Mithilesh Kumar

Novel Frequency Reconfigurable Microstrip Patch Antenna Based on a Square Slot for Wireless Devices

In this paper, a novel frequency reconfigurable antenna design and development is proposed for wireless devices. In the proposed design, a rectangular patch antenna with square slot using two PIN diodes at the centre frequency 10 GHz was designed and simulated frequency reconfiguration is achieved in the frequency range of 10-10.5 GHz and the measured results shows the same effect in the frequency range of 10.216-10.552 GHz. The frequency reconfiguration is carried out by switching the diodes on/off states. In the fabricated structure of proposed geometry the diodes are replaced by micro strip line for on-state as an ideal case. The antenna is designed on FR4 substrate (εr= 4.54) of thickness (H) 1.6 mm. The proposed structure was simulated by using the electromagnetic (EM) simulation software. The optimized structure was fabricated using microwave integrated circuit (MIC) techniques on same substrate. The return loss was measured using the Vector Network Analyzer. The simulated and measured return loss shows the close agreement.

Compact Planar UWB Patch Antenna with Integrated Bandpass Filter & Band Notched Characteristics

In this paper, a band-notched planar Ultra wideband (UWB) patch antenna with integrated band pass filter for UWB systems is presented. It is designed on a dielectric substrate and fed by a 50 Ω micro strip line, antenna consists of a square slot patch with a vertical coupling strip monopole, and a partial ground plane and feeding line with band pass filter has been demonstrated to provide an ultra wide 10dB return loss bandwidth and insertion loss with satisfactory radiation properties. The parameters that affect the performance of the antenna in terms of its frequency domain characteristics are investigated. The proposed antenna is easy to integrate with microwave circuitry for low manufacturing cost. The proposed antenna has a compact structure and the total size is 15×14.5mm2. The antenna design is simulated on electromagnetic (EM) simulation software using FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 mm. The simulated antenna has operating frequency band of 3.098-10.61 GHz and show the band-notch characteristic in the UWB band to avoid interferences, which is caused by WLAN (5.15-5.825 GHz) and WiMAX (5.25-5.85 GHz) systems. The simulation result shows the close agreement. The antenna structure is flat, and its design is simple and straightforward geometrically small, hence embedded easily in wireless communication systems.

Bandwidth Enhancement of Microstrip Patch Antennas by Implementing Circular Unit Cells in Circular Pattern

The micro strip patch antenna is the most preferred for low cost and compact design. The proposed antenna design is simulated using FR-4 substrate with dielectric constant of 4.54 and thickness of 1.60mm on electromagnetic (EM) simulation software. The antenna designed has a compact structure with a total size of 60x60mm square. The bandwidth of micro strip patch antenna is enhanced by replacing a conducting ground plane by a high impedance EBG layer. The circular unit cells are placed in a circular pattern and it is found that on increasing the radius of each circular EBG cell, the bandwidth is increased. It is also observed that on increasing the radii of vias, there is a slight decrement in the bandwidth of micro strip patch antennas. The bandwidth of micro strip patch antenna is increased from 13.41% to 18.68% when radius of EBG patches is increased from 2.5mm to 3.5mm which is much wider than the bandwidth of conventional antenna that is calculated to be 4.28%. The simulated results of the integrated antenna for wireless applications shows the good agreement with the proposed scheme.

A Novel UWB Band Notched Rectangular Patch Antenna with Square Slot

In this paper, a patch antenna with band notched characteristics for ultra wide band is proposed. The proposed antenna design is simulated on electromagnetic (EM) simulation software using FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 mm.The proposed antenna has a compact structure, the total size is 15×14.5 mm2 and fed with 50 Ω microstrip by optimizing the width of partial ground, the width of the feed line to operate in UWB.With the design, the return loss is lower than 10 dB in 3.1-10.6 GHz frequency range and show the band-notch characteristic in the UWB band to avoid interferences, which is caused by WLAN (5.15-5.825 GHz) and WiMAX (5.25-5.85 GHz) systems. In addition, band-notched filtering properties in the 5.15-5.825 GHz are achieved by rectangular slot on the radiating element.The proposed antenna is easy to integrate with microwave circuitry for low manufacturing cost. The antenna structure is flat, and its design is simple and straightforward.

Double Balanced Diode Ring Mixer for Ultra-wideband System

A double balanced diode ring mixer is presented for MB (multiband) UWB (ultra wideband) system. Diode ring mixers are suitable for economical front end of superhetrodyne receivers. Mixer is designed for RF (radio frequency) of 3.35 GHz and IF (Intermediate frequency) of 250 MHz. Proposed mixer is simulated at RF power level ranges from -50 dBm to -20 dBm with a reference RF power level of -42 dBm. Simulation results show conversion loss of 5.022 dB and OIP3 (third order output intercept point) of 4.737 dBm at RF power level of -42 dBm. Mixer effectively suppresses the harmonic and IMD (inter-modulation) products at IF port. Mixer is simulated by using the spice parameters of beam lead schottky diode HSCH-5531 of Avago Technologies, USA.

EIGHT SHAPE MICROSTRIP PATCH ANTENNA WITH CRESCENT SLOT FOR WIDEBAND APPLICATIONS

A new wideband small size Crescent slot Eight Shape Antenna (CSESA) with crescent slot is presented. A loss less material honeycomb dielectric of dielectric constant 1.11 is sandwiched between radiating patch and ground. The main motivation for this paper is to enhance the bandwidth of the Impedance. The simulation results verify that the proposed antenna has a 63 percent bandwidth for Return less than-10 dB which is around 3.2 GHz while covering S-Band (2-4 GHz) and C-Band (4 - 8 GHz) of microwave frequency bands. Different design parametric variation in proposed design is also discussed. The basic advantage of these designs is simple structure with no active element, no shorting pins and no vertical walls between the patch and the ground. The typical impedance behavior and far field radiation pattern characteristics of proposed configuration are presented. The antenna is designed, optimized and simulated using Electromagnetic (EM) simulation software. This antenna is suitable for wideband wireless communication systems.

Design of Multiband Antennas for Wireless Communication

Recent developments in the field of wireless communication industry continue to drive the requirements for small, compatible, and affordable multiband antennas. To overcome the challenges of multi-frequency operation a new scheme of multiband is proposed. In this paper, the design of a micro strip patch antenna for multiband operations is proposed. This antenna shows the three distinct frequency bands, centered at 4.02 GHz, 6.18 GHz and 11.13 GHz. Furthermore, to increase the frequency bands the same antenna structure is modified by attaching a T-shaped slit on the radiating patch. This proposed modified antenna has four distinct operating frequency bands centered at 3.92 GHz, 5.82 GHz, 7.88 GHz and 11.35 GHz with improved return loss. The proposed antennas has compact size of 25 × 28 × 0.82 mm3 including the ground plane and both antenna structures are designed on FR-4 substrate (er= 4.4) of thickness h=0.8 mm. The proposed structures were simulated by using the electromagnetic (EM) simulation software. The simulated return losses are less than-10 dB at resonance frequencies. The presented antennas are suitable for multiband wireless communication systems.

Compact Dual Band Microstrip Loop Antenna Using Defective Ground Plane

Present era of wireless communication thrust the need of miniaturization and multi-frequency operations to make the devices compact and affordable. To overcome the challenges of multi-frequency operation, in this paper a revised design is proposed for dual band microstrip antenna printed on RT-duroid substrate which can operate in two frequency bands with a single structure. To make the antenna compact the use of defective ground plane is justified as the size of the structure becomes almost one-third in comparison to the structure with full ground plain. The basic principal of its operation is the multiple resonance frequencies, the first frequency band occurs due to first resonance frequency and the second frequency band due to third resonance frequency which is the first odd harmonic of first resonance frequency. Due to the symmetry in the structure the even harmonics are cancelled out. The antenna is designed using 1.2 mm wide metal lines printed on a simple RT-duroid substrate (εr = 2.22) of thickness (H =15mils) it works like a coplanar waveguide micro-strip line of Z0 =50ohm, the structure is very simple rectangular loop printed as a microstrip line with characteristics impedance. Design is simulated using Electromagnetic simulator. We got exciting results of return loss is less than-30dB at both the resonance frequencies (1.5GHz & 4.2GHz).

Design of UWB Antenna for Short Distance Wireless Communication System

This paper presents a study on simplest printed antenna for various ultra-wideband (UWB) based applications. The gap between height of ground plane and lower edge of patch along width is varied to observe the magnitude of S11 in the UWB frequency range for the appropriate antenna dimensions. The proposed antenna exhibits a 10 dB impedance bandwidth from 3.1 to 10.5 GHz, which constitutes about 108.82%. The antenna radiates omni directionally in the radiation patterns plane over the UWB band defined by Federal Communication Commission. The proposed antenna has a compact substrate size of 50 mm by 50 mm and 1.6 mm thickness with relative permittivity of 4.4.

Modified U-Slot Microstrip Patch Antenna with Gain Enhancement

Micro strip patch antennas are strong candidates for use in many wireless communications applications. In this paper, the design, optimization and simulation of a dual-band modified U-slot micro strip patch antenna for WiMAX/WLAN application is presented. It operates on 2.45-2.57 GHz and 5.1-5.4 GHz bands. Radiating patch lies on the Rogers RT/duroid 5880 substrate which is having low dielectric constant of 2.2. Coaxial feeding technique is used to feed the antenna with 50 ohm impedance. This proposed antenna enhances the return loss of -19.5 dB at the 2.5 GHz and -30 dB at 5.27 GHz frequencies. Computer simulated results showing the VSWR value lesser than 2 at the 2.45-2.57 GHz and 5.1-5.4 GHz frequency range of WLAN standards. It exhibits maximum gain of 6.15 dB at 2.5 GHz and 9.1 dB at 5.27 GHz.