title: Multiplexed Cassegrain Reflector Antenna for Simultaneous Generation of Three Orbital Angular Momentum (OAM) Modes.
abstract: A multiplexed Cassegrain reflector antenna with a 2 × 2 open-ended rectangular waveguide (OERW) matrix feed and an orbital angular momentum (OAM) mode mux is proposed for the simultaneous generation of three OAM modes (l = 0, ±1). The OAM mode mux (OMM) was designed using sequential combinations of quadrature hybrids, crossovers, and phase shifters to multiplex and demultiplex three OAM modes at the same time. The 2 × 2 OERW matrix feed and the OMM were separately measured and their performances were verified according to proposed theories. A near-field antenna measurement for a multiplexed Cassegrain reflector antenna was conducted to obtain the far-field magnitude and phase patterns around polar elevation angle θ and azimuthal angle ϕ, thus confirming that our antenna can produce three OAM modes simultaneously. We also measured the communication link characteristics of two identical multiplexed antennas. The measurement results show that the channel isolation of three OAM modes is more than 12.7 [dB] and 17 [dB] for fixed and compensated receiver positions, respectively, indicating that the proposed antenna system can be used for independent communication links with the same frequency and polarisation.
authors.affiliation: RF &Antenna Technology Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Byun
authors.affiliation: RF &Antenna Technology Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Kwang Seon
authors.initials: KS
authors.lastname: Kim
authors.affiliation: RF &Antenna Technology Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Bong Su
authors.initials: BS
authors.lastname: Kim
authors.affiliation: RF &Antenna Technology Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Young Seung
authors.initials: YS
authors.lastname: Lee
authors.affiliation: RF &Antenna Technology Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Myung Sun
authors.initials: MS
authors.lastname: Song
authors.affiliation: RF Technology Research Department, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea.
authors.forename: Hyung Do
authors.initials: HD
authors.lastname: Choi
authors.affiliation: School of Information &Communication Convergence Engineering, Mokwon University, Daejeon, 35349, Korea.
authors.forename: Yong Heui
authors.initials: YH
authors.lastname: Cho