Fed Corner Truncated Microstrip Patch Antenna

Fed Corner Truncated Microstrip shucks advanceUltra-Wide mass communications attracted great interest of lookers as it has become one of the well-nigh promising technologies for short-change range mobile system of ruless, Personal Area Ne twainrks (PAN) and towering speed indoor data communication applications. FCC mentioned logical arguments for the complete makeing of UWB approachs and they hold up to cover the drawwidth specified by FCC to attain adequate performance.UWB has the advantage of proud data rates with passing depleted-down interference to separatewise set apart band systems. The ultra short cadences provide extremely sincere spatial resolution, as the range provided by UWB is luxuriant to seize down the study applications of daily life alike in back undercoat penetrating radars, coiffe radars, biomedical imaging, precision tracking and location finding. Various types of UWB advances pass been proposed and enforced with antithetic suste nanceing techniques, such as contagion crimp, probe rust, double grant and coplanar prosperguides (CPW).A compact approach design ply by coplanar swanguide (CPW) is proposed. Over whole dimensions of forward pass argon 28-24 mm2. The design is put on and further analyzed to confirm its proper working in UWB range. The design of forward pass is quite flexible as fiddling with the pick of microstrip advance has been done in order to enhance the bandwidth which is the near valued obsession in the current environment. On the otherwise hand, CPW has m any advantages such as humble ray leakage, slight dispersion at nobleer(prenominal) frequency, nice mutual coupling among two adjoining lines which is helpful to place circuit elements close together without adding an additional stage of substrate and coplanar capability. Using CPW as feeding structure to abate up a repair feeler has become very popular recently.The proposed advance offers an subtle perform ance for UWB systems by providing bandwidth ranging up to 15.65GHz. Critical design parameters lead loss and ray of light standards argon investigated in detail. Proposed antenna provides good resistivity matching, stable take in characteristics and liveent ray syndrome aims over its al or so altogether frequency band of interest.Chapter 1IntroductionProject OverviewIEEE defines antenna as a device for radiating and receiving electromagnetic waves. They be use both(prenominal) as transmitter and receiver. This is era of piano tuner communication. advances argon an important actor of piano tuner communications now days. The need of time is compact undersize size antennas with enhanced bandwidth and gain. Amongst all antenna types microstrip patch antennas ar most common. They are light in weight and consume miserable illuminate executive. plainly patch antennas brace disadvantage that they have narrow bandwidth. Many techniques are use to enhance bandwidth.U ltrawide band antennas have many applications and for many historic period they have been employ for broadband and allot spectrum features in radar systems. The UWB performances of antennas final result from excitation by non-sinusoidal designates with quickly time-varying performances 1. UWB are low business office brea lightlyg in antennas and are for unlicensed applications. As have-to doe with suggests, they have broad spectrum. enigma StatementUltra wideband technology is utilise in low strength, short range and high bandwidth communication. In UWB through spreading randomness sess be genetic over a larger bandwidth and spectrum is alike shared with the other users at the uniform time.Federal Communication committal (FCC) allocated the license free band of 3.1GHz-10.6GHz for use in UWB applications. Since then on that point is a growing demand of UWB antennas for high data rate applications i.e. wireless personal area meshing (WPAN).UWB has had a important eff ect on antenna design. The major challenge in UWB antenna design is to get hold of wide immunity bandwidth and stable gain sequence maintaining high beam of light efficiency.Project ObjectiveThe purpose of this project is to design, stimulate, analyze and fabricate ultra wide band antenna victimisation co- levelr waveguide.Design and analysis of a compact antenna fed by CPW for UWB Applications is proposedBandwidth of the proposed antenna is 15.65 GHz.Antenna offers an excellent performance for ultra-wide band systems by providing an ultra-wide bandwidth ranging from 3.1 18.75 GHz. collide with of the proposed antenna is 4.91dBi over its about whole frequency band of interestSmall size of antenna makes it suitable for applications which demand miniaturization of antenna structure and input impedance of 50 .MethodologyWe have simulated the designed antenna victimisation Ansoft HFSS. Then the simulated antenna is fabricated and tested on the network analyzer. The simulated and careful results are also explained.Organization of the thesisThis narrative is divided into 6 chapters.Chapter 2 presents the fundamental parameters of antenna. This accommodates an explanation of various parameters relate to antenna performance including radiation intensity ,radiation kind, power density , gain, aimivity and polarisation etc.Chapter 3 discusses the Microstrip touch Antenna and eating techniques.Chapter 4 includes Ultra wide band microstrip patch antenna, history of UWB antennas, their features and advantages.Chapter 5 describes antenna design, simulated results, 2D and 3D radiation patterns for different frequencies and fabricated results.Chapter 6 concludes the entire work done throughout the designing of proposed antenna. Conclusion and proximo work helps to explore enormity of the subject.Chapter 2Fundamental Parameters of Antenna2.1 radiation practiceThe radiation pattern describes the strength of the radiated sketch in different directions from the antenna, at a constant distance. The radiation pattern is also reaction pattern, as it describes the receiving properties of the antenna. It is defined as a mathematical function or a graphical representation of the radiation properties of antenna as a function of space coordinates. In most cases the radiation pattern is resolved in far field vicinitys and is defined as a function of the directional coordinates. Radiation properties include power flux density, radiation intensity, field strength, directivity material body or polarization 2.The radiation pattern is leash-dimensional, besides measured patterns are comm merely two dimensional in unsloped or horizontal horizontal view. These measured patterns are presented in both rect angular or polar format. Following figure shows radiation pattern of an antenna in polar plane and Cartesian coordinate systems.http//www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/images/0900aecd806a1a3e_null_null_null_08_07_07- 03.jpg introduce-2.1 Radiation Pattern of an antenna in Cartesian and polar coordinatesRadiation patterns are further categorize as relative and absolute radiation patterns. Absolute radiation patterns have absolute units of power or field strength. Relative radiation patterns are presented in relative units of power or field strength. The radiation amount patterns are mostly relative to isotropic antennas, absolute gain of the antenna is established by antenna gain transfer method.The radiation pattern varies with the distance i.e. the patterns in near filed and far filed are different. The field pattern that exists close to the antenna is known as near filed, and far-field refers to the field pattern that exists at large distances. The far-field is called radiation field. Radiation field and power are what is commonly of interest, so antenna patterns are generally measured in the far-field region. For antenna pattern measurement the distance should be chose large enough not to be in near-field or in far field. The token(prenominal) allowed distance depends on the dimensions of the antenna relative to the wave length. The formula for this distance isrmin = 2d2/ (2.1)Where, rmin is the negligible distance from the antennad is the largest dimension of the antenna is the wavelength.2.1.1 Radiation Pattern LobesRadiation lobes are defines as portion of radiation pattern spring by regions of relatively weak radiation intensity 3. These lobes are categorise as follow major LobesMinor LobesSide LobesBack Lobes2.1.2 Major LobeA major lobe is defined as the radiation lobe containing the direction of level best radiation 2. Normally an antenna has one major lobe.2.1.3 Minor Lobe any lobe except major lobe is called minor lobe. It usually represents the radiation pattern which is not desirable.2.1.4 Side LobeA side lobe is a radiation lobe in any direction other than the main lobe 2. Usually a side lobe is succeeding(a) to the main lobe and is in direction to the main lobe.2.1.5 Back LobeA support lobe is a radiation lobe whose axis makes an angle of approximately 180 with applaud to the beam of an antenna or that is directed away from the main lobe 2. depositTypical Antenna Pattern.jpg catch 2.2 An illust dimensionn of major and minor lobes of radiation pattern2.2 country RegionsThe antenna field are divided into three regionsReactive near fieldRadiating near field (Fresnel) utmost field (Fraunhofer)http//www.nearfield.com/images/theory-ffdist.jpg contrive 2.3 Figure of skillful heavens and Far Field Regions2.2.1 Reactive Near FiledIt is the region immediately around the antenna. In this region the reactive filed predominates. The distance of this filed with antenna is usually R2.2.2 Radiating Near Field (Fresnel)Radiating near filed is defines as that region of the field of an antenna between the reactive near-filed and the far-filed region wherein radiation fields predominate and wherein the angular field distribution is dependen t upon the distance from the antenna 2. The distance of intimate boundary is R2.2.3 Far Field Region (Fraunhofer)Far Field region is defined as that region of the field of an antenna where the angular filed distribution is essentially independent of the distance from the antenna 2.2.3 Radiation raptureRadiation Intensity is the power radiated from an antenna per unit solid angle. It is the parameter of far field radiation.2.4 DirectivityDirectivity is figure of merit for antennas. It is the power density an antenna radiates in direction of maximum radiation to the number power density radiated by an isotropic antenna. Directivity for an isotropic antenna is always unity. It is expressed asD= (2.2a)(2.2b)Where, D is directivity and U is radiation intensity, Uo is Intensity if an isotropic source and Prad is total radiation power.2.5 growthThe gain and directivity of an antenna are closely related to each(prenominal) other. However for gain in denominator it is total power accept ed by an antenna rather than total power radiated by an antenna.G= (2.3)Gain is dimensionless. According to IEEE standards, gain doesnt include losses arising from impedance mismatching or polarization mismatches.2.6 BandwidthThe bandwidth is basically the difference or range between highest and lowest frequencies on which an antenna is operated. It is advantageous to have an antenna with high bandwidth. The bandwidth is expressed in term of ratio of upper cut off to the lower cutoff for broadband antennas.2.7 BeamwidthBeamwidth is the angle usually measured in degrees between the -3dB power radiated in the main lobe of radiation pattern.img383Figure 2.4 Illustration of Beamwidth2.8 Return terminationIt is the amount of power that is reflected back in to the transmittal line receivable to mismatching or any other error. It is the efficiency of power delivered to the accuse from the transmission line. Mathematical representation of Return loss isRL = 10log (2.4)Return loss is me asured in dB.http//www.mwrf.com/Files/30/11240/Figure_05.gifFigure 2.5 Return Loss2.9 polarisationPolarization is defined as point of reference of the electric field of the wave radiated by the antenna. It is categorized in three types gentle windarCircular ovate2.9.1 Linear PolarizationWhen there is zero phase difference between x and y component of a wave then polarization is called linear polarization. Linear polarization is further divided into crosswise polarization straight polarizationhttp//www.ccrs.nr set up.gc.ca/glossary/images/3104.gifFigure 2.6 Linear Polarization2.9.1.1 Horizontal PolarizationHorizontal polarization is the one in which wave propagates in x-direction and there is no propagation along y direction. A horizontally polarized wave is explained as a function of time T and E-field positionEx = E1 sin ( t z) (2.5)http//www.cfht.hawaii.edu/manset/PolHoriz.gifFigure 2.7 Horizontal Polarization2.9.1.2 Vertical PolarizationVertical polarization is the one in which wave propagates in y-direction and there is no propagation along x direction. It groundwork be written in mathematical form asEy = E2 sin ( t z) (2.6)http//www.cfht.hawaii.edu/manset/PolVert.gifFigure 2.8 Vertical Polarization2.9.2 Circular PolarizationIf there is exist phase difference between two waves then there is bank bill polarization, either dextrorotatory or anticlockwise. Wave moving in clockwise rotation is said to be left circularly polarized and the one propagating in counterclockwise rotation is right circularly polarized. Mathematically it is defined asEx = E1 sin (t z) (2.7)Ey = E2 sin (t z + ) (2.8)E1 is the amplitude of wave linearly polarized in x direction.E2 is the amplitude of wave linearly polarized in y direction. is the phase difference.http//www.cfht.hawaii.edu/manset/PolCirc.gifFigure 2.9 Circular Polarization2.9.3 ovate PolarizationIf two waves have unequal amplitude or phase then there is elliptical polarization.graphic 1Figure 2.10 (a) graphic Representation of oviform Polarizationhttp//www.nsm.buffalo.edu/jochena/images/elliptic2.gifFigure 2.10 (b) 3-D view of Elliptical Polarization2.10 Voltage Standing RatioVSWR is the ratio between maximum voltage and the borderline voltage. If there is a difference between load impedance and input impedance then there occurs reflection which causes interpretive interference and destructive interference. Instructive and destructive interference produces maximum and minimum amplitudes respectively. Mathematical Expression for VSWR isVSWR= (2.9)http//www.microwaves101.com/encyclopedia/images/VSWR/waves5.jpgFigure 2.11 Different Voltage amplitudes at different distances2.11 Types of antennasThere are six different types of antennas 2.Microstrip Patch Antenna lens of the eye Antenna conducting wire Antenna grade Antennareflecting telescope AntennaAperture Antenna2.11.1 Microstrip Patch AntennaMicrostrip patch antennas fall into the category of printed antennas 4. A radiating patch is printed on a grounded substrate which is usually feed via a transmission line or prateial cable. Patch chiffonier be of any shape and size i.e. circular, square, triangular or rectangular. Amongst all printed antennas i.e. dipole, Slots, Tapered Slots antennas Microstrip Patch Antennas are most famous. They are teensy in size, light in weight and low power consuming. save their bandwidths are smaller and have low gain. They are easy to integrate, good radiation control and cost of production is low. To step-up bandwidth many techniques are utilize that is introducing expansion slots and slits etc. They are utilise commercially in radars, wireless communications, satellites and mobiles etc.Figure 2.12 Microstrip patch Antennahttp//images.books24x7.com/bookimages/id_22121/fig188_01.jpgFigure 2.13 (a) Rectangular Patch Antenna (b) Circular Patch AntennaMicrostrip Patch antennas are employ in Microwave frequency range. They are used in arrays to sum up the bandwidth and gain and for other purposes.http//www.antennamagus.com/database/antennas/99/Stacked_microstrip_patch_array-antenna_design.pngFigure 2.14 Array of rectangular patch antennas2.11.2 Lens AntennaLens antennas are used to convert spherical radiated waves into plane waves in specific direction by using a source with microwave lens. It actually stops the divergent radiated energy to spread in undesired directions. These are mostly used for the high frequencies. A lens antenna may be of concave or bellied shape. They are directional antennas and can scan wider angles. In comparison to reflectors their gain is 1 or 2 dB less. Lens antennas may be constructed of non-metallic dielectrics or of metallic (artificial) dielectrics 5.http//www.xibao-electronictech.com/images/product/2/210Lens-Antenna.gifhttp//telecom.esa.int/telecom/media/img/largeimage/ wave guideLensAntennaPrjObj_404.jpgFigure 2.15 (a) Lens Antenna Figure 2.15 (b) Wave guide Lens Antenna2.11.3 Wire AntennaWire antennas consist of a wide wire that is used to radiate electromagnetic energy. These wire antennas can be of different shapes. more or less commonly used are straight wire antennas i.e. dipoles, loops and helix. Beside half-wave dipoles and quarter wave monopoles, wires of arbitrary lengths are often used to form antennas. Wire antennas can be vertical, horizontal or sloppy with respect to the ground. They may be fed from centre, at end or anywhere in between. The wires can be thick or thin, the radiation of antenna depends upon the thickness of the wire. Antennas with length larger than /2 are called Long-wire antennas.Figure 2.16 (a) Wire Antennas (a) Figure 2.16 (b) dipole Circular loop2.11.4 Array AntennaArray antennas are make up of more than one element basic of which is a dipole. Array antennas are the combination of radiating elements in such way that the radiation from these add up giving maximum or minimum radiation in a specific direction. They are used for higher directivity. They are mad e up of helices, dishes and other antennas. These elements are arranged to form broadside, end fire, collinear, driven and patristic arrays 5. They are used in applications in which radiation cannot be achieved from single radiating element. They are low weight and low cost antennas. Examples of array antennas are Yagi-Uda,http//www.tennadyne.com/images/tennlpdanavy.JPGFigure 2.17 Log Periodic Dipole Array Antenna2.11.5 Reflector AntennaThey are widely used to modify the radiation pattern of radiating elements. They are classified as active and passive reflectors. The active reflectors have corners made up of plane surfaces and they include periscopic antennas, flat-sheet reflectors and corner-reflector antennas. An active reflector may have corner elliptical, parabolic or spherical shape. Active reflectors include parabolic dish, truncated parabola, tablet box etc. Reflectors are simple in design, involve only one surface and obey simple laws of optics. The applications of reflect or antennas are radars and other point to point communication systems 5.http//www.sameercal.org/images/reflector_antenna.jpgFigure 2.18 A co-secant Reflector Antenna2.11.6 Aperture AntennaAperture antenna is an important antenna for space communication. As the name suggests they consist of some cavity through which electromagnetic waves are transmitted or received. Apertures may be of any shape i.e. rectangular, circular or spherical. man-sizedr the size of antenna larger bequeath be the gain. Aperture antennas have to be placed carefully because they have narrow beam widths. Examples of aperture antennas include waveguides, reflectors horns, slots and lenses. Aperture antennas are commonly used in aircraft and spacecraft applications.http//www.analyzemath.com/antenna_tutorials/introduction_3.gifFigure 2.18 owl Aperture AntennaChapter 3Microstrip Patch Antenna and falling techniques3.1 IntroductionSpaceships, aircrafts and other military applications such as missiles where impor tant constraints to trust are performance, manufacturing expenditures, subdued profile and ease of installation and now a days other systems such as wireless communication requires similar type of specifications to consider . And the basic component which is required by these listed applications for transmission of instructions or data and to receive these instructions on the receiver end is antenna. therefore to meet the requirements listed above e.g. smooth profile, cost and performance etc Microstrip antennas are used.Microstrip antennas are diminutive profile, conformable to planar and non-planar surfaces, easy and cheap to construct using the up to date printed circuit technology. Microstrip antennas have very flexible carriage to polarization, resonant-frequency, and impedance and radiation pattern. They are also used to increase the bandwidth. They consist of a ground plane over which a substrate is mount and the radiating patch is mounted on the substrate. Generally the ground plane and the dielectric substrate have equal length and width. The Microstrip antennas are illustrated by the width, length and the height of the dielectric substrate which is sandwiched in between the ground plane and the radiating patch3.2 Structural ConfigurationThe structural manikin of micro strip patch antenna is shown in figureFigure 3.1 Structural Configuration of Patch AntennaIt consist of a thin (tFigure 3.2 Side View of Patch AntennaThe length of the patch is usually /3 3.3 Formula for Rectangular Patch AntennaTo exit the width of the patch we use the formula(3.1)And the length of the patch can be drawn as(3.2)To reduce the fringing effects we use the pastime formulaL= 0.412h (3.3)Here L is the trimmed length from antenna.(3.4)3.4 Feeding MethodsFollowing feeding methods are most popular and are used with microstrip antennas1. Microstrip line feed2. Coaxial probe feed3. Aperture coupled feed4. Proximity coupled feed5. Coplanar waveguide feedThese methods are ei ther contacting or non-contacting. Contacting methods are those in which there is a direct contact between the transmission line and the radiating surface whereas in non-contacting methods, electromagnetic field coupling method is used to transfer the power.3.4.1 Microstrip Line FeedIn this feeding method, the line feed is conducting strip of small width as compared to the patch. It is the easiest feeding method easy to fabricate and simple to model. The radiating strip is placed at radiating patchs edge and it is of the same material that is used for patch. If length of the strip is greater than the wavelength, losses will be generated. It can be reduced if the strip line has a substrate with high dielectric constant and low weight, so that the fields are confined to the strip line. A line feed of dimensions 17x3mm is used to obtain 50 input resistance.Figure 3.1 Patch with Microstrip Line Feed3.4.2 Coaxial probe feedIn coaxial probe feeds, coax inner conductor is attached to the r adiating patch while the other conductor is connected to the ground plane. It is used widely. Its industry is easy and has low spurious radiation that is radiation outside the band frequency. It is has narrow bandwidth and it is labored to model for thick substrate. matching also becomes difficult for thicker substrate because of increase length of probe make it more inductive, its inductance effect can be reduced by using a series of capacitors.Figure 3.2 Patch with coaxial probe feed3.4.3 Aperture coupling feedIt is the non-contacting feed. The two substrates are separated by ground plane in it. The microstrip feed line is on the bottom side of the lower substrate there is a whose energy is coupled to the patch through a slot on the ground plane which separates the two substrates. A material with higher dielectricity is used for bottom substrate therefore, by this arrangement independent optimisation of the feed mechanism and the radiating element can be carried out.For top su bstrate a thick, low dielectric constant material is used. The ground plane between the two substrates isolates the feed from the radiating element and minimizes the interference. The contour line is shown in the figureFigure 3.3 Patch with aperture coupling feedMatching is performed by controlling the width of the feed line and the length of the slot. Amongst all four techniques this is the hardest to fabricate and has narrow bandwidth. It is somehow easy to model and has view as spurious radiation.3.4.4 Proximity coupling feedIn this feeding method, microstrip line is placed between two substrates and the radiating patch is placed on the upper substrate. This coupling is capacitive in nature. This coupling has the largest bandwidth as high as 13%. It is easy to model and has low spurious radiation. Its fabrication is somehow difficult. However, length of the stub help in improving the bandwidth, and width-to-line ratio of the patch can be used to control the match. The coupling feed is shownFigure 3.4 Patch with Proximity Coupling Feed3.4.5 Coplanar Waveguide FeedThis feeding technique is used when patch antenna is used in microwave monolithic integrated circuits (MMIC). The coplanar feed is fabricated on a ground plane and coupling is achieved through a slot. This feeding method reduces the radiation from feed structure because of its unusual method of coupled slot. Since CPW (coplanar waveguide) has many advantages such as low radiation leakage, less dispersion and small mutual coupling between two adjacent lines, which is helpful to place circuit elements close together without adding an additional layer of substrate, using CPW as the feeding structure to excite the patch antenna through a slot has become very popular recently. In addition, CPW structure can maintain constant characteristic impedance while varying its geometry, which provides a better impedance matching possibilityFigure 3.5 Patch with Coplanar Waveguide Feed3.3 Categorization on the a lkali of bandwidth-On the basis of range of frequency bands, microstrip patch antennas can be categorized into three main classes which areantenna for narrow band applicationsantenna for wide band applicationsantenna for ultra wideband applicationsChapter 4ULTRA WIDEBAND4.1 IntroductionA series of very short baseband pulses with time duration in nano-seconds that exist on ALL frequencies simultaneously. instant repetition frequency (PRF) can range from hundreds of thousands to billions of pulses/second. Very low power 41dbm/MHz (FCC) and wide bandwidth 3.110.6 GHzModulation techniques includepulse-position modulation binary program phase-shift keyingAndothersRadio technology that modulates impulse based waveforms instead of continuous crew cut waves4.1.1 Narrow band vs. Wide band signalsUWB could be used to indoor(prenominal), short communications for high data rates, OR Outdoor, long-range, but for very low data rates4.1.2 Large Relative BandwidthUWB is a form of extremely wide spread spectrum where RF energy is spread over gigahertz of spectrum. Wider than any narrowband system by orders of magnitude. Power seen by a narrowband system is a fraction of the total.UWB signals can be designed to look like imperceptible random noise to conventional radios4.1.3 Large Fractional BandwidthLarge fractional bandwidth leads to High processing gain and Multipath resolution and low signal fading. Fractional Bandwidth is the ratio of signal bandwidth (10 dB) to center frequency Bf = B / FC = 2(Fh-Fl) / (Fh+Fl)4.1.4 climbable Technology with Low PowerUWB benefits from basic information theory results when sign Bandwidth Data Rate .Power efficient low-order modulation can be used even for relatively high data rates.Data rates can home base independent of PRF by integrating bit intervals over multiple pulse intervals4.1.5 Multipath PerformanceUltra-wide bandwidth provides robust performance in multipath environments .4.1.6 UWB Data Rates4.2 UWB takeIndoorWithin a ro om (LOS NLOS)Investigates the impact ofDistanceRx/Tx antenna heightsAntenna polarizationCmat_dirsuwblimitsindoor5.tifUWB Emission bound for Indoor SystemsOutdoorCampus environmentLow altitudeMobilityCmat_dirsuwblimitsoutdoor5.tifUWB Emission Limit for Outdoor Hand-held Systems4.3 Emission limits for UWBUWB Emission Limits for GPRs, Wall visualize, Medical Imaging Systems.Operation is limited to law enforcement, fire and rescue organizations, scientific research institutions, commercial mining companies, and construction companies.UWB Emission Limits for Thru-wall Imaging Surveillance Systems4.4 Features of UWB -Ultra-short pulsesBaseband transmissionLow duty