Multiband LNAs for Software-Defined Radios: Recent Advances in the Design of Multiband Reconfigurable LNAs for SDRs in CMOS, Microwave Integrated Circuits Technology

The last decade has witnessed an increasing number of wireless standards for civil, military, and space communications. Along with the advances in integrated circuit (IC) technologies and the ever-growing requirements of high data rates, next-generation radios are expected to operate over multiple frequency bands. For example, carrier aggregation is used in LTE-Advanced radios to increase the bandwidth. However, it is challenging for traditional radios to operate over multiple frequency bands. In response to this, software-defined radios (SDRs) have been proposed to handle multiple bands through reconfiguration. They can adapt carrier frequency, transmission bandwidth, modulation, and encoding schemes by modifying digital signal processing (DSP) software algorithms [1]. In contrast to SDR, legacy communication systems are approaching their capability limits. They usually operate on a single band and require dedicated hardware. Thus, SDR is a promising radio technology to increase the flexibility of radio devices and reduce hardware and manufacturing costs, chip size, and power consumption [2].