Li-Yu Chen

Small-Size LTE/WWAN Tablet Device Antenna With Two Hybrid Feeds

A small-size tablet device antenna formed by a simple folded metal plate excited by a low-band feed (direct feed with matching network) and a high-band feed (gap-coupled feed with matching network) for the LTE/WWAN operation in the 698-960 and 1710-2690 MHz bands is presented. The folded metal plate has a size of 3 × 5 × 30 mm3 and is disposed in a clearance area of 10 × 30 mm2 (300 mm2) above the top edge of the device ground plane. The matching network in the low-band feed compensates for additional capacitance for the folded metal plate with a resonant length much less than 0.25 wavelength in the lower band (698-960 MHz) and enhances the antennas impedance matching to achieve a wide lower band. The matching network in the high-band feed also enhances the antennas impedance matching to achieve a wide higher band (1710-2690 MHz). In addition, the coupling gap in the high-band feed can reject the low-band frequency. Also, the matching network in the low-band (high-band) feed includes a bandpass circuit which can help reject the high-band (low-band) frequency. Good isolation between the two hybrid feeds can, hence, be obtained, which makes the antenna with simple structure and small size have good radiation performances in both lower and higher bands. Details of the proposed antenna are presented.

2.4/5.2/5.8 GHz WLAN antenna for the ultrabook computer with metal housing

A promising small-size WLAN antenna suitable to be mounted along the hinge of the ultrabook computer with metal housing is presented. The antenna is formed by a two-branch structure of a monopole strip and a loop strip. The antenna has attractive features of low profile and wideband operation. In addition, by using the closed resonant path provided by the loop strip, possible coupling of the proposed antenna with nearby conducting elements for frequencies over the 2.4 GHz band can be expected to be decreased. Also, when the antenna is operated in the 5.2/5.8 GHz band, the loop strip is not at resonance and can serve as a shielding element for the monopole strip. This can also lead to decreased possible coupling of the proposed antenna with nearby conducting elements over the 5.2/5.8 GHz bands.

16-Antenna array in the smartphone for the 3.5-GHz MIMO operation

A 16-antenna array disposed in the smartphone for the LTE MIMO operation in the 3.5-GHz band (3400 ~ 3600 MHz) is presented. The array is fabricated by disposing four quad-antenna linear (QAL) arrays along two long side edges of the system circuit board of the smartphone. The QAL array has a planar structure occupying a small area of 3 mm × 50 mm. Two QAL arrays spaced 20 mm are disposed along each side edge. Acceptable antenna performances and ECC (envelope correlation coefficient) values are obtained for the antennas in the array. The calculated ergodic channel capacities of the 16-antenna array in a 16 × 16 MIMO system reach about 66 ~ 72 bps/Hz with a 20-dB signal-to-noise ratio. The obtained results of the 16-antenna array are presented.

Circuit-defined dual-wideband antenna for LTE tablet device

Small-size circuit-defined tablet device antennas for LTE dual-wideband operation are presented. Two cases with dual-feed and single-feed designs are discussed. For the dual-feed design, the antenna is formed by a simple folded metal plate excited by a low-band feed (direct feed with matching network) and a high-band feed (gap-coupled feed with matching network) for LTE operation in the 698~960 and 1710~2690 MHz bands. The dual-feed antenna occupies a small size and can be disposed in a clearance area of 10 × 30 mm2 (300 mm2) above the top edge of the device ground plane. The dual-wideband operation is controlled the two hybrid feeds with matching networks. The single-feed design shows a simplified matching network than the dual-feed design, with similar operating bands obtained. Details of the proposed antennas and their operating principle are presented.

Dual-wideband combined-type antenna for LTE tablet device

A dual-wideband combined-type antenna with its lower wideband and higher wideband respectively contributed by two separate radiating portions thereof is presented. The two separate radiating portions (one low-band antenna and one high-band antenna) are easily combined into a compact structure for the LTE operation in the 698~960 and 1710~2690 MHz bands. In addition, the proposed antenna requires a very small ground clearance of 10 × 30 mm2. By further using a simple matching circuit disposed on the device ground plane, the antennas low-band and high-band bandwidths can be greatly enhanced. Details of the proposed antenna are presented.