Direct Broadcast Satellite System Research Articles

A miniaturized left‐handed circularly‐polarized printed radiator for direct broadcast satellite application

SummaryThis article presents a highly compact printed radiator for direct broadcast satellite (DBS) systems that exhibits good gain and left‐handed circular polarization. The inferred pattern is accomplished by etching two isosceles triangles, one from each of the four corners of a square. From the center of the newly acquired structure, a circular geometric design is made up of 16 isosceles‐scaled triangles has been etched. This arrangement induces resonance in the antenna, aligning it with the desired frequency. The proposed antenna is designed using PCB laminated Rogger 5880 material and simulated in a CST EM simulator. The antenna under consideration exhibits a significant size reduction, achieving a miniaturization ratio of 21.03%. The LHCP antenna resonated at 12.61 GHz and offered a decent LHCP gain of 7.95 dBic. It gives 0.56 GHz CP bandwidth, which covers the DBS service band entirely. It also provides 96.43% radiation efficiency and 44.27 dB/m correction factor, respectively. All the measured findings of the prototype agree with its simulated one.

A printed tiny-RHCP antenna for direct broadcast application

The present study unveils a printed antenna design that achieves high gain and exhibits right-handed circular polarization (RHCP). The antenna is intended for use in direct broadcast satellite systems, operating within the frequency range of 12.20 to 12.70 GHz. The specified configuration is achieved by etching a pair of indistinguishable isosceles triangles from the vertex of a geometrically regular square. A circular geometric structure consisting of sixteen isosceles triangles scaled in proportion is meticulously engraved from the central point of the recently obtained geometry. The meticulous etching enhances the antenna’s effective length, which in turn helps achieve improved parametric performance at the desired frequency. The antenna under consideration was simulated using a SONNET EM simulator, cross-verified by the CST microwave studio, and afterward, it was fabricated using a cost-effective PCB laminated Rogger 5880 material. The antenna under consideration significantly reduces size, achieving miniaturization of 20.20%. The antenna is resonated at 12.52 GHz, and it exhibited a satisfactory circularly polarized gain of 8.46 dBic. It also provides a CP bandwidth of 0.54 GHz, capable of covering the entire DBS band. Additionally, it offers 97% radiation efficiency and 86% aperture efficiency. The antenna also offers 23 dB/m correction factor, which highlights its minimal EMI/EMC effects. All the measured outcomes align with the results achieved from the simulator.

Dual-Layer Beamscanning Reflectarray Antenna Operating at Ku-Band

This paper presents a beam scanning electronically reconfigurable reflectarray configuration for Ku-band applications using a single varactor diode. A 15×15 center-fed reconfigurable reflectarray antenna is designed consisting of 225 octagonal shaped unit cells. The proposed tunable element has a unit cell size of 9.8 mm, developed on a 1.575 mm thick Taconic TLY-5 substrate. A single varactor diode is integrated with the tunable element to produce a reflection phase variation of 340° at 14.1 GHz. In this work, both the varactor and biasing circuit are placed beneath the substrate to avoid unexpected reflections, which leads to achieving a pencil beam of 8.1° beamwidth. The simulation results of the reconfigurable reflectarray antenna (RRA) shows good beam-scanning radiation performance of scanning range ±30° and a peak gain of 27.6 dBi. This structure provides a convenient solution for Ku-band distinctive applications like uplink operation in the direct broadcast satellite system, digital video broadcasting, earth exploration satellites, space research satellites, and defense systems.

Design and Implementation of a Multiband Metamaterial-Loaded Reconfigurable Antenna for Wireless Applications

This article presents a multiband antenna with the implementation of a metamaterial split-ring resonator (SRR), quasicomplementary split-ring resonator (CSRR), and slots to achieve octaband characteristics for wireless standards. Multiband features are accomplished by the implementation of the slot approach within the radiating section part and loading the SRR and CSRR cells. The electrical dimension is 0.256λ × 0.176 λ × 0.0128λ (32 × 22 × 1.6 mm3) of the proposed design, at a lower frequency of 2.4 GHz. The proposed design indicates the frequency-band reconfigurability nature by using the switching PIN diode placed at the slotted section of the ground plane. During the OFF state of switching, the element structure resonates in eight wireless communication bands covering various high-speed multiple applications of Internet of Things (IoT) regarding wireless standards S-band WLAN (WiFi, Bluetooth, Z-wave, wireless HART, and WBAN), lower C-band (WAIC, satellite communication transmission application), C-band WLAN, X-band (ITU region 2), Ku-band (direct broadcast satellite system and terrestrial microwave communication system service), and K-band (radar communication application) at 2.4, 4.3, 5.8, 8.5, 11.1, 13.9, 16.1, and 18.9 GHz, respectively, with S11 ≤ −10 dB. The antenna achieves an optimum peak gain of 4.23 dBi and radiation efficiency of 82.78% at operating frequency regarding wireless standards. The average efficiency of the proposed design is more than 70% for all resonant modes. The radiation characteristics (gain/efficiency/patterns/impedance matching) are shown in the stable and improved form at achieved wireless modes.

Performance of the DBS Satellite Receiver under the Impact of Rainfall and Terrestrial Interference

This article presents a new study on the feasibility of operating a direct broadcasting satellite (DBS) system under the effect of both precipitation and interference from a fixed service (FS) at K‐band in a semiarid region. The carrier‐to‐noise plus interference ratio (CNIR) as a protection criterion has been adopted to make sure that the receiver of the DBS system operates with an acceptable performance under rainfall and interference from FS. Various measured data for rainfall in different areas have been utilized to investigate different rain rate exceedance percentages. Results have been shown that areas with high rain rates have a small CNIR at the DBS receiver and require large protection distances compared to low‐rain rate areas and vice versa. Some mitigation techniques have been suggested to alleviate the effect of rain and terrestrial interference on the DBS receiver performance.

Thinning of Antenna Arrays for Direct Broadcast Satellite System

In antenna array thinning some antenna elements are made ‘ON’ and some antenna elements are  made ‘OFF” strategically. Keeping some of the antenna elements ‘OFF’ and reducing use of digital beamformer, desired characteristics of the array can be achieved in direct broadcast satellite (DBS) communication, to achieve higher gain and saving power utilization. In this paper, array thinning is done using differential evolution (DE) algorithm, an optimization technique. DE optimized results are compared with corresponding fully populated arrays. Lower side lobe levels (SLL) are achieved using DE optimized thinned arrays compared to fully populated arrays. Both linear array and planar are considered for array thinning.

Rethinking the Commitment to Free, Local Television

One of the most enduring tenets of U.S. television policy has been the commitment to localism. I suggest that the FCC's localism policy can be disaggregated into four, more specific commitments: (1) the preference for locally oriented over nationally oriented programming, (2) the preference for free (i.e., advertising-supported) over pay television, (3) the preference for single-channel over multi-channel television technologies, and (4) the preference for incumbents over new entrants and new technologies. I then analyze each of these commitments in light of what is perhaps the most distinctive feature of the television industry, which is the fact that its cost structure gives television programming many of the qualities of a public good, and conclude that each of these four commitments is fundamentally flawed. I then employ the public goods analysis I develop to critique the manner in which policy makers are regulating conventional television broadcasting, cable television, direct broadcast satellite systems (DBS), digital television, and third-generation wireless devices (3G).

Dual-Polarized Planar Reflector Feed for Direct Broadcast Satellite Systems

This work presents a planar dual-polarized reflector feed for direct broadcast satellite (DBS) systems. The planar feed is a multilayered structure, featuring a suspended planar array with the aperture-coupling feed and the suspended-microstrip feed. The design of independent feeding circuits on each side of the ground plane provides effective isolation between the two feeding ports (35 dB). Radiation patterns for a 2 × 2 suspended array feed are similar to those of the conventional feed horn. The planar feed antenna gains are 12 and 30 dBi, as measured with a 20-in reflector at 12.2 GHz.

직접 위성방송 수신용 원편파 HTS 배열 안테나 관한 연구

We report the performance of a four-element, 11.67 GHz, <TEX>$high-{T}_c$</TEX> superconducting (HTS) microstrip antenna array with corporate feed network. The HTS antenna array used in this work had a circular polarization for direct broadcasting satellite (DBS) system. Our array antennas were designed and built on a 0.5 mm thick MgO substrate. To compare the superconducting antennas with normal conducting counterpart, One antenna pattern was fabricated from gold thin film, and a second pattern was fabricated from <TEX>${YBa}_2{Cu}_3{O}_7-x(YBCO)$</TEX> superconducting thin film. To improve the axial ratio of circularly polarized arrays, sequential rotation technique were used. Efficiency, radiation pattern, return loss and bandwidth were measured for both antennas at cryogenic temperature and room temperature. The array produced good circular polarization, and the gain of the array at 77 K, relative to a copper array at room temperature was approximately 1.54 dB. The measured return loss of our HTS antenna array was 35.79 dB at the resonant frequency of 11.67 GHz and The total effective bandwidth was about 3.4 %. The results showed that high-temperature superconductors, when used in microstrip arrays, improved the efficiency of the HTS antenna array for circularly polarization.

Circularly polarized HTS microstrip antenna array

A four-element, 11.67 GHz, high-T/sub c/ superconducting (HTS) microstrip antenna array with corporate feed network and circular polarization for direct broadcasting satellite (DBS) system was designed and built on a 0.5 mm thick MgO substrate. One antenna pattern was fabricated from gold thin film, and a second pattern was fabricated from YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) superconducting thin film. To improve the axial ratio of circularly polarized arrays, sequential rotation technique were used. Efficiency, radiation pattern, return loss and bandwidth were measured for both antennas at room temperature and at cryogenic temperatures. The array produced good circular polarization, and the gain of the array at 77 K, relative to a gold array at room temperature was approximately 1.54 dB. The measured return loss of our HTS antenna array was -35.79 dB at the resonant frequency of 11.67 GHz and the total effective bandwidth was about 3.4%. The results showed that high-temperature superconductors, when used in microstrip arrays, improved the efficiency of the circularly polarized HTS antenna array.

Digital radio takes to the road

While the transition of television to a digital technology with its improved picture and sound quality has been a much publicized and controversial process, radio, has stayed in the background. But in 2001, in the United States, radio broadcasting is making its own digital leap. Two start-ups are introducing a new type of radio broadcast-subscription-based digital audio sent from satellites. With satellite digital audio radio services (SDARS), listeners will be able to tune in to the same radio stations anywhere in the United States. SDARS differs from so-called digital music services, in which direct broadcast satellite or cable system operators provide digitized and compressed audio over their networks, both because of its programming and because SDARS can be received in a moving car, where much of today's radio listening takes place; existing digital audio services cannot. Meanwhile, the free, over-the-air terrestrial broadcasters are expected to choose digital audio broadcasting technologies for both the AM and FM bands by year-end.

A new analysis method and broad-band design of tap-offs for CATV/DBS systems

A new analysis method of tap-off for CATV (cable television) and DBS (direct broadcasting satellite) system was proposed and investigated by using 4-port and 3-port equivalent circuits. As a new analysis method the even-odd-mode theory of a symmetrical coupled-line directional coupler was introduced, and then it was applied to transformer type directional coupler and analyzed. By comparing the results of simulation and measurement the validity of proposed analysis method was confirmed. Furthermore, the tap-off has been broadened from 5 MHz to 2450 MHz by adopting the proposed theory.

The implementation of TS MAC (transmitter station monitor, alarm and control) system for digital DBS system

The implementation of TS MAC system for KOREASAT DBS (direct broadcast satellite) system is presented. This TS MAC controls and monitors the status of the TS equipment and gathers the alarm for them. The advantage of this system is the center-concentrated, real time processing, remote control, and object oriented module decomposing.

A flexible transmission technique for the satellite ISDB system

A new transmission technique which can achieve suitable quality and reliability for satellite ISDB (Integrated Services Digital Broadcasting) is introduced. The transmission system for satellite ISDB must have high spectrum efficiency, continuous service availability and also superior flexibility in its transmission scheme. This paper first studies appropriate transmission schemes, taking account of the 12 GHz band DBS (direct broadcasting satellite) system. Then, employing a hierarchical transmission technique and a newly proposed TMCC (transmission and multiplexing configuration control) signal, it describes the requirements for satellite ISDB. The hierarchical transmission extends the service availability under heavy rainfall conditions. The TMCC signal can change the transmission configuration depending on the program content and the weather conditions. In addition, a generalized method for the design of transmission configurations for satellite ISDB is presented.

Variable output power 21 GHz direct broadcasting satellite systems

This paper describes the 21 GHz band Direct Broadcasting Satellite transponder for wide RF band HDTV and reduction of satellite weight. The most difficult problem with this frequency band is rain attenuation. We studied a variable output power transponder system for a contoured six-beam antenna covering all of Japan. The output power of transponders corresponding to rain areas are boosted from the normal margin of 5 dB (the worst month service time rate 95%) to 9 dB (99%). This variable output power method can decrease about 30% of the satellite power and weight.

Direct broadcast satellites in Japan: A case study in government-business partnerships

Abstract The following case study examines government-business partnerships in the planning and implementation of direct broadcast satellite (DBS) communications in Japan. The country's decision to launch the world's first DBS system demonstrated a national commitment to advance the cause of a highly sophisticated technology. For Japan's Ministry of Posts and Telecommunications DBS was clearly a high-profile project that would invite both national and international attention. Less clear were the unintended consequences that would result from planning a new system of broadcast communication that involved balancing the unique requirements of a non-profit corporation in the form of NHK and Japan's five major commercial broadcasters.

Satellite receiver technologies

The technical issues pertinent to direct broadcast satellite(DBS) reception are elucidated, dividing them into system and component-oriented subjects. The former include the relationship of DBS and TVRO (television receive-only) systems, TVRO technology, scrambling technology, PCM audio systems, MAC systems and HDTV. The latter are classified according to the path of the signal, that is, an antenna, LNB, and a receiver. Future trends are projected both for systems and components.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

DBS systems: Perspectives from a profit seeking company

Considerable work has been reported on the tradeoffs associated with direct broadcast satellite (DBS) systems. These studies have considered total investment costs (space segment plus ground segment), but have not dealt with a number of other business-related parameters which affect system design. This article addresses some of these issues from the viewpoint of a commercial entity in the USA. It considers intial financing, short-term v long-term competitive advantages, system features v cost, effects of partially shifting the investment burden to the consumer, technology improvements, satellite constraints and economies of scale, flexibility, commercial alliances, and regulatory constraints. Examples are given to illustrate the tradeoffs involved and the effects of some of the factors.

Computer Aided System Synthesis and Costing of Direct Broadcasting Satellite Systems

For the planning of any direct broadcast satellite system, it is necessary to derive an optimum system configuration for a given set of requirements. Due to complex interrelationships of system components, use of a computer-aided approach becomes essential for the system optimization and sensitivity analysis. In this paper, concept of such a system synthesis and costing procedure has been presented. A computer programme which was developed, using this approach, has also been described. An example has been given which illustrates the design process using this computer-aided approach.

An Introduction to the RARC '83 Plan for DBS Systems in the Western Hemisphere

The 1983 Regional Administrative Radio Conference (RARC '83), sponsored by the International Telecommunication Union (ITU), adopted a plan that assigns to each country in ITU Region 2 (the western hemisphere) the frequencies and orbital positions it can use for direct broadcasting satellite (DBS) systems in the 12.2-12.7 GHz band. An earlier ITU conference, the 1977 World Administrative Radio Conference (WARC '77), had already made such a plan for countries of ITU Region 1 (Africa, Europe, the Soviet Union, and Mongolia) and Region 3 (the rest of Asia, Australia, and the southwest Pacific) in the 11.7-12.5 and 11.7-12.2 GHz bands, respectively. In addition to orbital positions and frequencies, both plans specify the satellite polarization, coverage, and maximum radiated power to be used by each country. This paper describes the RARC '83 Plan and compares some of its features to those of the WARC '77 Plan. The reference system parameters used for planning at RARC '83 and WARC '77 are summarized and discussed briefly. The RARC '83 Plan itself is described in terms of the satellite coverage areas; the channelization of the band; and the specific orbital position, frequency, and polarization assignments provided. Further details about the assignments in the plan and an assessment of their impact on the development of DBS systems in Region 2 are also included.