MEMS capacitive switch

Abstract

The invention belongs to the technical field of electronic science, and relates to an MEMS capacitive switch. The MEMS capacitive switch comprises a substrate with an insulation layer, a signal transmission line and ground electrodes on the two sides, a dielectric layer is arranged on the surface of the signal transmission line, three metal coverage areas are arranged on the surface of the dielectric layer, the two ground electrodes are respectively provided with a fixed anchor point, and the two fixed anchor points support a drive electrode structure. The drive electrode structure is of a two-wing type phase step structure, and comprises a first drive electrode in the middle, a second drive electrode and a third electrode, the second drive electrode and the third electrode are arranged on the two wings, the two sides of the first drive electrode are connected with the fixed anchor points through clamped beams, the second drive electrode and the third drive electrode are connected with the first drive electrode through cantilever beams, and the distance between the second drive electrode and the third drive electrode and the signal transmission line is larger than the distance between the first drive electrode and the signal transmission line. The areas of the three drive electrodes are increased in sequence. Three work frequency bands can be achieved, and the MEMS capacitive switch has the advantages of being low in insertion loss, high in isolation degree and low in drop-down voltage and can be applied to a radio-frequency or microwave communication system.

Description

technical field [0001] The invention belongs to the technical field of electronic science and relates to microelectromechanical systems (MEMS), in particular to a MEMS capacitance switch. technical background [0002] Switches are fundamental components in radio frequency (RF) and microwave communication systems, and radio frequency microelectromechanical (RF MEMS) switches have great application space at both the RF and microwave component and system levels. At the component level, radio frequency microelectromechanical (RF MEMS) switches can be used to construct voltage-controlled oscillators, filters (capacitive switches, inductors) and phase shifters, etc., which are indispensable components of modern radar and communication systems. Compared with traditional FET and PIN diode switches, radio frequency microelectromechanical (RF MEMS) switches have the characteristics of low DC power consumption, low insertion loss, high isolation, low intermodulation distortion, wide op...

AI Technical Summary

Problems solved by technology

However, all the switch beams of this structure are placed on the same plane. If the distance between the switch beam and the transmission line is too small, the up-state capacitance of the switch will be large, resulting in an increase in the insertion loss of the switch. If the distance between the switch beam and the transmission line is increased Due to the square relationship between the driving voltage and the spacing, the driving voltage of the switch will increase sharply. In addition, the roughness of the dielectric layer has a greater impact on the RF performance of the switch, which will severely limit the RF performance of the switch. Applications of MEMS switches

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