DOCSLIB.ORG

A Ka-Band Circular Polarized Waveguide Slot Antenna with a Cross Iris

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Ka-Band Circular Polarized Waveguide Slot Antenna with a Cross Iris applied sciences Article A Ka-Band Circular Polarized Waveguide Slot Antenna with a Cross Iris Sung-Joon Yoon and Jae-Hoon Choi * Department of Electronics and Computer Engineering, Hanyang University, Seoul 133-791, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-2-2220-0376 Received: 30 August 2020; Accepted: 2 October 2020; Published: 7 October 2020 Featured Application: Segment waveguide slot antenna for a satellite communication and radar. Abstract: A Ka-band circularly polarized (CP) waveguide slot antenna with a cross iris is proposed. To achieve the CP characteristic (LHCP) in the antenna, a hexagonal shaped cavity is used. The impedance matching is improved by adjusting the sizes of the hexagonal cavity and a rectangular matching cavity. To enhance the axial ratio bandwidth, a cross iris is used with two arms of different lengths. From experimental results, the proposed antenna has a 3 dB axial ratio bandwidth of 6810 MHz (31.72 GHz–38.53 GHz). The 10 dB reflection coefficient bandwidth of the proposed − antenna ranges from 31.51 GHz to 39.21 GHz (7700 MHz). Keywords: waveguide antenna; slot antenna; circular polarization; axial ratio enhancement 1. Introduction Millimeter-wave communication systems support a higher data rate and larger capacity. Millimeter wave frequency has therefore been widely used in various applications such as 5G mobile, radar, satellite, military, and automotive communications [1]. Because mm-wave signals can be easily distorted by atmospheric interference such as fog or dust, waveguide antennas have been considered among the most appropriate for mm-wave applications due to their high power handling, high gain, stable performance and low transmission loss [2,3]. The polarization of antennas is one of the important factors in determining the performance of the communication. For linear polarization antenna, if the polarizations of a transmitter and a receiver do not match each other, communication performance deteriorates. Meanwhile, circular polarization avoids polarization misalignment as the electric field rotates, and it reduces multipath fading with flexibility in orientation the angle between the transmitted receiver [4,5]. Therefore, circular polarized (CP) waveguide antennas in particular are widely used in modern satellite communication systems due to their advantages of enhancing the channel stability and reliability [6,7]. Several techniques have been introduced to realize the waveguide CP horn and aperture antennas such as using a printed circuit board with four printed hook shaped arms [7], loading two metallic arms with a 45◦ inclination angle [8], and inserting a meta-surface polarizer or chiral metamaterial transformer [6,9]. However, there are some limitations in applying them to various applications since these antennas are relatively bulky and heavy. In addition, they are not suitable for array systems because a large space is required for polarizers to be installed [10]. Therefore, such antennas are not appropriate for satellite communication systems requiring a high gain array structure with compact size. To overcome these drawbacks of bulk and mass, various types of circular polarized waveguide slot antennas have been studied [11–17]. Waveguide inclined slot, crossed slot, and v-type slot antennas have been widely used for CP array antennas to generate circularly polarized waves with high gain [13–17]. However, there are few reports on either widening Appl. Sci. 2020, 10, 6994; doi:10.3390/app10196994 www.mdpi.com/journal/applsci Appl. Sci. 2020, 10, 6994 2 of 15 the axial ratio bandwidth of the waveguide slot antenna at the millimeter-wave band region or the design of waveguide slot CP antennas [16,17]. This paper proposes a Ka-band circularly polarized waveguide slot antenna with a cross iris. To achieve a circular polarization characteristic, a hexagonal shaped cavity is used [18]. By mounting a cross iris,Appl. the Sci. circular2020, 10, x FOR polarization PEER REVIEW performance of the proposed antenna is enhanced. The2 of proposed15 antenna provides a 10 dB reflection coefficient bandwidth covering from 31.51 GHz to 39.21 GHz. − The 3 dBreports axial on ratio either bandwidth widening the is axial 6810 ratio MHz bandwidt (31.72h of GHz–38.53 the waveguide GHz). slot antenna The antenna at the millimeter- peak gains are wave band region or the design of waveguide slot CP antennas [16,17]. 9.08 dBi at 33.5 GHz and 7.33 dBi at 37.6 GHz. The boresight gains of 7.87 dBi and 5.76 dBi are achieved This paper proposes a Ka-band circularly polarized waveguide slot antenna with a cross iris. To at thoseachieve two frequencies, a circular polarization respectively. characteristic, a hexagonal shaped cavity is used [18]. By mounting a cross iris, the circular polarization performance of the proposed antenna is enhanced. The proposed 2. Antennaantenna Design provides a −10 dB reflection coefficient bandwidth covering from 31.51 GHz to 39.21 GHz. FigureThe 31 dBshows axial theratio structure bandwidth of is the 6810 proposed MHz (31.72 CP GHz–38.53 waveguide GHz). slot The antenna antenna consisting peak gains of are a rectangular9.08 dBi at 33.5 GHz and 7.33 dBi at 37.6 GHz. The boresight gains of 7.87 dBi and 5.76 dBi are achieved waveguide, an air metal box with hexagonal cavity and matching slot, and a cross iris at the bottom of at those two frequencies, respectively. the rectangular waveguide. The proposed antenna has dimensions of 10.1 mm 23 mm 7.06 mm and × × is made2. of Antenna a copper Design with a conductivity of 5.8001 107 S/m. The detailed parameters of the proposed × antenna areFigure shown 1 shows in Figure the 1structure and the of dimensionsthe proposed are CP givenwaveguide in Table slot 1antenna. The performancesconsisting of a of the proposedrectangular antenna waveguide, were simulated an air metal using box the with commercial hexagonal cavity electromagnetic and matching simulator,slot, and a cross High iris Frequency at Structurethe Simulatorbottom of the (HFSS) rectangular [19]. waveguide. The antenna The prop is fedosed from antenna the has rectangular dimensions of waveguide 10.1 mm × 23 to mm excite the × 7.06 mm and is made of a copper with a conductivity of 5.8001 × 107 S/m. The detailed parameters TE10 mode for high power handling capability. The dimensions (a = 7.11 mm and b = 3.56 mm) of the proposed antenna are shown in Figure 1 and the dimensions are given in Table 1. The of the feeding waveguide are determined by the cutoff frequency (21.077 GHz) using the following performances of the proposed antenna were simulated using the commercial electromagnetic equationsimulator, with dimensions High Frequency shown Structure in Figure Simulator2[ 20]. (HFS AsS) shown [19]. The in Figureantenna2 ,is the fed waveguidefrom the rectangular has its longest dimensionwaveguide along theto excite x-axis the (a ).TE mode for high power handling capability. The dimensions (= 7.11 mm and =3.56 mm) of the feeding waveguider are determined by the cutoff frequency (21.077 GHz) using the following equation 1with dimensionsmπ2 shownnπ in2 Figure 2 [20]. As shown in Figure 2, the waveguide has itsfcmn longest= dimension along the x-axis+ (a). , (1) 2π pµ0"0 a b 2 2 = + , (1) When a > b, the cutoff frequency of TE10 (m =1,n= 0) mode becomes When a>b, the cutoff frequency of TE10 (m = 1, n = 0) mode becomes 1 fc10 = , (2) = , (2) 2apµ0"0 μ ε . where µwhere0 and "00 andare the0 are permeability the permeability and and permittivity permittivity of free free space, space, respectively respectively. (a) Figure 1. Cont. Appl. Sci. 2020, 10, 6994 3 of 15 Appl. Sci. 2020, 10, x FOR PEER REVIEW 3 of 15 Appl. Sci. 2020, 10, x FOR PEER REVIEW 3 of 15 (b) (b) (c) FigureFigure 1. Geometry 1. Geometry of the of proposedthe proposed antenna: antenna: (a ()a) 3-D 3-Dview view of the proposed proposed antenna; antenna; (b) (topb) topview view of of the proposedthe antenna;proposed antenna; (c) side ( viewc) side of view the of proposed the propos antennaed antenna and and cross cross iris.iris. Tabley 1. Dimensions of the proposed antenna. Parameters C1 C2 S1 S2 L1 L2 (c) Value (mm) 6.5 4.4 4.3 8 6 5 Figure 1. GeometryParameters of the proposedb H1 antenna:H2 (a) 3-DH3 viewH of4 the proposedB1 B antenna;2 (b) top view of the proposed antenna;Value (c (mm)) side view7.06 of the 2.5proposed 0.5 antenna 1.2 and cross 5.9 iris. 3.28 y (μ0, ε0) 0 a x bz Figure 2. Geometry of the rectangular waveguide. Table 1. Dimensions of the proposed antenna. (μ0, ε0) Parameters Value (mm) 6.5 4.4 4.3 8 6 5 Parameters0 Value (mm) 7.06 2.5 0.5 1.2 a 5.9 x3.28 z FigureFigure 2. 2.Geometry Geometry of of the the rectangular rectangular waveguide. waveguide. Table 1. Dimensions of the proposed antenna. Parameters Value (mm) 6.5 4.4 4.3 8 6 5 Parameters Value (mm) 7.06 2.5 0.5 1.2 5.9 3.28 Appl.Appl. Sci. Sci. 20202020, ,1010, ,x 6994 FOR PEER REVIEW 44 of of 15 15 Appl. Sci. 2020, 10, x FOR PEER REVIEW 4 of 15 3. Antenna Analysis 3.3. Antenna Antenna Analysis Analysis In the proposed antenna design, the hexagonal shaped cavity with a rectangular waveguide shownInIn thein the Figureproposed proposed 3 is antenna antennaused as design, design, an initial the the hexagonal hexagonalmodel (first shaped shaped reference cavity cavity antenna) with with a a rectangular to realize the waveguide circular polarization.shownshown inin FigureFigure The3 ishexagonal3 usedis used as an shapeas initial an isinitial model similar (firstmodel to reference a (firstcorner reference antenna) truncated toantenna) realizepatch theantenna,to circularrealize which polarization.the circularcan be theoreticallypolarization.The hexagonal analyzedThe shape hexagonal is using similar ashape tocavity a corner is model similar truncated with to athe patchcorner magnetic antenna, truncated walls which resonatingpatch can beantenna, theoretically in TM which (Transverse analyzed can be Magnetic)theoreticallyusing a cavity mode analyzed model [21].
Load more

Recommended publications
  • A Dual-Port, Dual-Polarized and Wideband Slot Rectenna for Ambient RF Energy Harvesting
    A Dual-Port, Dual-Polarized and Wideband Slot Rectenna For Ambient RF Energy Harvesting Saqer S. Alja’afreh1, C. Song2, Y. Huang2, Lei Xing3, Qian Xu3. 1 Electrical Engineering Department, Mutah University, ALkarak, Jordan, [email protected] 2 Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom. 3 Department of Electronic Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, China. Abstract—A dual-polarized rectangular slot rectenna is they are able to receive RF signals from multiple frequency proposed for ambient RF energy harvesting. It is designed in a bands like designs in [4-7]. In [4], a novel Hexa-band rectenna compact size of 55 × 55 ×1.0 mm3 and operates in a wideband that covers a part of the digital TV, most cellular mobile bands operation between 1.7 to 2.7 GHz. The antenna has a two-port and WLAN bands. Broadband antennas. In [7], a broadband structure, which is fed using perpendicular CPW and microstrip line, respectively. To maintain both the adaptive dual-polarization cross dipole rectenna has been designed for impedance tuning and the adaptive power flow capability, the RF energy harvesting over frequency range on 1.8-2.5 GHz. rectenna utilizes a novel rectifier topology in which two shunt (2) antennas for wireless energy harvesting (WEH) should diodes are used between the DC block capacitor and the series have the ability of receiving wireless signals from different diode. The simulation results show that RF-DC conversion polarization. Therefore, rectennas have polarization diversity efficiency is greater 40% within the frequency band of like circular polarization [7]; dual polarization [8] and all interested at -3.0 dBm received power.
    [Show full text]
  • Design of Narrow-Wall Slotted Waveguide Antenna with V-Shaped Metal Reflector for X
    2018 International Symposium on Antennas and Propagation (ISAP 2018) [ThE2-5] October 23~26, 2018 / Paradise Hotel Busan, Busan, Korea Design of Narrow-wall Slotted Waveguide Antenna with V-shaped Metal Reflector for X- Band Radar Application Derry Permana Yusuf, Fitri Yuli Zulkifli, and Eko Tjipto Rahardjo Antenna Propagation and Microwave Research Group, Electrical Engineering Department, Universitas Indonesia Depok, Indonesia Abstract - Slotted waveguide antenna with wide bandwidth match to side lobe level requirement. Later, two metal sheets characteristics is designed at the 9.4-GHz frequency (X-band) as metal reflector are attached to the SWA edges to focus its for radar application. The antenna design consists of 200 narrow-wall slots with novel design of V-shaped metal reflector azimuth plane beam. The reflection coefficient, radiation to enhance side lobe level (SLL) and gain. New optimized slot pattern plots, and gain results of the antenna are reported. design results in SLL of -31.9 dB. The simulation results show 36.7 dBi antenna gain and 780 MHz bandwidth (8.67-9.45 GHz) for VSWR of 1.5. 2. Antenna Configuration Index Terms — slotted waveguide antenna, X-band, narrow- The 3-D view of the proposed antenna configuration is wall slots, high gain, metal reflector, radar shown in Fig 1. The antenna configuration consists of narrow wall slot waveguide with V-shaped metal reflector. The target frequency is 9.4 GHz. The slot antenna dimension 1. Introduction with its parameters is shown in Fig. 2. The antenna radiates Radar is essential component used for detecting hazards horizontal polarization and determines the parameters w = (such as coastlines, islands, icebergs, other objects or ships), 1.58 mm and t = 1.25 mm.
    [Show full text]
  • Revisiting Slot Antennas
    Revisiting Slot Antennas Chris Hamilton AE5IT Rocky Mountain Ham Radio NerdFest 2021 Who am I? • AE5IT, formerly KD0ZYF • Licensed 2014 to call for help in the woods • Immediately became a weird RF nerd • Slot antennas captured attention early, but no real use cases Early 2020 – no-drill mobile • Could I load the gap between body panels as a slot antenna? • Construction & waterproofing challenges • Working without a VNA, lots of guessing • Surprisingly difficult to load • Radiation pattern and polarization not ideal (pretty good for overhead ISS passes) • Went directly for 2m / 70cm dual-band The rest of 2020 & early 2021 • EVERYTHING WAS NORMAL AND FINE AND NOTHING AT ALL WEIRD HAPPENED • Returning to ham projects after a lost year • Coincidentally a recent increased interest in slot antennas among hams So what is a slot antenna? • Literally a slot cut into a large metal sheet • Mathematical & physical complement to a dipole antenna • Radiation pattern resembles a dipole, but with E & H planes swapped -- a vertical slot is horizontally polarized • Feedpoint impedances inverse of dipole Where & why are they used? • Practical at V/UHF and above • Common in aviation, TV broadcast, telecom • Used for cell towers & microwave arrays • The metal plane can be a waveguide – the support structure is the antenna • Allows for electrically steerable beams in compact & robust packages Largely unknown by hams • Wildly impractical at HF • Horns and dishes give more gain in smaller packages • Applications for V/UHF weak signal? • Some applications for stealth antennas in restrictive neighborhoods • Some new designs seem to contradict the literature, or my understanding of it Current work • Fundamentals • Build from reference designs: Kraus, Johnson & Jasik • Measure & compare performance • Figure out my weird VNA • Perform replication studies of recent popular designs Let’s build antennas! Minimal resonant slot 26 AWG copper wire Center-fed Textbook slot λ x λ/2 Aluminum sheet λ/20-fed This is not a test & measurement talk.
    [Show full text]
  • A Wide-Band Slot Antenna Design Employing a Fictitious Short Circuit Concept Nader Behdad, Student Member, IEEE, and Kamal Sarabandi, Fellow, IEEE
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 53, NO. 1, JANUARY 2005 475 A Wide-Band Slot Antenna Design Employing A Fictitious Short Circuit Concept Nader Behdad, Student Member, IEEE, and Kamal Sarabandi, Fellow, IEEE Abstract—A wide-band slot antenna element is proposed as a experimental investigations on very wide slot antennas are building block for designing single- or multi-element wide-band or reported by various authors [2]–[5]. The drawback of these dual-band slot antennas. It is shown that a properly designed, off- antennas are two fold: 1) they require a large area for the slot centered, microstrip-fed, moderately wide slot antenna shows dual resonant behavior with similar radiation characteristics at both and a much larger area for the conductor plane around the slot resonant frequencies and therefore can be used as a wide-band and 2) the cross polarization level changes versus frequency and or dual-band element. This element shows bandwidth values up to is high at certain frequencies in the band [2]–[4], and [6]. This 37%, if used in the wide-band mode. When used in the dual-band is mainly because of the fact that these antennas can support mode, frequency ratios up to 1.6 with bandwidths larger than 10% two orthogonal modes with close resonant frequencies. The ad- at both frequency bands can be achieved without putting any con- straints on the impedance matching, cross polarization levels, or vantages of the proposed dual-resonant slots to these antennas radiation patterns of the antenna. The proposed wide-band slot ele- are their simple feeding scheme, low cross polarization levels, ment can also be incorporated in a multi-element antenna topology and amenability of the elements’ architecture to the design resulting in a very wide-band antenna with a minimum number of of series-fed multi-element broad-band antennas.
    [Show full text]
  • Design of a Fractal Slot Antenna for Rectenna System and Comparison of Simulated Parameters for Different Dimensions
    CPUH-Research Journal: 2015, 1(2), 43-48 ISSN (Online): 2455-6076 http://www.cpuh.in/academics/academic_journals.php Design of a Fractal Slot Antenna for Rectenna System and Comparison of Simulated Parameters for Different Dimensions Nitika Sharma 1*, B. S. Dhaliwal2 and Simranjit Kaur3 1, 2 & 3Department of Electronics and Communication Engineering, G. N. D. E. College, Ludhiana, India * Correspondance E-mail: [email protected] ABSTRACT: In the modern era we required a compact system having a high gain, efficiency and broad band- width. For rectenna (antenna + rectifier) system we need such an antenna which can receive more radio frequen- cies from the surroundings and gives to rectifier which works on one or more frequency band or multiband oper- ation. For fulfill these requirements we proposed a fractal slot antenna which gives multiband operation on 2.45 GHz. In this paper, we compare the simulation parameters on the basis of dimensions. Keywords: Rectenna; Multiband; Efficiency; Fractal Slot antenna and Gain. INTRODUCTION: Modern wireless applications antennas used as rectennas, microstrip patch antennas have challenged antenna designers with demands for are gaining popularity due to their low profile, light low-cost and compact antennas along with a simple weight, low production cost, simplicity, and low cost radiating element, signal-feeding configuration, good to manufacture using modern printed-circuit technol- performance, and easy fabrication. In the modern era, ogy [4]. the large reduction in power consumption achieved in Another reason for the wide use of patch antennas is electronics, along with the numbers of mobiles and their versatility in terms of resonant frequency, polari- other autonomous devices is continuously increasing zation, and impedance when a particular patch shape the attractiveness of low-power energy-harvesting [5] and mode are chosen .
    [Show full text]
  • Various Types of Antenna with Respect to Their Applications: a Review
    INTERNATIONAL JOURNAL OF MULTIDISCIPLINARY SCIENCES AND ENGINEERING, VOL. 7, NO. 3, MARCH 2016 Various Types of Antenna with Respect to their Applications: A Review Abdul Qadir Khan1, Muhammad Riaz2 and Anas Bilal3 1,2,3School of Information Technology, The University of Lahore, Islamabad Campus [email protected], [email protected], [email protected] Abstract– Antenna is the most important part in wireless point to point communication where increase gain and communication systems. Antenna transforms electrical signals lessened wave impedance are required [45]. into radio waves and vice versa. The antennas are of various As the knowledge about antennas along with its application kinds and having different characteristics according to the need is particularly less thus this review is essential for determining of signal transmission and reception. In this paper, we present various antennas and their applications in different systems. comparative analysis of various types of antennas that can be differentiated with respect to their shapes, material used, signal In this paper a detailed review of various types of antenna bandwidth, transmission range etc. Our main focus is to classify which developed to perform useful task of communication in these antennas according to their applications. As in the modern different field of communication network is presented. era antennas are the basic prerequisites for wireless communications that is required for fast and efficient II. WIRE ANTENNA communications. This paper will help the design architect to choose proper antenna for the desired application. A. Biconical Dipole Antenna Keywords– Antenna, Communications, Applications and Signal There is no restriction to the data transfer capacity of an Transmission infinite constant-impedance transmission line however any pragmatic execution of the biconical dipole has appendages of constrained extend forming an open-circuit stub in the same I.
    [Show full text]
  • Uni-Directional CPW-Fed Slot Antennas Using Loading Metallic Strips and a Widened Tuning Stub on Modified-Shape Reflectors
    Uni-directional CPW-fed Slot Antennas Using Loading Metallic Strips and a Widened Tuning Stub on Modified-Shape Reflectors Sarawuth Chaimool 1, Prayoot Akkaraekthalin 1, and Monai Krairiksh 2 1 Department of Electrical Engineering, Faculty of Engineering, King Mongkut’s Institute of Technology North Bangkok, Bangkok 10800, Thailand, E-mail: [email protected] 2 Faculty of Engineering and Research Center for Communications and Information Technology King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand Abstract We have observed that the size and shape of the conducting reflector of CPW-fed slot antennas using loading metallic strips and a widened tuning stub have significant impact on the antenna impedance matching and radiation pattern. By shaping the reflecting conductor, noticeable enhancements in both radiation pattern which provides uni-directional all frequency operating band and characteristic im- pedance matching are achieved. 1. INTRODUCTION The technique for reducing back radiation of the CPW-fed slot anten- nas is of interest due to it is possible place some type of conducting reflector behind the slot in order to reduce backside radiation and increase the gain. Among the several popular reducing back radiation techniques, a flat conducting reflector is easy in fabrication and most popular method for the electrically thick substrate CPW-fed slot antenna [1]. However, the presence of the flat conducting reflector Fig. 1: CPW-fed slot antennas using loading metallic strips and a widened may cause problems such as power leakage in the parallel-plate tuning stub (a) antenna element, above (b) flat reflector, (c) corner reflector, Λ modes which degrade impedance bandwidth and radiation pattern.
    [Show full text]
  • Lecture 28 Different Types of Antennas–Heuristics
    Lecture 28 Different Types of Antennas{Heuristics 28.1 Types of Antennas There are different types of antennas for different applications [128]. We will discuss their functions heuristically in the following discussions. 28.1.1 Resonance Tunneling in Antenna A simple antenna like a short dipole behaves like a Hertzian dipole with an effective length. A short dipole has an input impedance resembling that of a capacitor. Hence, it is difficult to drive current into the antenna unless other elements are added. Hertz used two metallic spheres to increase the current flow. When a large current flows on the stem of the Hertzian dipole, the stem starts to act like inductor. Thus, the end cap capacitances and the stem inductance together can act like a resonator enhancing the current flow on the antenna. Some antennas are deliberately built to resonate with its structure to enhance its radiation. A half-wave dipole is such an antenna as shown in Figure 28.1 [124]. One can think that these antennas are using resonance tunneling to enhance their radiation efficiencies. A half-wave dipole can also be thought of as a flared open transmission line in order to make it radiate. It can be gradually morphed from a quarter-wavelength transmission line as shown in Figure 28.1. A transmission is a poor radiator, because the electromagnetic energy is trapped between two pieces of metal. But a flared transmission line can radiate its field to free space. The dipole antenna, though a simple device, has been extensively studied by King [129]. He has reputed to have produced over 100 PhD students studying the dipole antenna.
    [Show full text]
  • A Vhf and Uhf Stealth Antenna System for Those Who Live in Hoa’ S
    A VHF AND UHF STEALTH ANTENNA SYSTEM FOR THOSE WHO LIVE IN HOA’ S (AND IF YOU LIKE YOUR SATELLITE SERVICE YOU CAN KEEP YOUR SATELLITE SERVICE) By N5CEY 30 April 2016 March 2016 issue of QST had the fllfollowing articl e: “An Efficient 2 Meter Antenna Disguised as a TV Satellite Dish”. Pages 37 and 38 By John Portune, W6NBC I give all credit for this seminar to Mr. Portune. I simply followed his instructions and it worked very well. I also carried through with a 440 mhz version. A bit about Slot Antennas • What is a slot antenna? A slot antenna consists of a metal surface, usually a flat plate, with a hole or slot cut out. • Where are slot antennas commonly used? Slot antennas are very commonly used on commercial and military aircraft because they can be easily molded into the structure of the aircraft. Also used in cell phone towers at microwave frequencies •What frequencies are slot antennas commonly used at? Typically, slot antennas are used at 300 Mhz and above. Some typical slot antennas Look Familiar? Comparison with dipole The Sacrificial Lamb Provided by N5RGV 28” Dish Network dish in pretty fair condition Dish as received Cleaned out all the roaches! Funny Orange Coax Layyging out the slot, 24” long and 7.5” tails DESIGN FREQUENCY: 146.00 MHZ USING A DREMEL CUTOFF WHEEL TO MAKE CORNER CUTS FOR SABER SAW INSERTION More corner notches Where’s your safety glasses??? DREMELS are your friend! Cutting the slot USE A SHARP, METAL CUTTING SABER SAW BLADE AND TAKE YOUR TIME Checking Dimensions 24” LONG AND THE “TAILS” ARE 7.5” LONG Slot cut, Dish is unstable (physically) Very Unstable! Aha! 5 minute Epoxy! Taped across the slot on the front side and epoxied across the slot on the back.
    [Show full text]
  • Design and Characterization of Circularly Polarized Cavity-Backed Slot Antennas in an In-House-Constructed Anechoic Chamber
    Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 8-2012 Design and Characterization of Circularly Polarized Cavity-Backed Slot Antennas in an In-House-Constructed Anechoic Chamber Mangalam Chandak Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Electrical and Computer Engineering Commons Recommended Citation Chandak, Mangalam, "Design and Characterization of Circularly Polarized Cavity-Backed Slot Antennas in an In-House-Constructed Anechoic Chamber" (2012). All Graduate Theses and Dissertations. 1265. https://digitalcommons.usu.edu/etd/1265 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. DESIGN AND CHARACTERIZATION OF CIRCULARLY POLARIZED CAVITY-BACKED SLOT ANTENNAS IN AN IN-HOUSE-CONSTRUCTED ANECHOIC CHAMBER by Mangalam Chandak A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Electrical Engineering Approved: Dr. Reyhan Baktur Dr. Edmund Spencer Major Professor Committee Member Dr. Jacob Gunther Dr. Mark R. McLellan Committee Member Vice President for Research and Dean of the School of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2012 ii Copyright c Mangalam Chandak 2012 All Rights Reserved iii Abstract Design and Characterization of Circularly Polarized Cavity-Backed Slot Antennas in an In-House-Constructed Anechoic Chamber by Mangalam Chandak, Master of Science Utah State University, 2012 Major Professor: Dr. Reyhan Baktur Department: Electrical and Computer Engineering Small satellites are satellites that weight less than 500 kg.
    [Show full text]
  • ACE Deliverable 2.4-D6 Conformal Antennas Inventory of the On-Going Research
    ACE Deliverable 2.4-D6 Conformal Antennas Inventory of the On-going Research Project Number: FP6-IST 508009 Project Title: Antenna Centre of Excellence Document Type: Deliverable Document Number: FP6-IST 508009/ 2.4-D6 Contractual date of delivery: 31 December 2004 Actual Date of Delivery: 30 December 2004 Workpackage: mainly WP 2.4-3, but also related to WP 2.4-1 & 2.4-2 Estimated Person Months: 12 Security (PU,PP,RE,CO): PU Nature: R (Deliverable Report) Version: B Total Number of Pages: 46 File name: ACE_2-4_D6.pdf Editor: Zvonimir Sipus Other Participants: G. Vandenbosch, G. Caille, J. Herault, J.Freeze, M.Thiel, S. Sevskiy, A. Pippi , M. Lanne, L.Petersson, P. Persson, and G. Gerini Abstract The deliverable D6 represents a first step for structuring the research on conformal antennas, dispersed in several European universities and industrial Research centres. The inventory of the on-going research covers both the software and hardware activities, and it will help in defining most useful antenna architectures & geometries and in organizing students/Ph.D exchange between various European academies and companies. When designing conformal antennas it is convenient to use specialized programs for specific conformal geometries that are fast and often more accurate than general electromagnetic solvers since they explicitly take into account the antenna geometry. Therefore, a detailed description of the developed software packages for analysing conformal antennas is presented. The developed arrays covers most-interesting types of conformal antennas, and they will be used as conformal benchmarking structures to judge antenna software tools on its performance. This will help in selecting proper software for some particular problem, and in integration of different software tools.
    [Show full text]
  • Highlights of Antenna History
    ~~ IEEE COMMUNICATIONS MAGAZINE HlOHLlOHTS OF ANTENNA HISTORY JACK RAMSAY A look at the major events in the development of antennas. wires. Antenna systems similar to Edison’s were used by A. E. Dolbear in 1882 when he successfully and somewhat mysteriously succeeded in transmitting code and even speech to significant ranges, allegedly by groundconduction. NINETEENTH CENTURY WIRE ANTENNAS However, in one experiment he actually flew the first kite T is not surprising that wire antennas were inaugurated antenna.About the same time, the Irish professor, in 1842 by theinventor of wire telegraphy,Joseph C. F. Fitzgerald, calculated that a loop would radiate and that Henry, Professor’ of Natural Philosophy at Princeton, a capacitance connected to a resistor would radiate at VHF NJ. By “throwing a spark” to a circuit of wire in an (undoubtedly due to radiation from the wire connecting leads). Iupper room,Henry found that thecurrent received in a In Hertz launched,processed, and received radio 1887 H. parallel circuit in a cellar 30 ft below codd.magnetize needies. waves systematically. He used a balanced or dipole antenna With a vertical wire from his study to the roof of his house, he attachedto ’ an induction coilas a transmitter, and a detected lightning flashes 7-8 mi distant. Henry also sparked one-turn loop (rectangular) containing a sparkgap as a to a telegraph wire running from his laboratory to his house, receiver. He obtained “sympathetic resonance” by tuning the and magnetized needles in a coil attached to a parailel wire dipole with sliding spheres, and the loop by adding series 220 ft away.
    [Show full text]