Direct Broadcast Satellite Reception Research Articles

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.

The Use of Statistical Risk Assessment by the FCC in Spectrum Regulation

This paper explores the FCC’s approach to spectrum regulation by examining its quantification of harmful interference, analysis of service rules in its rule-making process, and the content of its final service rules. The paper was developed to support the Interference Studies project of the FCC TAC 2013 Spectrum and Receivers working group. The FCC has traditionally used worst-case analysis to determine whether new service rules will cause interference, and the FCC’s final service rules have traditionally been single-value. However, a worst case-analysis and single-valued rules arguably creates unnecessarily conservative rules that may not result in the maximum benefit to society. Thus, a number of analysts and regulators have argued for statistical approaches to spectrum policy. This paper continues as follows: Section I identifies the FCC’s regulation of interference in the following three contexts: 1. The discussion and definition of harmful interference. 2. The technical analysis of service rules done during the rule-making process. 3. The content of final service rules. In order to better understand the status quo in the FCC’s spectrum policy, Section I examines the three contexts based on the following five distinctions. The first option in each distinction is the FCC’s traditional approach: 1. The definition of harmful interference can be qualitative or quantitative. 2. Analyses of service rules can be worst-case or multi-case. 3. Analyses of service rules can be qualitative or quantitative. 4. Final service rules can be single-value or statistical. 5. Final service rules can be quantitative or qualitative. Section II explains our four findings. In summary, the FCC’s: 1. Technical analysis and final rules fail to quantify harmful interference. 2. Customary analysis of service rules is worst-case. 3. Resulting service rules are almost always single-value. 4. Analysis of service rules is generally qualitative and resulting service rules are usually quantitative. Section III presents the Northpoint case to illustrate the application of the above criteria and findings. “Northpoint” was a controversy about the FCC’s approval of Multichannel Video Distribution and Data Service (MVDDS) — a terrestrial wireless broadband technology. Northpoint, a developer of MVDDS, tried to obtain approval to operate terrestrial transmitters in the face of objections from the incumbent operators of direct broadcast satellite receivers. In Northpoint, the FCC never quantified harmful interference in its technical analysis nor final rules, and it started with a multi-case analysis of service rules that ended in single-value service rules.

Potential interference and rain attenuation at 21.4–22 GHz downlink broadcasting satellite signals

World Radio Conference WRC-1992 has allocated the frequency band 21.4–22.0 GHz to regions 1 and 3 to be utilised to carry direct broadcasting satellite (DBS) services. This high-frequency band is more susceptible to rain attenuation, leading to degradation of the signal quality. Moreover, this frequency band is assigned to two different services, i.e. satellite broadcasting and fixed mobile services at the same regions; hence, the impact of intersystem interference in a depredated signal is a critical issue in the DBS receiver. In this study, the effects of rain attenuation on the DBS downlink signals as well as the impact of the potential interference on the reception quality will be estimated. An interference scenario will be introduced to investigate the system performance in both propagation mechanisms of clear-sky and rain conditions.

SPSA-based step tracking algorithm for mobile DBS reception

A novel step tracking algorithm for Ku-band mobile satellite communication that will be used in mobile direct broadcasting satellite (DBS) reception is presented in this paper. The main idea for this improved step tracking algorithm is to use a highly efficient simultaneous perturbation approximation to the gradient using only two noisy measurements of the received signal strength. The antenna beam can be steered to coincide with the direction of DBS in both azimuth and elevation planes simultaneously in the direction of gradient using the novel step tracking algorithm. Computer simulations verify this improved step tracking algorithm is indeed robust and effective.

The development of radial line slot array antenna for direct broadcast satellite reception

Microwave antennas are extensively used in communications systems such as satellite, television and high-speed data transmission due to their wide and absolute bandwidth. Among the variety of microwave antennas, satellite communication commonly adopts an antenna of parabolic dish type, despite some drawbacks. In a primary fed design, there is considerable aperture blockage. An offset parabolic antenna design, which then eliminates the blockage, is susceptible to physical damage as its feed is significantly exposed from the body of reflector. The radial line slot array (RLSA) type antenna is thus designed to cope with the problems encountered in parabolic antennas. RLSA is a planar antenna suitable for direct broadcast satellite (DBS) reception, with advantages including high radiation efficiency (high gain), low profile, low cost and feed rear-mounted. The prototype development started with the selection of the cavity's dielectric material and construction of the feeding structure of coaxial-to-waveguide transition. Within the frequency band of interest, between 10.95 and 11.7 GHz, results, is showed a lower than −10 dB of return loss. A DBS receiver test-bed had been developed to test the constructed antenna prototypes and it revealed that the prototype has the capability of receiving TV programs from DBS.

Modeling Polarization Mode Coupling in Frequency-Selective Surfaces

An analysis of scattering from frequency-selective surfaces (FSS) is developed that correctly accounts for coupling between scattered polarization modes. This is useful for the design of FSS structures with obliquely incident radiation, such as polarization converters (polarizers) for direct broadcast satellite reception by linearly polarized ground terminal antennas. In the past, the neglect of polarization mode coupling limited the performance range of various FSS structures, such as meander-line polarizers, to near normal incidence where mode coupling is weak. The following analysis shows how a suitable pair of polarization modes can be selected to maintain modal independence. The result is a pair of independent equivalent circuits representing scattering of the two modes, together with mode transformation networks. To illustrate the theory, a four-layer meander-line polarizer is designed for an incident angle of 45/spl deg/ off normal. The resulting axial ratio is measured to be 0.3 dB at 12.45 GHz.

Natives on the Electronic Frontier

Natives on the Electronic Frontier

A new active phased array antenna for mobile direct broadcasting satellite reception

This paper represents a new active phase array antenna for a Ku-band mobile service that will be possible with satellite broadcasting. The main idea for the antenna is to use minimum active array elements with cost-effective one-dimensional subarrays with an inclined pencil beam structure for a 34 dBi gain. For this antenna, we also used the squint beam tracking algorithm. This tracking gives a different way to the traditional monopulse tracking method in tracking capability. The electronic scanning angle of the beam peak in this antenna is over /spl plusmn/12/spl deg/ wide only with 20 phase shifter elements for its scan ranges. This antenna with the attractive hybrid-tracking concept has about 142 times less array elements than antennas with a two-dimensional array.

Development of direct broadcasting satellite reception system for a small car

To realize the DBS (Direct Broadcasting Satellite) reception system for a small car, we have developed an antenna system concentrating on “Miniaturization” and “Low-cost”. In this paper, an outline and the features of the developed antenna system are described. It can be mounted on a small car, and is a small, low-cost antenna whose design is simplified by adopting the planar beam tilt antenna and abolishing elevation tracking.

A microstrip antenna array for direct broadcast satellite receivers

A uniformly illuminated square subarray of 16 circularly polarized patch elements is developed. It can be incorporated into a full-size direct broadcast satellite (DBS) receiver antenna. A stacked circular patch microstrip configuration is used to achieve increased bandwidth. Experimental results for the return loss, bandwidth, radiation pattern, and gain are presented. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15, 68–72, 1997.

GaAs converter IC's for C-band DBS receivers

GaAs downconverter Monolithic Microwave Integrated Circuits (MMICs) for use in C-band direct broadcast satellite (DBS) receivers were developed. The IC consists of four (4) RF functional blocks and a dc bias block. The RF section includes a low noise amplifier, IF amplifier, mixer, and local oscillator. The dc section incorporates an internal dc bias generation circuit to compensate for device parameter fluctuations in wafer processing. The IC makes it easy to design a complete out-door converter unit with only the addition of two low noise FETs, a band pass filter, and an external dielectric resonator. This IC is realized on a small chip of only 1.1 mm/spl times/1.6 mm. The gate length of the FET is 0.5 /spl mu/m. The active layers of the FETs and resistors are formed by an ion-implantation technique. This IC has a 3.0-dB noise figure and a 43-dB conversion gain at 80-mA total current consumption. To realize compact size and low cost, these ICs are offered in 12-pin QFP plastic packages. >

New type of DBS receiver utilizing optical fiber as IF transmission line

An optical fiber transmission system that transmits the IF signal for direct broadcasting satellite (DBS) TV channels from a low noise converter to the main chassis of the DBS receiver after the IF signal at 1 GHz is converted into the corresponding second IF signal at 300 MHz (35-335 MHz) is described. The differential gain and differential phase of the video signal are less than 2% and 3 degrees, respectively, and the signal-to-noise ratio (SNR) is 45 dB. >

A 22 GHz band low-cost, low-noise downconverter for DBS

A low-noise downconverter for 22 GHz DBS (direct broadcasting satellite) reception has been developed for future wideband HDTV. Only low-cost, packaged components that are already marketed for 12 GHz DBS have been used, and the design is compatible with existing mass-production assembly techniques. A prototype has been fabricated and a noise figure of only 1.7 dB measured.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A DBS antenna-receiver system for simultaneous multi-satellite reception

A hemispherical dielectric lens antenna is proposed as a simultaneous multisatellite DBS (direct broadcasting satellite) reception antenna. It adopts a novel offset feed for light weight, freedom from blockage, and beam separation. The prototype antenna and the converters used are described. The prototype antenna was evaluated and satellite TV signal reception tests were performed. The prototype showed good scanning characteristics and a wide frequency response. >

DBS program distribution network in local area through optical fiber

The authors describe a novel optical fiber audio/video signal transmission system for distributing DBS (direct broadcast satellite) programs to the displays/receivers in a local area where there is not enough space to install antennas for each receiver. A customer who has a DBS receiver but no space for setting up an antenna can receive the DBS programs through the optical fiber system. A customer who has no DBS receiver can also receive the DBS programs on a video display through the optical fiber system. The differential gain and differential phase of the transmission system for a video signal were under 3% and 3 degrees, respectively. The distortion factor for an audio signal was under 0.08% in mode A and 0.02% in mode B. The SNR (signal-to-noise ratio) of a video signal was above 45 dB (unweighed) and the SNR for an audio signal was above 60 dB in mode A and 70 dB in mode B. >

A high-performance, miniaturized X-band active mixer for DBS receiver application with on-chip IF noise filter

A GaAs monolithic microwave integrated circuit (MMIC) dual-gate FET active mixer at X-band is described that is designed for direct broadcast satellite (DBS) applications. All of the components of the mixer, including biasing circuitry, RF, LO, and IF matching networks, as well as the IF noise filter, are implemented monolithically into a 25-mil*30-mil area. The design was process tolerant, and layout was compact for manufacturability and low cost. The mixer was integrated monolithically into a complete single-chip DBS low-noise block (LNB) converter. The active mixer has a conversion gain of 5.5 dB and a single-sideband noise figure of 8.5 dB. The circuit is manufactured using a 0.5- mu m gate length, buried p/sup -/ depletion mode MESFET process without substrate-through via holes.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Planar antennas for satellite reception

Direct broadcast satellite (DBS) reception requires a circularly polarized antenna with high gain and low axial ratio. Recently, various types of planar antennas have been studied and developed for DBS reception in the 12-GHz band. A summary is presented of properties and classification of planar antennas both commercialized and reported. The basic configurations, working principles, and performance of various planar antennas are described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An Assessment of the Potential Terrestrial Interference Due to Direct Broadcast Satellite Television Receivers

The potential interference of spurious, radiation from the local oscillators of direct broadcast satellite (DBS) television receivers to terrestrial 11 GHz microwave radio services is examined. Typical parameters for DBS receivers are identified and used in a computer simulation to calculate the aggregate effect of a large number of units distributed about a terrestrial repeater site. The results of the analysis show that for a local oscillator frequency of 11.2 GHz, DBS LO leakage of -70 dBW/unit, and a density of 2600/km <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (1000/mi <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) the cumulative interference power would be comparable to the thermal noise level of a terrestrial radio system under realistic conditions. Methods of scaling the results for other system parameters are also presented.

GaAs Monolithic MIC's for Direct Broadcast Satellite Receivers

A 12-GHz low-noise amplifier (LNA), a 1-GHz IF amplifier (IFA), and an 11-GHz dielectric resonator oscillator (DRO) have been developed for DBS home receiver applications by using GaAs monolithic microwave integrated circuit (MMIC) technology. Each MMIC chip contains FET's as active elements and self-biasing source resistors and bypass capacitors for a single power supply operation. It also contairns dc-block and RF-bypass capacitors. The three-stage LNA exhibits a 3.4-dB noise figure and a 19.5-dB gain over 11.7-12.2 GHz. The negative-feedback-type three-stage IFA shows a 3.9-dB noise figure and a 23-dB gain over 0.5-1.5 GHz. The DRO gives 10.mW output power at 10.67 GHz, with a frequency stability of 1.5 MHz over a temperature range from -40-80°C. A direct broadcast satellite (DBS) receiver incorporating these MMIC's exhibits an overafl noise figure of /spl les/ 4.0 dB for frequencies from 11.7-12.2 GHz.

GaAs monolithic MIC's for direct broadcast satellite receivers

A 12-GHz low-noise amplifier (LNA), a 1-GHz IF amplifier (IFA), and an 11-GHz dielectric resonator oscillator (DRO) have been developed for DBS home receiver applications by using GaAs monolithic microwave integrated circuit (MMIC) technology. Each MMIC chip contains FETs as active elements and self-biasing source resistors and bypass capacitors for a single power supply operation. It also contains dc-block and RF-bypass capacitors. The three-stage LNA exhibits a 3.4-dB noise figure and a 19.5-dB gain over 11.7-12.2 GHz. The negative-feedback-type three-stage IFA shows a 3.9-dB noise figure and a 23-dB gain over 0.5-1.5 GHz. The DRO gives 10-mW output power at 10.67 GHz, with a frequency stability of 1.5 MHz over a temperature range from -40-80° C. A direct broadcast satellite (DBS) receiver incorporating these MMIC's exhibits an overall noise figure of ≤ 4.0 dB for frequencies from 11.7-12.2 GHz.