18-03-2014, 12:18 PM
YAGI-UDA ANTENNA
YAGI-UDA.ppt (Size: 640 KB / Downloads: 10)
INTRODUCTION
IN THE 1926, DR. SHINTARO UDA AND DR.HIDETSUGU YAGI OF THE TOHOKU IMPERIAL UNIVERSITY INVENTED A DIRECTIONAL ANTENNA SYSTEM CONSISTING OF AN ARRAY OF COUPLED PARALLEL DIPOLES.THIS IS COMMONLY KNOWN AS YAGI-UDA OR SIMPLY YAGI ANTENNA.
YAGI-UDA ANTENNA IS FAMILIAR AS THE COMMONEST KIND OF TERRESTRIAL TV ANTENNA TO BE FOUND ON THE ROOFTOPS OF HOUSES.IT IS USUALLY USED AT FREQUENCIES BETWEEN 30MHZ AND 3GHZ AND COVERS 40 TO 60 KM.
principle
YAGI-UDA ANTENNA IS AN ELECTROMAGNETIC DEVICE THAT COLLECTS RADIO WAVES. AN ANTENNA TUNED TO A PARTICULAR FREQUENCY WILL RESONATE TO A RADIO SIGNAL OF THE SAME FREQUENCY.
Working
REFLECTOR HERE DERIVES IT’S MAIN
POWER FROM A DRIVER , IT REDUCES THE SIGNAL STRENGTH IN IT’S OWN DIRECTION AND THUS REFLECTES THE RADIATION TOWARDES THE DRIVER AND DIRECTORS.
THE DRIVEN ELEMENT IS WHERE THE SIGNAL IS INTERCPETED BY THE RECEIVING EQUIPMENT AND HAS THE CABLE ATTACHED THAT TAKES THE RECEVIED SIGNAL TO THE RECEIVER
THE RADIATOR AND DRIVER CAN BE PLACED MORE CLOSER TO INCREASE THE RADIATION LENGTH TOWARDS THE DIRECTORS.
CONCLUSION
YAGI-UDA ANTENNA IS A UNIDIRECTIONAL ANTENNA. USED FOR TELEVISION RECIVERS.THEY PROVIDE BETTER TUNNING BECAUSE OF LARGE BANDWIDTH AND HAS DECENT GAIN.