Design, Fabrication and Measurement of Radio Frequency Micro-Electro-Mechanical Systems

Abstract

This article describes the fabrication and experimental results of a novel step structure Radio Frequency Microelectromechanical system (RF MEMS) switch integrated with a circular patch antenna. The RF MEMS switch is developed using surface micromachining technology and exhibits several desirable characteristics. The key findings and features of the proposed RF MEMS switch are as follows: The switch operates at a very low pull-in voltage of 4.4 V, which is advantageous as it requires low actuation voltage for switching operations. Low ON State Capacitance: The switch demonstrates a low ON state capacitance of 81.2 fF, indicating efficient switching performance. High Isolation: The switch exhibits high isolation of −60.68 dB at 23 GHz, which is the central frequency of the K-band. This high isolation ensures minimal interference and improved signal integrity. The RF MEMS switch is integrated with a circular patch antenna, enabling reconfigurability in the operating frequency of the antenna. The antenna's frequency can be adjusted by actuating the switches alternatively. The specific operating frequencies and return loss values are as follows: Both Switches ON: The antenna radiates the signal at a frequency of 19.2 GHz with a return loss of −26.7 dB. Only Switch A ON: The antenna radiates at a frequency of 21 GHz with a return loss of −17.6 dB. Only Switch B ON: The antenna radiates the signal at a frequency of 26.4 GHz with a return loss of −17.47 dB. The RF MEMS switch and antenna are optimized to transmit RF signals within the K-band frequency range. The integration of the step structured RF MEMS switches successfully enables reconfiguration of the antenna's operating frequency. The proposed antenna, integrated with the RF MEMS switches, has potential applications in various K-band systems, including surface movement radars, direct broadcast satellite, Direct-to-Home (DHT) television, and 5th Generation (5G) mobile communication. The reconfigurability of the antenna's frequency allows for flexibility and adaptability in different K-band applications.

Keywords

• RF MEMS switch
• pull-in voltage
• return loss
• insertion loss
• isolation
• surface micromachining