Analysis of current challenges in the design of low-noise broadband planar amplifiers: Review

• Comprehensive Review of LNA Technologies and Architectures: The paper provides an in-depth analysis of over 40 research publications from 2014 to 2023, focusing on various architectures and technologies used in wideband low-noise amplifiers (LNAs). It examines the impact of different substrates and transistor technologies on LNA performance, making it a valuable reference for future research. • Substrate Impact on LNA Performance: The study highlights the critical role of substrate materials in LNA design, particularly comparing FR4 and Rogers substrates. It shows that Rogers RO4003c, when combined with GaAs and GaN technologies, offers superior performance in terms of gain and noise figure, making it the preferred choice for high-performance LNAs. • Evaluation of Bandwidth Widening Techniques: The paper explores various bandwidth broadening techniques, such as resistive feedback, reactive matching, and inductive degeneration. It emphasizes the trade-offs between these techniques, particularly in achieving a balance between gain, noise figure, and linearity, which are crucial for optimizing LNA performance. • Challenges and Areas for Future Research: Despite significant advancements, the paper identifies ongoing challenges in adapting wideband planar LNAs to emerging technologies like 5 G. It proposes future research directions, including the development of low-power architectures, the integration of AI for design optimization, and the exploration of new materials capable of offering over 100 % fractional bandwidth. • Importance of Comprehensive Performance Metrics: The paper stresses the need for thorough evaluation of all key LNA parameters in research publications, including gain, noise figure, linearity, power consumption, and figure of merit (FOM). It argues that a more holistic approach to performance assessment will lead to more reliable and efficient LNA designs. This review article presents a thorough and in-depth analysis of recent advancements in wideband low-noise planar amplifiers (LNAs). It systematically examines the key factors influencing LNA performance and efficiency, providing a detailed quantitative and qualitative evaluation of over 40 relevant studies. The paper assesses the impact of various substrate materials, including FR4 and multiple Roger's substrates (RO 4003c, RT 5880, RO 4350, RO 3003, and RO AD250c), on amplifier characteristics. Additionally, it explores a wide range of bandwidth enhancement techniques and transistor technologies, such as GaAs, InGaAs, GaN, InGaP, and SiGe. By offering a thorough comparative analysis, this work highlights current challenges, proposes practical design recommendations, and serves as a valuable reference for researchers and engineers working on the development of next-generation wideband LNAs.