Multiplexers: A necessary extension for 4G/5G systems

Carrier Aggregation is one prominent method to increase the data throughput in mobile communication. Dependent on the band combination to be realized (about 270 different band combinations are currently under discussion) either diplexers or multiplexers need to be used to realize suitable hardware. Whereas already today diplexers are applied for single-feed antenna concepts to separate e.g. the 1GHz from 2GHz bands, multiplexers are required for all those cases where filters and/or duplexers of bands close to each other need to be combined. Besides the pure electrical aspects like low insertion loss, high isolation to all active Rx-bands, steep skirts, high linearity, just to name a few, also mechanical aspects like area consumption and height need to be considered in order to address customer demands. All three items will be discussed shortly and underline the need for continuous improvement not only at the acoustic but also packaging side.