A novel approach to RF/microwave stimulus for legacy ATE

Problem to be solved: With the Department of Defense's concerted effort to consolidate test systems, and associated TPSs (Test Program Set) to a common platform; backward compatibility is an increasing difficult task due to advances (differences) in newer test equipment. When a TPS is being migrated, to a different test platform, there are a number challenges that will be encountered in both software and hardware. This paper will focus on the hardware aspect of the compatibility as there have been many advances in code translation for software compatibility. While making the TPS software backward compatible is one of the key issues, in protecting the investment of the TPS, little has been done to make the hardware compatible of this same TPS. There are a number of contributing reasons why hardware compatibility has been difficult including: advances in test equipment (newer equipment has a performance difference versus legacy test equipment), timing of response to software commands will change the TPS response expectations, RoHS (Restriction of Hazardous Substances) has forced older equipment to be redesigned with available components, newer equipment may have a different architecture than legacy equipment, features available in legacy equipment are no longer available in newer equipment, etc. Specifying newer equipment is fraught with potential problems. This paper will discuss how the industry has changed the architectures in signal stimulus products, why these changes were made and a look at where the industry might be going. Additionally, a discussion about each of the hardware compatibility issues will be described in detail with possible alternatives to resolving them in a TPS migration. One novel approach to compatibility is using an Oscilloscope and Spectrum Analyzer to capture the performance of the original stimulus used in the TPS and recreate that same stimulus (whether from COTS (Commercial of the Shelf) test equipment or a custom piece of special test equipment) using and AWG (Arbitrary Waveform Generator). This recreated waveform will have the performance, including the imperfections, of the original waveform. This new, recreated, waveform can then be used as a compatible substitute. Using an AWG based stimulus will have some consequences of its own. These will be described in detail including the issues implementing them in a larger ATE system.