Ultra Wideband Signals and Systems in Communication Engineering

We propose a compact planar ultrawideband (UWB) antenna with 3.4/5.5 GHz dual band-notched characteristics. The antenna consists of a beveled rectangular metal patch and a 50 Omega coplanar waveguide (CPW) transmission line. By etching two nested C-shaped slots in the patch, band-rejected filtering properties in the WiMAX/WLAN bands are achieved. The proposed antenna is successfully simulated, designed, and measured showing broadband matched impedance, stable radiation patterns and constant gain. An equivalent circuit model of the proposed antenna is presented to discuss the mechanism of the dual band-notched UWB antenna. A UWB antenna and a single band-notched one are also provided for references.

A Compact Ultrawideband Antenna With 3.4/5.5 GHz Dual Band-Notched Characteristics

A novel compact printed ultrawideband (UWB) slot antenna for MIMO/diversity applications is presented in this letter. The antenna consists of two modified coplanar waveguides (CPWs) feeding staircase-shaped radiating elements for orthogonal radiation patterns, where a rectangle stub is placed at 45° between the CPW to ensure high isolations. By etching two split-ring resonator (SRR) slots on the radiators respectively, the band-notched property is achieved. Results show that this antenna meets a 10-dB impedance bandwidth and 15 dB isolation from 2.5 to 12 GHz, with a notched band at 5.5 GHz. The measurements of the radiation patterns and envelope correlation coefficient (ECC) denote that the antenna is suitable for multiple-input-multiple-output (MIMO)/diversity systems. Furthermore, it has a compact size of 48 × 48 mm2, which has been significantly reduced, and it is a good candidate for portable devices.

Compact Printed UWB Diversity Slot Antenna With 5.5-GHz Band-Notched Characteristics

New designs for compact reconfigurable antennas are introduced for mobile communication devices. The uniqueness of the antenna designs are that they allow various groups of their operating frequency bands to be selected electronically. In particular, each group of frequency bands, or mode, can be made to serve several different communication systems simultaneously. These systems may include various combinations of GSM, DCS, PCS, UMTS, Bluetooth, and wireless local-area network (LAN). Therefore, by electronically selecting different antenna modes, a variety of communication systems can be conveniently served by only one antenna. One advantage is that through the different operational modes, the total antenna volume can be reused, and therefore the overall antenna can be made compact. In these designs, the selection of the different modes is achieved by either i) switching different feeding locations of the antenna (switched feed) or ii) switching or breaking of the antenna's connection to the ground (switched ground). This paper demonstrates these two designs. For the first design of switched feed, it can support GSM, DCS, PCS, and UMTS. In the second design, the antenna makes use of a switched-ground technique, which can cover GSM, DCS, PCS, UMTS, Bluetooth, and 2.4 GHz wireless LAN. The designs are investigated when ideal switches and also various realistic active switches based on PIN diodes, GaAs field effect transistor, and MEMs configurations. The designs are verified through both numerical simulations and measurement of an experimental prototype. The results confirm good performance of the two multiband reconfigurable antenna designs.

Reconfigurable Multiband Antenna Designs for Wireless Communication Devices

Two CPW-fed elliptical monopoles were fabricated on liquid crystal polymer (LCP) with reconfigurable rejection band (band-notch) characteristics in the frequency range between 5 and 6 GHz. The first antenna uses a lambda/2 long, U-shaped slot and the second antenna uses two symmetrically placed lambda/4 long, inverted L-shaped stubs as resonating elements. Microelectromechanical system (MEMS) switches are used to activate and deactivate the resonating elements without the need of dc bias lines due to a novel design of the switch geometry. Transmission line models and surface current distributions are used to explain the effect of the added resonating elements. Reflection coefficient radiation pattern and gain measurements are presented to verify the design concepts featuring a very satisfactory performance.

UWB Elliptical Monopoles With a Reconfigurable Band Notch Using MEMS Switches Actuated Without Bias Lines

A planar monopole antenna with a staircase shape and small volume (25times26times1 mm3) is proposed in this paper. With the use of a half-bowtie radiating element, the staircase-shape, and a modified ground plane structure, the proposed antenna has a very wide impedance bandwidth measured at about 11.6 GHz (2.9-14.5 GHz, bandwidth ratio about 1:5) below VSWR 2 including the WLAN band notched in the vicinity of 5 GHz. An omnidirectional radiation pattern is obtained. The group delay which is an indication of linearity between two proposed antennas is less than 1 ns. The electrical characteristics in terms of frequency and time domains and physical ones of the proposed antenna make it attractive for use in ultrawideband (UWB) systems

A miniature UWB planar monopole antenna with 5-GHz band-rejection filter and the time-domain characteristics

This letter proposes a compact internal antenna of the modified planar inverted F antenna (PIFA) type with a parasitic patch. It also considers the influences of the handset case and battery. A low-profile design is implemented on both the top and bottom sides of the FR-4 substrate. The proposed antenna, with the small size of 27.5/spl times/12/spl times/7 mm/sup 3/, can be easily placed in the actual handset. The measured bandwidths of the proposed antenna with handset case and battery ( VSWR<2 ) can cover 140 MHz (1740-1880 MHz) in the Korean personal communication service (KPCS) band and 90 MHz (2400-2490 MHz) in the Bluetooth band. Numerical simulation and experiment results of antenna electrical performance are investigated by considering the antenna, the phone case, and the battery.

A dual-band internal antenna with a parasitic patch for mobile handsets and the consideration of the handset case and battery

This paper presents a dual-band internal WLAN PIFA for 2.4/5 GHz laptop applications in consideration of the influences of laptop housing and LCD. The prototype antenna is modified when installed along the perimeter of the display panel of the laptop housing. The proposed antenna has a small ground plane and achieves an impedance bandwidth of 250 MHz (2.37–2.62 GHz(in Bluetooth band and 950 MHz (4.98–5.93 GHz(near 5 GHz in WLAN band within 2:1 voltage standing wave ratio (VSWR(. It also shows good antenna gain with small volume. These features make it an alternative for use in dual-band WLAN antennas. Design details for the proposed antenna in the case of the antenna itself, and the application of laptop PC housing are described, and experimental results of the antenna achievements are investigated and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2349–2354, 2006;Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.21943

Dual-band internal wlan antenna for 2.4/5 GHz laptop PC applications

A noble planar monopole antenna with a staircase shape and very small volume (25 /spl times/ 26 /spl times/ 1 mm/sup 3/) is proposed in this paper. With the use of a half-bowtie radiation element, the staircase-shape, and a modified ground plane structure, the proposed antenna has a very wide impedance bandwidth measured at about 11.6 GHz (2.9 GHz /spl sim/ 14.5 GHz, bandwidth ratio about 1:5) below VSWR 2 including the WLAN band notched in the vicinity of 5 GHz. An omni-directional radiation pattern is obtained. The electrical and physical characteristics of the proposed antenna make it attractive for use in ultrawide band systems.

A miniature UWB planar monopole antenna with 5 GHz band-rejection filter

This paper presents a internal planar inverted-F antenna (PIFA) for 24/5 GHz Bluetooth and WLAN applications The proposed antenna has a small ground plane with the achievement of impedance bandwidth of 110 MHz (238 /spl sim/ 249 GHz) in the Bluetooth band and 900 MHz (51 /spl sim/ 60 GHz) near 5 GHz in WLAN band within 2:1 voltage standing wave ratio (VSWR), and an approximately omni-directional radiation pattern is obtained It also shows a good antenna gain These features make it alternative for use in dual-band WLAN antenna

http://ieeexplore.ieee.org/iel5/10688/33747/01606903.pdf

Young Jun Cho

Papers

A miniature UWB planar monopole antenna with 5-GHz band-rejection filter and the time-domain characteristics

A dual-band internal antenna with a parasitic patch for mobile handsets and the consideration of the handset case and battery

Dual-band internal wlan antenna for 2.4/5 GHz laptop PC applications

A miniature UWB planar monopole antenna with 5 GHz band-rejection filter

An internal PIFA for 2.4/5 GHz WLAN applications