Shou-Tao Fan

Triband Planar Monopole Antenna With Compact Radiator for WLAN/WiMAX Applications

A novel coplanar waveguide (CPW)-fed triband planar monopole antenna is presented for WLAN/WiMAX applications. The monopole antenna is printed on a substrate with two rectangular corners cut off. The radiator of the antenna is very compact with an area of only 3.5 × 17 mm2, on which two inverted-L slots are etched to achieve three radiating elements so as to produce three resonant modes for triband operation. With simple structure and small size, the measured and simulated results show that the proposed antenna has 10-dB impedance bandwidths of 120 MHz (2.39-2.51 GHz), 340 MHz (3.38-3.72 GHz), and 1450 MHz (4.79-6.24 GHz) to cover all the 2.4/5.2/5.8-GHz WLAN and the 3.5/5.5-GHz WiMAX bands, and good dipole-like radiation characteristics are obtained over the operating bands.

Bandwidth Enhancement of a Printed Slot Antenna With a Pair of Parasitic Patches

A printed microstrip-line-fed slot antenna with a pair of parasitic patches for bandwidth enhancement is proposed in this letter. By using the parasitic patches along the microstrip feed line, an additional resonance is excited, and a good performance of bandwidth enhancement can be obtained. The proposed antenna is designed and manufactured successfully. The measurement shows a good agreement with the simulation. From the measured results, the enhanced impedance bandwidth, defined by voltage standing wave ratio (VSWR) less than 2, is about 136% ranging from 2.1 to 11.1 GHz. In addition, stable and nearly omnidirectional far-field radiation patterns are observed over the entire operating band.

A NOVEL RECTANGULAR SLOT ANTENNA WITH EMBEDDED SELF-SIMILAR T-SHAPED STRIPS FOR WLAN APPLICATIONS

A novel rectangular slot antenna with embedded self- similar strips is proposed for wireless local area network (WLAN) applications. The proposed antenna comprises a T-shaped monopole and inverted self-similar strips embedded in the rectangular slot etched on the ground plane. The measured results of the fabricated antenna show that the impedance bandwidths (VSWR < 2) are 180MHz from 2.36 to 2.54GHz and 920MHz from 5.05 to 5.97GHz, which cover all the 2.4/5.2/5.8GHz WLAN operating bands. And the radiation patterns are almost omni-directional in the azimuthal plane within the lower operating bands.

A Novel Tri-Band Printed Monopole Antenna with an Etched ∩-Shaped Slot and a Parasitic Ring Resonator for WLAN and WiMAX Applications

A novel tri-band printed monopole antenna with an etched \-shaped slot and a parasitic ring resonator is proposed for satisfying wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications simultaneously. The proposed antenna comprises a rectangular radiation patch with an arc- shaped edge and an embedded \-shaped slot on the top and a parasitic ring resonator on the opposite side. The measured results show that the impedance bandwidths of the proposed antenna, deflned by voltage standing wave ratio (VSWR) • 1:5, are 350MHz (2370{2720MHz), 680MHz (3390{4070MHz) and 1080MHz (4920{6000MHz), which cover the required bandwidths for both WLAN (2400{2480MHz, 5150{5350MHz, 5725{5825MHz) and WiMAX (2500{2690MHz, 3400{3690MHz, 5250{5850MHz) applications. Furthermore, good monopole-like radiation characteristics with moderate peak gains are obtained over the operating bands.

A NOVEL SELF-SIMILAR ANTENNA FOR UWB APPLICATIONS WITH BAND-NOTCHED CHARACTERISTICS

A novel self-similar antenna for band-notched ultra- wideband (UWB) applications is proposed. The UWB performance is obtained by introducing a quasi-trapezoidal radiating patch and a self-similar ground plane. By etching two similar slots on the radiating patch, band-notched characteristic can be obtained. The measured results show that the antenna covers the band of UWB from 2.6 to 12.8GHz excluding the rejected bands from 3.3 to 3.6GHz and from 4.8 to 6.0GHz. In addition, the antenna exhibits nearly omni-directional radiation patterns and stable gains over the operating bands.

BROADBAND SINGLE-FED SINGLE-PATCH CIRCULARLY POLARIZED MICROSTRIP ANTENNA

The paper demonstrates a novel antenna which can achieve a broad impedance bandwidth and circularly polarized bandwidth with a suspended corner-truncated square patch and a new probe-fed rectangular strip. By incorporating a probe-fed rectangular strip inside a high substantial cavity (» 0:144‚0), a broad impedance bandwidth (VSWR < 2:0) of 770MHz (31.43%) is achieved. To obtain a good circularly polarized (CP) bandwidth matching with the impedance bandwidth, two stubs with optimized lengths are loaded at the non-radiating edges of the corner-truncated square patch symmetrically. Measured results show that the CP antenna features a wide operating bandwidth of 10% ranging from 2.41GHz to 2.66GHz (VSWR < 1:5 and axial ratio < 3dB) and that of 22.45% ranging from 2.31GHz to 2.86GHz (VSWR < 2 and axial ratio < 6dB) and good radiation patterns with cross-polarization level (LHCP) lower than the co-polarization level (RHCP) by more than 20dB at the broadside direction. The average gain of this antenna is recorded as about 8.16dBi across the operating bandwidth.

Compact Open-Ended L-Shaped Slot Antenna with Asymmetrical Rectangular Patch for UWB Applications

A novel compact open-ended L-shaped slot antenna with asymmetrical rectangular patch is demonstrated and designed for UWB applications. With the open-ended L-shaped slot and an asymmetrical rectangular patch fed by the micro-strip line, multiple resonant frequencies are excited and merged to form a measured widen operating bandwidth of 3.01 » 11.30GHz with 10dB return loss. The fractional bandwidth can be enhanced from previous 32% (3 » 4.15GHz) to 112% (3 » 10.66GHz) among three difierent antenna types in simulations. The details and vital parameters of the proposed slot antenna are also illustrated. In addition, the proposed slot antenna exhibits a small size of 25 £ 25mm 2 , which makes it an excellent candidate for UWB systems and portable applications.

BANDWIDTH ENHANCEMENT DESIGN OF COMPACT UWB STEP-SLOT ANTENNA WITH ROTATED PATCH

In this paper, a novel compact microstrip-fed ultra- wideband (UWB) step-slot antenna with a rotated patch is demonstrated and experimentally studied. With an efiective combination of the step-slot and rotated patch and proper dimensions bandwidth enhancement for UWB operation is obtained. From the simulated and measured results, the enhanced impedance bandwidth is brought up to about 117.5% from 2.88 to 11.08GHz deflned by 10dB return loss. Details of the proposed antenna are described, and experimental results are presented and discussed.

Novel smiling face-shaped antenna for dual band-notched ultra-wideband applications

This article presents the design of a novel ultra-wideband microstrip fed planar monopole antenna with dual band-notched characteristics. The shape of the antenna is a smiling face with double braids; its lovely and simple design has advantage to beatify the product By etching a mouth-shaped slot in the radiating patch and adding a double braids-shaped strip on the top, the dual notched bands for WiMAX and WLAN applications can be obtained, respectively. The eyes-shaped slots are just designed for beatification without affecting the characteristic of radiation. The simulated and measured results show that the center frequencies of the notched bands are greatly affected by the flare angle of the double braids-shaped strip and the mouth-shaped slot The fabricated antenna shows the broadband impedance-matching, stable gain, and near omnidirectional radiation pattern.

Compact UWB band-pass filter with ring slot resonator structure for improved upper stop-band suppression characteristic

In this paper, a novel ultra-wideband band-pass filter (UWB-BPF) is designed with the ring slot resonator (RSR), which is a hybrid micro-strip and ground slot resonator structure to yield a broad pass-band filtering characteristic. Using the modulated micro-strip stubs and a pair of slits etched on the RS R cell, the poor selectivity and almost no suppression at the upper spurious pass-band ca n be improved effectively. Simulated results are confirmed vi a experiment, showing a good UWB filtering performance with a fractional bandwidth of about 112% from 2.9 to 10.3GHz, a widened upper stop-band up to 20GHz with a rejection level better than 17.6dB, and a sharp skirt at 11.9GHz, simultaneously. In addition, a small area is only about 42.5% of the previous ones.