A frequency mixing and sub-sampling based RF-measurement apparatus for IEEE 1149.4

This paper demonstrates the possibility of performing radio frequency (RF) measurements in the IEEE 1149.4 environment using a selected combination of mixing and sub-sampling as the method to down-convert the RF signal into a low frequency suitable for the analogue busses specified by the 1149.4 standard. Signals generated by RF signal generators (2 GHz) and a commercial VCO (3 GHz) were used to demonstrate the operation of the developed RF-to-LF circuitry in cooperation with National´s SCANSTA400 IEEE 1149.4 analog test access device. The measured repeatability of RF power measurement through the whole system, i.e. from the RF input to the output of SCANSTA400, is ±0.15 dB and the measurement uncertainty of the RF frequency due to measurement instruments and signal sources is ±350 Hz. Interconnect measurements at 2.1 GHz were also demonstrated. Simple faults such as shorts, opens and missing components may readily be detected at the low-frequency output of the RF-to-LF circuitry.