IOT电视发射机的特点与维护经验

本文以泰克诺３０ｋＷ ＩＯＴ发射机为例，分析了ＩＯＴ发射机的特点，介绍了其主要电路的特点及工作原理，为了解掌握ＩＯＴ发射机提供了参考。文中介绍了ＩＯＴ发射机的维护，对使用该类发射机的台站有一定参考价值。     

300W调频发射机的使用维护研究

调频发射机是广播电视无线覆盖设备的重要组成部分,但随着使用时间的推移,故障的发生率极高。本文以300W调频发射机为例,在分析其工作原理的基础上,从技术层面上重点介绍了发射机的使用维护工作。     

浅析DX-600型发射机风量监测电路

DX系列中波广播发射机内部采取强制风冷却方式,风冷却系统是其重要的组成部分,是保证整机正常工作的必要条件。本文以DX-600KW发射机为例,重点分析计算发射机监测风流量的相关电路,阐明其风量监测原理及由于风量原因引起发射机内部保护的条件。最后结合工作实际,明确风冷系统维护的要点,为安全播音提供保证。     

VHF发射机的主要电路设计

VHF发射机是监控终端中的关键设备,也是典型的数字通信射频无线收发设备。文中详细阐述了VHF发射机的指标、链路以及模块电路工作原理,给出了载波频率为156.025～162.025MHz的VHF发射机各模块电路的设计方法。     

浅谈全固态电视发射机的原理及维护

1 引 言 目前义乌市广播电视台共有四台全固态电视发射机用于发射电视节目,两台lkW的发射机用于发射本地新闻节目及CMMB移动电视节目,两台300W的发射机用于发射两套中央台的节目.经过几年的运行,发射机工作稳定,安全可靠.确保了发射台的安全优质播出和有效覆盖.本文从全固态发射机的原理人手,将发射机的组成部分、主要特点和工作中的使用及出现的故障和维修经验做一介绍和分析探讨. 2 发射机的原理 全固态电视发射机在继电子管、速调管和IOT管发射机后现已成为电视发射机市场的主流,它采用模块化的设计思想,采用双激励器冗余、模块化的功率放大器合成技术和完善的自动监控系统,具有体积小,结构紧凑和高效可靠等特点,这些特点为其不间断、高可靠的运行奠定了基础.下面以我们台的lkW发射机为例,介绍其基本原理,并对工作过程中遇到的故障进行分析.     

中波广播发射机的维护及故障处理措施研究

中波广播发射机是中波广播系统的核心设备,其工作正常与否直接影响整个系统的正常工作,因此,中波广播发射机维护与故障的准确、及时处理,对保证中波广播发射机稳定运行意义重大,应引起广播单位的重视,做好中波广播发射机维护和故障处理研究工作。文章分析了中波广播发射机故障分析原则,探讨常见故障及故障处理方法,提出了日常维护相关策略,以供参考。     

GZ-GS10K-I型数字调幅广播发射机两起故障分析处理及思考

我台使用的哈广产GZ-GS10K-I型10kW全固态中波数字调幅广播发射机,是一种工作效率高,技术指标高,自动化程度高,工作稳定可靠的全固态中波发射机。目前此类型发射机在国内拥有量越来越大,维护和故障排除的问题越来越突出。为降低停播率,使发射机充分发挥其作用,现以该发射机两起故障的排除为例,谈谈此类发射机的故障处理和在维护中的思考。     

全固态调频发射机维护新理念探讨

本文就全固态调频发射机的日常维护,提出了变“被动维修”为“主动维护”的维护理念,使发射机稳定工作的时间得到延长.此方法日常维护下的发射机平均无故障工作时间将延长2～3倍.     

GZ-GS1OK-I型数字调幅广播发射机两起故障分析处理及思考

1 引言 我台使用的哈广产GZ-GS10K-I型10kW全固态中波数字调幅广播发射机,是一种工作效率高,技术指标高,自动化程度高,工作稳定可靠的全固态中波发射机。目前此类型发射机在国内拥有量越来越大,维护和故障排除的问题越来越突出。为降低停播率,使发射机充分发挥其作用,现以该发射机两起故障的排除为例,谈谈此类发射机的故障处理和在维护中的思考。     

后备UPS电源使用技巧及维护(针对短波发射机房)

后备UPS属于广播短波发射机机房系统中必不可少的部分,保证广播短波发射机正常安全发射.本文以短波发射机机房里的UPS设备为例,介绍其构成、工作原理、分类、运行方式、使用及维护.本论文的详细论述可以为短波发射机机房的后备UPS电源的使用及维护提供借鉴和参考.     

Receiver Power Allocation and Transmitter Power Control Analysis for Multiple-Receiver Wireless Power Transfer Systems

As different power has its own receivers, this paper analyzes and designs a multiple-receiver wireless power transfer (WPT) system systematically. The equivalent circuit model of the system is established to analyze the key parameters including transmitter power, receiver power, transmission efficiency, and each receiver power allocation. A control circuit is proposed to achieve the maximum transmission efficiency and transmitter power control and arbitrary receiver power allocation ratios for different receivers. Through the proposed control circuit, receivers with different loads can allocate appropriate power according to its power demand, the transmitter power and system efficiency do not vary with the change of the number of receivers. Finally, this control circuit is validated using a 130-kHz WPT system with three receivers whose power received is 3:10:12, and the overall system efficiency can reach as high as 55.5%.     

140Mb/s混合集成光发射机

研制了一种混合集成140Mb/s单模半导体激光器发射机。该发射机由高速缓冲整形放大、LD驱动功能模块、LDAPC——LD自动功率控制功能模块、LDATC——LD自动温度控制功能模块,LD保护及寿命,信号终断告警功能模块和调顶功能模块所构成。发射机调制出纤光功率为-6dBm～-3dBm、消光比≤10％,在0～45℃范围内光功率变化在±1dB以内。该发射机和本所同时研制的混合集成光接收机配套,构成了目前140Mb/sPCM数字光端机的全新产品。     

便携式UHF RFID阅读器中发射前端电路设计

采用0.18μm CMOS工艺设计并制作了一款应用于便携式UHFRFID阅读器的射频发射前端电路。所设计的有源I/Q上混频器通过开关控制Q支路的信号输入,实现了EPC Global Class-1Gen-2协议中所要求3种调制方式;驱动放大器通过实现增益7级数字可调有效地预放大混频器的输出信号。在1.8V的电源电压下,测得阅读器前端电路的主要性能参数如下:上混频器的输入端P1dB,达到-14.9dBVrms,转换增益和噪声系数分别为3.18dB和13.20dB;驱动放大器的输出端P1dB在50Ω阻抗上达到3.5dBm,转换增益可调范围和噪声系数变化范围,分别为7.90～16.30dB和3.10～5.00dB。     

Ku波段300W固态发射机的研制

介绍一种新成功研制的Ku波段固态发射机,该发射机采用波导合成技术,对4个80w末级功率模块进行功率合成,获得300W以上的峰值功率,发射机最大脉冲宽度为120μs,最大占空比为30％,合成效率大于93．7％。     

1.3μm低功耗光发射模块

本文简述了1.3μm低功耗光发射模块的设计要点、结构特点、主要制作技术及其实测性能。该模块主要用于34Mbit/s以下的单路或双路(业务信号、勤务信号)数字信号的光纤传输系统。出纤功耗≥-20dBm,功耗≤300mW,双路信号调制度5～25％、光上升沿3.5ns。     

Network Beamforming Using Relays With Perfect Channel Information

This paper deals with beamforming in wireless relay networks with perfect channel information at the relays, receiver, and transmitter if there is a direct link between the transmitter and receiver. It is assumed that every node in the network has its own power constraint. A two-step amplify-and-forward protocol is used, in which the transmitter and relays not only use match filters to form a beam at the receiver but also adaptively adjust their transmit powers according to the channel strength information. For networks with no direct link, an algorithm is proposed to analytically find the exact solution with linear (in network size) complexity. It is shown that the transmitter should always use its maximal power while the optimal power of a relay can take any value between zero and its maxima. Also, this value depends on the quality of all other channels in addition to the relay's own. Despite this coupling fact, distributive strategies are proposed in which, with the aid of a low-rate receiver broadcast, a relay needs only its own channel information to implement the optimal power control. Then, beamforming in networks with a direct link is considered. When the direct link exists during the first step only, the optimal power control is the same as that of networks with no direct link. For networks with a direct link during the second step only and both steps, recursive numerical algorithms are proposed. Simulation shows that network beamforming achieves the maximal diversity order and outperforms other existing schemes.      

自适应光学在光通信中的仿真与实验分析

从实验和仿真两方面研究了自适应光学(AO)补偿大气湍流的影响,改善2.5Gb/s光通信系统性能的有效性。仿真结果显示,同种湍流条件下,发射端AO校正后的平均接收光功率较接收端AO校正有所提高,且起伏更小。实验结果表明,接收端AO校正后,平均误码率比校正前降低2～3个数量级;发射端AO校正后,平均误码率比校正前降低近7个数量级。     

120-GHz wireless link using photonic techniques for generation, modulation, and emission of millimeter-wave signals

We present a wireless link system that uses millimeter-wave (MMW) photonic techniques. The photonic transmitter in the wireless link consists of an optical 120-GHz MMW generator, an optical modulator, and a high-power photonic MMW emitter. A uni-traveling carrier photodiode (UTC-PD) was used as the photonic emitter in order to eliminate electronic MMW amplifiers. We evaluated the dependence of UTC-PD output power on its transit-time limited bandwidth and its CR-time constant limited bandwidth, and employed a UTC-PD with the highest output power for the photonic emitter. As for the MMW generation, we developed a 120-GHz optical MMW generator that generates a pulse train and one that generates a sinusoidal signal. The UTC-PD output power generated by a narrow pulse train was higher than that generated by sinusoidal signals under the same average optical power condition, which contributes to reducing the photocurrent of the photonic emitter. We have experimentally demonstrated that the photonic transmitter can transmit data at up to 3.0 Gb/s. The wireless link using the photonic transmitter can be applied to optical gigabit Ethernet signals.     

A 0.65-to-1.4 nJ/Burst 3-to-10 GHz UWB All-Digital TX in 90 nm CMOS for IEEE 802.15.4a

We propose an all-digital UWB transmitter architecture that exploits the low duty cycle of impulse-radio UWB to achieve ultra-low power consumption. The design supports the IEEE 802.15.4a standard and is demonstrated for its mandatory mode. A digitally controlled oscillator produces the RF carrier between 3 and 10 GHz. It is embedded in a phase-aligned frequency-locked loop that starts up in 2 ns and thus exploits the signal duty cycle that can be as low as 3%. A fully dynamic modulator shapes the BPSK symbols in discrete steps at the 499.2 MHz chip rate as required by the standard. The transmitter can operate in any 499.2 MHz band of the standard between 3.1 and 10 GHz, and the generated signal fulfills the emission spectral mask. The jitter accumulation over a burst is below 6 ps_RMS, which is within specifications. The transmitter was realized in a 1 V 90 nm digital CMOS technology, and its power consumption drawn from a 1 V supply is from 0.65 mW at 3.1 GHz to 1.4 mW at 10 GHz for a 1 Mb/s data rate.     

L波段液冷固态功放组件的设计

功放组件是固态雷达发射机的重要组成部分,其热设计已成为发射机可靠性水平的重要标志之一。本文介绍了一种输出功率在工作频带内达2kW的液冷功放组件,对其电讯设计、电磁兼容及热设计都做了详细的阐述。该组件已运用于某型号雷达中。