By using complementary rhombus resonator (CRR), a small-size and low-profile microstrip patch antenna (MPA) with broad bandwidth has been proposed. Parametric studies were conducted to illustrate the working principle of the proposed antenna. An additional resonance is introduced by the CRR to broaden the bandwidth. Compared with the MPA without the CRR, the bandwidth of the proposed antenna is increased by 200%. The measured results are in good agreements with the simulated ones, which demonstrate that this design provides a way to obtain the broadband antenna.

One intriguing metamaterial absorber with anapole excitation in the microwave frequency range is proposed for the first time. The presented subwavelength structure is composed of three copper strips to effectively improve the absorptivity. Owing to the constructive interference between toroidal and electric dipoles, and all-right impedance matching with free space, the absorptivity can reach 77% at 10.27 GHz with structural parameter optimization. The simulated and experimental results show strong consistency. The anapole absorption could have numerous potential applications at microwave, terahertz, and optical frequencies, such as cloaking, ultrasensitive sensing, and secure information transfer.

The dual-band analog electromagnetically induced transparency (EIT) with intriguing toroidal has been presented at microwave frequency. The proposed construction is composed of the split resonant rings with different sizes in two layers to induce dual-toroidal resonance. By optimizing the structure, two transparency peaks derived from strengthened toroidal could attain to 0.97 at 5.36 GHz and 0.94 at 10.23 GHz, which could be certified by numerical simulation, near-field distribution and scattered power of far-field. The experiment and simulation are almost consistent, and the dual-toroidal analog-EIT could have potential applications in many fields, such as ultrasensitive sensing and secure data communication.