62.5-GHz Phased-Array Channel Sounder for Double-Directional Angle Estimation

The paper describes implementation of phased array antennas for use in a wideband channel sounding system. The antennas are 62.5 GHz prototypes, utilizing SiGe chips on a printed circuit-board. Each board consists of two 16-element series-fed patch array arrays with separate RF ports and IF sections. Each 16-element array can scan +/- 45 degrees with a fixed elevation beamwidth. The receiver uses 4 antenna boards oriented at 90 degrees to enable omni direction coverage when scanning. The transmitter consists of two array-boards also implemented at 90 degrees which allows 180 degrees transmitter coverage. Direction of departure and direction of arrival multipath measurements are made using Rubidium clocks at both the transmitter and receiver and a timing synchronization system to coordinate the receiver scanning with the transmitter scanning and the data acquisition system. The objective of the system is to collect directional propagation data utilizing prototype phased array boards and tracking algorithms at millimeter wave frequencies.