A Submillimeter-Wave Near-Field Measurement Setup for On-Wafer Pattern and Gain Characterization of Antennas and Arrays

This paper presents a measurement system for on-wafer characterization of antennas operating in the high millimeter wave (MMW) to sub-MMW bands. Most existing antenna measurement systems at these frequencies require complex custom-made structures, which are costly and hard to set up. To address this problem, a simple and yet effective near-field antenna measurement setup consisting of a vector network analyzer (VNA) with proper frequency extenders, a probe station, an on-wafer waveguide probe, and a precision XY-positioner is considered. The waveguide probe attached from one end to a frequency extender of VNA is used to feed the micromachined waveguide port of an on-wafer antenna. A second waveguide probe, connected to the other frequency extender of VNA, is moved over the antenna in the near-field region using the precision XY-positioner. The absolute gain measurement is accomplished by measuring and comparing the near field of a standard gain horn antenna against that of the antenna under test. To validate the performance of the setup, radiation characteristics of a beam-steering traveling wave array antenna and a standard pyramidal horn antenna are measured over 220-325 GHz band and good agreement between the measured and simulated radiation patterns and gains is shown.