The measurement of bidirectional bloodflow on a chronic basis is of critical importance in research on cardiovascular and pulmonary diseases. An implantable bidirectional Doppler ultrasonic bloodflow system was designed to satisfy this need. The system utilized quadrature detection to provide the directional information and multiplexing to transmit the quadrature signals over one FM telemetry link. A new family of three 1 V micropower bipolar integrated circuits were designed to implement the RF amplifiers, square law detectors, /spl plusmn//spl pi//4 phase shifters, audio amplifiers, a multiplexer, and the FM transmitter required for this system. An implanted system was used to measure pulsatile bidirectional bloodflow on a canine descending aorta. The results compared well with those in the literature and with a percutaneous EM flowmeter. 相似文献
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适应2Mbit/s PCM信号的微波锁相调频遥测发射机是21世纪再入遥测系统中的重要设备。文中介绍了该调频遥测发射机研制中使用的关键技术:准两点注入式调频技术,以及相关电路设计和实验结果。理论分析和实践表明,准两点注入式微波锁相调频遥测发射机具有平坦的宽带调制特性,能满足高码速率再入遥测发射设备的实际要求。 相似文献
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We present techniques for simulcasting low-power digital data and analog FM over fading channels. Our methods have strong connections to what are referred to as dirty paper coding techniques in that a low-power digital data signal is modulo-added to the host analog FM signal. Due to the low power levels of the digital data and the suppression capability of analog FM, a standard analog FM receiver can be used to reliably recover the analog audio signal. We develop digital receivers that work reliably over fading channels given imperfect channel state information. Spreadresponse precoding is exploited to not only provide rate-1 temporal diversity benefits, but also to simplify the design of the modulo-precanceler and the receiver. Our theoretical and simulation-based performance analysis of the digital receivers and our MSE-based analog FM distortion analysis suggest that precoded modulo-precanceling schemes provide substantially higher data rates than existing precanceling strategies at the cost of transmission delay and transmitter and receiver complexity. The systems we present are also readily compatible with conventional channel coding techniques as well as with analog FM postcancelers, which can improve the digital receiver bit-error-rate performance at the expense of receiver complexity. 相似文献
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The design of a peak limiter processor for FM broadcast audio is described. The limiter has four gain control stages. The basic peak limiting function is performed in the first and second stages by a slow-attach-slow-release stage followed by a fast-attack-fast-release stage. Preemphasis control is performed in the third and fourth stages, which are part of a filter that emulates the transmitter preemphasis network. A peak clipper at the output of the preemphasis controller provides protection from overmodulation by short duration peaks that are not controlled by the four limiter stages 相似文献