A Study on Design and Implementation of Wideband High Power Amplifier for Digital TV Repeater

In this dissertation, a high power amplifier has been implemented and performed evaluation, which is operating at UHF band (470 ~ 806 MHz) for Digital TV repeater. The theoretical consideration of 100 Watt power amplifier at UHF band used in Digital TV repeater is studied. After extracting target specification of each part, amplifier is designed and fabricated. When the driving amplifier stage is flown by bias voltage of 28 V DC and current of 900 mA, it has the gain of more than 53.5 dB, the gain flatness of ±0.5 dB and return loss of less than -12 dB in 470 ~ 806 MHz. Also, when two signals at 2 MHz frequency interval are input port into the driving amplifier stage with 1 Watt output, it resulted in excellent characteristics to design specification with showing intermodulation distortion characteristics of more than 48 dBc. The middle amplifier stage using 85 Watt device is fabricated by RO-4003 electric substrate which is 3.38 in dielectric constant and 32 mil-thickness. When the driving amplifier stage and the middle amplifier stage were flown by bias voltage of 28 V DC and current of 4 A, they revealed the gain of more than 66 dB, the gain flatness of ±0.2 dB and return loss of less than -16 dB. Also, when two signals at 2 MHz frequency interval in using frequency band is input port into the driving amplifier stage with 40 dBm of output power, it showed intermodulation distortion characteristics of more than 38.50 dBc. The 100 Watt unit power amplifier using temperature independent biasing for Digital TV repeater application is designed and fabricated. The DC operation point of this unit power amplifier at temperature variation from 20 ℃ to 100 ℃ is fixed by active bias circuit. The variation of current consumption in the 100 Watt unit power amplifier has an excellent characteristics of less than 0.6 A. The implemented unit power amplifier has the gain over 12 dB, the gain flatness of less than ±0.5 dB and return loss of less than 15 dB over the DTV repeater frequency range. This unit power amplifier yields intermodulation distortion of more than 32 dBc at 2 MHz offset, which satisfies the IMD at output power of 100 Watt (50 dBm). The broadband high power 3-way combiner was designed and fabricated for the digital TV repeater. To achieve increase of bandwidth and high power capability, Wilkinson type power divider was adopted in our research. First of all, Wilkinson type power divider of equal-split and unequal-split were combined, the characteristics variation of the same phase four port power combiner was simulated according to the various thicknesses of dielectric substrates. As the results of simulation, the power combiner fabricated by using dielectric substrate of 120 mil-thickness has the characteristics as follows: insertion loss of less than -6 dB, return loss of less than -13 dB, isolation among the output ports of less than -15 dB, and phase difference among the output ports of smaller than 13°. Therefore, this power combiner was possible to improve the limit of microstrip line width due to high impedance, the problems of power loss due to interaction between strip lines in high power combiner and narrow bandwidth simultaneously. Furthermore, since the fabricated 3-way combiner has good characteristics of insertion loss, the return loss, separation between ports and phase difference, making broadband and high power could be achieved. By using 3-way power divider and power combiner, 100 Watt unit power amplifier stage was designed and fabricated as a type of 3-stage balanced amplifier and to detect the final signal output power with using of 40 dB parallel coupled-line directional coupler. The fabricated 40 dB parallel couled-line directional coupler detects the signal power emitting to the antenna, and then supplies its voltage to the attenuator. In addition, this sets to be changed with a basic attenuation 8 dB, according to the changing of the power amplifier's temperature and 8-VSB modulator's input signal. Besides, in order to measure the fabricated 100 Watt power amplifier, the estimation technique function which makes equivalent mask by Tektronix RFA-300A was used. As a result of the measurement, the existence of pilot signal is confirmed and the signal transmitted at the rated output power 100 Watt is brought out the flat feature through 6 MHz bandwidth. And it resulted that its value was less than -47 dB at the edge of radiation channel and less than -110 dB at more than 6 MHz position from channel edge. Finally a positive results on the equivalent mask has been complied with related regulations.목차 Abbreviations Abstract 제1장 서론 = 12 1.1 연구 배경 = 12 1.2 연구 목적 = 14 제2장 디지털 TV 방송 시스템 = 16 2.1 통신 시스템의 형태 = 16 2.2 DTV 시스템 설계 파라미터 = 17 2.3 지상파 DTV 중계기 시스템 = 25 2.4 지상파 DTV HPA 서브 시스템 = 27 제3장 전력증폭기의 설계 및 구현 = 31 3.1 구동증폭단의 설계 및 구현 = 31 3.2 중간증폭단의 설계 및 구현 = 50 3.3 100 Watt 단위 전력증폭기의 설계 및 구현 = 62 3.4 결과 분석 = 75 제4장 100 Watt 전력증폭기의 구성 및 평가 = 77 4.1 3-Way 동위상 고출력 전력결합기 = 77 4.2 전력검출기 및 감쇠기 = 97 4.3 100 Watt 전력증폭기의 구성 및 특성 평가 = 103 4.4 결과 분석 = 115 제5장 결론 = 116 참고문헌 = 11

A common European Spectrum policy

This briefing note considers the European Commission\u2019s proposals for a common European spectrum policy through reviewing adopted legislation as well as recent communications and other initiatives. The report was produced against the background of the review of the regulatory framework for electronic communications and the recent World Radiocommunication Conference

Interface air pour systèmes de navigation en bande S : étude détaillée des signaux OFDM

Positioning in urban or indoor environment is a hot topic, either due to regulations such as the E911 requiring US mobile telecommunication operators to be able to locate their subscribers in case of emergency, or due to the market development, with the extension of location - based services targeting the mass market concentrated in metropolitan areas. In urban or indoor areas, it is generally recognized that satellite - based positioning systems are not suitable (alone) to provide a continuous, reliable and accurate position to the user. Therefore, alternative positioning techniques may be useful to complement or replace satellite positioning in these environments. This PhD study ha s studied the possibility of using a mobile TV system based on the DVB - SH standard as system of opportunity for positioning. The advantage s of using a DVB - SH system for positioning are multiple. First, such system has a good availability in metropolitan areas, including indoor. Secondly, the emitters are synchronized and their density should be sufficient to track signals from several emitters simultaneously. This opens the possibility of using timing measurements from several emitters to find a position by trilateration . Also, the large bandwidth of the TV signal, required for the transmission of video content, should be beneficial for the accuracy of the timing measurements and for the robustness against multipath . Therefore, DVB - SH system seems to be an interesting candidate as system of opportunity for positioning. However, several challenges are to be solved for such a solution to be relevant. First, the signals propagate in the urban environment, which creates challenging conditions for positioning su ch as strong power fading, blockage of the desired line - of - sight signal or large echoes. Secondly, the DVB - SH standard uses an OFDM modulation, which has not been studied for positioning purpose. Therefore, techniques for fine tracking of the first receive d signal replica will have to be developed. Finally, a particularity of modern broadcast system is the use of a Single Frequency Network, in which all emitters send the same signal on the same carrier frequency. Therefore emitter identification in a Single Frequency will be another issue to be solved. This PhD study has proved the feasibility of positioning using DVB - SH signals. The main contributions of this work are the propositions of (1) an OFDM signal delay tracking method working in urban propagation channels, and (2) a modification to the network deployment permitting emitter identification and (3) a first assessment of the position accuracy using the proposed algorithms. These two methods have very low impact on the initial TV broadcasting service if the right set of signal parameters is chosen: no signal modification is required and the network deployment modification uses a feature already present in the DVB - SH standard. The positioning method was simulated using real urban propagation channel measurements. The obtained position has root mean square error of 4 0m. The main error contribution comes from tracking a non - line - of - sight signal. Further work would be required to deal with this issue, which would lower the position root mean square error to 7 m, which has been locally observed in the simulation for good tracking conditionsLe positionnement en environnement urbain est un domaine de recherche actif, de par la croissance des services grand public liées à la localisation, et à cause de réglementations émergentes liées aux situations d'urgence (E911). En environnement urbain ou à l'intérieur des bâtiments, il est communément admis que les systèmes de positionnement basés sur des satellites ne sont pas suffisants pour fournir une position précise, fiable et de manière continue. Des techniques de positionnement alternatives sont donc développées afin de remplacer ou compléter les systèmes de positionnement par satellite. Cette thèse étudie la possibilité de fournir un service de positionnement utilisant un futur système de diffusion de télévison vers les mobiles basé sur le standard DVB-SH. Le principal attrait de ce système pour du positionnement est sa bonne couverture en milieu urbain, ainsi que l'utilisation d'un réseau d'émetteurs synchronisés. Il est donc possible d'employer des mesures de temps d'arrivée des signaux afin de réaliser une triangulation pour calculer la position d'un récepteur. Afin de fournir ce service innovant, des techniques spécifiques d'estimation de pseudo-distance et d'identification d'émetteurs ont été développées dans le cadre de cette thèse. Le principal résultat de cette étude est d'avoir montré la faisabilité du positionnement utilisant un système DVB-SH, ne nécessitant que de légères modifications du système qui n'apportent aucune dégradation auservice de diffusion TV. De premières simulations ont montré une précision de positionnement autour de 40m en utilisant des mesures réalistes de canal de propagation urbain

Potentzia domeinuko NOMA 5G sareetarako eta haratago

Tesis inglés 268 p. -- Tesis euskera 274 p.During the last decade, the amount of data carried over wireless networks has grown exponentially. Several reasons have led to this situation, but the most influential ones are the massive deployment of devices connected to the network and the constant evolution in the services offered. In this context, 5G targets the correct implementation of every application integrated into the use cases. Nevertheless, the biggest challenge to make ITU-R defined cases (eMBB, URLLC and mMTC) a reality is the improvement in spectral efficiency. Therefore, in this thesis, a combination of two mechanisms is proposed to improve spectral efficiency: Non-Orthogonal Multiple Access (NOMA) techniques and Radio Resource Management (RRM) schemes. Specifically, NOMA transmits simultaneously several layered data flows so that the whole bandwidth is used throughout the entire time to deliver more than one service simultaneously. Then, RRM schemes provide efficient management and distribution of radio resources among network users. Although NOMA techniques and RRM schemes can be very advantageous in all use cases, this thesis focuses on making contributions in eMBB and URLLC environments and proposing solutions to communications that are expected to be relevant in 6G

The Deep Space Network, volume 3 Progress report, Mar. - Apr. 1971

Deep Space Network telecommunication and ground support equipment for planetary and interplanetary flight project

The Wireless Craze, The Unlimited Bandwidth Myth, The Spectrum Auction Faux Pas, and the Punchline to Ronald Coase's 'Big Joke': An Essay on Airwave Allocation Policy

In 1959 the Federal Communications Commission invited economist Ronald Coase to testify about his proposal for market allocation of radio spectrum rights. The FCC's first question: 'Is this all a big joke'' Today, however, leading policy makers, including the current FCC Chair, decry the 'spectrum drought' produced by administrative allocation and call for the creation of private bandwidth markets. This essay examines marketplace trends driving regulators' change of humor, and considers the path of spectrum policy liberalization in light of emerging technologies, theories of unlimited bandwidth, reforms such as FCC license auctions, and recent progress in deregulating wireless markets in the U.S. and around the globe.

Energy: A continuing bibliography with indexes, issue 31

This bibliography lists 1111 reports, articles, and other documents introduced into the NASA scientific and technical information system from July 1, 1981 through September 30, 1981

Spectrum Rights in the Telecosm to Come

The spectrum of electromagnetic frequencies impact the way individuals and society communicate. The discussion involves reforming the structures governing the spectrum, a debate that centers on the benefits of public versus private control over the resources. This article focuses on articulating governmental standards for managing and regulating public or private control of the spectrum. However, standards will not be easy to establish given the difficult cost assessments necessary to balance the public interest against communication. A regulatory agency can better govern spectrum management that accommodates both commonly and privately owned spectrum. Spectrum conflicts can be remedied easily by defining a class of per se nuisances. The article concludes by encouraging attentiveness to the costs of dispute resolution, the regulators? roles in reducing these costs, and the policy choices inherent in spectrum management. Any regulator agency that is established must play a role in resolving spectrum conflicts

Third International Symposium on Space Mission Operations and Ground Data Systems, part 1

Under the theme of 'Opportunities in Ground Data Systems for High Efficiency Operations of Space Missions,' the SpaceOps '94 symposium included presentations of more than 150 technical papers spanning five topic areas: Mission Management, Operations, Data Management, System Development, and Systems Engineering. The papers focus on improvements in the efficiency, effectiveness, productivity, and quality of data acquisition, ground systems, and mission operations. New technology, techniques, methods, and human systems are discussed. Accomplishments are also reported in the application of information systems to improve data retrieval, reporting, and archiving; the management of human factors; the use of telescience and teleoperations; and the design and implementation of logistics support for mission operations

Air Traffic Management Abbreviation Compendium

As in all fields of work, an unmanageable number of abbreviations are used today in aviation for terms, definitions, commands, standards and technical descriptions. This applies in general to the areas of aeronautical communication, navigation and surveillance, cockpit and air traffic control working positions, passenger and cargo transport, and all other areas of flight planning, organization and guidance. In addition, many abbreviations are used more than once or have different meanings in different languages. In order to obtain an overview of the most common abbreviations used in air traffic management, organizations like EUROCONTROL, FAA, DWD and DLR have published lists of abbreviations in the past, which have also been enclosed in this document. In addition, abbreviations from some larger international projects related to aviation have been included to provide users with a directory as complete as possible. This means that the second edition of the Air Traffic Management Abbreviation Compendium includes now around 16,500 abbreviations and acronyms from the field of aviation