Showing papers by "Jayanta Mukherjee published in 2016"

Dual-Band Circularly Polarized Split Ring Resonators Loaded Square Slot Antenna

Abstract: A dual-band circularly polarized (CP) microstrip line fed slot antenna using a set of split ring resonators (SRRs) is proposed in this communication. Outer ring connected SRRs are placed on the back side of the slot to create the CP upper band. Diagonally opposite corners of the slot are truncated, which together with the SRRs give CP response in the lower band. The proposed dual-band CP antenna provides design flexibility to control the resonance frequency and sense of polarization at the dual bands, independently. The proposed antenna is designed to operate at 3.1 and 4.7 GHz, which is fabricated and tested. The experimental results show the −10-dB impedance bandwidths of 400 MHz in both the bands and the 3-dB axial ratio bandwidth of 3.1% (from 3.05 to 3.15 GHz) and 4.2% (from 4.65 to 4.85 GHz) in lower and upper bands, respectively. Finally, a metallic cavity is used with the antenna to achieve a unidirectional radiation pattern with front-to-back ratio of more than 15 dB without affecting the impedance bandwidth and CP performance of the antenna.

Wideband Circularly Polarized Rectangular Dielectric Resonator Antennas Using Square-Shaped Slots

Abstract: Two wideband single fed circularly polarized (CP) rectangular dielectric resonator antennas (DRAs) comprising square-shaped slots are proposed. Initially, two wideband linearly polarized DRAs are designed with high aspect ratio to simultaneously excite and merge two resonant modes, ${\rm TE}_{{111}}$ and ${\rm TE}_{{113}}$ . Then, CP is obtained by the technique of perturbation in the form of four and two square slots along the diagonal. The slots excite two orthogonal modes with same magnitude and quadrature in phase. Two antenna prototypes are experimentally verified. The measured impedance bandwidths are 48% (4.7–7.7 GHz) and 41% (4.6–7 GHz) in conjunction with the 3-dB axial-ratio bandwidth of 11.5% (5.7–6.4 GHz) and 24% (4.7–6 GHz).

Compact Broadband Directive Slot Antenna Loaded With Cavities and Single and Double Layers of Metasurfaces

Abstract: In this paper, a compact wideband directive metasurface (MS)-based antenna is proposed. A pair of edge-fed slots, assisted by a fictitious short, is used to excite the MS layer which is made up of a periodic arrangement of rectangular loop-based unit cells along both the $x$ - and $y$ -directions. The proposed MS-based slot antenna is compact and provides good matching over the entire bandwidth with a broadside radiation pattern. A metallic cavity and an artificial magnetic conductor-based cavity are integrated on the MS-based antenna to reduce its backward radiation. Finally, a pair of edge-fed slot antennas combined with two layers of MSs having compact ground plane area of 1.04 $\lambda _{0}^{2}$ ( $\lambda _{0}$ is the operating wavelength in free space) is proposed for the improvement of gain, bandwidth, and forward radiation. The overall antenna has a low profile of 0.05 $\lambda _{0}$ . The proposed configuration shows a 21% measured bandwidth with an average gain of 9.6 dB over its bandwidth. Over its bandwidth, the antenna efficiency is >89%. The design is validated by a full-wave simulation study followed by the experimental verification.

Frequency-Reconfigurable Slot Antenna Enabled by Thin Anisotropic Double Layer Metasurfaces

Abstract: A frequency-reconfigurable slot antenna using metasurface (MS) is proposed. Two identical anisotropic MS layers are loaded on top of a slot to achieve the frequency reconfigurability. The MS layer is composed of a periodic arrangement of I-shaped metallic inclusions placed in both the horizontal and vertical directions. The MS layers are fed by a linearly polarized slot antenna. The operating frequency of the proposed antenna is tuned by physically rotating the two MS layers with respect to the centre of the slot antenna. Rotation of the MS layers changes the effective permittivity and the loading on the slot antenna and hence the operating frequency changes. The proposed antenna has a low profile with the thickness of the antenna including the two MS layers being $0.07\lambda_{0}$ . The simulated and measured results show that using the proposed technique, the operating frequency can be tuned from 2.55 to 3.45 GHz with a fractional tuning range of around 28%. The antenna provides a minimum gain of 5.3 dB with the peak gain being 8.3 dB. The efficiency of the proposed antenna is more than 90% over its tuning range.

Design of wideband coaxial-TEM to circular waveguide TM01 mode transducer

Abstract: Coaxial TEM to circular waveguide TM01 mode transducer designs with wide bandwidth and compact size are presented in this paper. The coaxial feed with its centre conductor extended as a cone, is applied at the axis of a circular waveguide. Further modifications in the conical shape monopole are proposed (skirt and inverted cone), which result in a wide bandwidth (28.5% and 33.8% respectively) of TM01 mode excitation in a circular waveguide. Many of the High Power Microwave (HPM) sources generate output signal in the form of TM01 mode of circular waveguide. The proposed transducer is useful for low power calibration of an antenna or a mode converter designed for high power microwave applications.

Low-Power Linear Bulk-Injection Mixer for Wide-Band Applications

Abstract: A novel high third-order intermodulation product (IIP3), low-power, inverter-based bulk-injection mixer design is presented in this letter. The architecture of the proposed mixer consists of four complementary MOS (CMOS) inverters that are connected to form a double-balanced mixer. Radio frequency (RF) signals are applied to the input of the inverters, while local oscillator (LO) signals are applied directly to the bulk voltage terminals of the inverters. The proposed mixer achieves a IIP3 of 0 dBm, a 3-dB RF bandwidth that spans 1 GHz to 6 GHz with an intermediate frequency (IF) of 100 MHz.

A Novel ${\rm TM}_{01}$ to ${\rm TE}_{11}$ Mode Converter Designed With Radially Loaded Dielectric Slabs

Abstract: A novel linear shaped ${\rm TM}_{01}$ to ${\rm TE}_{11}$ mode converter having high efficiency and wide bandwidth is proposed. The design consists of a circular waveguide sectored by a horizontal metallic plate partition, and dielectric slabs radially attached in the lower semicircular waveguide. The mode converter is designed and simulated at an operating frequency of 3 GHz. A maximum bandwidth of 504 MHz (2.81–3.35 GHz) with conversion efficiency greater than 90% is achieved when three Polytetrafluoroethylene (PTFE/Teflon) slabs are placed radially in the mode converter. The mode convertor was fabricated and experiments were performed with PTFE as the dielectric slab material. The mode conversion was verified by measuring the far-field radiation pattern. The proposed mode converter is symmetric, compact, linear, and easy to fabricate. It can be used for S-band high-power microwave applications where wide bandwidth of mode conversion is required.

Mutual coupling reduction using shorting posts in UWB MIMO antennas

Abstract: A multiple input multiple output (MIMO) antenna consisting of two hybrid shaped monopoles for UWB applications is presented In the proposed antenna, a pair of rectangular strips terminated with shorting posts is used to achieve isolation ≥ 20 dB over UWB The variations in group delay and transfer-function response are within 1 ns and 13 dB respectively The envelope correlation coefficient < 005 over 31–106 GHz indicate that the proposed antenna is suitable for UWB MIMO applications

Fish-eye shaped dielectric flat lens design utilizing 3-D printing technology

Abstract: In this paper a novel dielectric flat lens has been proposed considering the phase contour of a pyramidal horn for better phase error correction. The developed fish-eye shaped flat lens provides improved gain and aperture efficiency for a broad frequency band of 25–45 GHz. Matching layer was designed to provide maximum transmission for the aforesaid frequency band. The three layered lens provides a maximum and minimum of 74.31% and 46.29% aperture efficiency respectively over the 20 GHz bandwidth. For fabrication of the lens, 3-D printing technology has been proposed where the accurate effective permittivity can be achieved by varying the fill density of printing for each diffractive element.

Underground communication system

Abstract: Embodiments herein provide a system for underground communication. The system includes a surface layer and an underground layer. The surface layer includes an unburied transceiver station connected to a base station. The underground layer includes a buried transceiver station connected to the unburied transceiver station. The underground layer includes an electronic device with a meta-material antenna and a transceiver in communication with the buried transceiver station. Further, the underground layer includes a coordinator in communication with a plurality of sensors nodes and a plurality of routers. The underground layer includes an unburied transceiver station in communication with the plurality of routers and meta-material antenna. The unburied transceiver station in underground layer communicates with the buried transceiver station. The communication is facilitated between the underground layer and base station in the surface layer through either a meta-material antenna or an unburied transceiver station in underground layer, by buried transceiver station.

Multiple band notch filter using contiguous split ring resonators (SRR)

Abstract: A novel, compact, multiple band notch filter (MBNF) is presented Contiguous and concentric split ring resonators (SRRs) and ring resonator are used to achieve desired multiple narrow band notches These band notches have been designed to avoid the undesired interference between co-existing wireless channels Proposed filter is implemented on RT/Duroid 5880 (e r =22) substrate of thickness 0785 mm and surface area of 14 × 14 sq mm Insertion loss of the proposed filter at notch bands is high (>13 dB) and low (<08 dB) elsewhere Measured results are correlated with simulated results and ensure proposed filter is a suitable candidate to mitigate interference caused by the co-existing and emerging wireless technologies

Dual band aperture coupled MIMO antenna

Abstract: A novel and compact dual band multiple input and multiple output (MIMO) antenna for Wireless Local Area Network (WLAN)(5.5 GH–5.85 GHz) band and International Telecommunications Union (ITU) (8.025 GHz–8.4 GHz) band is presented. Dual band characteristics are achieved by incorporating two slots in an aperture coupled micro strip patch resonator. The top radiating patch is designed such that effective length is guided half wavelength at 5.7 GHz for TM 01 mode. Second band at 8 GHz is obtained by introducing second slot on the ground plane. Mutual coupling between the two closely spaced elements of the MIMO antenna is reduced. Good isolation between the antenna elements is achieved (up to 40 dB). Fabricated prototype with optimized dimensions is measured to validate the obtained results.

Portable metamaterial inspired directional antenna for underground mine TTE communication

Abstract: This work presents an implementation of Through-the-Earth two-way voice communication system helpful during the emergency conditions in underground mine. A metamaterial inspired electrically small antenna has been incorporated in our system for system miniaturization and to solve the portability issue without affecting the antenna efficiency and bandwidth. Simulations are done considering the electrical properties of various types of earthy materials to obtain the communication range. The safety limits for electromagnetic radiation hazard are also verified using a male-human body phantom.

Band notch UWB band pass filter with additional GSM 1800 band

Abstract: A novel and compact planar ultra wide band (UWB) filter is presented. Stepped impedance resonator (SIR) is used as multi mode resonator (MMR). MMR is fed by inter digital coupled lines. Coupled lines are designed such that to ensure low insertion loss over a wide frequency range. SIR (i.e., MMR) produces three resonant modes in the UWB frequency range ensures wide pass band. To avoid the potential interference caused by the co-existing wireless services is mitigated by incorporating band notch characteristics. In addition to UWB pass band, GSM 1800 band for GSM mobile communication with center frequency at 1850MHz is also achieved. Filter exhibits narrow pass band from 1800MHz to 1950MHz and UWB pass band from 3.5 GHz to 10 GHz with reference to 3 dB. At band notch frequency filter exhibits high attenuation level up to 40 dB and ensures less interference caused by co-existing wireless local area network (WLAN) band from 5.6 GHz to 5.9 GHz. GSM 1800 Band is obtained by loading shorted stub to the MMR without disturbing the UWB pass band response. S-parameters of the filter depict good UWB characteristics along with GSM 1800 pass band. Proposed filter is designed based on RT/Duroid 5880 substrate with dielectric constant 2.2 and thickness 0.785 mm. Proposed filter design is aimed to be a compact over reported UWB filter (i.e., surface area of 0.24λ 0 × 0.14λ 0 (Where λ 0 is the free space wavelength at the 6.85 GHz)).

Symmetric/asymmetric CPW feed compact UWB antenna with polarization diversity characteristic

Abstract: A compact symmetric/asymmetric CPW feed UWB antenna with polarization diversity characteristic is presented The proposed structure consists of two orthogonally placed UWB antennas One of the antenna elements in the proposed structure is feed with symmetric CPW feed while another antenna is feed with asymmetric CPW feed The proposed feeding techniques minimize the mutual coupling (≤ 20dB) between the antenna elements The proposed structure provides an impedance bandwidth of more than 10 GHz, which covers Bluetooth/Wi-Fi bands along with UWB bandwidth The transmission and diversity characteristics of the proposed antenna are measured and results are reported in terms of group-delay, transfer-function response, and Envelop-Correlation coefficient response A good agreement between simulated and measured results shows that the proposed antenna can be used for UWB diversity application

Controllable dual-mode dual-passband filter using inductive short stub SRR (ISSSRR)

Abstract: A novel controllable dual-band bandpass filter (BPF) with excellent band-to-band rejection is presented in this paper The dual band filter consists of a dual split ring resonator having splits on opposite sides with inductive short stub split ring resonator (ISSSRR) Even and odd mode analysis has been performed to calculate the resonance frequencies Three transmission zeros(TZs) are achieved between two passbands by both electric or magnetic dominant coupling and also cancellation effect of electric and magnetic coupling, resulting in high passband selectivity and improved band-to-band isolation The proposed dual band pass filter has the advantages of being compact with more degree of freedom to achieve desired pass bands by controlling the electric and magnetic coupling The proposed BPF achieved insertion loss of 05 dB and 08 dB at 335 and 575 GHz, respectively