Design and realization of compact folded Lange coupler

A compact folded Lange coupler is presented in this paper. In order to reduce the circuit area, a single layer realization in a folded configuration is adopted. The coupler is modeled and simulated through Agilent ADS and is fabricated on Rogers 6010 laminate which has a dielectric constant of 10.2. The measurement results indicate an insertion loss of 1.7dB, a phase difference of 93.5 degrees between coupled port and through port at 1.5GHz and an isolation better than 17dB from 1GHz to 2GHz. A meander Lange coupler is also designed, simulated, fabricated and measured as a comparison. The proposed folded Lange coupler is well suited for MMIC technology and hybrid microwave integrated circuits using high dielectric constant laminate.