Noncontact Characterization of Antenna Parameters in mmW and THz Bands

Abstract

We present a novel, non-contact measurement technique for the characterization of conventional antenna parameters, including port reflection coefficient, gain and radiation pattern over a desired frequency range. Our method eliminates the need for an active measurement port connection to the antenna under test. Instead, the antenna parameters are indirectly determined by treating the test antenna input port and the port of the measurement device as a 2-port open-air fixture. The unknowns in the network representation of the open-air fixture model can be uniquely determined through a 1-port calibration process and each branch in the signal flow graph can be related to the usual antenna parameters such as input reflection coefficient, gain and radiation pattern. This approach is particularly attractive for characterizing antenna parameters when a direct connection to the antenna is either prohibitive, difficult, undesirable or expensive. On-chip antennas for mmW and THz applications, platform-integrated antennas, and body-implanted antennas are examples of the potential utility of the non-contact antenna characterization method presented here. To demonstrate the validity, scalability and overall efficacy of the proposed approach, we present the non-contact measurement of port reflection coefficient, gain and radiation pattern for various antennas of different types, with operation frequencies ranging from 60 GHz to 750 GHz.