A single nano electromechanical integrated-circuit filter that can replace the 10- 20 filter packages now found in typical multimode phone has been created by Boston University (Boston, MA) Associate Professor of Physics Mohanty Pritiraj, Professor of Physics Alexei Gaidarzhy and post-doctoral fellow Robert L. Badzey.
The new nano electromechanical integrated-circuit filter allows for several advantages, including the ability to integrate such a filter on a semiconductor chip with the rest of the transceiver architecture. Removing the 10-20 discrete filter packages in a typical multimode phone and replacing them with a single IC package is obviously a huge advantage.
Additionally, the ability to integrate the filters onto the same chip as the RFIC allows for even more space and power savings. It will also allow for a single device to be sensitive to all relevant communications bands. Additionally, such a filter's small size allows for the replacement of the RF/IF heterodyning structure of the modern architecture with a tunable direct-channel-select filtering scheme, encompassing hundreds or thousands of individual filters. This type of filter would necessitate a massive redesign of the RF transceiver, but the dividends would be enormous.
Among the advantages would be a fully integrated RF transceiver chip, drastically reducing production costs, RF board space, and power consumption. Additionally, a single RF transceiver would be capable of communicating on any band, in any channel, from 10 MHz up to 100 GHz or more. The transceiver could work in all of the cellular communications bands (GSM, CDMA, PCS, UMTS), wireless data bands (WiFi, EDGE, etc.), peripherals bands (Bluetooth), satellite radio, and GPS.
Current telecommunications platforms (such as cell phones) rely on a series of radiofrequency (RF) and intermediate frequency (IF) filters in order to isolate the desired communications channel from the crowded and noisy background. Currently, surface acoustic wave (SAW), bulk acoustical wave (BAW), film bulk acoustic resonator (FBAR) and ceramic filters are the devices of choice. However, in general, these filters are large, bulky, and expensive discretely packaged components that cannot be integrated with the rest of the transceiver architecture. While the front-end module of the transceiver can and does continue to miniaturize with improving lithographic processes and designs, the filter stands as the bottleneck to a truly integrated radio package.
More and more, a greater number of communications standards (GSM, CDMA, PCS, European/US, UMTS) and features (WiFi, cameras) are being incorporated into a single handset. While this allows for truly global communications, it comes at the cost of a larger and more power-hungry device. Adding more bands and modes means that more and more discrete packages are added onboard, with corresponding increases in overall board size and power consumption due to package-to-package signal losses.
Boston University's single nano electromechanical integrated-circuit filter fills the need for a type of filter that is small in size, utilizes minimal power and can be integrated with other discrete electrical elements.
More and more, a greater number of communications standards (GSM, CDMA, PCS, European/US, UMTS) and features (WiFi, cameras) are being incorporated into a single handset. While this allows for truly global communications, it comes at the cost of a larger and more power-hungry device. Adding more bands and modes means that more and more discrete packages are added onboard, with corresponding increases in overall board size and power consumption due to package-to-package signal losses.
Boston University's single nano electromechanical integrated-circuit filter fills the need for a type of filter that is small in size, utilizes minimal power and can be integrated with other discrete electrical elements.
Figure 4 from the patent application illustrates the nanometer scale electromechanical integrated-circuit filter.
The nano filter device can be manufactured lithographically with an electron-beam source, photolithography can also be used as the device dimensions are well within the feature size designated by the new deep-UV sources and masks. It may also be made using nano imprint lithography, self assembled techniques, bottom up chemical techniques and other similar nano fabrication techniques.
