International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 7 (2016) pp 5352-5356 © Research India Publications. http://www.ripublication.com 5352 Low Noise Amplifier Selection for Indian Regional Navigation Satellite System Gayathri K. M. and Dr. Thangadurai N. Department of Electronics and Communication Engineering, School of Engineering and Technology, Jain University, Bangalore, Karnataka, India. Abstract Indian Regional Navigation Satellite System (IRNSS) is a indigenous and autonomous satellite navigation system being developed by Indian Space Research Organization. IRNSS operates in two frequency bands namely L band (1176.45 MHz) and S band (2492.02 MHz). In this IRNSS receiver the Low Noise Amplifier (LNA) plays a very important role in the RF front end. The design of LNA is very critical in satellite communication system. This paper presents a design selection of LNA for the two frequency bands used for IRNSS. The design should be stable with a gain of 32dB and a noise figure of 0.9dB over a bandwidth of 25 MHz and with low power consumption. Keywords: Satellite Navigation System, Noise Figure, Gain, Power Consumption Introduction Indian Regional Navigation Satellite System (IRNSS) Indian Regional Navigation Satellite System (IRNSS) is a satellite based navigation system being developed by Indian Space Research Organization. It is developed to provide position information to users in Indian region extending up to 1500 km from its boundary [1]. In September 2014, signal in space interface control document was released, which contains the information of its system architecture, frequency spectrum, satellite constellation, signal spectrum, satellite constellation, signal structure, modulation scheme and information of the navigation payload. IRNSS consists of 3 segments namely: Space segment, Ground segment and User segment. The Space segment consists of seven satellites, 4 in geostationary orbit (GEO) which are positioned over 34°, 83° and 132 ° East respectively and 3 in inclined geosynchronous (IGSO) orbit which are positioned over longitudes of 55º E and 111.75º E respectively. Figure 1: Frequency Spectrum of Various Navigational Systems Six of the seven satellites are already in space. Figure 1 shows the frequency spectrum of IRNSS compared with existing navigational systems like GPS, GLONASS and GALILEO. IRNSS Receiver The Ground segment consists of the IRNSS Ranging and Integrity Monitoring stations (IRIM) and Navigation control centre (INC). IRIM receives the data from the space and transmits to navigation control centre. INC controls the IRNSS system and also maintains the accurate time reference with IRNSS network timing centre. Using CDMA ranging and laser ranging, the position of the satellite and orbit maintenance in space are monitored. The navigation uplink centres which are part of Spacecraft Control Facility (SCF) update the navigation data using Telemetry, Tracking and Command (TT&C) system. The block diagram of the IRNSS User receiver is shown in the Figure 2. Figure 2: IRNSS User Receiver The user segment consists of IRNSS receiver which operates in, single frequency (L5 or S band) or dual frequency (L5 and S band). It offers two services to the users: i) Standard Positioning Service (SPS) which is free of cost to the users and uses unencrypted data; ii) Restricted Service (RS) which uses encrypted data for authorised users. The SPS signal uses Code Division Multiple Access (CDMA) modulation with Binary Phase Shift Keying (BPSK). The navigation data rate is 50 Hz and Pseudo-Random Noise (PRN) code rate is 1.023 MHz with duration 1ms. The navigation data is modulo-2 added with the PRN code sequence followed by modulation with the Radio Frequency (RF) carrier at the L5 frequency. Some applications of IRNSS are: Terrestrial, Aerial and marine navigation, disaster management, vehicle tracking and fleet management, integration with mobile phones, precise timing, mapping and geodetic data capture, Terrestrial navigation aid for hikers and travellers, visual and voice navigation for drivers. Low Noise Amplifier (LNA) In radio wave propagation the loss is very high, so the signals