Hari Shankar Mewara

A novel ultra-wide band antenna design using notches and stairs

This paper describes the parametric study of a novel rectangular planar ultra-wide band antenna (UWB). The proposed design exploits U and T-shaped notches with stairs at two corners on the radiating patch along with stepped microstrip feed. The stairs are also used at the corners of the partial ground plane with a rectangular notch and an electromagnetically coupled stepped rectangular strip. The proposed UWB antenna is designed and simulated using Computer Simulation Technology Microwave Studio (CST-MWS). This antenna operates in a frequency band ranging from 3.0985 to 10.666 GHz with the overall dimensions of 34 mm (L), 37.5 mm (W) and 1.7 mm (H). The VSWR is less than 2 for entire operating frequency range. The impedance bandwidth of the proposed design is nearly 7.5675 GHz. This antenna finds its applications in 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX, 4 GHz C band and lower frequencies of X band. The effect of the stepped ground plane and the dimensions of U, T and rectangular shaped notches on the optimization of the return loss is parameterized and discussed in detail.

A band-reject frequency selective surface with stable response for WLAN applications

In this paper, a new design of band-reject frequency selective surfaces is proposed. Compared to previous compact structure, the FSS proposed has a better firm performance with the dimension of a unit cell only 0.126λ × 0.126λ, where λ represents the wavelength of the resonant frequency. Above design is aimed at rejection of WLAN band (5.15-5.725) GHz. Moreover, the proposed design has a stable response with respect to different polarization characteristics and different incident angles of the incident plane wave. The squashed performance can be further improve by changing radius of patch. The design is aimed at the rejection of WLAN band.

Design of Square Shaped Polarization Sensitive Metamaterial Absorber

In this paper, the polarization sensitive metamaterial absorber is proposed. The metamaterial absorber structure consist of a plus shaped structure surrounded by square loop has been proposed. The proposed metamaterial absorber unit cell provides approximately unity (99.99 %) absorption at 16.25 GHz. The design of an ultrathin polarization sensitive absorber based on Ku-band applications. Absorber design has been simulated for different incident and polarization angles to tune the single band and dual band response for different frequency slots of Ku-band. To obtain best response, FR-4 substrate material having substrate height of 1 mm is used. This metamaterial absorber is used in stealth technology for battlefield, solar cell and airborne radar.

An extremely wideband/multiresonance monopole antenna with multiple notched stop bands

A wideband/multiresonance monopole antenna with multiple notched stop bands is presented. A multiresonance characteristic 2.6–22 GHz is achieved by modifying ground plane and three notched stop bands at 3.36–4.11, 5.15–5.79, and 7.96–8.50 GHz are achieved by introducing three co-directional split ring resonators (SRRs) in the radiating patch. The individual notch frequency is controlled by the individual SRR and central notch frequency is calculated by the physical dimension of individual SRR.

UWB Microstrip Antenna with Inverted Pie Shaped Slot

This paper proposed a compact planar ultra wideband (UWB) antenna with single band-notched behavior. An inverted pie-shaped slot is etched in a circular patch for getting the notch behavior. The presented antenna is successfully designed, simulated and measured showing single notch nature in UWB band as this band interfere in it. This antenna is designed on FR-4 substrate with dielectric constant 4.4 and thickness of 1.6 mm. The antenna parameters such as return loss, VSWR, gain and directivity are simulated and optimized using commercial computer simulation technology microwave studio (CST MWS). The designed antenna is showing band notch property at 7 GHz (6.4–7.5 GHz for satellite communication) as this band interfere with the UWB. The main advantage of this antenna is that the designed structure is very simple and the cost for making this antenna is also low.

A Planar Ultra-Wide Band Antenna Design Using Circularly Truncated Corners and Notches

This paper describes the design and parametric study of a planar rectangular ultra-wide band antenna (UWB). The proposed design exploits U-shaped notch and T-shaped slot with circularly truncated corners on the radiating patch along with stepped microstrip feed. Circular truncation is also used at the corners of the partial ground plane with a rectangular notch along with an electromagnetically coupled truncated rectangular strip. This antenna operates in a frequency band ranging from 2.975 to 10.684 GHz with an impedance bandwidth nearly 7.709 GHz. This antenna finds its applications in 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX, 4 GHz C band, and lower frequencies of X band. The effect of the truncated ground plane and the dimensions of U, T and rectangular shaped notches on the optimization of the return loss is parameterized and discussed in detail.

A novel E-shaped microstrip patch tri-band antenna for wireless applications

A novel tri band planar antenna is presented in this paper this antenna is operating in frequency range 2.383-2.4484 GHz, 2.991-3.405 GHz and 5.438-5.545 GHz. All these frequencies are used for various wireless applications. The designed antenna consists of modified E shaped slot in rectangular patch. For simulation and optimization of this antenna CST Microwave Studio Software is used. The proposed antenna isoperating in three bands with bandwidth of 65 MHz, 414 MHz and 107 MHz at 2.41 GHz, 3.16 GHz and 5.48 GHz respectively. The return loss of proposed antenna at all resonant frequencies is less than -20dB. This antenna is advantageous because the structure is very simple compared to other proposed frequency reconfigurable antennas and as Fr-4 is cheap and easily available material so the cost for making this antenna is very low.

A Compact Band-Reject Frequency Selective Surface with Stable Response for Wimax Applications

In this letter, a new design of compact band-reject frequency selective surfaces is proposed. Compared to previous compact structures, the FSS proposed has a better compact performance with the dimension of a unit cell only 0.082λ × 0.082λ where λ represents the wavelength of the resonant frequency. Above design rejects Wimax band (3.3-3.8) GHz. Moreover, the proposed design has a stable response with respect to different polarization characteristics and different incident angles of the incident plane wave. The squashed performance can further be improved by changing width of patch. The design is aimed at the rejection of Wimax band.

A compact microstrip - fed band rejection ultrawideband monopole antenna with balanced slot

A compact and microstrip-fed ultra-wideband antenna with band rejection characteristics is proposed. Band stop property is realized using a balanced slot. The range of stop band can be adjusted using length and width of inserted slot. The simulated impedance bandwidth of proposed antenna is from 3.2 GHz to 10.65 GHz for VSWR <; 2 while having the band rejection characteristics in the frequency range of 4.8 GHz to 5.8 GHz(UNII Band). Also by using stepped ground enhanced impedance bandwidth are obtained. This antenna shows good radiation and gain characteristics.