A 150-GHz Butler Matrix in Quartz-IPD Technology

This paper presents the design of 150 GHz microstrip-line Butler matrix (BM) networks realized in quartz-IPD process, including a miniaturized one using the equivalent L-C-L low-pass filter structure to reduce the core area by 28%. The fabricated networks are characterized through two flip-chip bonded CMOS switches to enable signal path switching and provide absorptive termination. The chip delivers an insertion loss of 4.91 dB and phase error of 21 degrees, whereas the miniaturized version exhibits an insertion loss of 4.71 dB and phase error of 20 degrees. The core areas of the standard and miniaturized circuits are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.89 ~\text{mm}^{2}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.64 ~\text{mm}^{2}$</tex>, respectively.