A Wideband High Gain Arched Slotted Patch Array Antenna by Substrate-Integrated Coaxial Line

In this paper, a millimeter-wave wideband high gain arched slotted patch array antenna by substrate-integrated coaxial line (SICL) has been designed. Initially, antenna array is composed of a four-way power divider network and four arched patch elements, and its size is 8.41$\lambda_{0} \times 4.13\lambda_{0} \times 0.09\lambda_{0}$. Four arched E-shaped slotted patches with different orientations are adopted to improve the impedance bandwidth. A feeding structure is consisted of two two-way T-junctions and a 180° delay line to feed these patches, while the element excites 45° purified linearly polarized wave. Then, three two-way T-junctions with quarter-wavelength impedance transformer as the four-way power divider provide the equal amplitude and uniform phase to each element for maximizing the gain of the array. Over the frequency range of 39.7-44.4 GHz, the return losses are less than 10 dB, and the maximum peak gain is 16.0 dBi. Finally, these simulated results show that the proposed array antenna have the characteristics of high gain and wideband.