A comparative study on recent works on low noise amplifiers (LNAs) designed to be operated at mobile communication band is performed in this article. Here, specifications of different generations of mobile communication are listed, which are considered to classify recent works on LNAs. Even though gain and noise figure (NF) are the primary parameters of LNA; other parameters like power, linearity, bandwidth, and area also get importance. Due to this, optimization techniques handpicked for all those parameters are discussed. The inverse relation between gain and NF is exploited to achieve low noise and high gain together. While increasing the gain, power consumption is increased by drain current. Each LNA is found as good in terms of gain and other parameters to satisfy the requirements. The figure of merit is opted to find the performance of each LNA, and the comparison is performed. The best parameters reported in the comparison are 31.53 dB of gain, 0.7 dB of NF, 0.03 mw of power consumption, 18.14 dBm of third-order input intercept point (IIP3), 24 GHz bandwidth and 0.0052 mm 2 of area at different frequencies and technology nodes. In this survey, as per the optimized FoM for mobile communication, crosscoupled common gate differential LNA, which was designed to be operated at 0.3 to 2.96 GHz gives better results among CMOS LNAs.

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A complementary metal-oxide-semiconductor (CMOS) dual-band low-noise amplifier (LNA) for 2G/3G/4G mobile communications is presented. It operates at 0.9 and 2.3 GHz of frequencies. The dual-band operation is achieved by adding a modified notch-filtering path in the wideband LNA. The modified notch-filtering path does not require additional power to cancel the signals of the stop band frequency. The impact of the filtering path in the proposed LNA is analyzed. Improved results are observed in dual bands of frequency. Sustainability of the LNA under process corner variation and temperature variation are examined, and it is found to be suitable for the application. The proposed LNA is designed at 90-nm technology in Cadence Virtuoso with 0.5 and 0.6-V supply. The post-layout simulation shows 22 dB of gain (S 21 ), 2 dB of Noise Figure (NF), and −5.5 dBm of IIP3 at the high band. In the low band, 24 dB of S 21 , 2.7 dB of NF, and −6.65 dBm of IIP3 are reached. The circuit consumes 5.2 mW of power and 0.0918 mm 2 of area. The efficiency of the LNA is estimated by the figure of merit, and comparable results are secured in the proposed work.

The main objective of cognitive radio network is to provide flexible spectrum management, by permitting the secondary users (SUs) to temporarily access the licensed spectrum in the absence of a primary user. In the existing backward induction approach, each SU performs spectrum sensing and consequently reports the sensing details to the centralized controller. In the proposed work, an adaptive cluster-based heuristic approach (ACBHA) with cooperative spectrum sensing (CSS) scheme has been proposed for cognitive radio medium access control networks for 5G applications. To identify the availability of unused spectrum, the proposed CSS-based ACBHA algorithm adopts a cluster-based selection scheme. Simulation results show that the proposed CSS-based ACBHA provides a better result compared with existing techniques. The performance parameters such as false alarm probability, the probability of detection, spectrum sensing time, slot length, noise density have been analyzed using MATLAB R2012a.

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