Dual-linearly polarized travelling-wave array antenna based on triple plus slots fed by square waveguide

Dual-Polarization and Dual-Band Conical-Beam Array Antenna Based on Dual-Mode Cross-Slotted Cylindrical Waveguide

“…On the other hand, the mode TE01 is generated at the output CW by the excitation of the fundamental TE10 mode in the rectangular waveguide of port 2. A uniform four-way E-plane rectangular waveguide power divider is designed to generate the E-field distribution of the TE01 mode in the CW at the corresponding frequency band (37)(38)(39)(40). This kind of TE01 feeder has been widely analyzed in other works such as [41], but in our case the structure has been highly compacted.…”

“…14(b), the lower band will be barely excited by the TE01 mode because the S22 parameter is higher than -1 dB from 26 to 30 GHz (the cutoff frequency of the TE01 mode is 31.4 GHz). Nevertheless, the TM01 will be significantly excited in the higher band (37)(38)(39)(40) since the S11 parameter is below -3 dB. Despite this fact, it is not considered as an important issue because the power coupled by the TS array could be easily filtered out at port 1.…”

“…In the present work, longitudinal slots excited by the TE01 mode are also included in a dual mode CW. The authors presented in [38] a cross-slot travelling-wave array antenna fed by a square waveguide, where the degenerate fundamental modes TE10 and TE01 were excited by using an orthomode transducer to achieve dual polarization. Following the same idea, an array of crossslots capable of radiating with vertical and horizontal linear polarizations is proposed in this work.…”

“…Each polarization is directly related to either of the two modes excited in the feeding waveguide. Nevertheless, the complexity of this structure is significantly higher than the one presented in [38] because in this occasion two non-orthogonal, high-order modes of the CW with different cutoff frequencies are required. A dual-mode feeder will be designed to excite the TM01 and TE01 modes with a very high mutual isolation, providing orthogonally-oriented surface currents and consequently dual polarization.…”

“…Thus, two different conical-beam antenna topologies are proposed to cover the n257 (26.5-29.5 GHz) and n260 (37-40 GHz) frequency bands identified by the 3GPP for future 5G communications [12]. Firstly, a dual-polarized antenna only for the n260 band (37)(38)(39)(40), where the dual polarization is generated by the excitation of the TM01 and TE01 modes. In addition, a second design of a dual-band antenna covering both the n257 and n260 frequency bands, where the TM01 mode generates vertical polarization for the 26-30 GHz band while the TE01 mode generates horizontal polarization for the 37-40 GHz band.…”