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This paper presents the design process of a multi-radii monofilar helical antenna that can operate in three different bands with circular polarization. The antenna is comprised of two helical antennas with different radii that are embedded and supported by an innovative structural technique. This allows reconfigurable behavior, efficient folding, packaging, and deployment. The antenna is fabricated using 2-mil-thick-FPC Kapton with a 3-mil copper trace glued appropriately on the top. An actuation mechanism of telescopic form is used for the stress-free deployment of the proposed design. The proposed origami antenna can adjust its band of operation by changing its height; therefore, it is physically reconfigurable. The main advantage of this antenna is that it can cover multiple applications, such as GPS, WiMAX, and satellite radio communications with a measured maximum right-hand circularly polarized realized gain of 6.3, 12.7, and 10.5 dB, respectively, thereby eliminating the need for multiple antennas.

Aiming at the risk of electricity theft of wireless power transfer (WPT) technology due to its untargeted and non-directional characteristics, a novel method of identification and resonance decoupling based on frequency hopping communication is proposed. The basic principle of the identification method is to make the resonant frequency of transmitter coil and receiver coil jump synchronously and randomly according to the pseudo-random code sequence, which can identify the load in single-source single-user mode and single-source multi-user mode respectively by calculating energy consumption ratio. And if user is illegal, then the resonant frequency of system jumps randomly to cut off the power, which is named resonance decoupling. The experimental circuit is designed on the basis of theoretical analysis and the method is verified. The test results are consistent with theoretical analysis, which has proved the validity of the method. This paper not only provides a solution to the power management of WPT system, but also is a support for the measurement of electricity, moreover, it is conducive to the further application and promotion of WPT technology.

Pattern- and frequency-reconfigurable antennas are developed using metalized liquid crystalline elastomers that can change their geometries from flat to helical shapes. The pitch angle and the number of turns in this transformation are controlled by temperature. An external heat source is applied to reshape the geometry of these antennas, thereby reconfiguring their performance. The antennas are characterized using simulations and measurements.