Inter-band carrier aggregation (CA) is considered as the key enabling technology towards a wideband communication system that can exploit and aggregate non-contiguous spectrum from heterogeneous bands. However, the commonly suggested transceiver design using independent baseband (signal processing) modules for each band (component carrier) is not efficient and scalable. This paper addresses this challenge, by proposing a new filter-bank based transceiver design, able to achieve CA of two component carriers using a single baseband module. Appropriate information-theoretic performance metrics are employed in order to obtain universal designs that are independent of modulation format, channel statistics and decoding scheme. Various design methodologies are considered, whose performance is investigated numerically and analytically. It is demonstrated that there exist transceiver designs achieving two-component CA with small additional complexity compared to the conventional single component carrier transmission.