Flat Antenna to Transmit and to Receive the Circularly Polarised Signals

Introduction

Antenna is an integral part of wireless, cellular, satellite and vehicular communication system and used for transmitting and receiving signals. An antenna, which transmits circularly polarized signals can overcome the problem of polarization rotation and reduce the multipath effects. This could be achieved generally by the use of printed antennas or flat antennas. The printed antennas, though cost effective and lightweight, have major disadvantages like difficulty in construction and complicated to manufacture. Some of the other known antenna systems used to transmit and receive circularly polarized signals, split the input signals to two equal parts having a phase difference of 900 which are fed to a single or a pair of radiating elements to achieve circular polarization thus making the system more complex. These drawback have been overcome in the present development which can also transmit and receive circularly polarized signals at microwave and millimeter wave frequencies.

In the present embodiment, the antennae consists of a thin, flat, rectangular, dielectric substrate. On one face of the substrate a conducting pattern is printed photo-lithographically. The pattern comprises parallel, thin, closely place strips, the strips make an angle a with respect to the y-direction. The input signal is fed through a coaxial connector. The antennae radiates two beams symmetrically inclined to the y-z plane. The radiated beams are circularly polarized. The antennae are also used for receiving circularly polarized signals when properly oriented with respect to the direction of arrival of the signal.

Salient features:

Easy to manufacture and lightweight; Economical construction and easy transportation; Transmit and receive signals at various frequencies without any change in main configuration; Input signals are inherently suitable for circularly polarized signals; Has potential of relatively wider bandwidth; Improved operational characteristics.

Prospective Users: All communication system such as wireless, satellite, mobile, etc.

Type of Technology: Device fabrication

Status of IPR Protection: Indian Patent Application No 1202/DEL/1997 dated 8th May 1997 entitled "Flat Antenna to transmit and to receive the circularly polarized Signals"

Developed by : Dr. Aditya Sheel
Department: Electrical Engineering

Contact:

Managing Director
Foundation for Innovation and Technology Transfer (FITT)
Indian Institute of Technology, Delhi
Hauz Khas, New Delhi-110016, INDIA
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