Po-Wei Lin

Small-Size Uniplanar WWAN Tablet Computer Antenna Using a Parallel-Resonant Strip for Bandwidth Enhancement

The technique of using a parallel-resonant (PR) strip for bandwidth enhancement of a small-size uniplanar tablet computer antenna for the WWAN operation (824-960/1710-2170 MHz) is presented. The antenna is printed on a thin FR4 substrate of small size 12 × 40 mm2, and has a simple uniplanar structure of comprising a feeding strip, a shorted strip, and a PR strip. The antennas wide lower band is formed by the quarter-wavelength resonant mode of the shorted strip and an additional resonant mode generated owing to the presence of the PR strip, which occupies a very small area of about 7 × 7 mm2 only. The PR strip contributes a parallel resonance at about 1100 MHz which in turn generates an additional resonance near the quarter-wavelength mode of the shorted strip, thereby resulting in a new resonant mode to greatly enhance or double the bandwidth of the antennas lower band for the GSM850/900 operation. For the antennas upper band, it is formed by a higher-order mode of the shorted strip and a quarter-wavelength mode of the feeding strip, and covers the GSM1800/1900/UMTS operation. Details of the proposed antenna are presented.

Simple printed monopole slot antenna for WWAN mobile handset

A simple printed monopole slot antenna for penta-band WWAN operation (824∼960/ 1710∼2170 MHz) in the mobile handset is presented. The monopole slot has a length of 50 mm only and is embedded close to the bottom edge of the system ground plane of the handset with a small distance of 11 mm. By adding a small-size C-shaped strip connected orthogonal to the bottom edge of the system ground plane, good excitation of the monopole slot antenna at its fundamental (0.25-wavelength) and higher-order resonant modes can be obtained. The excited resonant modes form two wide operating bands to respectively cover the GSM850/900 operation (824∼960 MHz) and GSM1800/1900/UMTS operation (1710∼2170 MHz). Operating principle and radiation characteristics including the SAR (specific absorption rate) results of the proposed monopole slot antenna are described. Measured results of the fabricated antenna are also presented.

Integrated monopole slot and monopole strip for WWAN handset antenna

A novel handset antenna formed by a monopole slot and a monopole strip for the WWAN operation in the 824~960 and 1710~2170 MHz bands is presented. The monopole strip serves as a feed for the monopole slot and also functions as an efficient radiator. The monopole slot generates a quarter-wavelength slot mode in the antennas lower band, while the monopole strip contributes its quarter-wavelength mode in the antennas upper band. By including a vertical strip which can be enclosed inside the handset casing or be a part of the bezel surrounding the periphery of the handset casing and connected to the bottom edge of the system ground plane, the impedance matching of the excited slot mode can be greatly improved. With a small board space of 9 × 40 mm2, the proposed antenna can cover penta-band WWAN operation.

Small-size dual-antenna with π-shape grounded strip for LTE tablet device

A small-size dual-antenna for the LTE operation in its high band of 1710~2690 MHz is presented for the LTE tablet computer application. The dual-antenna occupies a small volume of 10 × 45 × 0.8 mm3. The dual-antenna provides acceptable isolation better than about 10 dB and good antenna efficiency better than about 55% over a wide operating band of larger than 1 GHz. This leads to acceptable envelope correlation coefficient (less than 0.3 for the proposed dual-antenna) obtained for the LTE high-band operation. Results of the fabricated dual-antenna are presented, and the MIMO performance of the dual-antenna is discussed.

Small-size LTE700/2300/2500 antenna and high-isolation antenna array using the same for the laptop computer

Small-size LTE700/2300/2500 antenna (9 × 45 mm2) and high-isolation antenna array using the same for the laptop computer are presented. The two antennas are mounted along the top edge of the supporting metal plate to be disposed on the inner surface of the upper cover of the laptop computer. Improved isolation (measured S21 better than -30 dB in the LTE700 band and -26 dB in the LTE2300/2500 bands) between the two antennas is easily achieved by adjusting the supporting metal plate to have a length of about 110 mm in the longitudinal direction to the antenna array. The high isolation is obtained because the length is close to a quarter-wavelength of a frequency in the LTE700 band, which makes the excited surface currents in the supporting metal plate stronger in the longitudinal direction and hence causes weaker surface currents flowing along the top edge of the supporting metal plate. This behavior leads to high isolation of the LTE antenna array in this study.