quencies without ET scheme has created some serious design issues. In order to meet the new, challenging per- formance requirements of wider channel bandwidth and HPUE, new PA topologies have been developed that deliver linear PA performance at higher frequencies and over much wider channel bandwidths. These new architectures must be capable of significantly outper- forming their LTE counterparts under more rigorous operating conditions. When implementing the sub-6 GHz modules, integrating the receiver LNA functionality inside the module allows considerable flexibility and improves performance. In Fig. 5.27, there are two receive LNAs optimized for n77, n78, and n79 bands. Integrated LNAs have been shown to improve performance when overcoming system loss, especially in high- frequency regions where there is generally more insertion loss due to the high-frequency roll-off of various RF components. Integrated LNAs typically contribute about 1.5-2.0 dB system-wide noise figure enhancement, which translates directly to improved receive sensitivity when compared to alternative methods such as populating discrete LNAs at or near the transceiver. In the case of sub-6 GHz applications utilizing new TDD spectrum, the legacy LTE systems are virtually non-existent. While many 3GPP specified bands exist today (e.g., B42/43/48), they have yet to be rolled out commercially in large volumes for LTE. The LTE bands only represent a small subset of the much larger NR band definitions. It is anticipated that n77, n78, and n79 RF front-end modules will be extensively deployed [28]. It must be noted that the passbands are significantly larger for these new NR bands. For example, n77 has a pass- band of 900 MHz; that is, 25% relative bandwidth, which is twice as large as the 5 GHz Wi-Fi band, and n79 has a passband of 600 MHz. In both instances, the conventional acous- tic filters are not well suited for these extremely wide passbands. There are additional com- plexities that will determine the extent of the NR wideband filter require