Production test technique for RF circuits using embedded test sensors

摘要

A single test stimulus and a simple test configuration with embedded envelope detectors are used to estimate all the specification values of interest for an RF circuit under test in an integrated circuit chip. Envelope detectors are deployed as sensors inside the circuit under test. Where more than one circuit is in an RF device in the integrated circuit, each RF circuit in the device may have its own envelope detector. A signal having, for example, time-varying envelopes is used as an optimized test stimulus. The test makes use of the time-varying and low frequency envelope of the test response. The response of the circuit under test to the optimized test stimulus has features highly correlated with the specifications of interest. The test stimulus is optimized for a set of training circuits, and each training circuit in the set is selected to provide one of a spectrum of test responses to the stimulus. Non-linear regression-based models are built from the set of specification values and set of envelopes derived from testing the training set of circuits. Thereafter when a circuit under test is tested by applying an optimized stimulus, the non-linear regression models are used to map an envelope from the test response of the circuit under test to specification values for the circuit.