A Novel Dual-Band Printed Diversity Antenna for Mobile Terminals

Abstract

A novel dual-band printed diversity antenna is proposed and studied. The antenna, which consists of two back-to-back monopoles with symmetric configuration, is printed on a printed circuit board (PCB). The effects of some important parameters of the proposed antenna are deeply studied and the design methodology is given. A prototype of the proposed antenna operating at UMTS (1920 ~ 2170 MHz) and 2.4-GHz WLAN (2400 ~ 2484 MHz) bands is provided to demonstrate the usability of the methodology in dual-band diversity antenna for mobile terminals. In the above two bands, the isolations of the prototype are larger than 13 dB and 16 dB, respectively. The measured radiation patterns of the two monopoles in general cover complementary space regions. The diversity performance is also evaluated by calculating the envelope correlation coefficient, the mean effective gains (MEGs) of the antenna elements and the diversity gain. It is proved that the proposed antenna can provide spatial and pattern diversity to combat multi-path fading. Index Terms-Diversity antenna, diversity gain, dual-band antenna, envelope correlation coefficient, mean effective gain (MEG). I. INTRODUCTION ntenna diversity is a well-known technique to enhance the performance of wireless communication systems by reducing the multi-path fading and co-channel interference [1]. Nowadays, in a cellular communication system, it is easy to be implemented at the base station where antenna separations of many wavelengths are readily available. However, in order to improve the quality of wireless downlink signal, more than one antenna is necessary for the terminal side. In this kind of mobile terminal, two or more antenna elements are envisaged and the restricted space available for antenna is an open issue [2]. Most designs of diversity antenna in mobile terminals are for WLAN operation [3][4], and they are applied in the PCMCIA

Compact Dual-Band Printed Diversity Antenna for Wimax/Wlan Applications

“…Generally, low envelope correlation may mean less overlapping between the two beam patterns. The envelope correlation coefficient can be calculated by using Sparameters or radiation patterns which are described in detail in [28] and [12,15,29,30], respectively. Here, the correlation coefficient, ρ eij , between the ith and jth elements (i, j = 1 to n, where n is the total number of antenna elements) is calculated through the complex correlation coefficient ρ cij as shown in Equation (3) [29]: Figure 14.…”

“…Thus, integrating multiple antennas closely in a small and compact mobile device while maintaining good isolation between them is a challenging task. A lot of efforts have been made to reduce the mutual coupling or enhance the isolation between closely placed antenna elements [7][8][9][10][11][12][13][14][15][16]. Decoupling networks for enhancing the port isolation between two closely spaced antennas are presented in [6,7].…”

“…Though good isolation is obtained by using these methods, they make the antenna complex and increase the cost of manufacture. Various ground branches such as T-shaped branch [8][9][10], vertical branch [11], dual inverted L-shaped branches [12], tree-like structure branches [13] are applied to achieve high isolation. By linking two planar inverted F antennas (PIFAs) with a suspended strip to cancel the reactive coupling, the isolation between them can be improved [14][15][16].…”

A Compact Four-Element Uwb Mimo Antenna With Qsca Implementation

“…Table 1 illustrates the measured total efficiencies and peak gains of the proposed MIMO array, which shows that the array has good efficiencies in 74∼91% and reaches high peak gains in 3.8∼5.4 dBi. According to [11][12][13], in an isotropic channel condition, the Table 2 gives the measured envelope correlation coefficients (ECC) of the proposed four-element UWB MIMO array, which are calculated by using far-field radiation patterns. It can be read that the far-field ECCs are all below 0.04 which make sure that the pattern correlation between antenna elements is quite low and obtain high diversity performance.…”

A Compact Multiband U Shape MIMO Antenna for Wireless Application

“…Two simple stubs and ground strips were applied to achieve isolation between two elements and increase the bandwidth. [9] All of the aforementioned techniques decreases the reflection coefficient, and therefore a wide impedance bandwidth with high isolation is difficult to obtain. Several methods used to increase the bandwidth of Microstrip antenna in addition to the common techniques of increasing the patch height, decreasing substrate permittivity.…”