Lecture

Antenna and Arrays: Uniform Linear Antenna

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In course

EE-548: Audio engineering

This lecture is oriented towards the study of audio engineering, room acoustics, sound propagation, and sound radiation from sources and acoustic antennas. The learning outcomes will be the techniques for microphones and loudspeaker design, as well as room ...

Description

This lecture covers the principles of linear antennas, including uniform linear antennas and phased linear antennas. It explores the application of antenna arrays in acoustics to control directivity, with examples like line array sound systems and microphone arrays. The lecture delves into the theory behind linear antennas, discussing the radiation pattern, directivity, and polar representations. Specific cases such as symmetric antennas and Uniform Linear Antennas are examined, along with their directivity diagrams and properties. The concept of directivity factor and radiation width are also explained in the context of antenna arrays.

Instructor

Hervé Lissek

Expertise Acoustics and audio engineering, Electroacoustics.Room acoustics.Active noise control.Acoustic metamaterials.Assisted reverberation.Psychoacoustics.Sound spatialization Expertise Acoustics and audio engineering, Electroacoustics.Room acoustics.Active noise control.Acoustic metamaterials.Assisted reverberation.Psychoacoustics.Sound spatialization Mission Head of the Acoustic Group at the Laboratory of Wave Engineering LWE. Research topics :Active Electroacoustic Resonators: turning conventional lou

Official source

Ontological neighbourhood

Electrical engineering

Radio-frequency engineering: Radio antennas

Related concepts (32)

Antenna array

An antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. The individual antennas (called elements) are usually connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase relationship. The radio waves radiated by each individual antenna combine and superpose, adding together (interfering constructively) to enhance the power radiated in desired directions, and cancelling (interfering destructively) to reduce the power radiated in other directions.

Collinear antenna array

In telecommunications, a collinear antenna array (sometimes colinear antenna array) is an array of dipole or quarter-wave antennas mounted in such a manner that the corresponding elements of each antenna are parallel and collinear; that is, they are located along a common axis. Collinear arrays are high gain omnidirectional antennas. Both dipoles and quarter-wavelength monopoles have an omnidirectional radiation pattern in free space when oriented vertically; they radiate equal radio power in all azimuthal directions perpendicular to the antenna, with the signal strength dropping to zero on the antenna axis.

Reflective array antenna

In telecommunications and radar, a reflective array antenna is a class of directive antennas in which multiple driven elements are mounted in front of a flat surface designed to reflect the radio waves in a desired direction. They are a type of array antenna. They are often used in the VHF and UHF frequency bands. VHF examples are generally large and resemble a highway billboard, so they are sometimes called billboard antennas. Other names are bedspring array and bowtie array depending on the type of elements making up the antenna.

Directivity

In electromagnetics, directivity is a parameter of an antenna or optical system which measures the degree to which the radiation emitted is concentrated in a single direction. It is the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions. Therefore, the directivity of a hypothetical isotropic radiator is 1, or 0 dBi. An antenna's directivity is greater than its gain by an efficiency factor, radiation efficiency.

Aperture (antenna)

In electromagnetics and antenna theory, the aperture of an antenna is defined as "A surface, near or on an antenna, on which it is convenient to make assumptions regarding the field values for the purpose of computing fields at external points. The aperture is often taken as that portion of a plane surface near the antenna, perpendicular to the direction of maximum radiation, through which the major part of the radiation passes.

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