Noncontact Characterization of Antenna Parameters in mmW and THz Bands

We present a novel, noncontact 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 two-port open-air fixture. The unknowns in the network representation of the open–air fixture model can be uniquely determined through a one-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 millimeter-wave and terahertz applications, platform-integrated antennas, and body-implanted antennas are examples of the potential utility of the noncontact antenna characterization method presented here. To demonstrate the validity, scalability, and overall efficacy of the proposed approach, we present the noncontact measurement of port reflection coefficient, gain, and radiation pattern for various antennas of different types, with operation frequencies ranging from 60 to 750 GHz.