Due to the increase of wireless standards using different radio communication frequencies there is a need to have receivers that can handle a very wide range of frequencies. A modern smartphone already uses dozens of different frequencies and this number is only growing. The challenge in these modern receivers is that the amount of filtering around the antenna input using bulky and expensive fixed-frequency filters should be minimized to save cost and volume. However these filters do serve an important purpose: to protect the transceiver from strong out of frequency band interferers. By abandoning this narrow-band approach, new receiver architectures are explored, which can work without these fixed-frequency filters. Challenges will be addressed and solutions will be presented. One example is the “noise cancelling technique” where electronic noise in amplifiers can be cancelled, increasing the sensitivity of the receiver, without needing narrow-band filters.
Bram Nauta, University of Twente