Shiban Koul - Academia.edu (original) (raw)

Uploads

Papers by Shiban Koul

International Journal of Rf and Microwave Computer-aided Engineering, Feb 7, 2023

Journal of Electromagnetic Engineering and Science

Typically, users engage with smartphones in either single-hand or dual-hand mode. To design anten... more Typically, users engage with smartphones in either single-hand or dual-hand mode. To design antennas that operate at 28 GHz and have high pattern integrity for both modes of operation, an orthogonal beam switching module is required as a single phased-arrays would fail. First, a corner bent corporate fed array operating at 28 GHz is proposed, which has a forward gain of 8.5 dBi and a high-front-to-back ratio of 20 dB. Second, a corner bent printed Yagi antenna that also operates in the 28 GHz band is proposed. Both the corner bent antennas are compatible with the panel edge of commercial smartphones. The radiation from both antennas is mostly directed away from the user. A corner bent co-polarized orthogonal beam switching module is presented and characterized. The antenna module also has a shared ground, making it a potential candidate for future 5G smartphones. Detailed results are presented with adequate justification.

Progress In Electromagnetics Research C, 2022

Signals and Communication Technology, 2021

Progress in Electromagnetics Research Letters, 2020

In this paper an oscillator-type GaN HEMT based active integrated antenna is proposed where the a... more In this paper an oscillator-type GaN HEMT based active integrated antenna is proposed where the active part of the circuit and patch antenna are in series. The patch antenna is designed to offer optimum impedance at second harmonic to generate maximum power at second harmonic and overall negative resistance at fundamental frequency for sustained oscillation. The circuit has been designed, fabricated, and characterized. The fundamental frequency of oscillation of this circuit is 1.5 GHz. This circuit has Effective Isotropic Radiated Power (EIRP) of 32.1 dBm at 3GHz. Power at the fundamental frequency is suppressed due to mismatch of input impedance of patch antenna and deviation from optimum load required for maximum radiation at fundamental frequency. The power radiated at fundamental frequency is 15.7 dB lower than the power radiated at second harmonic. This design technique can be used for radiating useful high power much beyond the cutoff frequency of the transition of active dev...

Progress In Electromagnetics Research C, 2021

Progress In Electromagnetics Research M, 2019

International Journal of Antennas and Propagation, 2021

This paper presents two compact textile-based planar dipole and loop antennas for wearable commun... more This paper presents two compact textile-based planar dipole and loop antennas for wearable communication applications operating in the 2.4 GHz industrial, scientific, and medical radio (ISM) bands. The antennas were fabricated on a 0.44 mm thin camouflaged-military print, cotton jean cloth using conductive copper threads, and sewing embroidery technique to create the radiating structure. Design and performance analyses of the antennas were carried out using simulations; further experiments were performed in anechoic chamber and indoor environment to validate the designs. The experiments were carried out in a free space scenario and on the various locations of the human subject such as the torso and limb joints. The performance of the antennas was investigated based on the reflection coefficient in normal and bent conditions corresponding to the different radii of the locations of the human limbs. The antennas perform well in free space and on-body scenarios in flat and bend conditio...