Byung-Su Kang

A Tilted Combined Beam Antenna for 5G Communications Using a 28-GHz Band

A novel combined beam antenna for 5G communications using a 28-GHz frequency band is proposed, which provides a tilted radiation on an elevation plane. Instead of applying a conventional array technique to produce a scanned beam, two different radiating elements have been combined in order to obtain a relatively wide beam but high gain in a tilted target direction. There are two main radiators; one is a group of microstrip patches, and the other is a waveguide aperture. The patches produce two split strong beams on the azimuth plane. The aperture further increases antenna gain on the elevation plane. Finally, by optimizing the constructive interference between the patches and the aperture, we can obtain relatively high antenna gain even with a wide beam spreading across an azimuthal plane. All experiments show good agreement with the simulation results, which proves the validity of our approach.

RF system of Dual mode Base Station for 802.16d and HSDPA

This paper focus on implementation results for RF analog base station sub-system supporting 802.16d standard, called WiMAX and HSDPA, which is designed and implemented for reconfigurable base station using SDR technologies

Design and measurements of Ka-band waveguide dielectric rod antenna for 7 channel digital beamformer for HAPS

HAPS system is required to have strict specification to reduce the interference between adjacent cells. One of the most efficient ways to suppress the grating lobe in visible rang is to shape FTEP (flat-topped element pattern). This work presents the design and experimental results of 7 waveguide dielectric rod array antennas for shaping FTEP in the Ka-band. The calculated element pattern and the measured element pattern are also compared. This prototype antenna will be applied to the multibeam antenna to generate 7 beams using digital beamformer.

Ka band active phase array antenna with digital beam former for the HAPS systems

HAPS(high altitude platform station) system have many attractive points for the next generation communication systems, focused on high data rate multimedia services. HAPS would be located around 20km above sea level and this altitude is very low when it is compared with satellite communication systems, even it is LEO systems. So HAPS systems could have enough link margin. In this paper, Ka band prototype active phase array antenna(APAA), including 19 channels with 7 beams controlled by means of digital beam former(DBF) is designed, we conclude that the APAA system based on the DBF technology is appropriate for the application in HAPS payload because DBF can achieve better performance than analog beam former.

Multi-faced and multibeam DBF antenna for high altitude platforms station stages of antenna development

Advantages of the multi-beam antenna for Stratospheric Communication System (or HAPS) with digital beam forming (DBF) are demonstrated in comparison with analogue beam forming (ABF). To cover the service area from nadir to a circle of radius 55 km by 199 beams, the antenna system of seven flat active phased array antennas (APAA) is proposed. Due to high accuracy of amplitudes and phases in channels of the APAA with DBF, optimal cell forming as well as high spatial isolation between cells is obtained. Stages of antenna creating are considered. Results of the work at initial stages are presented too.