Design, fabrication, testing and packaging of a silicon micromachined radio frequency microelectromechanical series (RF MEMS) switch
M S Giridhar Ashwini Jambhalikar Jiju John R Islam Ananda Behera C L Nagendra George Thachil M P Srikanth Shailesh Somani B H M Darukesha Srinivasarao Bollu
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RF characterization and packaging of a single pole single throw (SPST) direct contact microelectromechanical (MEMS) series radio frequency (RF) switch is reported. Precise thickness of the silicon MEMS structure is achieved using a specially developed silicon Deep Reactive Ion Etching (DRIE) thinning process. A stress free release process is employed which ensures a high yield of released microstructures. The design of the device is based on stiffness equations derived from ﬁrst principles. Displacement of the actuator under applied ﬁeld is measured to conﬁrm electrostatic pull in, which occurs in the 30–50 V range. The variation of contact resistance with time has been measured and is found to have a power law decay, in agreement with theoretical models. At the bare die level the insertion loss, return loss and the isolation of the switch were measured to be −0.43 dB, −25 dB and −21 dB, respectively at 10 GHz. The devices were packaged in commercially available RF packages and mounted in alumina boards for post package characterization. Due to the presence of bond wires in the signal path of the packaged devices, the RF performance was found to degrade at high frequencies. However, losses were measured to be at acceptable levels up to 2 GHz. Factors contributing to insertion loss at the die and package device levels are discussed in detail with possible solutions.
M S Giridhar1 Ashwini Jambhalikar1 Jiju John1 R Islam1 Ananda Behera1 C L Nagendra1 George Thachil1 M P Srikanth1 Shailesh Somani1 B H M Darukesha2 Srinivasarao Bollu2
Volume 48, 2023
Continuous Article Publishing mode
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