Faculty Publications
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Item A Wideband Microstrip Line-Based Balun Structure for High Power Amplifier Applications(Springer Science and Business Media Deutschland GmbH, 2023) Gupta, M.P.; Gorre, P.; Kumar, S.; Song, H.This paper proposes a balun matching technique to achieving a high output power and wide bandwidth. The proposed structure includes microstrip transmission line-based even and odd mode-matching circuits. A three-port unipolar microstrip line is designed to transform the balanced load termination to 50 Ω unbalanced port impedance. The proposed network design is based on real symmetrical four port network with open ended transmission line is inserted between the middle of the structure. To improve the isolation, transmission coefficient parameter and match the 50 Ω termination, a resistive network is inserted between the two balanced ports. The proposed structure is simulated in Keysight Technologies Advanced Design System (ADS), fabrication is done by using 0.51 mm RT Duriod substrate alignments. To verify the design concept, first of all, a wideband microstrip matching technique is designed and characterized at the frequency of L5 band (1.17 GHz). Then a prototype of microstrip transmission line-based wideband balun matching circuit is designed and fabricated. Analytical design equations have been derived for the even mode as well as odd mode techniques which satisfied the results. The proposed balun could overcome power loss mechanism over traditional transmission line structures and can utilize for high power application. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item A L/S/C/X/Ku-Band Three-Stack, Two stages Fully Integrated CMOS Power Amplifier with 20.9 % PAE Using T-Network(Institute of Electrical and Electronics Engineers Inc., 2023) Kumar, K.; Kumar, S.; Gupta, M.P.This work proposes an L/S/C/X/Ku-Band three-stack two stages fully integrated CMOS power amplifier (PA) that realized in 65nm and achieves high efficiency, high output power over wide impedance bandwidth from 2-20 GHz. The proposed PA circuit comprises of T-network broadband input power match design, interstage tuning network and output power stage. The interstage tuning network is employed to achieve an excellent gain (|S21|) flatness of 16.3 ± 0.9 dB. The proposed PA design is employed 3-stack of transistor under supply of 3V at stage-1 followed LC and stage-2 to achieve high output power. The load pull analysis is performed to optimize the T- type output matching network for achieving PAE of 20.9 % and output power of 15.97 dBm at 7 GHz with 50 Ω load impedance. Besides, this PA provides 1 dB output compression point of 11.2 ± 0.8 dBm over full frequency band and also achieves the output third order intercept point of 23.2 dBm at 7 GHz using two tone signal. © 2023 IEEE.Item Determinants of citizens’ electronic participation: Insights from India(Emerald Group Holdings Ltd., 2014) Alathur, S.; Ilavarasan, P.V.; Gupta, M.P.Purpose – The purpose of the present paper is to attempt to examine the determinants of citizens’ electronic participation with respect to the communication aspects. To accomplish this objective, using the extant literature, the paper delineated factors that determine and the theories that can explain citizens’ e-participation. An analysis of citizens’ democratic communication through multiple e-participation forums is carried out, and the determinants of electronic participation are described in the paper. Design/methodology/approach – In light of the literature, e-participation services were classified on the basis of characteristics of democratic communications. The factors that determine citizens’ online democratic participation were also identified and validated. Indian citizens who often e-participate were surveyed through online and offline questionnaires. A regression analysis of the 407 responses was carried out to predict the influence of individual, governance and technology components on various e-participation initiatives. Findings – Citizens’ participation efficacy, value system and participation freedom were found to determine different e-participation initiatives. Further, e-participation is also found to be varyingly determined by the governance and technology components. Research limitations/implications – The theoretical contribution of this study includes the classification of determining factors and the illustrative labeling (I, G and T) for an e-participation framework. The delineation of e-participation from democratic communication aspects also contributes to the e-participation literature. However, this research had considered only one set of e-participation services and had incorporated only select forms of e-participation that are in coherence with the services selected. Originality/value – Past studies often consider separate e-participation forums and infrequently report a simultaneous analysis of multiple e-participation forums. The factors that determine citizens’ e-participation from a democratic communication aspect are also inadequately discussed. The significant contribution of this study includes policy recommendations to improve e-participation in different information and communication technologies initiatives. © Emerald Group Publishing Limited.Item Determinants of e-participation in the citizens and the government initiatives: Insights from India(Elsevier Ltd, 2016) Alathur, S.; Ilavarasan, P.; Gupta, M.P.The paper attempts to examine the determinants of two types of citizens' e-participation - initiated by the citizens and the government. The factors of e-participation were delineated from a review of democracy and e-participation literature and a regression model was developed. On the basis of 407 responses collected through an online and offline survey among the Indian participants, the model was tested. The analysis showed that the citizens' participation efficacy and values determine e-participation of both types. For the citizens' initiatives freedom to participate and legal support for the participation efforts were also the determining factors. The extant research on types of e-participation services is inadequate. The paper attempted to fill the gap and contributes in i) explaining the importance of facilitating multiple stakeholders' initiatives for improved citizens' participation ii) differentiating determining factors among e-participation initiatives and iii) suggesting policy recommendations for successful e-participation initiatives. The future research can focus on determinants for collaborative service initiatives from the citizens and government. © 2016 Elsevier Ltd.Item A wideband, 25/40dBm high I/O power GaN HEMT ultra-low noise amplifier using even-odd mode techniques(Elsevier Ltd, 2022) Gupta, M.P.; Gorre, P.; Kumar, S.; Nulu, V.This paper presents a performance analysis of the low noise amplifier (LNA) for the first time using even-odd mode matching techniques in Gallium Nitride (GaN) HEMT Technology for marine communication. The proposed GaN LNA circuit consists of broadband stage I, main amplifier, and inverted broadband stage II, which provides a high input/output power, and ultra-low noise over wide bandwidth ranging from 0.5 GHz to 2.7 GHz with fractional impedance bandwidth of 138%. Broadband Stage I and Inverted broadband stage II are employed to provide input/output impedance matching transformation. The proposed LNA circuit with the incorporation of input/output broadband stages relax a 50Ω matching constraints and achieved high input and output power with good stability. The GaN HEMT LNA is analyzed and simulated using the RF simulator (ADS tool). The proposed GaN HEMT LNA is fabricated on RT Duroid substrate using Microwave Integrated Circuit (MIC) technology. The proposed LNA achieves a measured gain of 16 dB, while the simulated one is 17 dB with good insertion loss. An ultra-low noise figure of 0.6 dB flat is achieved over a wide bandwidth. In addition, the high output power is achieved 40dBm while input power is 25dBm which could overcome weak signal strength received by RF receiver for marine communication. A stability factor greater than one is achieved over a broad band ranging from 0.5 GHz to 2.7 GHz. The fabricated GaN HEMT LNA circuit has consumed power of 120 mW under a supply of 28 V. The area of the fabricated RF GaN HEMT LNA is 32 × 26 mm2. © 2022 Elsevier LtdItem A 0.15 μm GaN HEMT device to circuit approach towards dual-band ultra-low noise amplifier using defected ground bias technique(Elsevier GmbH, 2023) Gupta, M.P.; Kumar, S.; Elizabeth Caroline, B.; Song, H.; Kumar, V.; Gorre, P.This work presents a GaN HEMT device to circuit approach towards low noise amplifier (LNA) using defective ground bias (DGB) technique. This is the first MMIC GaN HEMT LNA design to offer dual-band of operation in both L and S-bands to the author's best knowledge. The proposed 0.15-μm GaN HEMT device fabrication achieves a high output power of 20 W using slot radiation phenomenon. The proposed DGB technique consists of gate and drain biasing topologies which achieves a dual-band of operation using microwave approach. The DGB technique is incorporated into GaN HEMT LNA which achieves high input and output power with good stability. To achieve an optimal noise, high I/O power, and almost flat gain at both L and S-bands, the defective ground structure of bias topologies is modeled and optimized. An artificial ground defect is created to offer resonant properties for the DGS of a microstrip line, which utilizes frequency-selective properties to improve the performance of the LNA circuit by suppressing the harmonics and scaling the size. The dedicated LNA shows the benefits of compact size, extremely low noise figure of 0.74/1.6 dB, high output power of 44 dBm and nearly flat gain of 14/11 dB at 1.17/2.49 GHz with the unique methodologies suggested. The compact GaN HEMT LNA could overcome the weak signal strength received by RF receiver for smart rail transport system. © 2023 Elsevier GmbHItem A new design approach of Rat-Race coupler based compact GaN HEMT power amplifier towards flat high efficiency over broadband(Elsevier GmbH, 2024) Gupta, M.P.; Kumar, S.; Naik Jatoth, D.; Gorre, P.; Song, H.This paper presents a high efficiency Rat-Race Coupler based compact GaN HEMT power amplifier (PA) design over broadband for high power transmitter in wireless communication. The rat-race coupler integrated PA Compact design is proposed for the first time as per author best knowledge. The design methodology used a higher order two open stubs and a rat-race coupler (RRC) at input/output sections to control harmonics impedances. The RRC is used to enhance the i/o power, and efficiency over broadband, which provides a good insertion loss, and consumes the least power and non-crucial impedance bandwidth for the normalized frequency band of interest. As a proof of concept, a PA is fabricated using a monolithic microwave integrated circuit (MMIC) 0.15 µm gallium nitride high electron mobility transistor (GaN HEMT) process. The measured result shows that the designed PA achieves a flat power added efficiency (PAE) of 65 % − 74 %, output power (Pout) of 44.8 dBm − 46 dBm, and drain efficiency (DE) of 72 % − 85 %, over a record wide frequency of 1.8 GHz − 3.6 GHz, which is the highest one among all reported harmonic tuned PAs. © 2024 Elsevier GmbHItem Performance Analysis of Novel Graphene Process Low-Noise Amplifier with Multi-stage Stagger-Tuned Approach over D-band(Springer, 2024) Nandini, P.; Naik, D.N.; Gorre, P.; Gupta, M.P.; Kumar, S.; Al-Shidaifat, A.; Song, H.This work reports an ultra-low noise, multi-stage stagger-tuned low-noise amplifier (MS-ST-LNA) over the D-band performance and achieves a best trade-off between noise, bandwidth, and gain parameters. The ultra-low-noise is achieved in three ways: First, the high-gain 3-stage stagger tuned amplifier (STA) realizes a 3X gain compared to the conventional single-stage amplifier, which sets a low floor noise. Second, the stagger-tuned amplifier achieves 1.6 times lower noise than the traditional single-stage amplifier. Finally, the stagger tune realizes a high-order transfer function, which mitigates the high-frequency noise. The full LNA is implemented and fabricated using a commercial nano-manufacturing 9-nm graphene film FET on a silicon wafer using a 0.065-?m commercial process, occupying an area of 0.21 mm2. The proposed design achieves an optimum performance: a maximum measured gain of 20.5 dB and a minimum noise figure (NF) of 4.2 dB over 123.7 to 162.5 GHz. The proposed LNA consumes ultra-low power consumption of 21.3 mW under the power supply of 1.2 V. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.