Shyh-Tirng Fang

Compact monopole antenna for GSM/DCS/PCS mobile phone

A novel planar monopole having a five-section copper line and wrapped into a compact structure with a height of 5 mm for 900, 1800 and 1900 MHz operations is presented. The antenna can be mounted on the top portion of a mobile phone housing with a small distance of 5 mm from the ground plane, resulting in a low profile of 10 mm (about 3% of the wavelength at 900 MHz), and the obtained 6-dB return-loss impedance bandwidths cover the GSM (880-860 MHz), DCS (1710-1880 MHz) and PCS (1850-1990 MHz) bands.

Tunable antenna matching architecture for LTE application

A broadband tunable matching architecture for LTE application is proposed. The proposed matching architecture is independent of PIFA antenna pattern by connecting an inductor at antenna ground terminal. The matching circuit architecture of this paper use the less number of expensive tunable elements to achieve broadband antenna matching, so as to lower overall implement cost.

Broadband dual-polarized slot loop antennas with high isolation orthogonal modes operation

A dual-polarized slot loop antenna fed by microstrip line is proposed. The dual-polarized slot loop antenna with dual radiating modes including microstrip line- and slotline-mode are excited by a wideband microstrip/slotline transition and a capacitively coupled “T” configuration stub, respectively, which are employed to enhance the impedance bandwidth. The planar design makes the antenna easy to integrate with RF circuitry on the same board. The slot loop antenna occupies an area of 12 × 18 mm2. From the measured data, the 25-dB port-to-port isolation of the antenna can be achieved. Also, the 10-dB return-loss impedance bandwidths of 32% and 67%, respectively, are obtained. Improved cross polarization level in both E-and H-plane patterns between the two polarizations about 20dB.

The improvement technology of radiation pattern for GPS antenna

This paper shows a radiation pattern improvement method for GPS antenna. By adding 2 wavetraps into a mobile device at a specific location, the upper hemisphere efficiency (UHE) with wavetraps is improved from 26% to 46%. This technology does not increase any antenna area and antenna clearance. It represents the technology is useful for mobile antenna, especially in GPS/GLONASS application.

Isolation enhancement of the dual polarized planar antenna with orthogonal electromagnetic band-gap backed structure

A dual-polarized planar antenna with EBG backed structure fed by microstrip line is proposed. The backed EBG structure is tiled 45 degrees to enhance the isolation between the dual polarized antennas. From the simulated results, the antenna isolation can be improved from 10dB to better that 29dB. Also, the polarization isolation can be improved from 8dB to 18dB with mid ground added and the gain response is more stable as well. The antenna occupies an area of 5.3 × 2 mm2 for millimeter wave (MMW) application. The planar design makes the antenna easy to integrate with RF circuitry on the same board, especially, in the MMW application.

MediaTek's R&D in microwaves

In this paper, novel antenna design concepts and chip-package-board co-design methodology are shown to demonstrate MediaTeks R&D activities in microwave. Various antenna technologies of broadband, low HAC (hearing-aid compatibility), and higher efficiency are developed for better OTA (over-the-air) performance. A co-design methodology, which integrates the aggressor, victim, and coupling path model into a single platform, is also presented to deal with system level desensitization problems in system-on-chip (SoC) and system-in-package (SiP) designs. With these key design considerations and methodology, MediaTek provides a reliable platform with good wireless performance guaranteed, and keeps being the pioneer in the microwave research and industry.