ATTENTION: DUE VIRUS ISSUE, ALL OF OUR SECTION, CHAPTER AND AFFINITY GROUP MEETINGS ARE BEING ORGANIZED ONLINE. MEMBERSHIP WILL BE NOTIFIED WITH THE DETAILS.
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May 13 @ 9:00 am - 11:00 am
Antenna Fundamental Parameters and Figures-of-Merit
By Constantine A. Balanis
Regents Professor Emeritus, School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ www.balanis.faculty.asu.edu
Abstract: Antennas, single elements and arrays, are ‘the electronic eyes and ears of the world.’ They are the transitional devices and transducers that convert, in the transmitting mode, guided waves to free-space waves; similarly, in the receiving mode, they transform free-space waves to guided waves. In addition to transmitting and receiving EM energy, advanced breakthrough designs for system optimization accentuate the radiation energy in some directions and suppress it in others. Thus, antennas also serve as directional devices, in addition to radiating elements. They are used in a plethora of wireless applications ranging from personal, aerospace, and biomedical systems. In this presentation, some of the fundamental parameters and figures-of-merit of antennas, used to describe and judge their performance and radiation characteristics, will be reviewed. This includes amplitude patterns, beamwidths, directivity, gain, realized gain and bandwidths. When reciprocity is applicable, the parameters are relevant in either the transmitting or receiving mode. They are based on the IEEE Standard Definitions of Terms for Antennas.
Basic Concepts of Antenna Characterization and Applications for EMC Measurements
By Zhong Chen, Director of RF Engineering, ETS-Lindgren, Cedar Park, TX
Abstract: There are some practical considerations for antennas used for EMC measurements; for example, EMC antennas are typically extremely broadband and low gain. At below 1 GHz, these antennas are used over a perfect electrical conductor (PEC) ground plane. This presentation provides an introduction and discussion of the antenna fundamental parameters from an application point of view, especially on how these antenna parameters are characterized and applied in EMC applications. We will review the definition of Antenna Factor (AF), its relationship to antenna gains, and mismatch losses. We will also look at other parameters often used in EMC applications, such as antenna balance, phase center, and site attenuation. A brief introduction to the EMC antenna calibration methods will be provided, including a reference to dipole-like antennas which are ubiquitous for EMC measurements below 1 GHz. Finally, we will discuss how these antenna parameters, such as the free-space antenna factors, are impacted by the presence of the conducting ground plane.