Showing papers by "Shiban K. Koul published in 2006"
01 Sep 2006
TL;DR: A novel bandwidth enhancing network is described, which is shown to improve the 10-dB bandwidth substantially and should be useful for X band communication systems, and scaled models for lower frequencies are easy to design.
Abstract: In this paper design and fabrication of microstrip line fed aperture coupled patch antenna is presented at 10 GHz using 0.762 mm and .508 mm thick (epsivr=3.2) substrates. The maximum size of proposed antenna is 35.4 mm by 35.4 mm. The design is optimized by means of parameter-variation studies that have been performed using a 3D electromagnetic simulator. A novel bandwidth enhancing network is described, which is shown to improve the 10-dB bandwidth substantially. The simulated and measured radiation pattern is suited for wireless communication applications. The gain of proposed antenna is 6.21dBi at 10 GHz. The proposed antenna should be useful for X band communication systems, and scaled models for lower frequencies are easy to design
17 citations
01 Dec 2006
TL;DR: In this article, the design and fabrication of high performance Ka-band inset-fed micromachined patch antenna using post-CMOS compatible process technology is reported. But the main emphasis of this paper is to demonstrate use of RF sputtering as potential metal-dielectric films deposition-process for rapid prototyping of many antenna structures in the absence of access to a well-established MEMS foundry.
Abstract: In this paper, we report the design and fabrication of high performance Ka-band inset- fed micromachined patch antenna using post- CMOS compatible process technology. The main emphasis of this paper is to demonstrate use of RF sputtering as potential metal-dielectric films deposition-process for rapid prototyping of many antenna structures in the absence of access to a well- established MEMS foundry. The fabricated antenna resonated at 35 GHz with 3.14% impedance bandwidth.
13 citations
01 Sep 2006
TL;DR: The simulated and measured radiation patterns show that the antenna functions as expected, with a gain of 7.52 dBi at 10 GHz, and should be useful for X band communication systems.
Abstract: In this paper, design of a quarter wave transformer-fed circular patch antenna is presented The maximum size of proposed antenna is 254 mm by 254 mm The substrate material used for this antenna has thickness of substrate 0762 mm and relative permittivity epsivr 32 The design frequency of the antenna is 10 GHz By selecting optimum parameters of proposed antenna, the measured return loss of proposed antenna at design frequency (10 GHz) is -24 dB A novel 3-stub broad-band matching network is described, which enhances the bandwidth by a factor of 2 The simulated and measured radiation patterns show that the antenna functions as expected, with a gain of 752 dBi at 10 GHz The proposed antenna should be useful for X band communication systems
10 citations
01 Sep 2006
TL;DR: In this article, the design, development and fabrication of high performance Ka-band square and circular micromachined patch antenna using post-CMOS compatible process technology is reported.
Abstract: In this paper, we report the design, development and fabrication of high performance Ka-band square and circular micromachined patch antenna using post-CMOS compatible process technology. The main emphasis of this paper is to use RF sputtering as potential metal-dielectric film deposition-process for rapid prototyping of many antenna structures in the absence of access to a well-established MEMS foundry. The fabricated antenna resonated at 35 GHz with 4.0 % impedance bandwidth.
5 citations
16 Mar 2006
TL;DR: In this paper, a Ka-band microstrip patch antenna fabricated using post-CMOS compatible process technology is reported, which uses an air cavity underneath the patch radiator that is supported on thin membrane.
Abstract: This paper reports a Ka-band microstrip patch antenna fabricated using post-CMOS compatible process technology. The antenna uses an air cavity underneath the patch radiator that is supported on thin membrane. To start with, a thin dielectric film of silicon dioxide is deposited on single crystal silicon substrates by RF sputtering process. The membrane is then realized using bulk micromachining technology. The antenna structure was analyzed and optimized using the finite-element method (FEM) based Ansoft High Frequency Structure Simulator software (version 9). The antenna structure mounted on a test jig with K-connector was used for testing its performance. The measured results of the fabricated prototype antenna agree quite closely with the simulated results. The fabricated antenna resonated at 36 GHz with -10 dB return loss bandwidth of 1.2 GHz. In the absence of access to well-established MEMS foundry, the RF sputtering process reported here can be advantageously used for rapid prototyping of many antenna structures.
4 citations
01 Aug 2006
TL;DR: In this article, a monopole printed patch antenna parasitically fed by an inverted-L shaped monopole is proposed for broadband applications in IEEE 802.1la / HiperLAN2 bands.
Abstract: A monopole printed patch antenna parasitically fed by an inverted-L shaped monopole is proposed for broadband applications in IEEE 802.1la / HiperLAN2 bands. The effect of various physical parameters, such as, dimensions of the parasitic element, coupling between inverted-L shaped monopole feed and the parasitic element is studied. A prototype antenna is fabricated with its dimensions optimized and its simulated and measured results are compared. The antenna offers a wide bandwidth of 60% in the IEEE 802.11a / HiperLAN2 bands.
1 citations
01 Nov 2006
TL;DR: In this paper, a triangular monopole antenna fed by a tapered-coplanar waveguide (CPW) is presented for IEEE 802.11a and HiperLAN2.
Abstract: A compact triangular monopole antenna fed by a tapered-coplanar waveguide (CPW) is presented. The simulated and measured return loss results are presented. The proposed antenna offers a wide bandwidth from 4.14?9.84 GHz (81%) covering WLAN frequency bands for IEEE 802.11a and HiperLAN2 as is seen from the measured results.
1 citations
01 Sep 2006
TL;DR: In this paper, a coplanar waveguide (CPW) fed printed monopole antenna for ultra wideband communications is presented, which is fabricated on a 0.762 mm thick GML (relative permittivity of 3.2) substrate.
Abstract: In this paper, we present a novel coplanar waveguide (CPW) fed printed monopole antenna for ultra wideband communications. The antenna was fabricated on a 0.762 mm thick GML (relative permittivity of 3.2) substrate. The antenna structure was analyzed using a transmission line matrix (TLM) method based Flomerics Micro-Stripes (version 7). The measured 10 dB return loss impedance bandwidth of the fabricated antenna is approximately 116%. The fabricated antenna exhibited omnidirectional radiation pattern and the measured results show a good agreement with the simulated one. Detailed characteristics of the antenna as a function of changes in various structural parameters are also reported.
1 citations
01 Oct 2006
TL;DR: In this article, a triangular monopole antenna fed by a tapered-coplanar waveguide (CPW) is presented for IEEE 802.11a and HiperLAN2.
Abstract: A compact triangular monopole antenna fed by a tapered-coplanar waveguide (CPW) is presented. The simulated and measured return loss results are presented. The proposed antenna offers a wide bandwidth from 4.14?9.84 GHz (81%) covering WLAN frequency bands for IEEE 802.11a and HiperLAN2 as is seen from the measured results.
1 citations
TL;DR: In this paper, the authors describe the full-wave numerical analysis of complex nonradiative dielectric (NRD) guide structures including linear or nonlinear lumped elements.
Abstract: This paper describes the full-wave numerical analysis of complex nonradiative dielectric (NRD) guide structures including linear or nonlinear lumped elements. The numerical results described in this paper, validated through experimentation, show that the method is suitable for NRD guide and similar circuits. Nonlinear analysis of a single-ended NRD guide mixer is carried out, and the results are experimentally verified. Nonlinear harmonic-balance analysis of a novel leaky-wave balanced mixer circuit with very good tolerance of manufacturing inaccuracies in NRD guide configuration in Ka-band is then carried out. Due to curved segments, and orders of magnitude difference in the dimensions of different parts, the analysis of this component requires certain simplifying assumptions. How these can be implemented without sacrificing much accuracy is described. Until now, the design of NRD guide components, especially those using nonlinear effects, has been mostly trial-and-error-based. Here we demonstrate that a more systematic approach is possible
1 citations
01 Aug 2006
TL;DR: In this article, the authors present a methodology for the design and development of passive and active micromachined antennas operating in the microwave and millimeter wave frequency region, where the passive antenna design is based on dividing the circuit into bulk feed line, MC line to MC transition and membrane supported MC antenna.
Abstract: This paper presents methodology for the design and development of passive and active micromachined antennas operating in the microwave and millimeter wave frequency region. The passive antenna design is based on dividing the circuit into bulk feed line, micromachined line to bulk feed line transition and membrane supported micromachined antenna. Each region is modeled using full wave electromagnetic simulation software HFSS. In the active antenna, the two-port membrane supported micromachined antenna is connected in positive feedback path of an MMIC amplifier chip using bulk feed lines. The fabricated micromachined passive antenna element resonated at 34.2 GHz. This antenna exhibited a bandwidth of 1.4 GHz for VSWR<2.0. The measured 3-dB E-plane and H-plane beam widths are 65-70 degrees that agrees fairly well with the simulated results. The initial active antenna oscillated at 35.64 GHz with 47.2 dBm power and showed a clean spectrum.
01 Sep 2006
TL;DR: In this paper, different technologies currently available for building RF to millimeter wave circuits are briefly described, including microstrip, suspended substrate line, dielectric integrated guide and microelectro-mechanical system technologies.
Abstract: In this paper, different technologies currently available for building RF to millimeter wave circuits are briefly described. These include: microstrip, suspended substrate line, dielectric integrated guide and Micro-electro-mechanical system technologies. Several major projects using the aforementioned technologies have been successfully completed at the Centre for Applied Research in Electronics (CARE). Novel techniques developed to analyze and build complex microwave and millimeter wave circuits using microstrip, suspended stripline, non-radiative dielectric guides and micromachined transmission lines are presented.