Considering 3GPP Release 10 to Release 14 [3] the number
of Carrier Aggregation (downlink only) related band
combinations (Fig. 2) increased over the years from three to
around 270 [4], where each has the potential to become an
integral part of a mobile phone frontend. Fig. 2 shows the
number of new suggested band combinations from Release 10
to Release 14, sorted into 2-CA cases further divided into
inter-band and intra-band cases (see Fig. 1), 3-CA, 4-CA, and
even 5-CA cases. In the later up to 5 bands will be combined
to form a large bandwidth to support high data-rates. In
addition diversity needs to be considered as a necessary and
integral part of any LTE concept. Taking into account that by
the time of writing of this paper 44 different frequency bands
for TDD and FDD links are allocated by 3GPP [5] the
required number of filters in future handhelds will be