Study of Wideband Microstrip Correlator for Ultra-Wideband Communication Systems

A new wideband microstrip correlator, which acts as the key component of six-port circuits for ultra-wideband (UWB) systems, is presented. This new correlator, with 40% relative bandwidth, is proposed at the frequency range of 3.1-4.8 GHz of UWB. This correlator utilizes three unique wideband 90deg 3-dB two-branch couplers and one 0deg 3-dB Wilkinson power divider to reach the required bandwidth. This correlator is designed using microstrips for the sake of low cost, simple design, and easy to implement and test. The insertion loss, amplitude imbalance and phase imbalance between ports are given. The results from measurements and simulations are compared, and methods to further improve this new correlator are discussed.