Answer to Question #274529 in Discrete Mathematics for Louise

Question

1. Classify and compare the different types of antenna using ah venn diagram. Discuss each type in each petal of the diagram.

Answer 1

• Turnstile – Two dipole antennas mounted at right angles, fed with a phase difference of 90°. This antenna is unusual in that it radiates in all directions (no nulls in the radiation pattern), with horizontal polarization in directions coplanar with the elements, circular polarization normal to that plane, and elliptical polarization in other directions. Used for receiving signals from satellites, as circular polarization is transmitted by many satellites.
• Corner reflector – A directive antenna with a moderate gain of about 8 dBi often used at UHF frequencies. Consists of a dipole mounted in front of two reflective metal screens joined at an angle, usually 90°. Used as a rooftop UHF television antenna and for point-to-point data links.
• Patch (microstrip) – A type of antenna with elements consisting of metal sheets mounted over a ground plane. Similar to dipole with a gain of 6–9 dBi. Integrated into surfaces such as aircraft bodies. Their easy fabrication using PCB techniques has made them popular in modern wireless devices. Often combined into arrays.