Dheeraj Bhardwaj

Square patch microstrip antenna with single notch having an air gap

The paper presents a modified rectangular patch microstrip antenna having a triangular notch in one of its straight arm and designed on dielectric material under the presence of variable air gap. The measured performances of this antenna without air gap are compared with those obtained through simulation results of this antenna under the presence of variable air gap. It is observed that the performance of antenna improves significantly.

Design of Square Patch Antenna with a Notch on FR4 Substrate

The simulation and experimental results of square patch antennas having a notch and designed on FR4 substrate are reported in this paper. The notch angle is varied and different radiation properties of antennas are tested. It is found that on reducing the notch angle thetas from 180deg to 164deg, the patch resonates at a single frequency. However on reducing notch angle further, the patch starts resonating at two different frequencies. The f2/f1 ratio almost linearly increases on decreasing the notch angle. The 10dB impedance bandwidth (VSWR 2:1) of antenna increases up to notch angle 151deg but thereafter that antenna behaves simply as a dual frequency antenna with narrow bandwidth at each resonance frequency.

Compact dual band convexo-concave microstrip patch antenna having bow tie slot with Alteration of Dielectric Substrate for remote sensing applications

Microstrip antennas are one of the most widely studied antenna structures, perhaps due to their inherent properties like compact size, light weight and their capability to get integrated with other circuit components. A three dimensional rectangular slot loaded dielectric (Alteration of Dielectric Substrate) of the antenna for dual-band (S & C) operation has been proposed for remote sensing applications. In this paper, first a single layer convexo-concave patch antenna with a concave bow tie slot is designed and analyzed. Then a superstrate layer is introduced with this antenna. A comparative study between the single layer and multilayer convexo-concave patch antenna is done and it is observed that after the application of a superstrate layer with alteration of dielectric substrate the antenna resonates at two different frequencies 3.17 GHz and 5.34 GHz with a bandwidth of 7 % and 17 % respectively.

Bandwidth enhancement of electromagnetic coupled nonuniform H-shaped microstrip patch antenna for higher band of Wi-MAX applications

The bandwidth enhancement of a stacked non-uniform electromagnetically coupled H-shaped Microstrip Antenna (SNHMA) with tapered edges is analyzed and simulated using the IE3D simulator. The proposed antenna prototype is drafted on FR-4 material and stacked further with an air discontinuity of 0.3 mm to the next layer. The various parameters optimized to achieve the best performance from the modified SNHMA primarily include a)length b)width of the patch c)air gap thickness. The redesigned antenna serves at two distinct frequencies with an elevated bandwidth of 30.85 % at the central frequency 5.762 GHz, approximately four times the bandwidth of the standard patch having the same dimensions. The simulated radiation patterns (E-plane and H-plane) are exhibited within the range of frequencies where the broadband response is observed. The specifications of the proposed structure make it promising for the higher band of Wi-MAX applications.

Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S11) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

A novel semilumped low-pass filter having finite frequency attenuation poles with defected ground structure

This paper presents the design and analysis of a novel filter configuration offering infinite attenuation at finite frequencies. The proposed filter has a cut-off frequency of 2 GHz with passband ripple of 0.1dB and a minimum stopband insertion loss greater than 40dB at 3.05GHz. The two infinite attenuation poles occur at 2.4GHz and 2.76GHz. In order to further enhance the filter performance, the elliptical response filter has been embedded with a dumbbell shaped defected ground structure and the results are analyzed.

Design of Dual Resonator Broadband Multilayer Electromagnetically Coupled Microstrip Antenna for X-Band Applications

This paper demonstrates the Dual resonator Broadband microstrip patch antenna for X-band applications with high bandwidth and gain. The antenna has wide bandwidth of 3880 MHz (7.12–11.0 GHz) or 42.76 % and covers wide band of X-band. 10.0 and 10.5 GHz are two resonant frequencies for the designed antenna. The antenna presented in this paper is microstrip patch antenna with rectangular geometry which has multilayer arrangement with two biangular uniform slots, which has been fed by Electromagnetic coupling with air-gap. This antenna designed and simulated has been carried out by IE3D simulation software.

Gain and Bandwidth Enhancement of Single-Layered Slotted Triangular-Shaped Microstrip Patch Antenna with Stub for WLAN Applications

The paper presents a triangle-shaped patch antenna designed for WLAN systems operating in the range of 5150–5350 MHz (IEEE 802.11 a,n) and 5725–5825 MHz (IEEE 802.11 a,n). This paper presents a single-layered equilateral triangle-shaped microstrip patch antenna having rectangular slots and one stub. The simulated antenna is resonating at two resonance frequencies 5.20 and 5.76 GHz with 18.01 % impedance bandwidth and, 7.94 and 6.24 dBi directivity, respectively. The performance along with the design of the patch antenna is optimized considering different slot variance to obtain an antenna with high gain and efficient bandwidth. The E-palne and H-plane radiation pattern have also been synthesized in accordance with the other parameters. The substrate material of FR4 Lossy with relative permittivity 4.4 and loss tangent of 0.025 is used in this proposed antenna. All the simulation work is carried using IE3D software.

Multi Frequency Rectangular Patch Mircostrip Antenna with T Shaped Slot for Ultra Wide Band (UWB) Communication Systems

A Multi Frequency wide Band Rectangular Patch Micro strip Antenna with T Shaped Slot with shorting wall (RPMATSSSW) is designed on glass epoxy FR-4 substrate. The performance of this antenna is compared with that of a simple rectangular patch antenna. The simulated results for this antenna are optimized by varying position, length and width of T shaped slot and also by introducing two shorting wall. The results indicate that the designed structure resonate at various closely spaced frequencies (as shown in figure-4) which are use full for Ultra wide band (UWB) communication systems, which has been allocated IEEE 802.15.3a standard for specifies the frequency range 3.1GHz to 10.6GHz. The Modified antenna offers much improved bandwidth 76.71% at central resonance frequency 7.62GHz in comparison to a rectangular patch antenna (having band width 3.27%). The directivity of antenna also improves significantly at some of the resonance frequencies.

Broad band parasitically coupled concentric semi circular elliptically ring antenna surrounding an elliptical patch with air gap

The paper presents the performance of a parasitically coupled semi circular elliptical ring antenna surrounding elliptical patch geometry having air gap between conducting patch and ground plane. With proposed modifications in the conventional circular patch geometry, the bandwidth of modified antenna with an air gap is around seven times higher than that of a simple circular patch antenna. The gain, directivity and efficiency of modified circular patch antenna with air gap is also improved to some extent but still these are less than desired values. The E and H plane radiation patterns presented by antenna in the frequency range where broadband performance is obtained are identical in shape and nature. Direction of maximum intensity retained by antenna at both frequencies is normal to patch geometry.