VEMIREDDY VENKATAREDDY
@unist.ac.kr
Postdoctoral researcher in Department of Electrical Engineering, UNIST, 50 UNIST-gil, Ulju-gun, Ulsan 689-798, South Korea
Ulsan National Institute of Science & Technology
Vemireddy Venkata Reddy, Ph.D., born on 14 July 1985, is a male from India with General category citizenship. Currently located in South Korea, you can reach him at (+82)10-2661-1576 or (+91) 9703051576, and through email at v.venkatareddy@, , and venkatareddy454@.
Research Interest:
Vemireddy Venkata Reddy's research interests encompass High-Power Microwave Devices, THz Vacuum Devices, Periodic Structures, Cold Cathodes, and Computational Electromagnetics.
Education:
Ph.D. in Electronics and Communication (2017-2022) from IIT (BHU), Varanasi, India, with a specialization in Microwave Engineering. The thesis focused on the "Design and Simulation Investigations of Single/Dual-band Relativistic Backward Wave Oscillator" under the supervision of Dr. M Thottappan. Achieved a CGPA of 7.9.
M.E. in Electronics and Communication (2008-2010) from Sree Sastha Institute of Engineering and Technology, Anna University, Chennai, India, with a score
EDUCATION
Ph.D. in Electronics and Communication 2017-2022 7.9 CGPA
Specialization: Microwave Engineering
IIT (BHU), Varanasi, India.
Thesis Topic: Design and Simulation Investigations of Single/Dual-band Relativistic Backward Wave Oscillator.
Supervisor: Dr. M Thottappan
M.E in Electronics and Communication 2008-2010 72.00%
Sree Sastha Institute of Engineering and Technology, Anna University, Chennai, India.
B. Tech in Electronics and Communication 2003-2007 66.44%
Malineni Lakshmaiah Engineering College, Singarayakonda, Andhra Pradesh, India.
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Management of Technology and Innovation
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
V. Venkata Reddy and M. Thottappan
Institute of Electrical and Electronics Engineers (IEEE)
In this article, a relativistic backward wave oscillator (RBWO) with sectional slow wave structures (SWSs) has been designed to generate a long high-power microwave (HPM) pulse at two different frequencies. Two individual SWSs were cascaded using a drift section (drift section-II) that separated them at a sufficient distance to generate dual microwave frequencies. The first section of the SWS (SWS-I) has been designed to generate S-band frequency and the second section of the SWS (SWS-II) to generate C-band frequency. A rectangular resonant reflector (RR) has been used to reflect the backward traveling wave into a forward wave toward the collector. The drift section-II also acted as an RR for the C-band frequency in addition to make the phase adjustment between the backward and forward microwaves and end reflections of SWS-I. The performance of the dual-band RBWO with sectional SWSs has been studied through the particle-in-cell (PIC) simulation by a finite difference time domain (FDTD)-based numerical code. The present simulation predicted a total RF output power of ~600 MW in TM01 mode at ~3.6 and ~4.5 GHz with a power conversion efficiency of ~20% for an annular electron beam with voltage ~550 kV, developed current ~5.4 kA, and the guiding magnetic field of ~1.3 T. A clear and more stable RF output power up to 100 ns of simulation time at both operating frequencies was observed with a frequency difference (between S- and C-band) of ~0.9 GHz.
Pratibha Verma, V Venkata Reddy, and M Thottappan
IEEE
An X-band Klystron like RBWO with a single extraction cavity has been designed and simulated for its beam-wave interaction behavior at lower guiding magnetic field using FDTD based electromagnetic code. The present simulation predicted a maximum RF output power ~1.1 GW with some stability at 9.48 GHz for an applied input DC voltage of 660 kV, beam current of 4.059 kA, and 0.58 T. The power conversion efficiency has been calculated as ~40%.
V Venkata Reddy, Pratibha Verma, and M Thottappan
IEEE
A dual-band Relativistic Backward Wave Oscillator (RBWO) has been designed and simulated under the lowest magnetic field using a finite difference time domain (FDTD) based 3D electromagnetic code. The dual-band oscillations were obtained by cascading two slow-wave structures (SWS) with the same transverse dimensions separated by a drift section. To reflect the dual-band microwave of the backward TM01 mode into a forward TM01 wave towards the collector, a rectangular resonant reflector (RR) was used. The effect of cyclotron and Cerenkov absorption on the dual-band frequency generation and average RF output power was presented to identify the operating magnetic field. An average RF output power ∼275 MW was predicted at both ∼3.6 GHz and ∼4.5 GHz with a magnetic field of ∼0.25 T.
V. Venkata Reddy, M. A. Ansari, and M. Thottappan
Institute of Electrical and Electronics Engineers (IEEE)
The overmoded slow wave structure (OSWS) and trapezoidal resonant reflector (TRR) have been used to study their effects on the microwave generation time in relativistic backward wave oscillator (RBWO) at the lower guiding magnetic field using a finite difference time domain (FDTD) based particle-in-cell (PIC) simulation “MAGIC” code. Electrons other than the primary electrons and positively charged hydrogen ions (PCHIs) have been identified as the major causes of RF pulse shortening. The pulse shortening analysis has indicated that these causes do not influence the microwave generation time in the overmoded RBWO with TRR for the entire simulation time. The predicted simulation results of the overmoded RBWO with TRR have been justified by comparing with the performances of other RBWO configurations, including a nonovermoded RBWO with rectangular resonant reflector (RR) and TRR individually and an overmoded RBWO with RR provided the inclusion of some of the practical causes of RF pulse shortening. The PIC simulation of pulse shortening analysis predicted that the overmoded RBWO with TRR generated the saturated RF output power of ~0.96 GW at ~3.7 GHz without any pulse shortening with the power duration of at least 70 ns at the lowest guiding magnetic field of ~0.19 T.
V. Venkata Reddy, M.A. Ansari, and M. Thottappan
Defence Scientific Information and Documentation Centre
An S-band high power relativistic backward wave oscillator using a trapezoidal resonant reflector and overmoded slow-wave structure is demonstrated by finite difference time domain based Particle-In-Cell code. The trapezoidal resonant reflector and slow-wave structure are chosen to improve the RBWO power handing capability to gigawatt (GW). The Trapezoidal resonant reflector enhances the pre-modulation during electron beam propagation, thus increasing the generated RF signal overall efficiency and coherency. The particle-in-cell simulation generated an RF output power ~5.4 GW in TM01 mode at ~3.6 GHz in a 2.0 T magnetic field and developed a 13.5 kA current for a 1.2 MV DC cathode voltage. The power conversion efficiency is achieved as ~33 %. Further, the influence of different design parameters on frequency, RF output power, and efficiency are analysed through Particle-In-Cell simulations.
V Venkata Reddy, M. A. Ansari, and M. Thottappan
IEEE
In this paper, an S-band Relativistic Backward Wave Oscillator (RBWO) with Trapezoidal Resonant Reflector (TRR) has been studied at low guiding magnetic field by using 3D Particle-In-cell (PIC) code. The overmoded TRR and slow-wave structure (SWS) are more favourable in view of high-power handling capability under the low guiding magnetic field. In order to generate the GW level of power, the device is operated with ~1.2 MV of DC beam voltage and ~12.5 kA of developed electron beam current. The annular electron beam at the beam-wave interaction is guided by an external guiding magnetic field of 0.32 T. The PIC simulation predicted an average RF output power of ~5.0 GW at ~3.6 GHz in pure TM01 output mode with the conversion efficiency of ~34%. The obtained saturated RF power generation has been last up to 100 ns of simulation time without any pulse shortening.
V Venkata Reddy, M.A. Ansari, and M. Thottappan
IEEE
An overmoded sinusoidally corrugated Relativistic Backward Wave Oscillator (RBWO) has been designed and simulated for Gigawatt power level at low guiding magnetic field. In the upstream, a trapezoidal cavity resonant reflector (TRR) is used to reduce the over modulation of the electron beam. The applied DC voltage is 550 kV and the developed electron beam current is ∼5.9 kA under the guiding magnetic field 0.19 T. The Particle-in-Cell (PIC) simulation predicted an RF power of ∼0.97 GW at operating frequency ∼3.6 GHz with the corresponding power conversion efficiency of ∼30%. Further, the device is investigated for the cyclotron resonance absorption region near to $\\pi$-mode of operation.
Malladi Lakshmi Lavanya, Avireni Srinivasulu, and V. Venkata Reddy
Springer Singapore
Ravipati Linita, V. Venkata Reddy, and Avireni Srinivasulu
IEEE
An integrator circuit is presented in this paper that has used Differntial Difference Current Conveyor Transconductance Amplifier (DDCCTA). It has one DDCCTA and one passive component. It has been realized only with first order low pass response. The operation of the circuit has been observed and enforced at a supply voltage of ± 1.8V (bias current 50pA) using cadence and the model parameters of gpdk 180nm CMOS technology. The worthy of the proposed circuit has been test checked using DDCCTA and further tested for its efficiency on a laboratory breadboard. In this commercially available AD844AN and LM13600 ICs are used. Further, the circuit presented in this paper is impermeable to noise, possessing low voltage and insensitive to temperature.
Suma Madira, V. Venkata Reddy, and Avireni Srinivasulu
IEEE
A The paper presented here mainly focus on the Current mode Schmitt trigger designed on the basis of ZC-Current Differencing Transconductance Amplifier (ZC-CDTA). The ZC-CDTA used in this proposed circuit is well suited for signal processing applications and biomedical applications. This circuit implementation has been carried out using voltage supply of about ±0.85V and bias current of about 20μA using Cadence and gpdk 180 nm CMOS technology model parameters are used. The Schmitt trigger realized using ZC-CDTA is hermetic to noise, temperature insensitive and high output impedance.
Ravipati Linitha, Avireni Srinivasulu, and V. Venkata Reddy
IEEE
Among various active building blocks, the Differential Difference Current Conveying Transconductance Amplifier (DDCCTA) is emerging as a very flexible and versatile building blocks for analog circuit design and has been used for realizing a variety of functions. In this paper, a new current-mode electronically-tunable Schmitt trigger circuit is proposed using Differential Difference Current Conveyor Transconductance amplifier (DDCCTA). The proposed Schmitt trigger consists of single DDCCTA block without any passive components which is advantageous from the point of view of an integrated circuit manufacturing. The performance of the proposed Schmitt trigger circuit is examined using Cadence and the model parameters of a 0.18 μm CMOS process.
Vemireddy Venkatareddy, Pelluri Sambaiah, and Saladi Krishna
IEEE
In this paper, the design of a wideband reactive-feedback Low Noise Amplifier based on current-reuse transconductance boosting is described. The circuit is implemented in UMC 0.13um CMOS process. The simulated noise figure (NF), input return loss (S11), output return loss (S22) and the total power consumption are less than 3dB, -10dB, -10dB and 10mW respectively at 1.2V power supply.
Kunchala Sivakumari, Avireni Srinivasulu, and V. Venkata Reddy
IEEE
A simple low voltage operational amplifier is introduced with an efficient class-AB output stage. Two biasing transistors are present in between common source stage. This amplifier is simulated in 0.18 μm CMOS technology. The proposed class-AB amplifier is designed to operate from ±500 mV supplies. The simulated phase margin of proposed class-AB amplifier is 87° at the load of 10 kΩ∥1 pF. The class-AB amplifier's total compensation capacitance is 5 pF, which is less than 50% of conventional amplifiers. The unity gain frequency of proposed class-AB amplifier is 21.17 MHz, when driving a resistive load from 10 kΩ to 500 kΩ and capacitive loads from 1 pF to 5 pF. The slew rates of modified amplifier are 7.5 V/μs and 8.57 V/μs. This modified amplifier greatly increases the slew rate compared to the conventional circuits.