Rashid Ahmad Bhatti

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.

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.

Hepta-Band Internal Antenna for Personal Communication Handsets

Modern personal communication handsets are shrinking in size and are required to operate at multiple frequency bands for enhanced functionality and performance. This poses an important challenge for antenna designers to build multiband antennas within the limited allowable space. In this paper, an internal antenna covering seven frequency bands is presented for personal communication handsets. The proposed antenna operates at GSM (880-960 MHz), DCS (1710-1880 MHz), PCS (1880-1990 MHz), UMTS (1900-2170 MHz), WiBro (2300-2390 MHz), Bluetooth (2.4-2.48 GHz), and WLAN (5.0-5.5 GHz) frequency bands. Measured input return loss of the antenna is better than dB at all the frequency bands with reasonable radiation performance. Antenna volume is 30 mm times15 mm times 4.0 mm (1.8 cm) that makes it attractive for modern multiband and multifunctional slim handsets.

Design of a Compact Internal Antenna for Multi-Band Personal Communication Handsets

In this paper, we propose a compact internal antenna for modern slim personal communication handsets that require reduced height multi-band antennas for location independent operation. The antenna operates at DCS, PCS, UMTS, WiBro, ISM/Bluetooth and WLAN (5.17 - 5.85 GHz) standards. Measured return loss of the antenna is better than -10 dB with acceptable radiation performance at all the targeted frequency bands. Height of the antenna is 4.0 mm resulting in a total volume of 1.5 cm3 that makes it attractive for modern slim personal communication handsets.

A Spiral-Dipole Antenna for MIMO Systems

A new circular polarization spiral-dipole antenna has been proposed for multilple-input-multiple-output (MIMO) systems. A dipole antenna is loaded with spirals at both of its ends to generate omnidirectional left-hand or right-hand circular polarization. The sense of polarization [left-hand circular polarization (LHCP) or right-hand circular polarization (RHCP)] depends on the orientation of the spirals. The measured bandwidth of the antenna is 8% at the center frequency of 5.2 GHz with 3.6-dBic gain. The isolation ( S 21) between collocated LHCP and RHCP antennas is better than 30 dB that makes them suitable for MIMO.

Design of a Novel Multiband Planar Inverted-F Antenna for Mobile Terminals

In this paper, we propose a PIFA based multiband internal antenna that can support seven frequency bands. The antenna is designed to operate at GSM (Global System for Mobile Communications, 880-980 MHz), PCS (Personal Communication Services, 1880-1990 MHz), UMTS (Universal Mobile Telecommunications System, 1.9-2.17 GHz), WiBro (2300-2390 MHz), Bluetooth (2.4-2.48 GHz), S-DMB (Satellite-Digital Multimedia Broadcasting, 2.630 ~ 2.655 GHz) and WLAN (Wireless Local Area Network, 5.16 ~ 5.5 GHz) frequency bands. Multiple frequency bands have been realized by using slots and quarter-wave length resonating strips. A matching stub and multiple short circuiting strips are utilized for improving impedance matching across the targeted frequency bands. A prototype antenna is fabricated and characterized by measuring return loss and radiation patterns. Comparison of the measured and simulated results is given in the paper.

Design of a Planar Slotted Waveguide Array Antenna for X-band Radar Applications

A planar slotted waveguide array antenna has been designed at 9.37 GHz for X-band radar applications. The antenna consists of multiple branchline waveguides with broadwall radiating shunt slots and a main waveguide to feed the branch waveguides through a series of inclined coupling slots. The antenna feed point is located at the center of the main waveguide. Element weights in the array have been calculated bysampling a continuous circular Taylor aperture distribution at the 25 dB sidelobe level in both the E and Hplanes. A commercially available electromagnetic (EM) simulation tool has been used to characterize the individual isolated slot and that data hassubsequently been used to design the planar array. The array is finally analyzed in a CST Microwave studio and the measured and simulated results have been found to be in good agreement.

Design of a novel multiband internal antenna for personal communication handsets

Modern personal communication handsets are required to operate at multiple frequency bands for location independent operation and enhanced functionality. This poses an important challenge for antenna designers to build multiband antennas within the limited allowable space. In this paper, a compact PIFA based internal antenna is proposed for GPS, DCS, PCS, UMTS, WiBro, ISM/Bluetooth and WLAN standards. Measured VSWR of the antenna is within the acceptable limit over all the frequency bands with reasonable radiation performance. Height of the antenna is 4.0 mm resulting in a total volume of 2.4 cm3 that makes it attractive for modern slim personal communication handsets.