A Highly Integrated Wireless Downlink Interface for Cm-range Contactless Testing Systems

Abstract

As much more complicated features implemented in IC (integrated circuits), the cost of IC testing is getting higher. For the general requirement, a typical SOC contains analog, digital, memory or even front-end circuits. However, to satisfy these complicated demands, testing equipment will face to higher frequency, pin count, and timing accuracy issues. To overcome these challenges, a new testing methodology that uses contactless correction is proposed. To achieve contactless testing, all the testing functions have to be embedded. Moreover, these needs a wireless interface to support the communications between the device under test (DUT) and automatic test equipment (ATE). In this work, we will focus our research on the integrated antenna and the downlink path (ATE to DUT) designs. Because the communication space is limited within centimeter range, an integrated antenna using near field coupling is adopted. The transmitted antenna size has been carefully evaluated for both signal receiving and adjacent channel interfering. For downlink receiving, we select 915MHz ISM band to distinguish the channel for uplink. Amplitude Shift Keying (ASK) serves as the modulation scheme for minimal receiver hardware. The receiver comprises a wideband amplifier, a class-C rectifier and a dual-tracking slicer. In addition, a PWM code is embedded into line coding therefore the timing information can be extracted from the wireless channel. With these techniques we can realized a low cost downlink wireless interface. The whole circuits have been verified in a contactless testing system.