Wideband Differentially-Fed Slot Antenna and Array With Circularly Polarized Radiation for Millimeter-Wave Applications

Abstract

A wideband differentially-fed slot antenna is presented for millimeter-wave (mmWave) applications. A novel method of using stepped corner-shaped slot is first utilized to establish the wideband circularly polarized (CP) radiation. In the configuration of corner-shaped slot, two wide open slots at the ends are utilized for effective orthogonal radiation, while the narrow slot at the center is utilized for power transmission and quadrature phase delay. An equivalent circuit is given to illustrate the inner working principle for CP radiation. In addition, square cuts are etched on the four corners of the radiating patches to further increase the axial ratio (AR) and impedance bandwidth. Based on this design concept, the antenna element was first designed and fabricated for performance verification. Then, a 1×4 linear array with beam scanning performance and a 4×4 planar array with high gain and stable radiation were designed and fabricated. Both the simulated and measured results show that the 1×4 linear array and 4×4 planar array can have wide overlapped impedance and AR bandwidths of 30.6% and 33.6% with thickness of 0.16𝛌 𝟎 . The advantages of compact size and wide bandwidth make the presented antenna a good candidate for mmWave applications.

Wideband Circularly Polarized Magneto-Electric Dipole Antenna Array with Metallic Walls for Millimeter-Wave Applications

“…As listed in Table 2, the overlapping impedance and AR bandwidth of the proposed design exceeds most of the referenced arrays. Although [10,18] have Finally, the performances of the proposed array are compared with other Ka-band CP antenna arrays. As listed in Table 2, the overlapping impedance and AR bandwidth of the proposed design exceeds most of the referenced arrays.…”

“…As listed in Table 2, the overlapping impedance and AR bandwidth of the proposed design exceeds most of the referenced arrays. Although [10,18] have wider bandwidth, they need four substrate layers. Although the SIW design in [15] and the microstrip line in [26] also need two substrate layers, the bandwidth of the two arrays is much narrower.…”

“…Over the previous decades, many wideband CP elements have been presented for array designs [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Stacked patch [5][6][7], ME dipole [8,9], curl antenna [10][11][12], spiral antenna [13,14], cavity antenna [15][16][17], slot antenna [18], and dielectric resonator antenna [19][20][21] are the popular elements.…”

“…Over the previous decades, many wideband CP elements have been presented for array designs [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Stacked patch [5][6][7], ME dipole [8,9], curl antenna [10][11][12], spiral antenna [13,14], cavity antenna [15][16][17], slot antenna [18], and dielectric resonator antenna [19][20][21] are the popular elements. For example, in [6], a wideband circularly polarized radiation is generated owing to the combination of a pair of shorted pins with four identical square patches, and the 3-dB AR bandwidth of the stacked patch array achieves 25.4%.…”

“…In [9], by truncating several corners and adding L-shaped branches into the ME dipole element, 3-dB AR bandwidths of the element and the 4 × 4 array are 17.3% and 16%, respectively. In [18], a differentially fed slot antenna contains 20.4% AR bandwidth, whereas the 4 × 4 array possesses a bandwidth of 33.6%. However, among the above-mentioned designs, some arrays have a relatively narrow bandwidth, while others require more substrate layers or a high profile.…”