Wideband S-C Band Monolithic Phase Shifter

Multifrequency Measurements of Radar Ground Clutter at 42 Sites. Volume 2. Appendices A through D

“…At VHF, however, propagation variation exhibits less scintillation, and we did investigate using SEKE to predict and separate F from our VHF measurements. However, this attempt to separate F at VHF was unsuccessful because the local cell-to-cell variations in clutter strength a 'F4 were not well correlated with the SEKE predictions of F. Consequently, the resultant separated distributions of intrinsic a0 became broader instead of nanower than the corresponding distributions of c°F 4 .…”

“…In thus appreciating the significant effects of propagation F in clutter strength c OF 4 , it is oversimplifying to attribute most of the variability in a oF 4 over any given spatial region to propagation. Attempts to model the low-angle clutter phenomenon as constant a' with a subsequent overlay of propagation computation are not realistic.…”

“…In Figure B-2, the height of the antenna above the tilted plane is h , the height of the clutter source above the tilted plane is h r . the range along the reflecting plane from the antenna to the clutter source is R, and the range along the reflecting plane from the antenna to the bottom of the hill is r. We wish to know the clutter strength eF 4 from the indicated clutter source, where e 0 is the intrinsic reflectivity of the source (i.e., e equals the RCS of the clutter source divided by the ground area in the resolution cell), and F is the propagation factor (i.e., the ratio of the field strength at the source in the presence of the tilted reflecting plane divided by the field strength that would exist at the target in free space). Under the conditions that R>>ha , ht>>h a , and the reflection coefficient equals -1, the factor F 4 is given by where A equals RF wavelength, and Oh = h/R.…”

“…(1B.4) Thus, after the active facet is determined, its parameters are used to determine ha by means of Equation (B.4), and then the active facet slope a and ha are used in Equation (B. ) to determine multipath loss F 4 . Figures B-4 and B-5 plot F 4 from Equation (B.1) as a function of facet slope but they do so only for values of ha equal to antenna mast height q.…”

Design of a 3-State Reconfigurable CRLH Transmission Line Based on Mems Switches

“…With respect to different commonly adopted technological solutions (PIN diodes or FET switches) [8][9][10][11][12], the use of MEMS switches in order to achieve a reconfigurable behaviour results in a lower loss, wider band performance, and a lower DC power consumption [13][14][15][16][17][18][19][20][21][22]. Furthermore, the advantages related to the use of MEMS devices in designing CRLH TLs have been already demonstrated in [20,21], where a MEMS series capacitor has been used to control a CRLH TL phase shifter.…”