Study on behaviour and application of orbital angular momentum antennas

Abstract

Recently, a well-known concept of optical and quantum physics, orbital angular momentum newline(OAM) has been experimentally introduced in microwave frequency to enhance the spectrum newlineefficiency and channel capacity by multiplexing of orthogonal OAM modes. In the present study, newlinethe concept of orbital angular momentum (OAM) wave generation using a Uniform Circular Array newline(UCA) antenna with the help of mathematical equations is discussed with the help of three different newlineorientation geometry of eight rectangular patch antenna elements UCA. Investigation on the purity newlineof OAM phase front for different OAM modes (±1, ±2, ±3 and ±4) and physical design parameters newlineof OAM antenna are presented. The results of simulated radiation pattern and phase pattern are newlinewell satisfying the generation of OAM modes and the measured results show the close agreement newlinewith the simulated result. newlineMiniaturized OAM antenna is proposed for first order and higher order OAM modes. An edge fed newlinesquare shaped antenna geometry (design-1), is used to generate OAM wave using UCA concept newlineand this concept is supported by mathematical analysis. A single four corner-fed square patch newlineantenna is simulated and fabricated at 5.5 GHz. The reflection coefficient, radiation pattern and newlinephase pattern measurement of both fabricated antennas are presented. The geometry of integrated newline+1 and -1 OAM antenna for edge-fed and corner-fed geometry is also proposed. newlineA wide band UCA antenna is designed using eight Vivaldi antenna elements for the generation of newlineOAM mode 0, +1 and -1. Vivaldi UCA is fabricated and measured for OAM mode 0. newlineA design of a four-port, dual-band uniform circular array (UCA) of annual slot to generate OAM newlinemode 0, +1 and -1 at two frequency 2.45 GHz (ISM band/WLAN) and 5.4 GHz (WLAN) is newlinepresented. The effects of variation in physical parameters (like the length of 50-Ohm line, the newlineradius of annular slot and annular slot width) on reflection coefficient and the radiation pattern are newlinediscussed.