In this paper, we report a novel three-state Radio Frequency Microelectromechanical Systems (RF MEMS) switch, which is based on origami structure for large tunable capability. Combined with the origami structure, the switch can achieve the deep-on state by raising the height of the origami beam. This switch has been designed and fabricated successfully with the silicon process. Experimental results show that the origami beam can be raised to $76~\mu $ m at the deep-on state with an amplification factor of 12.6 compared to the on state. In the frequency range of 10-30 GHz, when the switch is at the on state, the insertion loss is better than −0.4 dB and the return loss is better than -18dB. At the deep-on state, the return loss achieves −31dB with the improvement of 13 dB. At the off state, the isolation of the switch is better than −20 dB. As a result, the presented switch based on origami structure can be a promising choice for low loss, high isolation, and large tunable range applications.[2024-0221]

A novel design method based on a novel origami process that can create a solid structure swiftly and at a low cost is presented for rectangular waveguide-type microwave devices in this paper. A planar structure was fabricated by the lamination and laser cutting of polystyrene membranes and aluminum foils and was converted into a solid structure via origami in accordance with the selective absorption of infrared light. A rectangular waveguide, a rectangular waveguide-type coupler, and a power divider based on an origami structure with a multi-layer structure and a single-layer structure were fabricated and tested, demonstrating easy assembly and good microwave performance. The measured results of the rectangular waveguide indicated that the insertion loss was superior to −0.9 dB. Meanwhile, the results of the coupler showed that the coupling degree increased from −12.8 dB to −8.9 dB in the range of 11.0 GHz to 12.0 GHz. Correspondingly, the prepared power divider demonstrated that the return loss dwindled from −8.9 dB to −11.3 dB and that the insertion loss of one output port was approximate to that of the remaining one, varying between −3.5 dB and −5.2 dB in the range of 10.5 GHz to 11.5 GHz—verifying the effectiveness of the origami-based design method.

To meet the requirements of parameter testing under special environments, we conduct research on multiparameter integrated sensors. This article proposes a flexible multisensor system based on MEMS beam structures, which utilizes MEMS double-clamped beam and MEMS V-shaped beam to test two parameters of curvature and threshold temperature. Due to the interference between loading temperature and loading curvature during the testing of the multisensor system, a multiphysics coupling model of the system is established to analyze the mutual effect between the two sensors under the loading of temperature and curvature. Multiple sensors have been designed and fabricated on flexible liquid crystal polymers (LCPs) substrate, and the effects of substrate bending and temperature variation on sensor performance testing are characterized. The experimental results of the curvature sensor are consistent with the theoretical predictions within a maximum error of 6.81%. When the ambient temperature is below the threshold temperature, the curvature sensitivity is 5.2 MHz/m $^{-\text{1}}$ and the influence of ambient temperature on curvature testing is negligible. When the ambient temperature reaches the threshold temperature, the curvature sensitivity is 5.4 MHz/m $^{-\text{1}}$ The experimental results of the threshold temperature sensor agree with the theoretical predictions within a maximum error of 9.68% when substrate curvature varies. The resonant frequency offset of the substrate in a flat state is 350 MHz at the threshold temperature.

A novel stress suppression design for flexible RF MEMS switches has been presented and demonstrated through theoretical and experimental research to isolate the stress caused by substrate bending. An RF MEMS switch with an S-shaped microspring structure was fabricated by the two-step etching process as a developmental step toward miniaturization and high reliability. The RF MEMS switches with an S-shaped microspring exhibited superior microwave performance and stable driving voltage under different substrate curvatures compared to the conventional non-microspring switches, demonstrating that the bending stress is successfully suppressed by the S-shaped microspring and the island structure. Furthermore, this innovative design could be easily extended to other flexible devices.

In this paper, an innovative reconfigurable microstrip RF device design method is proposed, which is inspired by origami structures. The experimental results of the reconfigurable low-pass filter indicate that the maximum origami folding height is 3 mm, resulting in the frequency tuning range of the filter being 524~568 MHz, the return loss is below −15.0 dB and the insertion loss is below 2.5 dB up to 500 MHz. It is demonstrated that the proposed design method for reconfigurable microstrip RF devices is fairly effective through theoretical and experimental research. This work provides a groundbreaking method for reconfigurable RF devices with origami structures.