Low Loss Two-Port Lumped Element Isolator using Improved Gyrator Circuit

Design equations for a new low loss two-port isolator are derived by analyzing the conventional two-port isolator and improved gyrator circuit. The isolator performance is simulated using the admittance matrix; the result provides an insertion loss, 0.25dB less at 1920MHz to 1980MHz, compared to conventional two-port isolator. Using these design equations, a 3.2X3.2X1.5mm³ cellular phone isolator which insertion loss is 0.36dBmax. at 1920MHz to 1980 MHz, is realized.