Guo-Ping Gao

A DOUBLE-PRINTED TRAPEZOIDAL PATCH DIPOLE ANTENNA FOR UWB APPLICATIONS WITH BAND- NOTCHED CHARACTERISTIC

In this paper, a novel double-printed trapezoidal patch dipole antenna suitable for UWB applications with band-notched characteristic is presented and investigated. The band-notched characteristic is achieved by inserting T-shape slots on the trapezoidal radiating patches. The impedance characteristic, radiation patterns and the transfer function are studied. Experimental results show that the proposed antenna covers the entire UWB band (3.1{10.6GHz) while it has a notched band for the IEEE 802.11a frequency band (5.15{5.825GHz). Measured group delay, transmission characteristics and Time domain characteristics indicate that the proposed antenna satisfles the requirement of the current wireless communications systems.

A PRINTED VOLCANO SMOKE ANTENNA FOR UWB AND WLAN COMMUNICATIONS

A novel printed version of the classic volcano smoke antenna is presented and investigated in this article. The effects of some important parameters on the VSWR of the proposed antenna have been investigated in the design. The measured bandwidth of VSWR< 2 is from 1.80 to 14.35GHz, which covers all UWB (3.1– 10.6 GHz) and 2.4 GHz WLAN (2.4–2.4835 GHz) bands. Moreover, the antenna features near omnidirectional characteristics in the operation range and good radiation efficiency. A gain variation from 2.04 to 7.02 dBi (2–13 GHz) is obtained.

Removal of Ocular Artifacts in EEG—An Improved Approach Combining DWT and ANC for Portable Applications

A new model to remove ocular artifacts (OA) from electroencephalograms (EEGs) is presented. The model is based on discrete wavelet transformation (DWT) and adaptive noise cancellation (ANC). Using simulated and measured data, the accuracy of the model is compared with the accuracy of other existing methods based on stationary wavelet transforms and our previous work based on wavelet packet transform and independent component analysis. A particularly novel feature of the new model is the use of DWTs to construct an OA reference signal, using the three lowest frequency wavelet coefficients of the EEGs. The results show that the new model demonstrates an improved performance with respect to the recovery of true EEG signals and also has a better tracking performance. Because the new model requires only single channel sources, it is well suited for use in portable environments where constraints with respect to acceptable wearable sensor attachments usually dictate single channel devices. The model is also applied and evaluated against data recorded within the EUFP 7 Project-Online Predictive Tools for Intervention in Mental Illness (OPTIMI). The results show that the proposed model is effective in removing OAs and meets the requirements of portable systems used for patient monitoring as typified by the OPTIMI project.

Double-printed U-shape Ultra-wideband Dipole Antenna

A double-printed u-shape antenna for ultra-band application is proposed in this paper. With two U-shape dipole arms printed on the dielectric substrate and fed by a microstrip line, the antenna realized its ultra-wideband character by multistage impedance conversion. The impedance characteristic, radiation patterns and the transfer function are studied both by numerical simulation and experiment. The radiation patterns are approximately omni-directional with the VSWR < 2 from 3.08 to 11.57 GHz. Both transfer functions and group delay are smooth with linear phase which is valuable for the transmission of UWB signals.

Bending and On-Arm Effects on a Wearable Antenna for 2.45 GHz Body Area Network

Three types of flexible textile antennas for 2.45 GHz body area network (BAN) are compared in this letter. Two types of conducting materials are used to form radiation patch and ground plane; they are called copper foil tape (CFT, 0.05 mm thickness) and Shieldex (SH, 0.13 mm thickness, 0.009 Ohm surface resistivity). The substrate is a thin felt with relative permittivity of 1.2 and the thickness of 2 mm. In order to satisfy these requirements of small frequency shifting when the antenna is bent and placed on human body, two shorting probes are used to connect the radiation patch and ground plane. Compared to the antenna without shorting probes, the size of proposed antenna is reduced from 96 ×47 to 70 ×25 mm2, and the measured minimum value of S11 in free space is also decreased from -14.59 to -33.30 dB. Furthermore, an antenna with smaller size of 46 ×25 mm2 is designed by modifying the proposed structure, and it can act as a wearable antenna as well.

Double-Printed U-Shaped Dipole Antenna with Band-Notched Function for UWB Communications

A novel double-printed U-shaped dipole antenna with a band-notched function suitable for UWB application is presented and investigated in this paper. The band-notched characteristic is achieved by connecting L-shaped strips to the antenna rather than inserting slot to the antenna. Compared with cutting slot on the antenna, the method of connecting L-shaped strips is more suitable for the U-shaped dipole antenna because of the limited space to locate the slot. The measured results show that the frequency band of VSWR < 2 covers 3.1 to 10.6 GHz UWB band, while the notched frequency range is 5.10–5.88 GHz which covers 5 GHz WLAN band of 5.15–5.825 GHz. Transfer function and time domain characteristics are also studied in this paper.

A CPW-FED C-Shape Arc Slotted Monopole UWB Antenna with Band-Notched Characteristic

In this paper, a printed C-shape monopole antenna with band-notched feature for UWB application is presented and investigated. By inserting a circular arc slot on the C-shape radiator, the band-notched characteristic is achieved. The measured results show that the proposed antenna meets the requirement of wide-working band-width of 3.1–10.6 GHz with VSWR < 2, while avoiding the interference with the WLAN band (5.15–5.825 GHz). The proposed antenna has a compact size, good radiation characteristics, ultra wide band-width, and good time-domain behaviors to satisfy the requirement of the current wireless communications systems.

Frequency Domain and Time Domain Study of a Novel Compact CPW Fed Monopole UWB Antenna with L Shaped Slots for Band Notched Characteristics

In this paper, the design, simulation and fabrication of a CPW fed monopole UWB antenna with band-notched function suitable for UWB application are presented and investigated. The band---notched characteristic is achieved by inserting two L shaped slots symmetrically in the radiation element. Experimental results show that the proposed antenna meets the requirement of VSWRi?ź<i?ź2 in the working bandwidth of 3.1---10.6i?źGHz except the stop band 5.0---5.9i?źGHz for avoiding the WLAN band. The study of transfer function magnitude of S21 and group delay and time domain characteristic fidelity and power spectrum density PSD verify the band-notched function of the antenna. The proposed antenna have compact size, good radiation characteristics, ultra wide band-width and good time-domain behaviors, which satisfy the requirement of the current wireless communications systems.

Parallel feed wearable ZigBee antenna with symmetry meander lines

A flexile, compact textile antenna that operates in the 2.4 GHz Zigbee band is proposed. The substrate and conductive plane are constructed by textile materials, which make it is easily to be integrated with clothes and also comfortable to be wear. Two types of conductive materials are used to form the radiation element and ground plane. The measured result shows that the impedance bandwidth of antenna with SH is 5.1% and antenna with CFT is 1.62%. The minimum value of S11 of antenna with SH is -22.96 dB and antenna with CFT is -25.77 dB. The effects of human body and antenna bending are studied in this letter. The simulated and measured results show that the proposed antenna is very suitable for body area network.

Transfer Function Characteristics of a Printed Rectangular Dipole UWB Antenna

Transmitting transfer function and receiving transfer function of a printed dipole UWB antenna based on frequency domain measurement are studied in this paper. The measured results show that the amplitude of Transmitting transfer function is quite flat, and the phase responses of transfer functions are linear in 3.1-10.6 GHz band. The group delay and impulse responses of transfer functions are also studied. Furthermore, radiated pulse is obtained by convolving the input signal with the impulse response of the transmitting antenna, and the result is validated by software simulation.