0.7-dB Insertion-Loss D-Band Lange Coupler Design and Characterization in 0.13 μm SiGe BiCMOS Technology.

Design, measurement, and characterization of a low-loss Lange coupler on Si-substrate up to 170 GHz are presented in this paper. How to determine the value of the even number of the strip lines according to the process design rules is illustrated carefully based on odd- and even-mode impedance theory and calculation. The deembedding procedures of GSG pads and 50 Ω termination resistors are illustrated in details. Simulation and measurement results indicate that the fabricated on-chip 50 Ω resistors can be used for characterization of four-port Lange coupler by two-port network analyzer within expected measurement errors. Measurement results show that the minimum insertion loss of 0.7 dB at central frequency of 140 GHz is achieved, which is in excellent agreement with simulated data. [ABSTRACT FROM AUTHOR]