A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array forC-Band Applications

Abstract

A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in the C-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm 2 . Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.

A Planar Wideband Two-Level Sequentially Rotated Array Antenna for X-Band Cubesat

“…As shown in Table 1, our design yields a significantly smaller size, a simpler configuration, and a comparable global bandwidth (the global bandwidth is overlapped bandwidths for |S 11 | < −10 dB, CP radiation, and 3-dB gain) relative to the arrays in [11,12]. In comparison with the array using single-feed CP elements [13,14], the proposed antenna achieves a significantly wider global bandwidth, nevertheless a similar complexity. λ is a free space wavelength referring to the center frequency…”

“…Also, the patches and feeding networks are built on different substrates; they are connected by using vias passed through multi-layers. By using series-parallel strips with curved structures, the feeding networks and patches of the proposed array and the priors in [13,14] are implemented on the top side of a single-layer substrate. As shown in Table 1, our design yields a significantly smaller size, a simpler configuration, and a comparable global bandwidth (the global bandwidth is overlapped bandwidths for |S 11 | < −10 dB, CP radiation, and 3-dB gain) relative to the arrays in [11,12].…”

“…With the medium gain (up to ∼ 13 dBic), these 4-patches array antennas are suitable for CubeSat satellites without high-precision attitude determination and control system. In order to further increase the gain and broaden the AR bandwidth, planar array antennas have been incorporated with two-level sequentially rotated feeding networks [11][12][13][14]. Typically, the feeding networks [11,12] utilized microstrip lines with different electric lengths to achieve the desired phases, and consequently, they required a large area for deploying the microstrip lines.…”

“…Typically, the feeding networks [11,12] utilized microstrip lines with different electric lengths to achieve the desired phases, and consequently, they required a large area for deploying the microstrip lines. The compact array antennas [13,14] used series-parallel strips with curved structures in their feeding networks. These arrays employed narrow-band primary radiation elements, i.e., slotted disk-based patch [13] or truncated-corner patch [14], and therefore, their operational bandwidths were only up to 14% or less.…”

“…The compact array antennas [13,14] used series-parallel strips with curved structures in their feeding networks. These arrays employed narrow-band primary radiation elements, i.e., slotted disk-based patch [13] or truncated-corner patch [14], and therefore, their operational bandwidths were only up to 14% or less.…”