Seong-Ook Park

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

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

Analysis of the small band-rejected antenna with the parasitic strip for UWB

A novel band-rejected ultrawideband antenna with one parasitic strip is presented in this paper. It is designed to work on a substrate FR4 that has a thickness of 1 mm and relative permittivity of 4.6, and to operate from 3 to 17 GHz. The proposed antenna is fed by microstrip line and utilizes the parasitic strip to reject the frequency band (5.15-5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2. The size of the antenna is 20/spl times/20 mm/sup 2/ and this antenna has good radiation characteristics. Effects of varying the location and length of the parasitic strip and the structure of the ground and monopole patch on the antenna performance have also been studied.

Compact Antenna Array With Port Decoupling for LTE-Standardized Mobile Phones

A compact dual-element antenna has been designed at 710 MHz for newly emerging long-term evolution (LTE) personal wireless communication standard applications. The proposed antenna consists of two printed meander-line monopoles with edge-to-edge separation of nearly ¿/45. The antenna elements are printed on FR-4 substrate and are located at the top edge of the ground plane measuring 50 × 87 mm2. An LC-components-based branchline hybrid coupler is used to decouple the antenna elements. The prototype antenna has been evaluated through the scattering parameters, radiation patterns, envelope cross correlation, and the channel capacity measurements. Isolation between the ports is better than 35 dB with matched ports at 710 MHz. The antenna offers reasonable multiple-input-multiple-output (MIMO) performances that make it suitable for LTE-standardized mobile phones.

Analysis of Mutual Coupling, Correlations, and TARC in WiBro MIMO Array Antenna

This paper presents the evaluation of multiple-input-multiple-output (MIMO) arrays by analyzing the mutual coupling, correlation coefficient, and total active reflection coefficient. The meaning and analysis of the three parameters are demonstrated in this paper. We show the effect of spatial and pattern diversity on MIMO arrays. We also attempt to achieve optimization of the array antennas allocation for wireless broadband MIMO applications by performance evaluation

A Simple PIFA-Based Tunable Internal Antenna for Personal Communication Handsets

A simple planar inverted F antenna (PIFA)-based tunable internal antenna is proposed for personal communication handset applications. The antenna can covers following frequency bands: DCS (1710-1880 MHz), PCS (1880-1990 MHz), UMTS (1900-2170 MHz), WiBro (2300-2390 MHz), WLAN (5.2 and 5.8 GHz), Bluetooth (2400-2480 MHz), and ISM band (2500-2700 MHz). Varactor diode is used to get tuning over the wide frequency range. Overall size of the antenna is 19.5 mm times 9.5 mm times 4 mm (0.741 cm3) makes it suitable for 4 G handsets and can be easily integrated inside commercial mobile handsets. The antenna was designed and optimized by using CST microwave studio program. Measured return losses (S11) and radiation patterns of the antenna were carried on Anritsu 37377C vector network analyzer and in standard anechoic chamber room. Return loss of the antenna is within acceptable limit with reasonable radiation performance.

3D Polarized Channel Modeling and Performance Comparison of MIMO Antenna Configurations With Different Polarizations

We propose a three-dimensional (3D) polarized MIMO channel model, which takes into account 3D power angular spectrum and comprehensive propagation characteristics of electromagnetic waves excited by polarized antennas. Based on the model, we derive a close form expression of the spatial correlation as a function of the physical parameters representing both characteristics of arbitrary antennas and propagation environment in 3D space. The spatial correlation expression allows to use the Von Mises Fisher (VMF) distribution, resulting in a more accurate and general channel model. Through simulation, we evaluate and compare performance, in terms of the spatial correlation and capacity, of 2 × 2 MIMO configurations with different polarizations, i.e., V/V, V/H, and slanted ±45° polarizations, as a function of critical input parameters including elevation angle, antenna orientation, antenna spacing, cross-polarization discrimination (XPD), and signal-to-noise ratio (SNR). The effect of the parameters on the performance is analyzed, and verified in certain cases through the literature.

Quad-Band MIMO Antenna Array for Portable Wireless Communications Terminals

A low-profile quad-band antenna array for multiple-input-multiple-output (MIMO)-enabled wireless communication terminals has been presented in this letter. The proposed dual-element antenna array operates at the following frequency bands: 2.4-2.5 GHz, 3.4-3.6 GHz, 5.15-5.35 GHz, and 5.75-5.875 GHz. A combination of a C-shaped slot and a T-shaped slit is used to excite three current modes in a conventional single-band planar inverted-F antenna (PIFA). A lambda/4 resonator is integrated into the triband antenna structure in order to get an additional resonance for quad-band operation. The proposed array has been designed over a small ground plane measuring 50times100 mm2, whereas each element in the array occupies a volume of 0.63 cm3. Mean effective gain (MEG) and envelop correlation analysis have been used for the array analysis in addition to the capacity and diversity gain measurements in a reverberation chamber. The prototype array exhibits quite low mutual coupling with good input return losses at the desired four frequency bands.

A PIFA-Type Varactor-Tunable Slim Antenna With a PIL Patch Feed for Multiband Applications

A novel varactor-tuned compact multiband slim antenna for covering the digital cellular system (DCS; 1710-1880 MHz), personal communication service (PCS; 1850-1990 MHz), Universal Mobile Telecommunications System (UMTS; 1900-2200 MHz), WiBro (2300-2390 MHz), and wireless LAN (WLAN; 5150-5350 and 5725-5850 MHz) bands is presented. The proposed antenna consists of a main patch and a planar inverted-L (PIL) patch with a feed line for the broadband characteristic. A varactor diode is attached to the radiating element for frequency shift. This antenna occupied in a total volume of 27 mm times 11 mm times 5 mm can be easily placed in commercial mobile handsets. The computer simulation technology (CST) microwave studio is used to design and optimize the antenna. We found good agreement between the simulated and measured results

Analytical evaluation of the asymptotic impedance matrix of a grounded dielectric slab with roof-top functions

An analytical technique is derived to solve the asymptotic part of impedance matrix elements for printed circuit structures using roof-top subdomain expansions. The key to this problem is the analytical transformation from an infinite double integral to a suitable finite one-dimensional (1-D) integral. The newly developed formula is applied to the monostatic radar cross section (RCS) of a microstrip patch. Comparisons are made with measurements and conventional method of moments predictions.

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

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.