Microwave imaging techniques are prone to signal corruption from unwanted multipath signals. Near-field systems are especially\r\nvulnerable because signals can scatter and reflect from structural objects within or on the boundary of the imaging zone. These\r\nissues are further exacerbated when surface waves are generated with the potential of propagating along the transmitting and\r\nreceiving antenna feed lines and other low-loss paths. In this paper, we analyze the contributions ofmulti-path signals arising from\r\nsurface wave effects. Specifically, experiments were conducted with a near-field microwave imaging array positioned at variable\r\nheights from the floor of a coupling fluid tank. Antenna arrays with different feed line lengths in the fluid were also evaluated.\r\nThe results show that surface waves corrupt the received signals over the longest transmission distances across the measurement\r\narray. However, the surface wave effects can be eliminated provided the feed line lengths are sufficiently long independently of the\r\ndistance of the transmitting/receiving antenna tips from the imaging tank floor. Theoretical predictions confirm the experimental\r\nobservations.
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