Anil Kumar Gautam

Design of Compact F-Shaped Slot Triple-Band Antenna for WLAN/WiMAX Applications

This communication presents a small, low-profile planar triple-band microstrip antenna for WLAN/WiMAX applications. The goal of this communication is to combine WLAN and WiMAX communication standards simultaneously into a single device by designing a single antenna that can excite triple-band operation. The designed antenna has a compact size of

Design of Koch Fractal Circularly Polarized Antenna for Handheld UHF RFID Reader Applications

19 \times 25\;\text{mm}^{2}

Triple band circularly polarized compact microstrip antenna with defected ground structure for wireless applications

(

Frequency Agile Triple Band Microstrip Antenna for WLAN/WiMAX Application

0.152 \lambda_{0}\;\times 0.2 \lambda_{0}

Dual-band stacked circularly polarized microstrip antenna for S and C band applications

). The proposed antenna consists of F-shaped slot radiators and a defected ground plane. Since only two F-shaped slots are etched on either sides of the radiator for triple-band operation, the radiator is very compact in size and simple in structure. The antenna shows three distinct bands I from 2.0 to 2.76, II from 3.04 to 4.0, and III from 5.2 to 6.0 GHz, which covers entire WLAN (2.4/5.2/5.8 GHz) and WiMAX (2.5/3.5/5.5) bands. To validate the proposed design, an experimental prototype has been fabricated and tested. Thus, the simulation results along with the measurements show that the antenna can simultaneously operate over WLAN (2.4/5.2/5.8 GHz) and WiMAX (2.5/3.5/5.5 GHz) frequency bands.

Single-feed circularly polarized stacked patch antenna with small-frequency ratio for dual-band wireless applications

In this study, a novel design of circularly polarized antenna based on Koch fractal geometry is presented and experimentally investigated. Circular polarization and size reduction are achieved by placing two asymmetric Koch fractal geometries on x-and y-planes of the single-probe feed square radiator. Further, to tune resonant frequency around the 911MHz, four arrow-shaped slots are inserted in diagonal axes of the square radiator. It is perceived that compact size of the antenna can be achieved by increasing the overall size of the arrow-shaped slots and indentation angles of Koch fractal geometry. The antenna is fabricated on FR4 substrate with a size of 54 × 54 × 1.6 mm3 (0.162λ0 × 0.162λ0 × 0.0048λ0 at 900 MAbstract-In this study, a novel design of circularly polarized antenna based on Koch fractal geometry is presented and experimentally investigated. Circular polarization and size reduction are achieved by placing two asymmetric Koch fractal geometries on xand y-planes of the single-probefeed square radiator. Further, to tune resonant frequency around the 911MHz, four arrow-shaped slots are inserted in diagonal axes of the square radiator. It is perceived that compact size of the antenna can be achieved by increasing the overall size of the arrow-shaped slots and indentation angles of Koch fractal geometry. The antenna is fabricated on FR4 substrate with a size of 54 × 54 × 1.6 mm3 (0.162λ0 × 0.162λ0 × 0.0048λ0 at 900 MHz) and tested to validate the proposed design. The 3-dB axial-ratio bandwidth and impedance bandwidth of the proposed antenna design are found to be 8 MHz (907.0-915 MHz) and 37.0 MHz (891.0-928.0 MHz), respectively. The measured results confirm that the proposed design covers US radio-frequency identification (RFID) band (902-928 MHz) and can be used for RFID short-range reading applications.Hz) and tested to validate the proposed design. The 3-dB axial-ratio bandwidth and impedance bandwidth of the proposed antenna design are found to be 8 MHz (907.0-915 MHz) and 37.0 MHz (891.0-928.0 MHz), respectively. The measured results confirm that the proposed design covers US radio-frequency identification (RFID) band (902-928 MHz) and can be used for RFID short-range reading applications.

An inverted L-strip UWB microstrip antenna

Asymmetric slits loaded irregular shaped microstrip patch antenna with three different ground structures is proposed. All three antennas show triple band characteristics. First antenna with regular ground plane resonates at 1.95, 2.4, and 4.90 GHz with good radiation characteristics and shows right-hand circular polarization at 1.95 GHz. 18.75% of compactness is achieved with triple band characteristics. Further, same patch is used with different defected ground structures. Second antenna resonates at 1.85, 2.4, and 4.85 GHz with suppressed cross-polarization level and antenna shows right-hand circular polarization at 1.85 and 4.85 GHz. Compactness is further improved to the value of 22.91%. The third antenna resonates at 1.95, 2.4, and 4.85 GHz with better gain and radiation characteristics and antenna shows right-hand circular polarization at 1.95 and 2.4 GHz. The small frequency ratio f 2 /f 1 is achieved and the value of f 2 /f 1 is 1.29 and 1.23 for second and third configuration, respectively. Proposed structures show right-hand circularly polarized with suppressed left-hand circularly polarized radiations and suitable for fixed mobile wireless communication applications. All structures are analyzed using Ansoft HFSS v.14 based on finite element method and measured results satisfy the simulated results.

Design of UWB Monopole Antenna for Oil Pipeline Imaging

 Abstract—A frequency agile triple band microstrip antenna using defected ground structure for WLAN/WiMAX application is presented, in which frequency agility is electronically achieved by changing the bias voltage of varactor diode. A defected ground structure rectangular patch with dual inverted L-shaped fed with a cross shaped strip line is used to achieve multiple bands. Simulated results are validated by the experimental results and show a good agreement between simulated and experimental results. The proposed antenna has small size and operates 2-2.15 GHz, 2.75-3.5204 and 5.4-5.9 GHz. The lower and upper band remains almost constant while resonance frequency of the middle band is changing with the bias voltage of varactor diode and frequency agility of 768.4 MHz is achieved. Thus the proposed antenna is suitable to be used for WLAN and WiMAX applications.

Circularly polarized square slot microstrip antenna for RFID applications

A single-fed circularly polarized microstrip antenna is proposed where the antenna structure exhibits truncated corners in the radiating square patch. The truncated corners square patch structure is loaded with a circular slot and is resonating at 2.25 GHz with circular polarization. Furthermore, the proposed antenna is stacked using an upper circular patch thus achieving a dual-band circularly polarized pattern. The dual-band antenna resonates at 2.25 GHz in the first band and with impedance bandwidth ranging from 4.4 to 5.5 GHz in the second band. The size of the proposed stacked structure is compact compared with the conventional circularly polarized stacked antenna designs. Proposed structures are fabricated and fed using Subminiature version A (SMA) connector. The measured results are in good agreement with the simulated. The antenna shows stable radiation characteristics for the entire band of operation.

Square-ring microstrip for CP Operation

A single-feed dual-band circularly polarized stacked microstrip patch antenna with a small-frequency ratio is presented. Two pair of orthogonal slits is cut on the lower circular patch for achieving circular polarization and truncated corner square patch is used as the upper parasitic element. The frequency ratio of the dual-band is 1.03. The 3 dB axial ratio bandwidth is 1.3% for the upper band and 1.1% for the lower band. Proposed structure is fabricated on the FR-4 epoxy substrate and fed by SMA connector. The measured results are in good agreement with the theoretical and simulated results. The antenna shows stable radiation characteristics in both bands of operation.