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 3.2×3.2×1.5mm³ cellular phone isolator which insertion loss is 0.36dBmax. at 1920MHz to 1980 MHz, is realized.