2.45 GHz Active Isolator based on asymmetric coupler

Abstract

An active isolator achieving both high isolation and low insertion loss at 2.45 GHz is proposed. The isolator is based on an asymmetric coupler and is designed to leverage the gain and reverse isolation of an amplifier and coupling coefficients between the input and output of the coupler. The insertion loss and isolation of the isolator are enhanced by using the coefficients, and the power level with optimal isolation can be determined for a target specification. The asymmetric coupler increases the power handling capability of the proposed isolator that has a low coupling coefficient and achieves highly efficient isolation with a high coupling coefficient. Electromagnetic-circuit co-simulation results show that the proposed isolator with operation stability has ≥40 dB isolation and <1 dB insertion loss for input power between 0−8 dBm.

Keywords

• active isolator
• asymmetric coupler
• amplifier
• high isolation
• optimum design methodology