Insertion loss analysis of small isolator for portable phones

The insertion loss of lumped element isolator for portable phones was analyzed using the developed circuit simulator, which includes three loss factors: linewidth /spl Delta/H of garnets, resistance R of central conductors and dielectric loss, tan/spl delta/ of capacitors. By comparison between the experimental results and calculations, the contribution ratios of /spl Delta/H and R towards insertion loss, in 7 mm square isolators at 941.5 MHz, were each determined to be almost 50%, and that of tan/spl delta/ to be negligibly small.