Surface-wave coupling of active antennas for homodyne sensor systems

In this paper, we present a novel method for significantly enhancing the performance of low-cost millimeter-wave sensor systems based on active integrated antennas. Our method uses the planar active antenna's parasitic surface-wave field as a local oscillator signal for a mixing rectenna. Compared to a self-mixing active 67-GHz antenna, the surface-wave coupled rectenna receiver shows a considerably improved minimum detectable signal (10 dB lower) and the possibility for high-quality homodyne in-phase/quadrature signal detection.