A general purpose reconfigurable MEMS-based attenuator for Radio Frequency and microwave applications

In this paper we present a power attenuator for RF (radiofrequency) and microwave signals entirely designed in MEMS (microelectromechanical-system) technology. It is fabricated in the RF-MEMS technology available at Fondazione Bruno Kessler (FBK) based on a surface micromachining process. The network is realized in a low-cost manufacturing process and its dimensions are significantly compact compared to traditional implementations of RF power attenuators. More interestingly, employment of MEMS technology for such architecture enables a very large reconfigurability, making the network compatible with different standards and usable in several wireless communication systems. Electromechanical and RF behaviour of the discussed network are simulated and compared against experimental results collected by the first fabricated samples. RF measured performances are rather promising in spite a technology issue occurred during the fabrication deteriorating the attenuator low-frequency characteristic. RF modelling of such issue (already fixed in the batches being currently fabricated) is shown and discussed through this paper.