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Author

Jawad Y. Siddiqui

Bio: Jawad Y. Siddiqui is an academic researcher from University of Calcutta. The author has contributed to research in topics: Microstrip antenna & Microstrip. The author has an hindex of 19, co-authored 93 publications receiving 1223 citations. Previous affiliations of Jawad Y. Siddiqui include Royal Military College of Canada.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the design of a compact split ring resonator (SRR) loaded coplanar waveguide (CPW) fed ultrawideband circular monopole antenna having frequency notch characteristics is presented.
Abstract: This paper presents the design of a compact split ring resonator (SRR) loaded coplanar waveguide (CPW) fed ultrawideband circular monopole antenna having frequency notch characteristics. The electromagnetic coupling of the SRR with the CPW yields the frequency notch. Fabricated prototypes were measured and compared with simulations and good agreement was obtained. The impedance and radiation plots confirm the suppression of the desired notch frequency. A theoretical formulation to calculate the notch frequency is also proposed and validated.

192 citations

Journal ArticleDOI
TL;DR: In this paper, a dual-split-ring-resonator (SRR)-loaded coplanar waveguide (CPW)-fed ultrawideband circular monopole antenna exhibiting dual frequency notch and wideband notch characteristics is presented.
Abstract: This letter presents the design of a compact dual-split-ring-resonator (SRR)-loaded coplanar waveguide (CPW)- fed ultrawideband circular monopole antenna exhibiting dual frequency notch and wideband notch characteristics. The SRR pairs are inductively coupled to the radiator and loaded on the back side of the CPW line. Fabricated prototypes were measured and compared to simulations, and good agreement was obtained.

124 citations

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TL;DR: In this paper, a defected ground structure (DGS) consisting of concentric circular rings in different configurations is experimentally studied to examine the stopband characteristics, and a metallic shielding is introduced at the back of the DGS to suppress any leakage or radiation.
Abstract: A new defected ground structure (DGS) consisting of concentric circular rings in different configurations is experimentally studied to examine the stopband characteristics. Unlike previous DGS designs, a metallic shielding is introduced at the back of the DGS to suppress any leakage or radiation, and this would be advantageous for microwave circuit applications. A wide stopband is demonstrated with a set of prototypes designed for X-band. Its application to suppressing mutual coupling in microstrip patch arrays is demonstrated

110 citations

Journal ArticleDOI
TL;DR: A simple design formulation to compute accurate resonant frequencies of circular microstrip antennas covered with dielectric superstrates that shows the closest approximation with the measurements revealing average percent error as low as 0.52%.
Abstract: A simple design formulation to compute accurate resonant frequencies of circular microstrip antennas covered with dielectric superstrates is proposed. It alleviates the rigorous mathematical analyzes and large computational time of some earlier works. This theory is widely applicable to both high and low dielectric constant superstrates as verified with the experiments and other theoretical models. Of all theories, the present one shows the closest approximation with the measurements revealing average percent error as low as 0.52%. The extension of this formulation to predict the accurate design data for conventional microstrip circular antennas are also verified with different experiments and available improved theories for various sets of antenna parameters.

83 citations

Journal ArticleDOI
TL;DR: In this article, a tunable equilateral triangular microstrip patch (ETMP) antenna with a variable air gap between the substrate and the ground plane has been studied theoretically and experimentally, and the tunability of the antenna as a function of the air gap height is studied theoretically showing over 200% tunable range of an ETMP with 50 mm side length printed on a substrate with /spl epsiv/sub r/=10.5.
Abstract: A tunable equilateral triangular microstrip patch (ETMP) antenna with a variable air gap between the substrate and the ground plane has been studied theoretically and experimentally. Calculated resonant frequencies for different air gap heights have been verified with measurements of a coax-fed antenna. The tunability of the antenna as a function of the air gap height is studied theoretically showing over 200% tunable range of an ETMP with 50 mm side length printed on a substrate with /spl epsiv//sub r/=10.5. The computed results for the antennas with zero air gap height are compared with a standard spectral domain moment method analysis supported by other previously reported experiments. Very close agreement is revealed in all comparisons.

69 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, a defected ground structure (DGS) pattern is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna, which is simple and easy to etch on a commercial microstrip substrate.
Abstract: A defected ground structure (DGS) is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna. The proposed DGS pattern is simple and easy to etch on a commercial microstrip substrate. This will only reduce the XP radiation field without affecting the dominant mode input impedance and co-polarized radiation patterns of a conventional antenna. The new concept has been examined and verified experimentally for a particular DGS pattern employing a circular patch as the radiator. Both simulation and experimental results are presented.

275 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG, and several theoretical techniques for analysing the Defected Ground Structure are discussed.
Abstract: Slots or defects integrated on the ground plane of microwave planar circuits are referred to as Defected Ground Structure. DGS is adopted as an emerging technique for improving the various parameters of microwave circuits, that is, narrow bandwidth, cross-polarization, low gain, and so forth. This paper presents an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG. A basic concept behind the DGS technology and several theoretical techniques for analysing the Defected Ground Structure are discussed. Several applications of DGS in the field of filters, planar waveguides, amplifiers, and antennas are presented.

273 citations

Journal ArticleDOI
TL;DR: In this paper, a novel phased array is presented to extend array scanning range by using pattern reconfigurable antenna elements and weighted thinned synthesis technology, which is capable of reconfiguring its patterns from broadside to quasi-endfire radiation by shifting states of PIN diode switches integrated on parasitic strips.
Abstract: A novel phased array is presented to extend array scanning range by using pattern reconfigurable antenna elements and weighted thinned synthesis technology in this paper. The pattern reconfigurable microstrip Yagi antenna element is used as a basic element in array and it is capable of reconfiguring its patterns from broadside to quasi-endfire radiation by shifting states of the PIN diode switches integrated on parasitic strips. A weighted thinned linear array synthesis technique is analyzed and some interesting conclusions have been made. A linear array composed of eight pattern reconfigurable antenna elements is manufactured to demonstrate the excellent performance of the array. The active element pattern of each element is measured and pre-stored. Based on active element patterns and weighted thinned linear array synthesis technique, the pattern scanning performance of the novel array is synthesized. The results indicate that the array can scan its main beam from φ = -60° to φ = 60° in H-plane with gain fluctuation less than 3 dB while maintaining low side lobes, and the -3 dB beam width coverage is about from φ = -68° to φ = 68°. The performance is superior to the traditional phased array made of wide-beam elements.

183 citations

Journal ArticleDOI
TL;DR: In this article, a microstrip patch antenna integrated with two-dimensional photonic bandgap (PBG) and one-dimensional defected ground structure (DGS) jointly in ground plane is presented.
Abstract: This letter presents a microstrip patch antenna integrated with two-dimensional photonic bandgap (PBG) and one-dimensional defected ground structure (DGS) jointly in ground plane. It is demonstrated that application of both PBG and DGS eliminates the second and third harmonics and improves the return loss level. Moreover, the combination use of PBG and DGS decreases the occupied area by 70% compared to the conventional PBG patch antenna.

140 citations