To create a next-generation mobile satellite communication system that offers large communication capacity, the onboard antenna system must be a multi-beam system consisting of a light weight 20-m class reflector and a light weight 100-beam class antenna feed system. We clarify that the antenna gain decrease created by the reflector surface distortion in orbit is relatively large. This paper pr...

The Japan Aerospace Exploration Agency (JAXA) plans to launch a geostationary satellite called Engineering Test Satellite VIII (ETS-VIII) in FY 2006. In this paper, a microstrip line array antenna, which has a very simple structure, is introduced to radiate a circularly polarized wave aiming at ETS-VIII applications. This antenna consists of a triangular conducting line with its vertexes rounde...

In order to track the carrier phases of Global Navigation Satellite Systems (GNSS) signals in signal degraded environments, a dual antenna joint carrier tracking loop is proposed and evaluated. This proposed tracking loop processes inputs from two antennas, namely the master antenna and the slave antenna. The master antenna captures signals in open-sky environments, while the slave antenna capt...

This article presents the design of rectangular microstrip antenna. The prototype antenna is designed and fabricated on FR4 substrate of dielectric constant Єr = 4.4 and thickness h = 1.66 mm. The proposed antenna is excited using co-axial probe feed. The experimental result of rectangular-shaped microstrip antenna exhibits the excellent radiation characteristic corresponding to impedance bandw...

Mobile satellite systems allow truly ubiquitous wireless communications to users anywhere and anytime, NASA’s Advanced Communications Technology Satellite (ACTS) provides an ideal spacebased platform for the measurement of K/Ka-band propagation characteristics in a land mobile satellite application. Field tests for K-band propagation were conducted in three basic environments: clear line-ofsigh...

This paper presents the study on a slot-etched rectangular patch antenna directly fed by the 50 Ω semi miniature A-type (SMA) co-axial connector for wireless systems. The dual frequency behaviour by etching the slots on plane patch surface is studied experimentally. The proposed patch antenna has also achieved 28% compactness with a gain of 9.74 dB. Other antenna parameters such as antenna inpu...

Multiple-Input Multiple-Output (MIMO) technology is widely applied in terrestrial wireless communication system, which greatly increases the system capacity. Satellite communication system has many advantages such as wide coverage and strong flexibility. Therefore, how to make a better use of MIMO technology in satellite communication system has become a research hotspot in recent years. The pu...

This paper attempts to apply an adaptive network-based fuzzy inference system (ANFIS) for analysis of the resonant frequency of a single-layer single-patch microstrip rectangular patch antenna with two equal size slots which are placed on the patch in the form of parallel to resonance edges. The resonant frequency is calculated as the position of the slots is shifted from the right endpoint to ...

NAVSYS High Gain Advanced GPS Receiver (HAGR) uses a digital beam-steering antenna array to provide additional gain in the direction of the GPS satellite signals. This increases the received signal/noise ratio on the satellites tracked and also improves the accuracy of the pseudo-range and carrier-phase observations. The directivity of the digital beams created from the antenna array also reduc...

This paper will describe the Energetics Satellite Locating Service (ESLS) which is a unique, patented, proprietary satellite based geolocation system. This system called SAT/TRAC for Satellite Tracking, Ranging and Communications may be used to quickly determine the present location within 50 feet of any person, vehicle or object that is equipped with a ESLS low power transmitter. This technolo...