Antennas -- in 50 Minutes or Less! Cynthia Furse Department of Electrical and Computer Engineering Utah State University

Introduction to Antennas Antenna Parameters Types of Antennas Where to find out more

Antenna Parameters Radiation Pattern –Directivity –Gain –Planes ( E or H, Elevation or Azimuth) –Lobes (HPBW, FSLBW, etc.) Input Impedance Link Budget

Common Types of Antennas Wire Antennas –Dipoles, Monopoles, Monopoles above Gnd Patch, Printed circuit board antennas Slots, apertures Dishes, Reflector Antennas Arrays

Dipole Antenna From:

Folded Dipole From:

Monopole Antenna From:

Monopole Antenna From:

The University of Utah mm-resolution Head Model Furse, Lazzi, Gandhi, “FDTD Computation of Power Deposition in the Head for Cellular Telephones,” Proc IEEE APS Symposium

Applications: Cellular Telephones SAR Distribution in Adult MHz - Simplified Phone Model  /4 antenna Pandit,McDermott,Lazzi,Furse,Gandhi, “Electrical Energy Absorption in the Human Head,” presented at IEEE Visualization ‘96, S.F., CA 1996

SAR Distributions MHz (adult, 10 year old, 5 year old) Adult 5 year old 10 year old From: Gandhi, Lazzi, Furse, IEEE Trans. MTT 44(10) 1996

Monopole Antenna above Ground =Dipole Antenna

V-Antenna v.gif From:

Loop Antenna From:

Pagers From:

Discone Antenna From:

Reflector (Dish) Antenna From:

Arecibo Observatory -- Puerto Rico From:

Arecibo Observatory From:

Arecibo Observatory From:

Horn Antennas From:

Conical Horn Antenna From:

GPS Antennas From:

GPS Antenna From : SEN SENSOR SYSTEMS L1

GPS Antenna with Choke Ring From: SEN cr SENSOR SYSTEMS L1 WITH CHOKE RING

GPS Antenna LEI AT302 From:

Antenna Arrays Two Elements -- Pattern adds constructively or destructively From:

Antenna Arrays More Elements: Higher Directivity Sidelobes From:

Scanning Antenna Array Changing the phases on the element feeds can make a scanning array. From:

Arrays From:

Yagi-Uda Arrays From:

Satellite Antenna Array From:

HAARP Observatory From: HAARP (High frequency Active Auroral Research Program) is to be a major Arctic facility for upper atmospheric and solar-terrestrial research. HAARP is being built on a DoD-owned site near Gakona, Alaska.

HAARP Antenna Array From: The HF antenna system to be used for Active Ionospheric Research at the HAARP site will assist other facility instruments in the study the overhead ionosphere. As a result, it too has been designed to optimize or restrict the transmission pattern to lie within a narrow overhead region. To achieve this desirable antenna pattern, the HAARP system uses an "array" of individual antenna elements. The HAARP antenna array is similar or identical to many other types of directive antenna types in use for both military and civilian applications including air traffic control radar systems, long range surveillance systems, steerable communication systems and navigation systems.

HAARP -- Feed Sytem From: HAARP/images/ant/tpile.jpg

HAARP -- Matching Networks From:

Corner Reflector Antenna From:

Anything Radiates … Fan-tenna From:

The Bottom Line ANYTHING radiates. Sometimes you want it to, and sometimes you don’t. To choose an antenna for your design, prepare a LINK BUDGET to determine the necessary gain and directivity of your antenna. Don’t forget MATCHING NETWORKS to prevent reflection between your antenna and your circuit.

Antenna References on the Web General: GPS Antennas Lowe Industries : Antenna Calibration: Ham: North Country Radio: Antenna Elmer: HAARP Observatory: Arecibo Obervatory: