karthik rudramuni
@nitk.ac.in
RESEARCH SCHOLR
NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA
ANTENNA DESIGN ENGINEER
EDUCATION
BE M.TECH PH.D
RESEARCH INTERESTS
ANTENNA DESIGN
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Dushyant Kumar Sharma, Karthik Rudramuni, Ahmad Zakaria Ahmad, Mohammad Abdul Shukoor, and Karun Rawat
IEEE
This paper presents an efficient, linear, and broadband Doherty power amplifier (DPA) design in n78 C-band. In order to achieve improved performance, a modified load combiner network (MLCN) approach is incorporated into an inverse Doherty PA (IDPA) architecture. Proposed PA is realized through a premier and cutting-edge n78 band device, GTRB384608FC. Proposed DPA covers entire n78 band from 3.3 to 3.8 GHz (500 MHz) with enhanced efficiency of 40.5% to 46.5%, for an average power of 47.5 dBm and attained peak power, ranging from 54 dBm to 55.5 dBm. As well as it able to sustain an output PAPR in between 6.5 dB to 8 dB across the spectrum in continuous wave (CW) signal excitation.
Puneeth Kumar Tharehalli Rajanna, Karthik Rudramuni, and Krishnamoorthy Kandasamy
Wiley
Amit Kumar, Karthik Rudramuni, Dushyant K. Sharma, Gande Arun Kumar, and Mohammad Farukh Hashmi
IEEE
In this paper, a novel Doherty Power Amplifier configuration with broadband and highly efficient characteristics is proposed. It is based on the synthesis of key approaches such as non-infinite output impedance of auxiliary power amplifier and optimizing the impedance of λ/4 transmission line. A detailed analytical analysis of drain efficiency at peak power level and at 6-dB output power back-off level is performed. The proposed methodology has yielded the peak power efficiency as well as the 6-dB output power back-off efficiency always greater than 70% in the entire frequency range. Thus, a highly efficient Doherty Power Amplifier with a very wide fractional bandwidth of 80% is obtained.
Puneeth Kumar T.R, Karthik. R, and Krishnamoorthy. K
IEEE
A zero-index based metasurface (MTS) is used to increase the gain of a circularly polarized (CP) patch antenna. The patch antenna is truncated at its corner to obtain the CP wave. The patch antenna gain in increased by loading the metasurface. The proposed CP antenna with enhanced gain is fabricated and verified experimentally. A measured impedance bandwidth (< –10dB) of 530 MHz and axial ratio bandwidth (< 3dB) of 100 MHz is achieved. The peak gain of 12.15 dBiC is obtained at the center frequency of 7.47 GHz with a better level of cross-polarization.
Karthik Rudramuni, Basudev Majumder, Puneeth Kumar Tharehhalli Rajanna, Krishnamoorthy Kandasamy, and Qingfeng Zhang
Institute of Electrical and Electronics Engineers (IEEE)
In this article, two configurations of novel dual-band half-mode substrate integrated waveguide (HMSIW) leaky-wave antennas are presented. The first proposed antenna radiates linearly polarized (LP) waves in the lower band and circularly polarized waves in the upper band when the unit cells are cascaded sequentially. The second antenna, where the sidewall via of the HMSIW unit cells is connected alternatingly, provides simultaneous dual beams with different polarization in the upper operational band in addition to the LP beam in the lower operational band. The unit cells of the two antennas are analyzed in terms of their dispersion behaviors. Finally, the performance of both the antennas is experimentally verified.
Karthik Rudramuni, Basudev Majumder, and Krishnamoorthy Kandasamy
Wiley
Puneeth Kumar Rajanna, Karthik Rudramuni, and Krishnamoorthy Kandasamy
Cambridge University Press (CUP)
AbstractThis paper presents a novel design of a low profile circularly polarized (CP) metasurface (MTS) antenna with in-band radar cross-section (RCS) reduction property. The MTS is loaded as a superstrate on slot antenna and it can be viewed as a polarization-dependent MTS (PDMTS). The rectangular patch-based PDMTS is analyzed using characteristic mode analysis to find two orthogonal degenerate modes, which produces CP waves. Linearly polarized slot antenna is used to excite the PDMTS. The performance of PDMTS loaded slot antenna is analyzed numerically using full-wave analysis method. The PDMTS CP antenna is fabricated and its performance is tested experimentally. The proposed antenna has a compact structure and it has an overall size of $0.52{\\lambda _0}\\times 0.52{\\lambda _0} \\times 0.078{\\lambda _0}$ (where ${\\lambda _0}$ is the free space wavelength). The measured results show that the PDMTS antenna achieves $-10\\,{\\rm dB}$ impedance bandwidth of 29.41$\\%$, 3-dB axial ratio bandwidth of 9.05$\\%$, broadside gain of 6.34 dB, and monostatic RCS reduction of $-30.2\\,{\\rm dBsm}$ at the resonant frequency of 5.86 GHz. The simulated results are in well agreement with the measured results and it is well suited for C-band Radar and Satellite communication.
Karthik Rudramuni, Puneeth K. T. Rajanna, Krishnamoorthy Kandaswamy, Basudev Majumder, and Qingfeng Zhang
Wiley
Puneeth Kumar Tharehalli Rajanna, Karthik Rudramuni, and Krishnamoorthy Kandasamy
Wiley
Puneeth Kumar Tharehalli Rajanna, Karthik Rudramuni, and Krishnamoorthy Kandasamy
Institute of Electrical and Electronics Engineers (IEEE)
In this letter, a novel high-gain circularly polarized (CP) antenna based on the zero-index metamaterial (ZIM) is presented. A square ring with two asymmetrical splits is used as a unit cell to achieve high gain and circular polarization. The 9 × 9 periodic array unit cells act as an aperture efficient focusing metasurface lens and polarization converter for a primary source antenna. The focusing effect of the ZIM enhances the gain of the microstrip patch antenna placed above it by an amount of 5–6 dB. Also, the ZIM converts the linearly polarized wave emitted by the patch antenna into circularly polarized waves. The circular polarization is achieved by optimizing the two split gaps on the ring of the unit cell, which gives two orthogonal polarizations with the required phase. The proposed design is fabricated and verified experimentally. The prototype has measured impedance bandwidth from 7.04 to 7.68 GHz. The 3 dB axial ratio is achieved from 7.11 to 7.56 GHz, with a peak gain of 12.31 dBic at 7.45 GHz. The gain of around 11.5 dBic is achieved over the entire CP bandwidth with a good cross-polarization level.
Puneeth Kumar Tharehalli Rajanna, Karthik Rudramuni, and Krishnamoorthy Kandasamy
Korean Institute of Electromagnetic Engineering and Science
This paper presents the design of a coplanar waveguide (CPW)-fed single-layer wideband circularly polarized (CP) planar slot antenna backed by a frequency selective surface (FSS). The planar slot antenna is fed with a stub-loaded modified CPW feed line to tune and optimize the impedance bandwidth. The corners of the square slot antenna are perturbed to produce two orthogonal degenerate modes required for a wideband CP operation. The FSS layer is placed under the slot antenna to increase the gain and axial ratio bandwidth. The measured results of the proposed antenna provide an impedance bandwidth of 63.22% and an axial ratio bandwidth of 31.14% with a peak gain of 4.87 dB. The proposed antenna has a simple geometry, a wide CP bandwidth, and a good gain.
T.R. Puneeth Kumar, R Karthik, and K Krishnamoorthy
IEEE
In this paper, a dual band circularly polarized (CP) slot antenna loaded with asymmetric cross strips is proposed. It consists of a corner perturbed slot and two asymmetric strips oriented diagonally with the slot. The slot antenna is excited by $50\\Omega$ microstrip line. The proposed antenna resonates at 2.7 GHz and 3.2 GHz. Two orthogonal degenerate modes produced by the perturbed slot antenna gives CP in lower band and the combination of slot and strip mode gives CP in upper band. The proposed antenna is fabricated and experimentally verified with axial ratio (AR) bandwidth of 13.27% and 13.31% in lower and upper band respectively. The peak gain of 4.68 dB at lower band and 4.81 dB at upper band is achieved. The simulated and measured results are in well agreement and it is good candidate for WiMax and WLAN applications.
Karthik Rudramuni, Krishnamoorthy Kandasamy, Qingfeng Zhang, Xiao-Lan Tang, Abhishek Kandwal, Puneeth Kumar Tharehalli Rajanna, and Haiwen Liu
Institute of Electrical and Electronics Engineers (IEEE)
A Goubau-line leaky-wave antenna (LWA) with a large scanning angle is presented in this letter. In contrast to the conventional Goubau-line leaky wave with a small scanning angle range, this letter employed a periodically bending Goubau line, which not only brings in a periodic perturbation for leaky-wave radiation, but also enhances the scanning range due to the increased delay for each line element. The simulation and experimental results show that the proposed LWA provides $90\\%$ radiation efficiency and 7–10 dBi radiation gain from backfire to endfire through broadside as frequency changes. The proposed antenna features good radiation performance and has a compact and low-profile configuration.
Karthik Rudramuni, Krishnamoorthy Kandasamy, Abhishek Kandwal, and Qingfeng Zhang
IEEE
In this paper, spoof surface plasmon polariton (SSPPs) and substrate integrated waveguide (SIW) based bandpass filter is proposed. The metal strip on the top of the substrate is composed of periodic slots which supports surface wave mode of SPP within the closed substrate integrated waveguide. The dispersion relation of the proposed structure shows that it has both low-pass feature of SSP and the high-pass feature of SIW, and hence the combination of these two features leads to a bandpass filter (BPF). The results show that the passband is from 11.5–19 GHz with relative bandwidth of 49%. Bandwidth can be controlled by properly adjusting the parameters of the design. The proposed design features a compact size and easy fabrication, due to the integration of SPP in a closed SIW.