The diagonal orientation of the microstrip patches in Figure 1 is not inherent in the LCP implementation: instead, it is part of an example design for a typical intended application in radar measurement of precipitation, in which there would be a requirement that both the 14- and the 35-GHz arrays exhibit similar orthogonal-polarization characteristics, including high degrees of polarization purity. The diagonal orientation helps in realizing a symmetrical feed network for both polarizations with similar impedance characteristics and radiation patterns. RF MEMS switches would be included in a production model but are not included in the prototype: Instead, to simplify computational simulation and testing, switching of polarizations is represented by the presence of hard-wired open and short circuits at switch locations.
This work was done by Dane Thompson, Ramanan Bairavasubramanian, Guoan Wang, Nickolas D. Kingsley, Ioannis Papapolymerou, Emmanouil M. Tenteris, Gerald DeJean, and RongLin Li of Georgia Institute of Technology for Glenn Research Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Semiconductors & ICs category.
Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW- 17980-1.