...Name Instructor Course Date Antennas This report provides details of different types of antennas used in ships as well as maintenance procedures and precaution measures when dealing with antennas. An Antenna is a component capable of radiating and capturing radio waves. Thus, antennas are useful elements of a ship and together with radio equipment are a means of communication between the vessel and the control tower. The first type of antenna used on ships is the quarter wave vertical antenna widely used at all frequencies from MF to VHF. The quarter wave vertical antenna is simple to construct and erect in locations with limited space like a ship. For VHF and UHF, it is important to elevate the antenna above close obstacles. One advantage is that, the single element vertical antennas have a multi-directional radiation design meaning they do not require re-alignment in a mobile application and are thus suitable for ships. A quarter wave aerial with a quarter-wave radials exhibits 50-ohms impedance thus uses a 50-ohm coaxial cable (Stutzman and Thiele). In summary, the quarter wave antenna is popular for its convenience and simplicity. The second type of antenna is the dipole antenna that is one of the commonly used RF antenna types. Primarily, it consists of two poles into which radio frequency current flows and together with a voltage causes radiation of a radio signal. There are several types of dipole antennas that include, half wave dipole, multi-half wave...
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...IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 54, NO. 12, DECEMBER 2006 3755 A New Compact Microstrip-Fed Dual-Band Coplanar Antenna for WLAN Applications Rohith K. Raj, Manoj Joseph, C. K. Aanandan, K. Vasudevan, Senior Member, IEEE, and P. Mohanan, Senior Member, IEEE Abstract—A novel compact microstrip fed dual-band coplanar antenna for wireless local area network is presented. The antenna comprises of a rectangular center strip and two lateral strips miprinted on a dielectric substrate and excited using a 50 crostrip transmission line. The antenna generates two separate resonant modes to cover 2.4/5.2/5.8 GHz WLAN bands. Lower resonant mode of the antenna has an impedance bandwidth (2:1 VSWR) of 330 MHz (2190–2520 MHz), which easily covers the required bandwidth of the 2.4 GHz WLAN, and the upper resonant mode has a bandwidth of 1.23 GHz (4849–6070 MHz), covering 5.2/5.8 GHz WLAN bands. The proposed antenna occupy an area of 217 mm2 when printed on FR4 substrate . A rigorous experimental study has been conducted to confirm the characteristics of the antenna. Design equations for the proposed antenna are also developed. ( = 4 7) Index Terms—Coplanar waveguide, dual-band antennas, printed antennas, wireless local area networks (WLANs). I. INTRODUCTION IRELESS LOCAL area networks (WLAN) are being widely recognized as a viable, cost effective and high speed data connectivity solution, enabling user mobility. The rapid developments in WLAN technologies...
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...of an Antenna Introduction: Antenna impedance is a measure of the resistance to an electrical signal in an antenna. Many factors have an impact on an antenna’s ability to transmit a signal, including the environment that the antenna is in and the design and composition of the antenna. Understanding antenna impedance is important when designing components that connect an antenna to a receiver or transmitter. The ratio to voltage current, which is equal to antenna impedance, is expressed in ohms. The antenna impedance represents the power that is absorbed by the antenna as well as the power that is dispersed by it as it comes into contact with electromagnetic waves. Voltage and Current Relationship: Antenna impedance relates the voltage to the current at the input to the antenna. Let us assume that the antenna has an impedance of 50 ohms. And if a sinusoidal voltage is applied at the antenna terminals with amplitude of 1 volt, then the current will have amplitude of I=VR=150=0.02 A. Since the impedance is a real number, the voltage is in phase with the current. Alternatively suppose the impedance is given by complex number say Z=50+j50 ohms. If Z=50+j50, then the impedance has the magnitude equal to: 502+502=70.71 The phase will be equal to: tan-1ImZReZ=45° This means the phase of the current will lag the voltage by 45°. That is the current waveform is delayed relative to the voltage waveform. To spell it out, if the voltage with frequency f at the antenna terminals...
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... for which flat panel antennas (FPAs) have emerged as the most popular innovation in recent years. The limited speed and large size of mechanically-steered and the 1st generation of electronically-steered flat panel antennas drew many to wonder if the Holy Grail of the satellite world – a cost-competitive, electronically-steered flat panel antennas with an ultra-low profile- would ever be within reach. But the journey to this goal has been a long, difficult one because of the many desired features of such a product as depicted in the figure below. NSR has often noted the tremendous increase in satellite mobility bandwidth demand has driven many operators to add new HTS systems and constellations to meet this demand. But at the same time, the industry metric has put more emphasis on cost-efficiencies, which is where NSR expects flat panel antennas (FPAs) to play a key role in this transformation. As service providers look to provide more bandwidth at lower cost to end-users, falling capacity prices, next generation modems with beam switching capabilities, and better software are icing on the cake of the HTS capacity onslaught, in which FPAs are a perfect fit. In NSR’s recently released Flat Panel Satellite Analysis report, both the mobility and fixed satellite side of the business were analyzed, and commercial aeronautical connectivity was observed on top as the biggest driver and revenue generator for FPAs. Indeed, a low-profile antenna is a necessity for lower...
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...Digital Commons FIU Electronic Theses and Dissertations University Graduate School 11-12-2009 Effective Reconfigurable Antenna Designs to Enhance Performance and Enable Wireless Powering Shishir S. Punjala Florida International University, spunj001@fiu.edu Follow this and additional works at: http://digitalcommons.fiu.edu/etd Recommended Citation Punjala, Shishir S., "Effective Reconfigurable Antenna Designs to Enhance Performance and Enable Wireless Powering" (2009). FIU Electronic Theses and Dissertations. Paper 108. http://digitalcommons.fiu.edu/etd/108 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact dcc@fiu.edu. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida EFFECTIVE RECONFIGURABLE ANTENNA DESIGNS TO ENHANCE PERFORMANCE AND ENABLE WIRELESS POWERING A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in ELECTRICAL ENGINEERING by Shishir Shanker Punjala 2009 To: Dean Amir Mirmiran College of Engineering and Computing This dissertation, written by Shishir Shanker Punjala, and entitled Effective Reconfigurable Antenna Designs to Enhance Performance and Enable Wireless Powering, having been approved in respect to style and intellectual content...
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...ANALYSIS OF THE PHYSICAL PARAMETERS INFLUENCING BEAM PATTERN OF A UNIFORM LINEAR ARRAY OF ANTENNAS Final Year Project Report Presented by SAJID UR REHMAN CIIT/SP08-BET-090/ISB USMAN ULLAH ASIF CIIT/SP08-BET-121/ISB In Partial Fulfillment Of the Requirement for the Degree of Bachelor of Science in Electrical (Telecommunication) Engineering DEPARTMENT OF ELECTRICAL ENGINEERING COMSATS INSTITUTE OF INFORMATION Technology, ISLAMABAD JAN 2012 Declaration We, hereby declare that this project neither as a whole nor as a part there of has been copied out from any source. It is further declared that we have developed this project and the accompanied report entirely on the basis of our personal efforts made under the sincere guidance of our supervisor. No portion of the work presented in this report has been submitted in the support of any other degree or qualification of this or any other University or Institute of learning, if found we shall stand responsible. Signature:______________ Sajid Ur Rehman Signature:______________ UsmanUllah Asif COMSATS INSTITUTE OF INFORMATION Technology, ISLAMABAD JAN 2012 ANALYSIS OF THE PHYSICAL PARAMETERS INFLUENCING BEAM PATTERN OF A UNIFORM LINEAR ARRAY OF ANTENNAS An Undergraduate Final Year Project Report submitted to the Department of ELECTRICAL ENGINEERING As a Partial Fulfillment...
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...workshop in NIT Trichy. * Undergone detail training in understanding EMBEDDED SYSTEM trained at ACCEL IT academy, Adyar ,Chennai. * Experienced the different phases of a project execution under antenna approach. Professional & Academic Qualifications B.E. Electronics and communication Engineering., Periyar Maniammai University, THANJAVUR . CGPA : 8.54/10. Current GPA : 8.71. year of passing : 2013 Class : First class. * Higher Secondary Ramakrishna vidhayala matric Higher Secondary School, VILLUPURAM.(Tamil Nadu State Board) Percentage : 72.25% Year of Passing : 2009 Class : First Class. * SSLC Ramakrishna vidhayala matric Higher Secondary School, VILLUPURAM. (MATRICULATION) Percentage : 71.72% Year of Passing : 2007 Class : First Class Project profile Mode of project : Self project. Title : Multiband Antennas for SDR Applications. Simulators : HFSS (high frequency structure simulator) ANSIS Description : SDR- software defined radio, the most emerging product in RF signaling field, in this as platform, I have work in the area of antenna design with the developed...
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...1.) A Netgear wireless access point is using a Marconi antenna, Figure 1. Let’s assume the antenna is working in ISM Band @ frequency, f=2.4 [GHz], and is having the impedance, Za=50 [Ω]. They ask to calculate: 1a.) lambda_0[m] = c_0/f[Hz] lambda_0[m] = (3*10^8)/(2.4[GHz]) lambda_0[m] = 0.125[m] 1b.) la[m] = k_1 * (lambda_0[m])/4 la[m] = 0.95 * (0.125[m])/4 la[m] = 0.0296875 1c.)Va[Vrms] = ((50)^(1/2))*10^((15-30)/20) Va[Vrms]= 1.25743343 =====================================================================2.) A LAN server is located on the first floor level of a bank building and is connected via RG-58 cables, to various client computers located on all of the floors of the skyscraper. Let’s assume that you are a field engineer working for a LAN service company and you have the task to find out a faulty cable serving the client. To locate the failure in that cable you are using a Fluke DSP-2000 Cable Analyzer, connected at the floor level, set on TDR test. The screen of the instrument is illustrated in Figure 2. Based on the screen reading, they ask to: 2a). Locate the distance to the failure point on that cable, d [m], with respect to the LAN server’s position, and back-and-fourth propagation time, t [nsec], of the test pulses generated by the instrument, if the velocity factor of the UTP cable, k=0.66 (Given: Speed of light in free space, c_0=3*108 [m/sec]). Reading of the DSP-2000 screen is providing the distance to the failure point, d[m]: d[m]=______30...
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...A GPR is made up of three core components, control unit, antenna, and the power supply. The control unit is what contains the electronics which trigger the energy pulses to the antenna that sends it into the ground. The GSSI SIR 20, which was used in this lab, has a laptop with software loaded on it already which processes and interprets the data. The antenna is what receives the electrical pulse from the control unit and transmits it into the ground. The frequency is a huge factor in the depth penetration. The frequency that used was 200 MHz which is right between the high and low pass filter allowing a the signal to go deeper. The time interval for collecting this data was 400 ns with 20 traces per meter. In this amount of time and traces per meter, 12 transecs were collected. The AGC was used to amplify the GPR lines getting better data. The data from the GPR was then brought back to the lab and the lines and sections were examined to figure out the GPR facies. The equipment used for coring was an auger core....
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...CH. 12 1. Transmission – Conductive connect6ions between system elements that carry signal power. 2. CAT6/5e – Category 5e computer networking cable capable of handling a 1000MHz bandwidth up to a length of 100m. 3. RJ-45 – the four pair termination commonly used for terminating CAT6/5e cable. 4. Attenuation – amount of loss in the signal strength as it propagates down a wire. 5. Near-end Crosswalk – measure of the level of crosstalk or signal coupling within the cable, with a high NEXT (db) value being desirable. 6. Crosstalk – Unwanted coupling caused by overlapping electric and magnetic fields. 7. ACR – combined measurement of attenuation and crosstalk; a large ACR indicates greater bandwidth. 8. Delay Skew – measure of the difference in time for the fastest ti the slowest wire pair in a UTP cable. 9. Power-Sum next testing – measures the total crosstalk of all the cable pairs to ensure that the cable can carry data traffic on all four pairs at the same time with minimal interference. 10. Return loss – measure of the ratio of power transmitted into a cable to the amount of power returned or reflected. 11. Unbalanced line – electrical signal in a coaxial line is carried by the center conductor with respect to the grounded outer conductor. 12. Balanced line – same current flows in each wire 180 degrees out of phase. 13. Common mode rejection – when signals are 180 degrees out of phase cancel each other out. 14. Baluns – circuits that convert between balanced and...
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...the reflector surface. When using also a copy on thicker cardboard, glue the tin foil on the copy of the reflector and than glue them together and glue also the copies of the holder together. Use a good kind of glue like Bisonkit transparant. 5. Cut the crosses in the holder with a hobby- or break-knife. 6. Assemble by placing the six tabs of the holder in the six slots of the reflector. Fold the tabs after placing and fix them with glue. 7. Place the assembly on the WiFi antenna and aim the reflector in the direction of the ‘target’ (to WiFi dongle, Router or AP) to get maximum performance. Tell a friend about this idea. Note: If printed at the download size you will see about 6-9 dBi of gain. If you double the size of the image before you print it you will see about 9-12 dBi of gain. If you place two reflectors on an AP or router with two antennas you will see an additional increase in performance. * Types without external antennas can’t be improved this way, but a USB WiFi dongle with external antenna can! Een mathematical example: http://www.ies.co.jp/math/java/conics/focus/focus.html See also the video on YouTube: http://www.youtube.com/watch?v=sUTT8wdN_VA Six inch reflector pattern at 2.4 GHz...
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...facilitated a wider range of astronomical discovery through improvements to the instruments by which radio astronomers study celestial objects at radio frequencies. Radio waves are a type of electromagnetic radiation, and differ from ordinary visible light due to a longer wavelength and lower frequency. Engineer Karl Guthe Janksy is associated with the first radio antenna built in 1931 to identify astronomical radio sources. This involved an arrangement of reflectors and diploes, or pairs of equal and oppositely magnetized poles separated by a distance, intended to receive short wave radio signals. Labelled “Janksy’s Merry Go Round” due to its position on a turntable, Janksy monitored his instrument over several months and was able to measure the length of an astronomical sidereal day, which is the time it took for a fixed object located on the celestial sphere to return to the same location in the sky. Most notably, was his serendipitous discovery of the Milky Way in 1933 through comparison of his observations with optical astronomical maps, and eventual conclusion that the radiation source peaked when his antenna was aimed at the densest part of the Milky Way in the constellation of Sagittarius. Furthering Jansky’s work in 1937 was Grote Reber’s first parabolic single dish radio telescope designed to broaden the search and detection for static or noise. The information Janksy and Grote discovered was presented in a mixture of properties, such as frequency, amplitude, and repetitive...
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...UNIVERSITY OF SAINT LOUIS Mabini Street, Tuguegarao City Experiment No. 3 THE YAGI-UDA ANTENNA Fyne D. Talay BSECE-5 Date Submitted: September 24, 2012 Date Due: September 24, 2012 Gerino Mappatao, PECE, MSECE, PhD. ECE (Professor) The Yagi-Uda Antenna Objective: To demonstrate the effect of parasitic elements on the gain and radiation pattern of cylindrical half-wave dipole. Introduction: A Yagi-Uda antenna is familiar as the commonest kind of terrestrial TV antenna to be found on the rooftops of houses. It is usually used at frequencies between about 30MHz and 3GHz, or a wavelength range of 10 meters to 10 cm. (There are some obsessional amateur radio enthusiasts who construct Yagi-Uda antennas for the 80 meter wavelength band. This is rather impractical as spacing them from the ground by more than half a wavelength is difficult.) The rod lengths in a Yagi-Uda are about a half wavelength each, and the spacings of the elements are about 1/3 of a wavelength. This puts the overall sizes of Yagi-Udas in the ranges freq transverse length length length dimension 3 elements 5 elements 15 elements (lambda/2) 30MHz 5 m 6 m 13 m 47 m 100MHz 1.5 m 1.8 m 3.9 m 14 m 300MHz ...
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...This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar This is a radar...
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...TABLE OF CONTENTS PAGE NO. CHAPTER 1- INTRODUCTION 1.1 INTRODUCTION 6 1.2 WHAT IS OFDMA? 9 CHAPTER 2 - SUBCARRIER ALLOCATION SCHEMES 2.1 STATIC SUBCARRIER ALLOCATION 12 2.2 DYNAMIC SUBCARRIER ALLOCATION 14 2.2.1 THE PROPOSED DSA SCHEME 15 CHAPTER 3- FLOW CHART AND ALGORITHM 4.1 FLOW CHART 17 4.1.1 MAIN FLOWCHART 17 4.1.2 WHEN 2 USERS FALL IN RANGE NUMBERED 3,5,8,14 20 4.1.3 WHEN 3 USERS FALL IN RANGE NUMBERED 3,5,8,14 22 4.2 ALGORITHM 24 CHAPTER 5-BLOCK DIAGRAMS 5.1 CONTROL FRAME TRANSCEIVER 28 5.2 DATA TRANSMISSION 29 5.3 DATA RECEPTION 31 CHAPTER 6- IMPLEMENTATION AND RESULTS 6.1 MATLAB 34 6.1.1 INSTRUCTIONS USED IN CODE 35 6.2 CONTROL FRAME TRANSMISSION AND RECEPTION 39 6.3 DATA GENERATION...
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