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A single-layer ±45° dual-polarized directional array antenna for millimeter wave (mm-wave) applications is designed in this communication. Based on the theory of orthogonal circularly polarized (CP) wave multiplexing, two ports of a series-fed dual CP array are fed with equal amplitudes, and the array can radiate a linearly polarized wave with ±45° polarization orientations through the adjustment of the feeding phase difference. As the two ports of the series-fed array are simultaneously excited, the antenna can achieve directional radiation. In addition, the cross-polarization level of the array can be effectively suppressed by placing two series-fed arrays side by side. A prototype of the designed array antenna operating at 30 GHz is fabricated and measured; the working bandwidth of the proposed antenna is approximately 3.5%. Owing to its simple structure and directional radiation, the proposed antenna array is a competitive candidate for mm-wave applications.

Most Android users are unaware that their smartphones are as vulnerable as any computer, and that permission by Android users is an important part of maintaining the security of Android smartphones. We present a method that uses manifest files to determine the presence of spyware and the security level of apps. Furthermore, to ensure that no leaked data occurs in Android smartphones, we propose new method for the encryption of data from Google Suite applications.

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