Propagation loss and MSSW delay lines

Abstract

Propagation loss measurements of magnetostatic surface waves are reported and related to recent theory. They are also compared with other published loss data. Recently, a frequency independent damping parameter, λ, for MSSW's has been related to the dB/μsec loss. Using our data we find <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda = 0.88 \times 10^{4}</tex> Hz. This compares favorably with an estimated value of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.163 \times 10^{4}</tex> Hz based on FMR linewidth. A tabulation is provided of other experimental low loss measurements which relate to MSSW propagation loss. For our measurements two independent measuring techniques were employed which allow propagation and coupling losses to be separated. One technique is independent of coupling loss and measures the power difference of a single pulse over a given time delay differential. The second technique is dependent on coupling conditions. The later technique measures total insertion loss versus time delay. The relation between insertion loss and time delay is linear. The proportionality constant gives the propagation loss and the intercept the coupling loss. At 6 GHz we measure a propagation loss of 23 dB/μsec and a two way coupling loss of 10 dB. The characteristics of a 6 GHz delay line are described.