Animesh Biswas

Bio: Animesh Biswas is an academic researcher from Indian Institute of Technology Kanpur. The author has contributed to research in topics: Antenna (radio) & Dielectric resonator antenna. The author has an hindex of 16, co-authored 207 publications receiving 1248 citations. Previous affiliations of Animesh Biswas include Oregon State University & Indian Institute of Technology Delhi.

Broadband Substrate Integrated Waveguide Cavity-Backed Bow-Tie Slot Antenna

Abstract: A novel design technique for broadband substrate integrated waveguide cavity-backed slot antenna is demonstrated in this letter. Instead of using a conventional narrow rectangular slot, a bow-tie-shaped slot is implemented to get broader bandwidth performance. The modification of the slot shape helps to induce strong loading effect in the cavity and generates two closely spaced hybrid modes that help to get a broadband response. The slot antenna incorporates thin cavity backing (height <;0.03λ 0 ) in a single substrate and thus retains low-profile planar configuration while showing unidirectional radiation characteristics with moderate gain. A fabricated prototype is also presented that shows a bandwidth of 1.03 GHz (9.4%), a gain of 3.7 dBi over the bandwidth, 15 dB front-to-back ratio, and cross-polarization level below -18 dB.

Design of Self-Diplexing Substrate Integrated Waveguide Cavity-Backed Slot Antenna

Abstract: In this letter, a novel design technique to realize planar self-diplexing slot antenna using substrate integrated waveguide (SIW) technology is presented. The proposed antenna uses a bowtie-shaped slot backed by SIW cavity, which is excited by two separate feedlines to resonate at two different frequencies in X -band (8–12 GHz). By properly optimizing the antenna dimensions, a high isolation of better than 25 dB between two input ports is achieved, which helps to introduce self-diplexing phenomenon in the proposed design. The behavior of the individual cavity modes at two resonant frequencies is explained using half-mode theory. The proposed antenna resonates at 9 and 11.2 GHz with unidirectional radiation pattern and a high gain of 4.3 and 4.2 dBi, respectively.

Substrate Integrated Waveguide Cavity-Backed Dumbbell-Shaped Slot Antenna for Dual-Frequency Applications

Abstract: In this letter, a novel dumbbell-shaped slot along with thin substrate integrated waveguide (SIW) cavity backing ( ${\rm height} ) is used to design dual-frequency slot antenna. The proposed design exhibits unidirectional radiation characteristics, high gain, high front to back ratio (FTBR) at each resonant frequency while maintaining low profile, planar configuration. The unique slot shape helps to introduce complex current distribution at different frequencies that results in simultaneous excitation of hybrid mode at higher frequency along with conventional ${{\rm TE}_{120}}$ mode in the cavity. Both conventional mode and the hybrid mode helps the modified slot to radiate at the corresponding resonant frequencies resulting in compact, dual-frequency antenna. A fabricated prototype is also presented which resonates at 9.5 GHz and 13.85 GHz with impedance bandwidth more than 1.5% at both resonant frequencies and gain of 4.8 dBi and 3.74 dBi respectively. The front-to-back ratio of the antenna are above 10 dB at both operating frequencies.

Wideband multiple-input–multiple-output dielectric resonator antenna

Abstract: A two-element multiple-input–multiple-output (MIMO) dielectric resonator antenna having wideband characteristics is presented The wideband operation is achieved by using a mushroom shaped dielectric resonator excited by a conformal trapezoidal patch In order to realise two-element MIMO configuration, two wideband radiators are arranged orthogonally which offers polarisation diversity The measured bandwidth (VSWR ≤ 2) for Port1 is 61% (508–950 GHz), whereas for Port2 it is 65% (489–961 GHz) The isolation between the two ports is better than 20 dB for the desired frequency band The antenna exhibits broadside radiation with cross polar level below 15 dB The peak gain of antenna varies from 334 to 740 dBi at Port1 and from 234 to 79 dBi at Port2 Moreover, the various MIMO performance metrics including envelope correlation coefficient (ECC), diversity gain, channel capacity loss and total active reflection coefficient are investigated The ECC is less than 001 and capacity loss is under 05 bps/Hz throughout the operating bandwidth The results confirm that the antenna offers effective MIMO/diversity performance The proposed antenna can be suitable for WLAN and upper ultra wideband frequency band applications

Dielectric Image Line-Based Leaky-Wave Antenna for Wide Range of Beam Scanning Through Broadside

Abstract: In this communication, a dielectric image line (DIL)-based leaky-wave antenna is proposed with planar feeding. The dominant mode of DIL is perturbed by making holes periodically in the DIL and fast-wave space harmonics are generated. The proposed antenna is designed for Ku-band (12–18 GHz) and its impedance bandwidth in the fast-wave region is 36% (11.8–17 GHz). The scan range of the proposed antenna in the working band is 90° (−65° to 25°) and the gain is varying from 10 to 16 dBi in the fast-wave region. The proposed antenna can be directly scaled to other frequency bands by taking into account the corresponding dispersion characteristic in respective frequency bands. This scaling property is demonstrated in $V$ -band. A prototype is fabricated and measured in Ku-band, which fairly agrees with simulated results.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Gain enhancement methods for printed circuit antennas

Abstract: Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.