Ultra Wide Band Antenna for High Speed Microwave Applications
UWB ANTENNA FOR MICROWAVE APPLICATIONS Prepared by: Ahmed Tarek Omar Hussien Sherif Shawki Sherif Zahran Supervised by: DR/Mahmoud Abdallah
Agenda What is Antenna. What is UWB. What is Micro-strip antenna. Initial Design Results. Single micro-strip antenna. Circular & Rectangular UWB antenna.
Antenna Antenna: Is an electrical device which converts electric power into radio waves, and vice versa. Theory of operation.
Antenna Parameters Radiation pattern : Plot of the relative field strength of the radio waves emitted by the antenna at different angles. Antenna directivity: The ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions.
Antenna Gain: Parameter which measures the degree of directivity of the antennas radiation pattern. Antenna Polarization: Is the orientation of the electric field of the radio wave with respect to the Earths surface and is determined by the physical structure of the antenna and by its orientation.
Input impedance: Electro-magnetic wave travels through the different parts of the antenna, at each interface some fraction of the waves energy will reflect back to the source.
UWB UWB: Ultra Wide Band, Also known as(ultra band). A series of very short baseband pulses with time duration in nano-seconds that exist on ALL frequencies simultaneously. UWB in the frequency range from 3.1 to 10.6 GHz.
UWB transmissions transmit information by generating small pulses at specific time intervals. Each pulse occupies a large BW, overcoming The multipath fading but not the ISI.
UWB pulses are very short so most signal reflections do not overlap the original pulse (less than 1nsec).(less than 60 cm for a 500 MHz pulse, less than 23 cm for a 1.3 GHz pulse), up to 1.3 Gp/sec providing a continuous stream of UWB pulses according to application. it operates parallel to other systems so energy has to be low to get no interference.
UWB coexistence with systems No interference with systems because of low power. Power limit for UWB Tx is -41.3 dBm/MHz. High data rates according to Shannons theory.
UWB Applications AUTOMOTIVE INDUSTRY-Back collision avoidance.-Wireless key.-Moving objects detection while driving.-Improving airbags activation and suspension performance. COMMUNICATION-High multipath areas.-Low range-high rates areas.-Home personal area networks.(pcs,hd TV, hr printer, hr scanner,hd cameras, game consoles)
UWB Applications Security Apps-Ground penetrating radars(GPR).-Through wall surveillance.-Tracking applications(specially indoors unlike GPS) For children,personnel,equipments,cars-Guarding objects (ex. in museums).
Why UWB? High data rate and capacity(400-800Mbps ). High speed. High Security (cannot jam the large BW). Low power (operates at low energy level). Working parallel with other systems. Fading overcoming.