The OmniTRACS/sup R/ Mobile Satellite Communications and Positioning System

Abstract A class of multi-band planar diplexer with sub-sets of frequency-contiguous transmission bands is reported. Such a radio frequency (RF) device is suitable for lightweight high-frequency receivers aimed at multi-band/multi-purpose mobile satellite communications systems. It consists of two channelizing filters, each of them being made up of the in-series cascade connection of replicas of a constituent multi-passband/multi-embedded-stopband filtering stage. This building filtering stage defines a multi-passband transfer function for each channel, in which each main transmission band is split into various sub-passbands by the multi-stopband part. In this manner, each split passband gives rise to several sub-passbands that are imbricated with their counterpart ones of the other channel. The theoretical RF operational principles of the proposed multi-band diplexer approach with sub-sets of imbricated passbands are detailed by means of a coupling–routing–diagram formalism. Besides, the generation of additional transmission zeros in each channelizing filter for higher-selectivity realizations by exploiting cross-coupling techniques into it is also detailed. Furthermore, for experimental demonstration purposes, a microstrip proof-of-concept prototype of second-order octo-band diplexer in the frequency range of 1.5–2.5 GHz that consists of two quad-band channelizing filters with pairs of imbricated passbands is developed and characterized.

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Calibration method for array antenna considering mutual coupling in mobile satellite communications [International Communications Satellite Systems Conference]

Advances in Communications Satellite Systems. 37th International Communications Satellite Systems Conference (ICSSC-2019) ◽

10.1049/cp.2019.1241 ◽

2019 ◽

Author(s):

H. Tsuji ◽

Y. Abe ◽

T. Kondo ◽

Y. Kikuchi ◽

S. Adachi

Keyword(s):

Mutual Coupling ◽

Satellite Communications ◽

Calibration Method ◽

Array Antenna ◽

Satellite Systems ◽

Mobile Satellite

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Access Control Algorithm with Limited Power Constraint for Mobile Satellite Communications

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.548-549.1286 ◽

2014 ◽

Vol 548-549 ◽

pp. 1286-1289

Author(s):

Ya Zhe Gao ◽

Xiao Han Xia ◽

Zi Ming Su ◽

Xi Luan ◽

Jian Jun Wu

Keyword(s):

Admission Control ◽

Control Algorithm ◽

Load Capacity ◽

Satellite Communications ◽

Satellite System ◽

Power Constraint ◽

Priority Service ◽

Limited Power ◽

Mobile Satellite ◽

Service Priority

The problem of admission control caused by the limitation of resource in hotspot beams in satellite system is considered in this paper. Based on the idea of borrowing resources from surrounding beams, we give a scheme that the beam reserve resources is borrowed proportionally. After that, the original admission control algorithm based on service priority is modified in order to protect access rate of the low priority service. Simulation results prove that the proved scheme can increases the available beam load capacity effectively and provide a guarantee for the access of those services with low priority.

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