In this paper, we introduce a reconfigurable artistic patch antenna with unidirectional circular-polarization (CP) radiation. The novel geometry composed of a Chinese character Meng ( )- shaped patch and dual L-shaped feeding probes that are connected to a PIN-diode-based switching circuit. The simulated and experimental results show that the proposed antenna achieves the operating bandwidth from 2.4 to 2.5 GHz that covers dynamically the 14 channels of IEEE 802.11/b/g/b/ax. By switching the L-probes, either left-handed CP or right-handed CP can be generated to cover different seven-channel blocks in order to enhance the channel efficiency. A broadside realized gain varying between 5–6 dBic and an efficiency of −0.5dB were recorded. The proposed antenna holds an overall dimension of $0.72\lambda _{0}\times 0.72\lambda _{0}\times 0.12\lambda _{0}$ with an aperture efficiency of 59% at 2.45 GHz.

Dielectric characterization of concrete is essential for the wireless structural health monitoring (SHM) of concrete structures. Guo Biao (GB) concrete refers to the concrete mixed and cast in accordance with the Chinese standard. Currently, China is the largest producer and consumer of concrete in the world. However, minimal attention has been paid to the dielectric properties of GB concrete. This paper presents the results of the dielectric constant of GB concrete, where three regression models have been used to present the measurement data from 10 MHz to 6 GHz. The objective is to provide a data set of nominal values of the dielectric constant for ordinary GB concrete. The final goal is to facilitate a compressive strength evaluation via the measured dielectric constant. Measurements of the dielectric constant and compressive strength for five types of ordinary concrete have been undertaken, after 28 days of curing. As the main contribution in this work, the correlation model between the compressive strength and dielectric constant of GB concrete is realized.