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This communication presents a dual-polarized series-fed array antenna with 30° beam-pointing for millimeter-wave (MM-Wave) applications. The 45° and −45° polarized subarrays share the aperture in an interdigital shape. The spacing between subarrays with the same polarization orientation is set to $0.56\lambda _{0}$ through the use of narrower T-type folded substrate integrated waveguide (TFSIW) instead of substrate integrated waveguide (SIW). The substrate integrated coaxial line (SICL) is adopted to design the array feeding network. To validate the proposed design, a $4 \times 6$ (single polarization) dual-polarized array antenna operating at 28 GHz with 30° beam-pointing is fabricated. Based on the measurement, the return losses are lower than −10 dB from 27.5 to 28.5 GHz, the isolations between the two polarization ports are higher than 30.0 dB in the frequencies mentioned above, the maximum gain at the center frequency is 15.7 dBi, and the cross-polarization levels are lower than −18.5 dB. The proposed antenna only needs one-step processing with the standard PCB technology without additional stitching assembly. Simulated and measured results of the proposed antennas were compared. [ABSTRACT FROM AUTHOR]

A slot helix antenna working in Global Positioning System (GPS) L1 and L2 bands is proposed in this paper. Adopting sequential rotation technique, the proposed antenna is equipped with six helix radiation arms and fed by a microstrip line with folded shape. The whole antenna can be built on a full printed circuit board; so, it is easy to process the proposed antenna. The circularly polarized radiation mechanism of a circular array is analyzed in a new perspective to guide the design. A double-faced slot radiation structure is also established for dual-band operation. Additionally, a traveling wave feeding network suitable for the proposed antenna is presented. The experimental results show that the proposed antenna has good properties in GPS L1 and L2 bands. [ABSTRACT FROM PUBLISHER]

Single fed low profile cavity backed crossed slot antennas for dual frequency dual linear polarization and circular polarization applications are first presented in this paper. By employing the substrate integrated waveguide (SIW) technique in the antenna designs, the low profile backed cavity structure can be realized by using only a single layer of low cost printed circuit board (PCB) substrate. A single grounded coplanar waveguide (GCPW) is employed as the feeding element to excite the TE120 and TE210 modes in the SIW cavity. A crossed slot structure is used as the radiating element in order to radiate the desired dual linearly or circularly polarized wave. From the measurement results, it is seen that these novel antennas retain the advantages of conventional metallic cavity backed antennas, including high gain, high front-toback ratio (FTBR), and low cross polarization level (CPL). Furthermore, the proposed antennas also possess the advantages of low profile, light weight, low fabrication cost, and easy integration with planar circuits. [ABSTRACT FROM AUTHOR]