A 20-GHz On-Chip Six-Port Reflectometer Using Simple Lumped Passive Devices and Bipolar Junction Transistors

Abstract

This paper proposes an on-chip six-port reflectometer (SPR) fabricated in the 0.13-μm IBM BiCMOS-8HP technology. The SPR enjoys a compact circuit structure, with only four amplitude detectors as active devices, one resistive power divider, and one lumped phase shifter as passive devices. The power divider and phase shifter are responsible for manipulating the radio-frequency (RF) signals appropriately, whereas the detectors are responsible for sensing the processed signals. The chip area, which can be further reduced, is 1.25 mm in width and 1 mm in height. The SPR can perform in-situ measurement of reflection coefficients of devices under test (DUTs) and reduce testing costs of RF chips by using vector network analyzers (VNAs). The SPR demonstrates excellent performance in measuring the reflection coefficients of DUTs at around 20 GHz. The experimental results indicate that the maximum error of the measured reflection coefficients in absolute value is about -26 dB.