Miniature transparent UWB antenna with tunable notch for green wireless applications

Copyright @ 2011 IEEEA miniature transparent UWB antenna with tunable notch that can be incorporated with a solar panel for harnessing solar energy has been proposed and presented. The antenna demonstrates a good omni-directional radiation pattern throughout the FCC bandwidth of 3.1 – 10.6 GHz and a comparable gain making it a good candidate for future green wireless applications

Planar Monopoles with Different Radiator Shapes for UWB Body-centric Wireless Communications

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A 5 th-order analog predistorter for NADC system

This paper presents the design of a 5th-order analog predistorter using the inband intermodulation (IM) signals for predistortion of base-station high power amplifiers (HPAs) for the North American Digital Cellular (NADC) system. The predistorter employs two mixers with same configuration to generate 3rd-order intermodulation (IM3) products and 5th-order intermodulation (IM5) products, to suppress the 3 rd-and 5th-order intermodulation distortion products (IMDP3 and IMDP5) at the HPA output. The predistorter is implemented and tested using the pi/4-DQPSK signal of the NADC system at 2.2GHz in a practical 100W-HPA. The results show that, at the HPA output powers of 65.6, 56.2, 50 and 41.3 W, the predistorter can suppress the adjacent channel power ratio (ACPR) of the pi/4-DQPSK signal at ± 20 kHz from the center frequency by 15.16, 15.83, 16.17 and 15.17 dB, respectively. © 2010 IEEE.published_or_final_versionThe 12th IEEE International Conference on Communication Systems (ICCS 2010), Singapore, 17-19 November 2010. In Proceedings of 12th ICCS, 2010, p. 19-2

Design of 5 th-order analog predistorter

This paper presents the design of a 5th-order analog predistorter to suppress the 3rd-and 5th-order intermodulation distortion products (EVTDP3 and EVTDP5) at the output of a base-station power amplifiers (PAs). The predistorter consists of two mixers: one mixer generating the 3rd-order intermodulation (IM3) products and another mixer of same configuration generating the 5th-order intermodulation (IM5) products using the IM3 products generated by the other mixer, thus simplifying the design and hardware implementation. The predistorter is implemented and tested using two-tone and the CDMA (IS-95) signals at 2.2GHz in a practical 10W-PA. The two-tone test results show that the proposed predistorter can suppress the IMDP3 and IMDP5 by 17dB and lldB, respectively. For the CDMA (IS-95) test, results show that the predistorter can improve the adjacent channel power ratio (ACPR) by 10 dB at ± 887 kHz from the center frequency. © 2010 IEEE.published_or_final_versionThe 2010 IEEE Region 10 International Conference (TENCON 2010), Fukuoka, Japan, 21-24 November 2010. In TENCON (IEEE Region 10 Conference) Proceedings, 2010, p. 876-87

Dual-band monopole antenna with frequency-tunable feature for WiMAX applications

A planar dual-band monopole antenna with a frequency-tunable band is presented. The structure of the antenna radiator has a stem connecting to two branches that are used to generate two frequency bands at around 2.4 and 3.4 GHz for Worldwide Interoperability for Microwave Access (WiMAX) applications. The lower band covers the WiMAX frequency band of 2.3-2.4 GHz, while the higher band is frequency-tunable to the WiMAX frequency bands of 3.3-3.4, 3.4-3.6 and 3.6-3.8 GHz. The frequency tunability is achieved by using the reverse-bias voltage across a varactor that is placed between the stem and one of the radiating branches of the radiator. In this study, the radiating branch responsible for the higher band is selected for tuning. A simple and novel biasing circuit, consisting of two radio frequency (RF) choke resistors and an L-shaped stub, is designed for biasing the varactor. Results show that the higher band can be continuously tuned in frequency, yet keeping the lower band unchanged. The reflection coefficient, radiation pattern, and efficiency of the antenna are studied using computer simulation and measurement. © 2013 IEEE.published_or_final_versio

An ISM/UWB antenna with offset feeding and slotted ground plane for body-centric communications

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A dual-band antenna for wireless USB dongle applications

In this paper, the design of a dual-band antenna for universal-serial-bus (USB) dongle applications in the 2.4-GHz wireless-local-area network (WLAN) and 3.5-GHz Worldwide Interoperability for Microwave Access (WiMAX) systems is presented. The antenna consists of two folded inverted-F radiating elements. One inverted- F element generates a 2.45-GHz band for the WLAN band (2.4-2.484 GHz), and both inverted-F elements together resonate at around 3.5 GHz to generate a wide frequency band for the WiMAX system (3.3-3.8 GHz). The antenna is designed on a 25×70 mm2 printed-circuit board (PCB), same size of an USB dongle PCB. For verification of simulation results, a prototype is fabricated and measured. Measured results show that the antenna has two impedance bandwidths, 2.39-2.5 GHz and 3.24-3.8 GHz, for the WLAN and WiMAX applications, respectively. The simulated and measured radiation patterns, efficiencies and gains of the antenna are all presented. © 2013 IEEE.published_or_final_versio

Dual-band antenna with compact radiator for 2.4/5.2/5.8 GHz WLAN applications

This paper presents a dual-band planar antenna with a compact radiator for 2.4/5.2/5.8-GHz wireless local area network (WLAN) applications. The antenna consists of an L-shaped and $E$-shaped radiating elements to generate two resonant modes for dual-band operation. The L-element fed directly by a 50-Ω microstrip line is designed to generate a frequency band at around 5.5 GHz to cover the two higher bands of the WLAN system (using the IEEE 802.11a standard). The E-element is coupled-fed through the L-element and designed to generate a frequency band at 2.44 GHz to cover the lower band of the WLAN system (using the 802.11 b/g standards). As a result, the L-and E-elements together are very compact with a total area of only 8× 11.3 mm 2. Parametric study on the key dimensions is investigated using computer simulation. For verification of simulation results, the antenna is fabricated on a 40× 30× 0.8mm3 substrate and measured. The effects of the feeding cable used in the measurement system and the housing and liquid crystal display of wireless devices on the return loss, radiation pattern, gain and efficiency are also investigated by computer simulation and measurement. © 2012 IEEE.published_or_final_versio

Simple dual-band notched design for CPW-coupled-fed elliptical UWB monopole antenna

This paper presents the results of a CPW-coupled-fed elliptical UWB monopole antenna (CCFEUMA) with a simple dual-band notched design for the WLAN Band. The antenna has a large bandwidth covering the frequency band from 2.5 to 14.6 GHz with the return loss larger than 10 dB. Two band notches at the lower (5.15-5.35 GHz) and higher (5.725-5.825 GHz) WLAN band are realized by cutting two half-elliptical arc-slots on the radiator. The return loss, radiation pattern, peak gain and efficiency of the antenna are studied using computer simulation and measurement. © 2012 IEEE.published_or_final_versio

A small patch antenna using a single CRLH TL unit cell

IEEE Radio Wireless Week 2012 (RWW2012)This paper presents the design of a small patch antenna, which consists of one unit cell of composite right/left handed transmission line (CRLH TL). Due to the resonant frequency of the CRLH TL unit cell is determined not by the physical length but by the inductance and capacitance values loaded in the cell, the size of the patch antenna consisting CRLH TL unit cell can be reduced by tuning the LC values. The antenna is fed by a microstrip line. In order to improve the matching, a thinner microstrip line and two rectangular notches etched on the patch are used. The patch antenna including the feeding line is fabricated on a 33 cm 2 substrate with r of 3.5 and thickness of 1.5 mm. The size of the patch is reduced to 9 mm12.9 mm, which is 0.18 g0.26 g at the resonant frequency of 3.59 GHz, owing to the characteristic of the CRLH TL unit cell. The measured results exhibit a bandwidth of 24 MHz and conventional patch-like radiation pattern. The gain of 4.7 dBi and efficiency of 20% are achieved. © 2012 IEEE.published_or_final_versionThe 2012 IEEE Radio and Wireless Symposium (RWS), Santa Clara, CA., 15-18 January 2012. In IEEE Radio and Wireless Symposium Proceedings, 2012, p. 299-30