Shadi Danesh

Novel Design of Compact UWB Dielectric Resonator Antenna With Dual-Band-Rejection Characteristics for WiMAX/WLAN Bands

A novel compact dual band-notched dielectric resonator antenna (DRA) for ultrawideband (UWB) applications is proposed. Here, the bandwidth enhancement and the first band notch is realized by embedding a stub that is located to the hollow center of a U-shaped feedline simultaneously. By etching an inverted T-shaped parasitic strip at the back plane of an antenna that is surrounded by a dielectric resonator (DR), the second band rejection is created. By cutting a slot at the proper position on the ground plane, the width of the second band notch is controlled. The proposed antenna size is 12 ×30 ×6 mm3 or about 0.124 λ×0.31 λ×0.062 λ at 3.1 GHz. The measurement results demonstrate that the proposed DRA provides acceptable radiation performances such as an ultra-wide impedance bandwidth of around 122% with two sufficient band rejections in the frequency bands of 3.22-4.06 and 4.84-5.96 GHz, high radiation efficiency, and nearly constant gain.

Frequency-Reconfigurable Rectangular Dielectric Resonator Antenna

A coplanar waveguide (CPW) reconfigurable dielectric resonator antenna (DRA) is presented and investigated. The DRA is capable of frequency tuning at three different frequency bands between 3.45 and 6.77 GHz. The overall size of the antenna is 50 × 57 mm2. The dielectric material is a rectangular block of ceramic with a permittivity of 15. Two switches, implemented using p-i-n diodes, are located on the lines of a feed network that is connected to the dielectric element. Single-band modes with impedance bandwidths of 8% and 16% are achieved by switching “on” one of three connecting feedline networks, whereas a wide band, with an impedance bandwidth of 65%, is achieved by switching “on” two connecting lines. Frequencies in the single band can be independently controlled using switch positions without affecting the wideband mode. The prototype has a low profile with a dielectric resonator thickness of 4 mm. The characteristics of this antenna were studied, and good agreement was found between the numerical and measured results.

A Compact Frequency-Reconfigurable Dielectric Resonator Antenna for LTE/WWAN and WLAN Applications

A compact frequency-reconfigurable dielectric resonator antenna (DRA) for LTE/WWAN and WLAN applications is investigated and presented. The proposed antenna provides the frequency tuning between 1.60 and 2.71 GHz. The design consists of four identical rectangular dielectric resonators with permittivity of 10 each and three p-i-n diode switches that are located on the feedline network between each of two dielectric resonators. The proposed antenna size is 20 ×36 ×5.57 mm3, which is suitable for mobile devices. The measurement and simulation results are applied to demonstrate the performance of the proposed antenna. From the measured results, it is found that the proposed antenna with acceptable performance provides four single-band modes with the impedance bandwidths of 17%, 11%, 14%, and 6%.

A wideband trapezoidal dielectric resonator antenna with circular polarization

A new design of a circularly-polarized (CP) trapezoidal dielectric resonator antenna (DRA) for wideband wireless application is presented. A single-layered feed is used to excite the trapezoidal shaped dielectric resonator to increase resonant frequency and axial ratio. Besides its structure simplicity, ease of fabrication and low-cost, the proposed antenna features good measured impedance bandwidth, 87.3% at 4.21 GHz to 10.72 GHz frequency bands. Moreover, the antenna also produces 3-dB axial ratio bandwidth of about 710 MHz from 5.17 GHz to 5.88 GHz. The overall size of DRA is 21 mm × 35 mm, which is suitable for mobile devices. Parametric study and measurement results are presented and discussed. Very good agreement is demonstrated between simulated and measured results.

Planar wideband circularly polarized dielectric resonator antenna

A wideband and compact circularly polarized (CP) C-shaped dielectric resonator antenna (DRA) is presented. The proposed C-shaped DR is excited by a microstrip feed in one side of the dielectric substrate. DR is housed inside the thin dielectric substrate above the vertical ground plane edge. By using one narrow short circuit strip, CP bandwidth of the proposed antenna is enhanced. The final design achieves CP with 44% axial ratio (AR) bandwidth. The proposed circularly polarized DRA with good radiation characteristics offers an impedance bandwidth of 67% between 3.35 and 6.76GHz for VSWR <; 2.

Ultra wideband dielectric resonator antenna design

An ultra-wideband dielectric resonator antenna (DRA) is studied and investigated for wireless application. The dielectric resonator is fed by a microstrip line. The overall size of the proposed DR antenna is 20 × 35 mm2, and the thickness of the dielectric resonator is only 5.12 mm, which is suitable for mobile device. The design simulation is done by using computer simulation Technology Microwave studio suite 2012 (CST). The results represent that by using N-shaped dielectric resonator, a wideband impedance bandwidth of 111% for VSWR≤ 2 covering a frequency range from 3.59 to 12.61 GHz. A parametric study is presented.