Characterize Types of Antennas Flashcards
What is an Isotropic Antenna?
A theoretical antenna that radiates energy in all directions equally in the shape of a sphere
Gain is determined by what two factors?
Directivity and Efficiency
What is Reciprocity and the Reciprocity Theorem?
Reciprocity:
Describes the antenna’s capability to transmit and receive
Reciprocity Theorem:
In a perfect environment, TX gain = RX gain
What are the three types of gain?
- Active
- Passive
- Computational
What is EIRP?
Effective Isotropic Radiated Power
Total power leaving an antenna relative to an isotropic radiator
Describe Radiation Lobes
Main lobe, secondary lobe, tertiary lobe, etc… Side lobes are “spillover” from the main lobe and contain significantly less power
What is Half Power Beam Width?
The angular separation between the half-power points on the radiation pattern
What is a Monopole Antenna?
One feed point at the base of the antenna radiating out to the sides, but not above or below
What is a common Dipole Antenna model?
Yagi-Uda
What are the three elements of the Yagi-Uda Array?
Driven Element, Reflector, and Directors
Circularly polarized to combat Faraday Rotation and Scintillation
What is an Array Antenna?
Multiple antennas working as a single unit
What are the elements of a Parabolic Antenna?
Feedhorn, Sub-reflectors, and LNA/LNB
What is the relation between waveguides and wavelength?
They are proportional
What does an Orthomode Transducer do?
Allows different polarities to transmit or receive simultaneously without interference
