A MEMS Filter Bank Receiver
Jesse Aaron Richmond, Jan M. Rabaey and Clark Nguyen
Gigascale Systems Research Center
A popular vision among many in the field of wireless communications has been to achieve ubiquitous communications, in which nearly everything we interact with is connected wirelessly to a network. Such a system could have applications ranging from biomedical ones, such as implantable sensors, to smart houses that can track their occupants’ presence and automatically adjust such things as lighting, temperature, and music or video to suit the individuals’ preferences. In both instances, the radios that comprise the network must consume very little energy, to allow long battery life or operation using energy scavenged from the environment, and must be very small in size to permit them to disappear into the environment. This project aims to provide a highly integrated, extremely low-power radio that would be suitable for this type of application.
The performance of traditional wireless receivers is limited in large part by the lack of a narrow bandwidth, low loss, and reconfigurable filter at the RF band, which leads to designers needing to use circuit techniques to ensure adequate linearity and allow channel selection. Recent developments in high-quality micromechanical resonators enable new circuit designs featuring ultra-low-power consumption and an extremely small size. The system will be based around an array of filters with individual ultra-low-power receivers to perform sub-carrier separation and allow a multi-tone, OFDM-like signal to be received in the analog domain, enabling reliable and flexible wireless reception. A reconfigurable digital baseband will be used to allow the receiver to operate using a wide variety of configurations between the channels, allowing the user to change the performance characteristics, such as sensitivity and data rate, at run time.
Figure 1: Block diagram illustrating the multi-tone receiver concept