Efficiency Measurement of Probe-Fed Antennas Operating at Millimeter-Wave Frequencies

In this letter, we propose a new method to compute the radiation and total efficiency of millimeter-wave probe-fed antennas. This hybrid method combines the measurement of the realized gain radiation pattern over a quasi-3-D sphere and the simulation values of this realized gain over the nonmeasured part of this sphere. To demonstrate the usefulness of the method, 60-GHz probe-fed antennas radiating in broadside, backside, and endfire directions with high, medium, and low directivity are measured. To validate the accuracy of the method, the computed efficiencies of those antennas are compared to simulation results.