Energy-efficient microwave components for mobile communication [Guest Editorial]

In the coexisted world of 3G, 4G, 5G and many other specialized wireless communication systems, billions of connections could be existing for various information transmission types. Unluckily, data show that the increase of network capacity is heavily more than the increase of the network energy efficiency in recent years, which could lead to more energy consumption per transmitted bit in the future network. As basic units in mobile communication systems, microwave/RF components and modules play key roles in energy-efficiency of the wideband/broadband wireless communication systems due to the high peak-to-average power ratio (PAPR) in the modulated signals. This leads to high frequency- spectrum efficiency but low energy-efficiency. With further increasing both PAPR and bandwidth in 4G and 5G systems, the challenge of energy-efficiency originating from microwave components will dramatically increase. That is why the guest editors organized this Special Topic Issue.