Ji-Hyuk Kim

Performance Enhancements of a Microstrip Antenna with Multiple Layer Substrates

Performance enhancements of a microstrip antenna with multiple layer substrates a small size broadband microstrip patch antenna for 5 GHz WLAN applications with multi-layer substrate has been fabricated using MEMS process. A microstrip antenna fabricated on top of silicon substrate can be realized in small size but has limited bandwidth while a microstrip antenna fabricated on top of glass substrate results in large size with moderate bandwidth. Multiple layer substrates of silicon and glass have been implemented to realize small size and broadband characteristics. The size of the proposed antenna is larger that the antenna fabricated on silicon substrate but it showed broader bandwidth compared with the antenna fabricated on glass substrate. The size of the microstip antenna is 8*12*2 mm3 and the size of the ground plane is 15*15 mm2. The experimental results show that the proposed antenna has the gain of 1dBi and bandwidth of 400 MHz at 5.3 GHz.

A WLAN/WMAN Dual Mode Transceiver System for Indoor/Outdoor Application

WLAN (IEEE 802.11a)/VMAN (IEEE 802.16a) dual mode transceiver chip has been proposed, designed and fabricated. Transceiver RF IC chip with packaged size of 6 mm*6 mm was fabricated using 0.25 um SiGe BiCMOS process. Power amplifier and PLL/VCO chip were fabricated using the same process. Ceramic front-end filter were also fabricated for WLAN/WMAN frequencies. To make compact transceiver system, these chips was mounted on 2 cm*2 cm double side PCB. The full system has been tested with external ADC/DAC and baseband modem. The measured results show that fabricated transceiver system meets the requirements for WLAN/WMAN standards