Fundamental Performance Characteristics That Influence EHF MILSATCOM Systems

Cummings, William C.; Jain, P. C.; Richardi, L.

doi:10.1109/tcom.1979.1094310

Cited by 14 publications

(4 citation statements)

References 2 publications

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“…The use of MMW for military satellite communications [13][14][15][16] is currently on the threshold of considerable exploitation and technological development. The bulk of military satcoms currently operate at microwave frequencies in the 7 to 8 GHz band with some use of the UHF band at 225-400 MHz.…”

Section: Millimeter Wave Satellite Systemsmentioning

confidence: 99%

An Overview of Millimeter Wave Communications for Military Applications

Bains

1993

DSJ

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The use of millimeter wave for Defence communications can offer a number of benefits to the user. Apart from the benefit of wider capacity, millimeter wave also offers ability to provide secure and survivable communication in the presence of enemy threats. In this paper, some of the important benefits for Defence communication are reviewed. An overview of millimeter wave military communication applications, technology development, present status and trends are also given.

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Section: Millimeter Wave Satellite Systemsmentioning

confidence: 99%

An Overview of Millimeter Wave Communications for Military Applications

Bains

1993

DSJ

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“…Several EHF bands, each with one or more gigahertz of bandwidth, are allocated for satellite communications [6]. Planners of next-generation MILSATCOM systems are therefore considering the use of higher frequencies to achieve larger downlink capacities and enhanced jamming protection.…”

Section: Anti-jammentioning

confidence: 99%

“…Generation of large amounts of jamming EIRP at higher frequencies is extremely difficult because of technological limitations on RF power generation and realization of high antenna gains [6]. The antenna diameter d required to produce high spatial discrimination between the user and jammer directions can be estimated from the satellite's altitude h and the userjammer separation distance r.…”

Section: Anti-jammentioning

confidence: 99%

Architectural trends in military satellite communications systems

Jain

1990

Proc. IEEE

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“…Such a loss is an exponential function of (AO/HPBW)', where HPBW denotes the half-power beam width of the antenna. 6 Since HPBW is proportional to L / D for a given antenna tracking accuracy of the mechanical pointing system, the beam pointing loss also increases with increased frequency of the carrier. Note, however, that A0 may contain a component proportional to HPBW and the dependence on X may be less severe than would be predicted by the exponential function.…”

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confidence: 99%

Multi‐element array signal reconstruction with adaptive least‐squares algorithms

Kumar

1992

Adaptive Control & Signal

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For a mechanical antenna system with a perfect parabolic reflector surface of diameter D the antenna gain is proportional to (D/X,)', where X, denotes the received carrier wavelength. However, for a practical system a n increase in D/X, is also associated with a decrease in antenna efficiency due to the imperfect reflector surface. Since the antenna efficiency is a very sensitive function of the RMS surface deviation or effectively of D/X,, the loss in efficiency can more than offset the increase in directivity. The loss in efficiency results owing to the dispersion of the signal in the focal plane, with the result that only a fraction of the available signal power is collected by the focal feed. A configuration wherein several feeds are placed in the focal plane of the antenna is considered so as to capture all the available power. However, the signal phase and amplitude at the outputs of the various feeds vary randomly with time owing to the time-varying deformation of the reflector surface induced, for example, by vibrational modes set up by gravitational or thermal fields or wind. Coherent signal combining techniques based on an adaptive least-squares algorithm are investigated for nearly optimally and adaptively combining the outputs of these feeds. The performances of the two proposed versions of the least-squares algorithm are evaluated by simulations. It is shown for the example considered that both the adaptive least-squares algorithms are capable of offsetting most of the loss in the antenna gain incurred owing to reflector surface deformations.

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Fundamental Performance Characteristics That Influence EHF MILSATCOM Systems

Cited by 14 publications

References 2 publications

An Overview of Millimeter Wave Communications for Military Applications

An Overview of Millimeter Wave Communications for Military Applications

Architectural trends in military satellite communications systems

Multi‐element array signal reconstruction with adaptive least‐squares algorithms

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