Y.-Z. Yin

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.

Compact Tri-Band Rectangular Ring Patch Antenna with Asymmetrical Strips for WLAN/WiMAX Applications

A novel rectangular ring patch antenna with tri-band operation is presented for WLAN and WiMAX applications. The proposed antenna consists of a rectangular ring patch and a pair of straight strips with different lengths. By placing the two strips asymmetrically with respect to the microstrip feed line, the proposed antenna can operate in triple bands. The 10 dB return loss bandwidths of them are 310 MHz (2.39–2.70 GHz), 490 MHz (3.38–3.87 GHz) and 2680 MHz (4.82–7.50 GHz) respectively, which can cover both the WLAN bands (2.4–2.484 GHz, 5.15–5.35 GHz, and 5.725–5.825 GHz) and the WiMAX bands (2.4–2.6 GHz, 3.4–3.6 GHz, 5.25–5.85 GHz). In addition, the overall dimensions of this proposed antenna are 36 mm (length) × 20 mm (width) × 1 mm (thickness), which is compact compared to conventional tri-band antennas.

A Novel Triple-Band Monopole Antenna with Double Coupled C-Shaped Strips for WLAN/WiMAX Applications

In this paper, a novel triple-band monopole antenna with double coupled C-shaped strips for WLAN/WiMAX applications is presented. By adjusting the dimensions of the outer and inner C-shaped strips, three separated impedance bandwidths of 20% (2.28 ∼ 2.78 GHz), 14% (3.33 ∼ 3.83 GHz) and 19% (4.86 ∼ 5.86 GHz) can be obtained. Especially, the asymmetry inner C-shaped strip can be used to adjust the middle and high band characteristics. With these double coupled C-shaped strips, the proposed antenna shows a good triple-band property to satisfy the requirements of 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX 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 Y-Shaped Tri-Band Monopole Antenna with a Parasitic M-Strip for PCS and Wlan Applications

A Y-shaped tri-band monopole antenna is proposed in this paper. The antenna consists of a parasitic M-strip and an elliptical slot etched in the ground. With the helps of the parasitic M-strip and the slot, the Y-shaped monopole antenna can easily obtain tri-band characteristic. The proposed antenna has been constructed and tested. The simulated and measured results show that the proposed antenna has three good impedance bandwidths (VSWR < 2) of 220 MHz (about 26% centered at 1.85 GHz), 580 MHz (about 24% centered at 2.4 GHz) and 886 MHz (about 16% centered at 5.4 GHz), which make it easily cover the required bandwidths for PCS band (1850–1990 MHz), and WLAN band (2400–2480 MHz, 5150–5350 MHz, and 5725–5825 MHz) applications.

Study on a Dual-Band Notched Aperture UWB Antenna Using Resonant Strip and CSRR

An ultra-wideband (UWB) aperture antenna with dual band-notched characteristic is presented. The antenna consists of a circular monopole on the front side and a U-shaped aperture on the back ground plane. By attaching a rainbow-shaped resonant strip on the aperture plane and etching a complementary split ring resonator (CSRR) on the circular monopole, two notched band, 3.3–3.6 GHz for WiMAX and 5.15–5.825 GHz for WLAN, are achieved respectively. The antenna is successfully simulated and measured, showing that dual-band notched characteristic can be obtained by using two different structure. Moreover, the band notched structure is also studied based on the input impedance of the proposed antenna.

A Novel Band-Notched Antenna with Self-similar Flame Slot used for 2.4 Ghz Wlan and UWB Application

In this paper, a novel microstrip antenna with a self-similar flame-shaped slot fed by a microstrip-line is presented, which can work at both 2.4–2.5 GHz (WLAN) and 3.1–10.6 GHz (UWB). A C-shaped slot is etched on the patch to produce a notched band which can eliminate 5.15–5.825 GHz band-limited by IEEE 802.11a and HIPERLAN/2. Effects of varying the C-shaped slot parameters on the antennas performance show that the notched band can be finely tuned. The proposed antenna is simulated and measured. The measured results agree reasonably with the simulated ones. According to the measured results, the proposed antenna operates at the range of 2.36–11 GHz with VSWR < 2, except the notched band of 4.6–6 GHz for 5 GHz WLAN. The radiation characteristics of the proposed antenna satisfy UWB systems. The size of the actual antenna is 35 × 35 mm2.

Double Screen FSSs with Multi-Resonant Elements for Multiband, Broadband Applications

Design investigations are presented for double screen frequency selective surfaces (DSFSSs) with multi-resonant elements. The DSFSS is composed of two identical single layer frequency selective surfaces (FSSs) separated by a foam layer. By tuning the thickness of the foam, a four-band FSS with improved S-band performance and a dual-band band-stop FSS with broad bandwidths and rapid rolloffs are designed. Both designs are angle and polarization insensitive. The Fabry-Perot interferometer (FPI) theory demonstrates that DSFSSs with a large distance between the metallic arrays are not suitable for broadband band-stop applications due to the interruptions of undesired transmission peaks, which are the results of array interference. An equivalent circuit model is developed to give an insight into the response of the DSFSS. Experimental verifications are carried out. The calculated results agree well with the measured ones.

Study on a CPW-Fed UWB Antenna with Dual Band-Notched Characteristic

A compact ultra-wide band (UWB) CPW-fed antenna with dual band-notched characteristic is proposed. By using only one H-shaped slot etched on the radiation patch, two notched band, 3.3–3.6 GHz for WiMAX and 5.15–5.825 GHz for WLAN, are achieved. The antenna yields an impedance bandwidth of 3.1–10.6 GHz with VSWR < 2, except the notched bands. The antenna is successfully simulated and measured, showing dual band rejected characteristic can be obtained by using the only one H-shaped slot. Moreover, conceptual circuit model, which is based on the input impedance of the proposed antenna, is also shown to discuss the dual band notched characteristic.

A Novel Tri-Band Circular Slot Patch Antenna with an Ebg Structure for Wlan/WiMAX Applications

In this paper, an electromagnetic band-gap (EBG) structure is proposed to achieve tri-band operation for a novel circular slot patch antenna, which is suitable for WLAN and WiMAX applications. The proposed antenna consists of a rectangular radiation patch with an etched circular slot, a circular ring, and a mushroom-like EBG structure, all of which are printed on the top side of the substrate. By embedding a circular ring in the circular slot, the antenna can generate two impedance bandwidths. With the use of EBG structure, the proposed antenna can operate in three separate bands. Simulation results are compared with the measurements, and a good agreement is obtained. The measured results show that the 10 dB return loss bandwidths of the proposed antenna are 530 MHz (2.28–2.81 GHz), 470 MHz (3.29–3.76 GHz) and 1250 MHz (4.87–6.12 GHz), which can cover all the 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. In addition, a design evolution and a parametric study of the proposed antenna are presented to provide information for designing, modifying, and optimizing such an antenna. At last, good omnidirectional radiation patterns with appreciable gain are obtained over the operating bands.