Embedded loopback test for RF ICs

This paper explores the use of on-chip or on-wafer loopback implementations for verifying performance of 5-GHz wireless local area network (WLAN) IC circuits. The loopback test diagram, the test-circuit design, and the characterization data are reported for subcircuits (attenuators, and switches) necessary to implement 5-GHz transceiver loopback. A loopback circuit that can be applied to transceiver loopback measurements is demonstrated. This research is exploratory in nature and is a first attempt at a new on-chip RF test technique.