Chengyuan Liu

Analysis and Investigation of a Cantor Set Fractal UWB Antenna with a Notch-Band Characteristic

A coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna with a notch band characteristic is presented in the paper. The radiation patch of the proposed UWB antenna is designed using cantor set fractal technology. The bandwidth is broadened by setting two symmetrical triangular tapered corners at the bottom of the wide slot of the proposed UWB antenna. The notched band characteristic is achieved by employing a T-shaped tuning stub at the top of the wide slot. The notched band can be controlled by adjusting the length and the width of the T-shaped tuning stub to give tunable notched band function. The proposed cantor set fractal wide slot UWB antenna has been designed in details and optimized. Experimental and numerical results show that the proposed antenna, with compact size of 26 £ 21mm 2 , has an impedance bandwidth range from 2.8GHz to 11GHz for voltage standing-wave ratio (VSWR) less than 2, except the notch band frequency 5.0GHz{6.3GHz for HIPERLAN/2 and IEEE 802.11a (5.1GHz{5.9GHz).

Two UWB-MIMO antennas with high isolation using sleeve coupled stepped impedance resonators

Two printed ultra wideband (UWB) antennas integrated with stepped impedance resonators for Multiple Input Multiple Output (MIMO) communications applications are proposed in this paper. The proposed MIMO antennas consist of two simple printed microstrip-fed monopole antennas. The high isolations are obtained by using sleeve coupled rectangle stepped impedance resonator (R-SIR) and sleeve coupled roundness stepped impedance resonator (RD-SIR) on the ground plane, respectively. The proposed antennas operate over a wide impedance bandwidth ranging from 3.1GHz to 10GHz. And the antennas have high isolation over 23dB. The return loss and the isolation of the antenna are investigated by means of HFSS. The results show that the proposed UWB-MIMO antennas have high isolation and good impedance match characteristic.

A Novel UWB Filter with Notch-band Characteristic Using Radial-UIR/SIR Loaded Stub Resonators

This paper presents a novel approach for designing compact ultra-wideband (UWB) bandpass filter with a good notched band characteristic. A notch band characteristic is obtained by using the radial-uniform impedance resonators (UIR)/stepped impedance resonators (SIR) loaded stub resonator. The main advantage of the proposed filter is that the frequency of the notched band can be tuned easily in a wide frequency range. Current density and equivalent model is also given depending on the odd/even excitation resonance condition. The characteristics of the filter are analyzed. To verify the proposed methods, two filters are designed and fabricated. Measured results show that the proposed UWB properties from 3 to 10.8 GHz and the notch band can be changed optionally from 4 GHz to 10 GHz. These filters can be integrated in UWB radio systems and efficiently enhance the interference immunity from undesired signals such as wireless local area network (WLAN) and WiMAX.

A printed diversity Cantor set fractal antenna for ultra wideband communication applications

In this paper, a printed diversity Cantor set fractal antenna for ultra wideband (UWB) applications is proposed. The antenna consists of two identical wide slot antennas and the radiation patches are designed by using Cantor set fractal technology. The proposed antenna operates over a wide band spanning from 4.5 GHz to 10.6 GHz. The diversity antenna has a high isolation over 20dB. The high isolation is obtained using multiple slots etched in its CPW ground plane. The return loss and the isolation of the antenna are investigated by means of HFSS. The diversity performance of the antenna is assessed by isolation and radiation patterns. The results show that the proposed antenna provides stable patterns diversity, which enables the designed antenna to combat multi-path in wireless channels used in UWB systems.

A Toothbrush-shaped Patch Antenna for Millimeter-wave Communication

A printed toothbrush-shaped antenna is proposed for millimeter wave communication. The designed antenna features with a compact size is 7 × 10 mm2, and satisfies the VSWR requirement less than 2.0 in the frequency band from 32 GHz to more than 38 GHz. Simulated and measured results for main parameters such as return loss, impedance bandwidth, and radiation patterns are also discussed herein. The study shows that modeling of such antennas, with simplicity in designing and feeding, can well meet millimeter-wave wireless communication.

A SLEEVE MONOPOLE ANTENNA WITH WIDE IMPEDANCE BANDWIDTH FOR INDOOR BASE STATION APPLICATIONS

A sleeve monopole antenna, which has a wide impedance bandwidth for indoor base station applications, is successfully realized experimentally and numerically. The proposed antenna consists of dual sleeves, loaded circular disc and two shorted pins which are connected to the circular ground plane. The antenna possesses 14-dB impedance bandwidths of 30.3% and 46.5% at the lower and higher bands, respectively. And the 10-dB return loss bandwidth of the antenna is 128.2%, which is about 48 times that of the traditional monopolar wire- patch antenna. The antenna is successfully simulated, designed, and measured, showing dual-band and wide band characteristics, stable gain and good omni-directional radiation patterns.

Compact CPW-fed ultra-wide band antenna with dual band notched characteristics

A CPW-fed ultra-wideband antenna with dual band-notch characteristics is realized experimentally and numerically. Two notched frequency bands are obtained by utilizing a tuning stub between the fork-like radiation element and a rectangle slot in the CPW ground plane. The two notched bands can be controlled by adjusting the length of the tuning stub and the length of the rectangle slot. Experimental and numerical antenna shows that the proposed antenna, with compact size of 21×28mm2, has an impedance bandwidth ranging from 3.1GHz to 10.6GHz for voltage standing-wave ratio less than 2, expect two notch band frequency 5GHz-6GHz for WLAN and 7.7GHz-8.5GHz for X-band for satellite and military applications.

A compact wide slot antenna with dual band-notch characteristic for ultra wideband applications

A compact CPW-fed ultra-wideband antenna with dual band-notch characteristic is presented. Two notched frequency bands are obtained by embedding two U-shaped slots in the radiation patch and a rectangle slot in the ground plane. The two notched bands can be controlled by adjusting the length of the responding slots. The proposed antenna is successfully simulated, fabricated and tested. Experimental and numerical antenna shows that the proposed antenna with compact size of 21×28mm2, has an impedance bandwidth range from 3.1GHz to more than 11.0GHz for voltage standing-wave ratio less than 2, expect two notch band frequency 5GHz-6GHz for WLAN and 7.7GHz-8.5GHz for X-band for satellite communications in China.

Research on a novel microstrip UWB notch-band BPF

A novel microstrip UWB notch-band BPF is presented which has good out-of-band performance using hybrid microstrip/coplanar waveguide (CPW) structure. The proposed filter is comprised of a CPW open-end resonator and two short-circuited resonators whose performance has showed by simulation and experiment respectively. Measured results demonstrated the UWB properties from 3.4 to 9.1 GHz (−3 dB bandwidth), which is fractional bandwidth of 92% at the center frequency 6.2 GHz and the notch band can be changed optionally by adjustment of mismatch of the two resonators. In addition, the filter exhibits good out-of-band performance by the adoption of a short stub-loaded resonator.

Cantor set fractal antennas for switchable ultra wideband communication applications

Two Cantor set fractal antennas with switchable and notched band characteristics for ultra wideband (UWB) applications have been investigated in this paper. The notch functions are achieved using a U-shaped slot etched in the coplanar waveguide (CPW) ground plane and a T-shaped stub inserted in the inner of wide slot, respectively. The switchable characteristics are obtained using switches in the middle of the U-shaped slot and the T-shaped stub. The notch band can reduce the potential interference between UWB and wireless local area network (WLAN). The switchable characteristic can control the proposed antennas which can work in UWB, notch band UWB and dual band communication applications. The proposed antennas have been designed, simulated and analyzed in details herein.