Advances in Satellite Communications

... July, 2 011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Advances in Satellite Communications, ... Advances in Satellite Communications Edited by Masoumeh Karimi and Yuri Labrador Published by InTech Janeza Trdine 9, 510 00 Rijeka, Croatia Copyright © 2 011 InTech All...

Ngày tải lên: 19/06/2014, 19:20

... 1.8 1.9 2. 1 2. 2 2. 3 2. 4 Frequency (GHz) 2. 5 2. 6 2. 7 2. 8 2. 5 2. 6 2. 7 2. 8 a) 3.6 3.4 3 .2 VSWR 2. 8 2. 6 2. 4 pec practical design copper lossy dielectric coating non-loss EDT lossy EDT 2. 2 1.8 1.6 ... 0.14 0 .25 A1: ka = 0.7 121 ; A2: ka = 0.8794 0. 12 A: ka = 1 .25 51 B: ka = 1 .29 17 0 .2 1 .2 1 .25 1.3 1.35 1.4 ha/cot(Ψ) a) 1.45 1.5 1.55 1.6 0.1 1.1 B1: ka =...

Ngày tải lên: 19/06/2014, 19:20

... average of the 32 Advances in Satellite Communications Will-be-set-by -IN- TECH quantity inside the brackets Thus the medium fluctuates inhomogeneously in the z direction and homogeneously in the r direction ... Propagation, Vol 23, No 3, (May 1975), pp 39 2 -39 7 , ISSN 0018-926X Helical Antennas in Satellite Radio Channel 25 Klock, P (19 63) A study of wave propagation of...

Ngày tải lên: 19/06/2014, 19:20

... (r, 0, z) exp − (44 ) 40 12 Advances in Satellite Communications Will-be-set-by -IN- TECH Results 3.1 Modulus of complex degree of coherence 3.1.1 Uplink Substituting ( 24) and (27) into (30), the ... various aperture radius of the receiving antenna ae 42 14 Advances in Satellite Communications Will-be-set-by -IN- TECH As shown in Fig 9, it is found that the decrease in...

Ngày tải lên: 19/06/2014, 19:20

... 36(4): 56 3 56 9 Martini, E., Freni, A., Facheris, L & Cuccoli, F (2006) Impact of tropospheric scintillation in the Ku/K bands on the communications between two LEO satellites in a 52 24 Advances in ... VSAT satellite network has its downsides The limitations of VSAT technology 56 Advances in Satellite Communications include the extremely high start-up cost needed for...

Ngày tải lên: 19/06/2014, 19:20

... original form The original block of packets will be divided into individual packets according to the original size of each combined packet After that, these individual packets are stored in the ... topology Scenario Satellite link characteristic (low bandwidth) Uplink bandwidth: 64 kbps Downlink bandwith: 256kbps Round-trip delay: 64 4ms (high bandwidth) Uplink bandwidth: 1024kbps Downl...

Ngày tải lên: 19/06/2014, 19:20

... Salento - Department of Engineering for Innovation Lecce (Italy) Introduction Security problems in satellite environments are one of the obstacles to the widespread deployment of satellite IP ... refer to gure In theory, for each single change in the users’ base, the TEK (K I in the gure) should be changed Although grouping changes occurred in a given time interval and updating...

Ngày tải lên: 19/06/2014, 19:20

... Hybrid Satellite/ Terrestrial Networks 103 21 Down-link LAN Up-link Down-link Down-link Reaching path S Receiving path Receiving path Down-link Ss R1 Sr1 RM SrM Receiving path SrM-1 RM-1 LAN Receiving ... 20 Advances in Satellite Communications Will-be-set-by -IN- TECH than PH If the sender receives even a single NACK, it will abort the Unwinding phase and will re-initiate the Windin...

Ngày tải lên: 19/06/2014, 19:20

... processing algorithms are included or further developed depending on the morphological terrain The operation of these “Optical Observers” is mainly based on 118 • • • • Advances in Satellite Communications ... sustainable and dedicated sensing network capable of providing reliable early detection and 112 Advances in Satellite Communications surveillance services to the authori...

Ngày tải lên: 19/06/2014, 19:20

... incident angle, the surface material (typically aluminum), and the coating process applied to the metallic surfaces (e.g silver-plating, alodine coating) In order to gain a physical insight into ... provided during the crisis are near real time fire mapping (the so called rapid mapping) at high and very high spatial resolution, as well as continuous monitoring 130 Advances in Satellite...

Ngày tải lên: 19/06/2014, 19:20

... required to refine the initial solution In particular, such an approach could lead to sub-optimum designs owing to the presence of local minima in the pertaining cost function In order to overcome ... Chains for High Capacity Satellite Communications Systems 141 Integration lines y z Fig 3.4 In- phase field lines in the plane x=0 of the E-plane WR75-waveguide symmetric stub-filte...

Ngày tải lên: 19/06/2014, 19:20

... either pyramidal, cylindrical or parallelepiped shape should be introduced in the back of the junction (see Fig 5.4) in order to improve the matching 156 Advances in Satellite Communications The ... MTT-S International Microwave Symposium Digest, 2009, 7 -12 June 2009, pp 124 5 -124 8 Lui P.L., "Passive intermodulation interference in communication systems", Electronics & Com...

Ngày tải lên: 19/06/2014, 19:20

... antenna array for satellite tracking in ground station The aim of using a single antenna for tracking many satellites at the same time avoiding mechanical movements as well as its inexpensive cost ... Technology in satellite communications has revealed an increasing interest in novel smart antenna designs Phased-array based designs are basic in electronically reconfigurable devi...

Ngày tải lên: 19/06/2014, 19:20

... characteristics 4.3 Beamforming techniques for satellite tracking Some satellites transmit useful information inside its frames for synchronization and tracking purposes The gathering of satellite data requires ... of the data rate In this kind of schemes, there is an important cost 186 Advances in Satellite Communications consideration in real-time applications and the requir...

Ngày tải lên: 19/06/2014, 19:20

... July, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Advances in Satellite Communications, ... Antennas in Satellite Communications Helical Antennas in Satellite Radio Channel Maja Škiljo and Zoran Blažević University of Split, Faculty of electrical engineering, m...

Ngày tải lên: 15/04/2015, 17:20