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WELCOME. HELICAL ANTENNA. CONTENTS. INTRODUCTION Working application ADVANTAGES Conclusion references. INTRODUCTION. A helical antenna is a specialized that antenna emits and responds to with rotating (circular) polarization.
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CONTENTS • INTRODUCTION • Working • application • ADVANTAGES • Conclusion • references
INTRODUCTION A helical antenna is a specialized that antenna emits and responds to with rotating (circular) polarization. These antennas are commonly used at earth-based stations in satellite communications systems. This type of antenna is designed for use with an unbalanced such as The center conductor of the cable is connected to the helical element, and the shield of the cable is connected to the reflector.
WORKING OF HELICAL ANTENNA • A helical antenna is an antenna consisting of conducting wire wound in the form of a helix. • this antenna can operates in one of two principle modes, • NORMAL MODE • AXIAL MODE
NORMAL MODE In this modes the dimension of helix are small compare with the wavelength this antenna typically used mobile communication
AXIAL MODE • In this modes the helix dimensions • are at above the Wavelength of • Operation. • The antenna the falls under the class • of waveguide antenna and produces • True circular polarization. • These antenna are best suited for space communication
EXAMPLE OF HELICAL ANTENNA • Model 8617-810 - High Gain UHF High Power Helical Antenna • For uplinks to UHF satellites, this antenna operates from 236 - 330 MHz with right-hand circular polarization with a gain of 12 to 17 dBic. • Overall length is 10 feet. A special perforated metal cup reflector increases gain and reduces side lobes. • The antenna comes complete with an elevation/azimuth pipe mount allowing for elevation adjustments from horizon to 65°. Equipped with a type N connector, this antenna can handle up to 1 KW of RF
APPLICATION • High Gain • RH Circular Polarization • Adjustable Tilt Stainless Steel Bracket • Type N Female Connector • DC Grounded for lightening protection • Rugged, Lightweight and Waterproof
ADVANTAGES • Greater Bandwidth (range 400MHz to 900MHz,14dB) • greater gain • more flexibility • Uni-directional antenna • crystal clear transmision
CONCLUSION We conclude A Helical antenna is broadband VHF and UHF. This antenna are right hand circular polarization. This antenna can operates in one of two principle modes,
REFERENCE: Electronics Communication System Author George Kennedy & Bernard Davis Website :- en.wikipedia.org/wiki/helical_antenna and google search
Presented by: MICHAEL CHETAN SANDEEP