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A novel waveguide-to-microstrip transition is developed using a new design methodology based on iris coupling. Key features of the design are a single-layer substrate, new matching topology, and new cavity enclosure. The transition lends itself to a low-cost implementation, while maintaining the enclosure's hermetic integrity. An extensive tolerance study shows that the present design is robust and very stable with respect to manufacturing and assembly variations. Careful consideration has been given to the mechanical aspects of the transition's implementation in order to achieve seamless integration into the overall package manufacturing and assembly process without sacrificing electrical performance. Proof of concept was achieved by implementing a Q-band (f0 = 44:5 GHz) design on alumina, a W-band (f0 = 94 GHz) design on z-cut quartz, and a W-band design on fused silica. All exhibited better than 22-dB return loss at their center frequencies with less than 0.3-dB insertion loss, and at minimum a 10% 15-dB return-loss bandwidth.

Coliphage removal efficiency and the effects of wetland hydrology on virus transport were determined for constructed wetlands in San Jacinto, CA. Mathematical models were used to further characterize virus transport. MS2, an F‐specific RNA (FRNA) coliphage was used as a model for human enteric viral behavior. Two wetland types were studied, a one‐phase cell and three‐phase cell. These wetlands received unchlorinated secondary effluent at a constant rate. The mean residence time in the wetlands was 9 ± 3 d as determined using bromide as a conservative tracer. Assuming 100% porosity, a plug flow model predicts this mean residence time within the experimental standard deviation (8 d). This suggests that a negligible volume was occupied by vegetation and settled solids. The convection‐dispersion equation adequately simulated the residence time distribution of the conservative tracer. MS2 removal in the wetlands was experimentally determined to be 97 ± 3%. There was no distinction between the two wetland types in terms of removal efficiency. The average coliphage decay rate was calculated to be 0.44 per day. However, the error involved with using the first order decay rate was high, 83 ± 12%. Therefore, first order decay does not adequately describe removal processes within the wetland. Most virus removal occurred within the first 3 m (k = 4.0 ± 1.8 d−1) with a removal efficiency of 85.3 ± 0.6%. The remainder had a decay rate of 0.20 ± 0.17 d−1 with a removal efficiency of 56 ± 33%.

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We demonstrate that the transmission of far-and near-field incident light through a periodic array of subwavelength holes in a vanadium-dioxide ͑VO 2 ͒ thin film is enhanced in the infrared range with respect to transmission through the unperforated film when VO 2 undergoes its semiconductor-to-metal transition. We explain this enhancement by analyzing the loss of transmitted intensity due to leaky evanescent waves inside the holes and scattering at the entrance and exit apertures. Numerical simulations based on the transfer-matrix formalism provide qualitative support for the model and reproduce the principal features of the experimental measurements.

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