A frequency scanning satellite system for land mobile communications

Abstract

A frequency scanning system for mobile applications has been assessed for a European mission at Lband. Feasibility evaluations, electrical design and analysis have been performed for both the antenna and the entire repeater. Efforts have also been made to solve accommodation, thermal and mechanical problems, so as to demonstrate the actual feasibility of the frequency scanning concept in user-oriented applications. The very promising results obtained are presented in this paper.

Applications Of Antenna Arrays To Mobile Communications, Part I: Performance Improvement, Feasibility, And System Considerations

“…a) Fixed-shape beams: In a simplistic situation, beams of fixed shape and size may be generated to cover the area of interest, allowing normal handoff as the mobiles roam from one cell to another or as the beams move in a low orbit multiple satellite system covering different areas. Proposed fixed-beam antennas using multibeam phased arrays for mobile communications and featuring frequency-reuse facility and flexibility of variable beam power allocation have been reported in [105].…”

“…The capability of the system to generate multiple spot beams with independent power control and frequency use makes it attractive for mobile communications. These capabilities, along with a frequency scanning system, have been evaluated for the European geostationary satellite system in various ESA contracts [105], [106].…”

“…The frequency scanning system considered in [105] and [106] uses an array of active antennas to provide a highgain beam with the capability to steer it at any user location using frequency-dependent interelement phase shift. The same array is used for the transmit as well as for the receive mode.…”

“…The other system developments and experiments to carry out the feasibility studies of antenna arrays for mobile communications include the study of an array mounted on an aircraft using the ETS-V satellite in Japan [115], the study of an array mounted on the roof of a car to receive the German SAT-2 [112], a feasibility study of a frequency scanning satellite system [105], [106], hardware implementation of a four-element adaptive array for high-speed digital mobile communications [125], and a laboratory prototype of a low-power system for mobile communications [165]. The setting up of a consortium to investigate the feasibility of adaptive array technology in third-generation mobile communications systems in Europe is reported in [157].…”

A comparative analysis of frequency scanning and multispot beam satellite systems for mobile communications

“…In particular, the proposed system has been assessed, quantifying the impact of the payload architecture on geostationary spacecraft and launcher, evaluating technological requirements and addressing critical areas. 3 The work has provided confidence in the applicability of the frequency scanning approach in practical missions, as many critical areas have been widely investigated.…”