Wide Band Series Switch Fabricated Using Metal As Sacrificial layer

Series switches with metal-to-metal contact have been fabricated to operate from dc to 40 GHz. The insertion loss has been measured to be less than 0.4 dB at 5 GHz and 0.8 dB at 40 GHz when switch is on and the isolation ranges from 38 dB at 2 GHz to 15 dB at 40 GHz when the switch is off. The results agree well with simulation by Zeland IE3D. Cantilever beam is used as the mechanical structure and CPW line works as the transmission line. The cantilever is made of SiO2 and Al is used as the sacrificial layer

Power Handling of Electrostatic MEMS Evanescent-Mode (EVA) Tunable Bandpass Filters

This paper presents the first theoretical and experimental study on the power handling capabilities of electrostatically tunable MEMS cavity filters. The theoretical analysis indicates that the frequency-dependent RF voltage inside a narrow-band filter may play an important role in the generation of electromechanical nonlinearities such as frequency response distortion, frequency shift, and bifurcation instability. This analysis also reveals that the filter\u27s power handling capability is dependent on several critical factors, including the capacitive gap, stiffness of the diaphragm actuator, and the overall quality factor (Q) of the evanescent-mode (EVA) resonators. A nonlinear computer-aided design (CAD) model is proposed as a practical tool for capturing the important tradeoffs in high-power design. An EVA tunable resonator and a two-pole 2% filter are fabricated and measured as vehicles to validate the theory and the CAD model. Specifically, a medium-power filter with a tuning range of 2.35-3.21 GHz (1.37: 1) and an extracted unloaded quality factor (Q(u)) of 356-405 shows measured power levels of 23.4 dBm (0.22W) before bifurcation instability occurs. The measured IIP3 of this filter are 52.1 dBm. The theory and modeling, backed up by the measurements, provide significant insights into the high-power design of electrostatic tunable cavity filters

System-level characterization of bias noise effects on electrostatic RF MEMS tunable filters

This paper presents the first system-level characterization of the effects of bias noise on the performance of high-Q electrostatic RF MEMS tunable filters. By looking at the system-level performance of such a tunable filter, this paper shows that bias noise, if not well controlled, can degrade the RF performance of the tunable filter. Quantified by error vector magnitude measurement, such system level degradation due to bias noise is found to be dependent on the frequency and amplitude of the noise signals

Characterization of Parylene-N as Flexible Substrate and Passivation Layer for Microwave and Millimeter-Wave Integrated Circuits

Investigation of Parylene-N (Pa-N) as a flexible substrate, multilayer dielectric material, and passivation layer for microwave and millimeter-wave integrated circuits is presented. For the first time, the electrical properties of Parylene-N have been characterized up to 60 GHz using various microstrip ring resonators and transmission lines. As a flexible substrate, Parylene-N measures a nearly invariant relative dielectric constant (epsilon(gamma)) of 2.35-2.4, and a loss tangent (tan delta) of lower than 0.0006 for frequencies up to 60 GHz. Because of the above properties, as a passivation layer, Parylene-N causes insignificant modifications to the properties of underlying passive and active structures. Measurement of coplanar waveguide transmission lines before and after passivation reveals that a 5-mu m Parylene-N barely changes the insertion loss (below measurement accuracy) while a 10-mu m-thick Parylene-N layer increases the insertion loss by only 0.007 dB/mm (below measurement error) at 40 GHz. Ring resonators before and after a 5 or 10 mu m passivation show a frequency shift of less than 0.05% or 1.51%, respectively, up to 40 GHz. The influence of Parylene-N passivation on the RF performance of GaAs MESFETs is also found to be negligible. Finally, humidity studies with dew point sensors reveal that with a 10-mu m-thick passivation at 25 degrees C and 100% relative humidity, the MTTF is about 481.6 days. In summary, the results indicate that Parylene-N is an excellent and promising material for application at microwave and millimeter-wave frequencies