I-Fong Chen

A Novel Hexa-Band Antenna for Mobile Handsets Application

A novel hexa-band antenna for mobile handsets application is proposed and analyzed in this communication. An asymmetric T-type monopole antenna with a shorted-line is designed to be operated in code-division multiple access (CDMA, 824-894 MHz), global system for mobile communications (GSM, 880-960 MHz), digital communication system (DCS, 1710-1880 MHz), personal communication system (PCS, 1850-1990 MHz), wideband code division multiple access (WCDMA, 1920-2170 MHz) and Bluetooth (2400-2484 MHz) bands. A prototype of the proposed antenna with 50 mm in length, 3 mm in height and 15 mm in width is fabricated and experimentally investigated. The experimental results indicate that the VSWR 2.5:1 bandwidths achieved were 17.8% and 37.1% at 900 MHz and 2100 MHz, respectively. The specific absorption rate (SAR) for an input power of 24 dBm in CDMA, GSM and WCDMA bands, and an input power of 21 dBm in DCS and PCS bands all meet the SAR limit of 1.6 mW/g. Experimental results are shown to verify the validity of theoretical work.

Bandwidth Enhancement of Internal Antenna by Using Reactive Loading for Penta-Band Mobile Handset Application

A metal-wire-cutting bended monopole antenna (BMA) fed by mini-coaxial cable jointly with a thin printed ground-line which protrudes from ground-plane to be a balance-feed structure for bandwidth enhancement is proposed. A prototype of the proposed antenna with 40 mm in length, 6 mm in height and 5 mm in width has been fabricated and experimentally investigated. The humans hand effect on impedance bandwidth and radiation characteristics of the proposed antenna is studied. A prototype is designed to cover penta-band: CDMA (824-894 MHz), GSM (880-960 MHz), DCS (1710-1880 MHz), PCS (1850-1990 MHz) and WCDMA (1920-2170 MHz). Experimental results are shown to verify the validity of theoretical work.

Printed Broadband Monopole Antenna for WLAN/WiMAX Applications

In this letter, a printed broadband monopole antenna design for wireless communication applications in WLAN and WiMAX operation in the 2.4-GHz (2.3-2.7 GHz) band, 3-GHz (3.3-3.8 GHz) band, and 5-GHz (4.9-5.85 GHz) band is presented. This antenna consists of a printed monopole with a tapered slot and shorted coplanar waveguide (CPW) feeding structure, making it easy to combine omnidirectional, multiband, and broad bandwidth. The experimental results of the constructed prototype are provided.

Printed Broadband Asymmetric Dual-Loop Antenna for WLAN/WiMAX Applications

In this letter, a printed broadband asymmetric dual-loop antenna is presented for wireless communication applications in Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) to operate at the 2.4-GHz (2.3-2.7 GHz) band, 3-GHz (3.3-3.8 GHz) band, and 5-GHz (4.9-5.85 GHz) band. This antenna consists of two asymmetric radiated loops (there are ground-traces in each loop) and asymmetric feeding structure, making it easy to combine omnidirectional, multiband, and broad bandwidth. A prototype of the proposed antenna with 31 mm in length and 11 mm in width has been fabricated and experimentally investigated. The experimental results indicate that the S11 ≤ -10 dB bandwidths achieved were 72% and 20% at 2.5 and 5 GHz, respectively. Experimental results verify the validity of theoretical work shown.

A Novel Reduced-Size Edge-Shorted Patch Antenna for UHF Band Applications

In this letter, we present a novel printed patch antenna design in the UHF band. This antenna consists of an edge-shorted patch, parasitic element, and metal reflector, making it easy to combine directional, high-gain, low cross-polarization and wide bandwidth. Reduction in patch size of up to 50% with respect to a traditional rectangular patch operating at the same frequency is obtained. The experimental results of the constructed prototype are presented.

A Faster Means to Estimate SAR Values for Mobile Phone Applications

Based on experimental studies, a robust transformation factor is introduced for transforming the far-field energy to the near-field one. A simple formula is proposed that accurately and quickly estimates the peak 1-g or 10-g averaged specific absorption rate (SAR) in a human phantom exposed to a mobile handset. It is demonstrated experimentally that the proposed formula has higher accuracy for both 1-g and 10-g averaged SAR across different systems (e.g., CDMA, GSM, DCS, PCS, and WCDMA) by using 100 mobile handsets in four different types to be the device under test (DUT). The corresponding root mean squared errors of the calculated results are 9.96% and 6.82% for 1-g and 10-g averaged peak SAR, respectively, thereby confirming the performance predictions.

Compact Modified Pentaband Meander-Line Antenna for Mobile Handsets Applications

A printed pentaband antenna for mobile handsets application is proposed in this letter. This antenna consists of a printed nonuniform meander line with perpendicular feed and open-stub structure, making it easy to operate in code-division multiple access (CDMA, 824-894 MHz), Global System for Mobile communications (GSM, 880-960 MHz), digital communication system (DCS, 1710-1880 MHz), personal communication system (PCS, 1850-1990 MHz), and wideband code division multiple access (WCDMA, 1920-2170 MHz). The experimental results of the constructed prototype are evidenced by mitigating the degradation of antenna bandwidth due to human head and hand effect, and the measurement results of specific absorption rate (SAR) are also presented.

Printed Asymmetric Dual-Dipole Antenna for Tablet PC Applications

In this letter, a printed asymmetric dual-dipole antenna design for tablet PC applications in Long Term Evolution (LTE) operation at 700-960 and 1500-2500 MHz is presented. This antenna consists of two bended dipole antennas with V-shaped feeding structure, making it easy to combine omnidirectional, multiband, and broad bandwidth. The experimental results of the constructed prototype are provided.

Bowtie-Feed Broadband Monopole Antenna for Laptop Applications

In this letter, a metal-wire-cutting folded monopole antenna design for laptop applications in Long-Term Evolution (LTE) operation in the bands 1, 7, 8, and 20 is presented. This antenna consists of a folded tab monopole with bowtie feed and shorted structure, making it easy to combine omnidirectional, multiband, and broad bandwidth. The experimental results of the constructed prototype are provided.

Printed ACPW feed monopole antenna for LTE /WLAN applications

In this article, the ability of a single layer strip fed printed monopole antenna, which is composed of top-loading, asymmetric co-planar waveguide (ACPW) and stepped-feeding structure, to operate at four wide frequency bands (698MHz~960MHz, 1710MHz~2690MHz, 2400MHz~2500MHz and 3410~3600MHz) to cover LTE and WLAN operation has been demonstrated. The finite-size ground-strip of ACPW is not a perfect-ground, it has significant reactance. Therefore, the result of printed ground-strip versus monopole antenna should be regarded as an additional planar radiator rather than a normal ground-plane. A prototype of the proposed antenna with 106 mm in length, 0.8 mm in thickness and IS mm in width is fabricated and experimentally investigated. The experimental results indicate that the VSWR 2.5:1 bandwidths achieved were 66%, 29%, 24% and 14% at 750MHz, 1900MHz, 2500MHz and 3550MHz, respectively. Experimental results are shown to verify the validity of theoretical work.