Browsing by Author "Vignesh, R."

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A 2.71-pA/√Hz ultra-low noise, 70-dB dynamic range CMOS transimpedance amplifier with incorporated microstrip line techniques over extended bandwidth
(John Wiley and Sons Ltd, 2023) Gorre, P.; Vignesh, R.; Kumar, S.; Song, H.; Roy, G.M.
Recent advancements in the area of telemedicine have focused on remote patient monitoring services as a new frontier in medical applications. The present work reports a 65-nm complementary metal–oxide–semiconductor (CMOS)-based transimpedance amplifier (TIA) in an optical radar system for non-contact patient monitoring. A T-shaped microstrip line (MSL) integrated with variable gain common source TIA using MSL peaking technique and off-chip post-amplification integration is a newly proposed architecture to achieve a ultra-low noise, high dynamic range (DR) and high figure of merit over broadband than a traditional TIAs. First, the integrated T-shaped MSL develops an additional resonant frequency that resonates with a photodiode capacitance improving the bandwidth performance at higher Q values. Second, the shunt MSL peaking technique that introduces an additional conjugate pole-pair that cancels the effect of input capacitance helps to further improve the bandwidth of the TIA. Finally, an active feedback concept achieves a wide linear dynamic range enabling high TIA detectability. The proposed TIA realizes an impedance bandwidth of 770 MHz ranging from 7.12 to 7.89 GHz with a transimpedance gain of 105.1 dBΩ and ultra-low input-referred noise (IRN) density of 2.71 pA/√Hz. A high linear DR of 70 dB is achieved by employing a variable gain control scheme with a low group delay variation of 0.81 ns. The proposed work demonstrates a 1-Gb/s data rate while a bit-error rate less than 10−12 is achieved. The TIA consumes a power of 0.82 mW under the supply voltage of 1.2 V. © 2022 John Wiley & Sons Ltd.
A 28-32GHz CMOS LNA with broadband approach for 5G Mm-wave communication cells
(Institute of Electrical and Electronics Engineers Inc., 2019) Vignesh, R.; Gorre, P.; Kumar, S.; Song, H.
This paper first time reports a wideband low noise amplifier (LNA) with achievable minimum atmospheric absorption frequency band for 5G millimeter wave communication cells. A novel suspended substrate line based parallel-series network is optimized and analyzed that demonstrates a wideband response. The proposed LNA consists of two stage Cascode topology with incorporated parallel-series network and microwave components that provides broadband ranging from 28GHz to 32GHz. A full of two stage Cascode LNA overcoming the traditional mismatching constraints with consideration of suspended substrate lines (SSL) and Tee-junction in the proposed design. It is observed that suspended lines reduce parasitic and bulk effects of devices and enables LNA to provide broadband communication for 5G macro and micro cells. The proposed design is realized using RF 65nm Magna Hynix CMOS process with layout cell. The simulation results reveals that 28GHz-32GHz wide band with maximum forward gain of 25dB. The minimum noise figure of 2.5dB is achieved with optimization of passive components. The input impedance (real and imaginary) and smith chart realization for LNA provides satisfactory performance. Â© 2019 IEEE.
A 61.2-dB?, 100 Gb/s Ultra-Low Noise Graphene TIA over D-Band Performance for 5G Optical Front-End Receiver
(Springer, 2021) Gorre, P.; Vignesh, R.; Song, H.; Kumar, S.
This work reports in first time a 100-Gb/s, ultra-low noise, variable gain multi-stagger tuned transimpedance amplifier (VGMST-TIA) over the D-band performance. The whole work is binding into two phases. The first phase involves the modeling and characterization of graphene field-effect transistor (GFET) with an optimized transition frequency of operation. While in the second phase, a TIA design employs a T-shaped symmetrical L-R network at the input, which mitigates the effect of photo diode capacitance and achieves a D-band of operation. The proposed work uses a VGMST to establish TIA, which realizes optimum noise performance. The high gain 3-stage VGMST-TIA effectively minimizes the white noise and illustrates a sharp out-of-band roll-off to achieve considerable noise reduction at high frequencies. The active feedback mechanism controls the transimpedance gain by tuning the control voltage which results better group delay. Besides, an L-C circuit is employed at the output to enhance bandwidth. The full TIA is implemented and fabricated using a commercial nano-manufacturing 9-nm graphene film FET on a silicon wafer using 0.065-?m process. The TIA achieves a flat transimpedance gain of 61.2 dB? with ± 9 ps group delay variation over the entire bandwidth. The proposed TIA measured an impedance bandwidth of 0.2 THz with ultra-low input-referred noise current density of 2.03 pA/?Hz. The TIA supports a 100-Gb/s data transmission due to large bandwidth; therefore, a bit-error-rate (BER) less than 10?12 is achieved. The chip occupies an area of 0.92 * 1.34 mm2 while consuming power of 21 mW under supply of 1.8 V. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
A 64 ?dB?, 25 ?Gb/s GFET based transimpedance amplifier with UWB resonator for optical radar detection in medical applications
(Elsevier Ltd, 2021) Gorre, P.; Vignesh, R.; Song, H.; Kumar, S.
This work reports a novel Graphene Field Effect Transistor (GFET) based transimpedance amplifier (TIA) for optical radar detection in medical applications. Design-I includes a microstrip line (MSL) based UWB resonator circuit which enables the TIA design to operate in UWB range of frequency with high Q-factor. Design-II comprises MSL UWB resonator integrated stagger-tuned CR-RGC TIA which enhances the transimpedance limit and mitigates the effect of photodiode capacitance results in higher bandwidth performance. The proposed TIA realizes a 2.6 times lesser noise compared to the conventional CR-RGC TIA. A flat transimpedance gain of 64 ?dB? and ultra-low input-referred noise current density of 8.9 pA/?Hz are achieved using gain and noise optimization methods. Additionally, a dynamic range of 49 ?dB with a group delay variation (GDV) of ±25 ps is achieved over the entire UWB range. The TIA demonstrates a 25 ?Gb/s data rate while a bit-error-rate (BER) less than 10?10 is achieved. The chip occupies an area of 0.67?0.72 ?mm2 while consuming power of 19 ?mW under the supply voltage of 1.8 ?V. © 2021 Elsevier Ltd
A K/Ka-Band Switchless Reconfigurable 65 nm CMOS LNA Based on Suspended Substrate Coupled Line
(Institute of Electrical and Electronics Engineers Inc., 2022) Vignesh, R.; Gorre, P.; Song, H.; Kumar, S.
This article presents a K/Ka (18-40) GHz dual-band switch-free reconfigurable 65nm CMOS Low-Noise Amplifier (LNA) realized by inter-stage and output-stage Suspended-Substrate Coupled-Lines (SSCL) for the first time to the author's best knowledge. The amplified input signal from the broadband drive stage is divided into two parallel single band stages by the proposed inter-stage SSCL. Two split-band signals are amplified by the corresponding High-band (Ka) and Low-band (K) stages. The proposed output-stage SSCL combines the amplified two single-bands at the output. The proposed SSCL also provides the required network matching to the LNA. The single band of operation can be achieved by simply turning off the unused transistor band's drain voltage. The proposed LNA achieves a maximum noise figure (NF) taken in dual-mode of 1 dB and 1.2 dB and a gain of 27 dB with 0.2 dB and 2 dB variation in the K-band and Ka-band, respectively. Statistical analysis and design of experiment (DoE) are applied to predict the percentage error tolerance and validate the contribution of the parameters towards gain, return loss, and noise figure. This LNA exhibits an input and output 1-dB compression point (IP1dB OP1dB), third-order input output intercept point (IIP3 OIP3) of -17/-16 dBm, +7.1/6.4 dBm, 0 dBm and +25/+23 dBm over 18-24/25-40 GHz respectively. The fabricated LNA draws 21.4 mA from 1.2 V with a size of 0.61 $\times $ 0.92 mm2. © 2013 IEEE.
A novel wide bandwidth FBSSIR integrated low noise amplifier for satellite navigational receiver system
(Elsevier Ltd, 2021) Vignesh, R.; Gorre, P.; Kumar, S.
This paper presents a Folded Butterfly Stub Stepped Impedance Resonator (FBSSIR) integrated low noise amplifier (LNA) implemented using packaging technology for the satellite navigation receiver system. By employing a novel structural deformation of a stepped-impedance-resonator (SIR), the proposed FBSSIR is achieved with a more compact structure, controllable transmission zero, adjustable center frequency, and adjustable bandwidth. The designed FBSSIR acts as a filter, and the input-output matching network is integrated into the proposed core LNA circuit. The Design-of-experiment (DoE) analysis is performed to analyze the passive component's sensitivity becoming desensitized, while statistical analysis is presented for the proposed FBSSIR integrated LNA to predict the percentage error tolerance. Its measurement result provides gain above 22 dB in the wide bandwidth from 1.6 GHz to 2.5 GHz, minimum NF of 2.7 dB at 1.8 GHz, which varies from 3 dB to 4.5 dB. The calculated area of FBSSIR integrated LNA is 10.7 × 2 cm2, while LNA is 3.3 × 1.6 cm2. It exhibits an input and output 1-dB compression point (IP1dB & OP1dB) of ?23dBm and +2.3dBm. © 2021
A Review of mm-Wave Power Amplifiers for Next-Generation 5G Communication
(Springer, 2020) Gorre, P.; Vignesh, R.; Arya, R.; Kumar, S.
In this paper, a review study of millimeter wave-based power amplifiers for 5G communication is presented. This literature mainly focuses on major component of the RF transceiver IC, i.e., power amplifier (PA). The upcoming 5G communication envisioned broadband modulation, high speed data rate, and new integration technologies which could overcome key challenges in the design of mobile devices and communication buildings. The power amplifiers in the 5G base station require high output powers (ranging from 2 to 10Â W), high efficiency (up to 95%), and high gain (up to 40Â dB). The basic building blocks, device technologies, architecture of RF power amplifiers, and parametric performances will be considered in this review. This study reviewed all device technologies (especially IV and III-V semiconductor technologies) for power amplifiers and found that a gallium nitride (GaN)-based PA is the best candidate to provide high output power, high efficiency, and high back-off power. In addition, various architectures of PAs have been reported while doherty power amplifier is one of best candidate for 5G base station. Â© 2020, Springer Nature Singapore Pte Ltd.
A strip line technique based 1 Gb/s, 70-dB linear dynamic range transimpedance amplifier towards LiDAR unmanned vehicle application
(Elsevier Ltd, 2022) Gorre, P.; Vignesh, R.; Kumar, S.
1This work reports a Microstrip Line (MSL) based Dual-Gate MOSFET (DGMOSFET) Transimpedance amplifier (TIA) for LIDAR unmanned vehicle application under different weather conditions. TIA (Design-I) is proposed under normal weather, while TIA (Design-II) for foggy weather conditions. TIA (Design-I) employs a variable gain common gate topology with post-amplification, resulting in high gain, wide bandwidth, and high dynamic range (DR). TIA (Design-II) incorporates a series MSL section at the input of TIA (Design-I), which further enhances the bandwidth performance. TIA (Design-I) realizes a fractional bandwidth of 104.3% with a transimpedance gain of 100.4 dBΩ and low input-referred noise (IRN) density of 4.29 pA/√Hz. TIA (Design-II) achieves a fractional bandwidth of 178.4% with transimpedance gain, IRN, and DR of 100.42 dBΩ, 3.81 pA/√Hz, and 70 dB, respectively. TIA (Design-II) demonstrates a 1 Gb/s data rate with a bit-error-rate < 10−10. The TIA (Design-I) and TIA (Design-II) consume the power of 33 mW and 39 mW under the supply voltage of 2 V. © 2022 Elsevier Ltd
Highly robust X-band quasi circulator-integrated low-noise amplifier for high survivability of radio frequency front-end systems
(John Wiley and Sons Ltd, 2021) Vignesh, R.; Gorre, P.; Song, H.; Kumar, S.
In this brief, an X-band quasi circulator (QC)-integrated low-noise amplifier (LNA) implemented in 65-nm Complementary Metal Oxide Semiconductor (CMOS) technology is presented. This work is the first QC-LNA for the X-band to the author's best knowledge, which achieves 30-dB flat gain in 8–12 GHz with only 0.5-dB variation across the band. This QC-LNA uses two-stage current reused techniques with variable impedance load. QC provides the minimum insertion loss of 0.9 dB with good return and isolation losses. Statistical analysis is presented for QC-LNA to predict the percentage error tolerance. Quasi-Newton (QN) control algorithm is used to optimize the parameter of the whole design. The design of experiment (DoE) is performed to claim the contribution towards gain, return loss, and noise figure. The proposed LNA measurement provides a minimum NF of 1 dB at 9.5 GHz, which remains less than 1.4 dB across 8–12 GHz. The fabricated LNA works with a supply voltage of 1.2 V and is unconditionally stable across the frequency. The calculated chip area is 0.84 × 0.52 mm2. This QC-LNA exhibits an input and output 1-dB compression point (IP1dB and OP1dB) of ?15 and +13.8 dBm, respectively. It also exhibits third-order input and output intercept point (IIP3 and OIP3) of +10 dBm and of +40 dBm, respectively. The proposed QC-LNA draws only 8.7 mA from 1.2 V. © 2021 John Wiley & Sons, Ltd.
Techniques to improve gain-bandwidth 5g ics
(Springer Science and Business Media Deutschland GmbH, 2021) Vignesh, R.; Kumar, R.; Song, H.; Kumar, S.
This chapter introduces a basics of designs and techniques to improve gain-bandwidth for 5G ICs. The major focus would be on the various network topologies that yield to provide easy implementation of on-chip components for 5G-ICs. Section 1 discusses the basics of RLC tank networks, which includes RC parallel network, RLC network and series to parallel resonant network. The parameters such as quality factor, noise of filter networks are shortly refresh while foundation of resonant circuits would set-up for 5G transceiver ICs. Section 2 introduces coupled resonator networks can be used as microwave components to achieve a better gain-bandwidth trade-off. Finally, Sect. 3 will provide transformer resonators and circuit to reduce bulky components and enhance gain-bandwidth of ICs. © Springer Nature Singapore Pte Ltd. 2021.