Low-cost phase noise testing of complex RF ICs using standard digital ATE

IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst.

Azaïs²,

Latorre

et al. 2021

Error Vector Magnitude (EVM) or alternately Offset Error Vector Magnitude (OEVM) is one of the most important performance to verify for RF circuits such as ZigBee transmitters in order to ensure that the quality of the generated modulated-signal complies with the requirements of the wireless communication standard. The conventional solution to measure this performance relies on the use of an Automatic Test Equipment (ATE) equipped with expensive RF channels. This paper presents a low-cost solution that permits to realize EVM measurement using only a standard digital ATE. The approach is based on 1-bit under-sampled acquisition of the RF modulatedsignal by a digital tester channel associated with a specificallytailored processing algorithm. This algorithm involves many different steps that are detailed in this paper, including phase and amplitude fluctuation extraction, RF signal reconstruction, symbol clock recovery, symbol bits detection and synthesis of reference data for EVM calculation. The proposed digital test solution is first evaluated through lab hardware experiments and then validated with EVM measurements on an industrial ATE.

Section: Introductionmentioning

confidence: 91%

Low-Cost EVM Measurement of ZigBee Transmitters From 1-bit Undersampled Acquisition

IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst.

Azaïs²,

Latorre

et al. 2021

“…The idea is then to develop dedicated post-processing algorithms able to retrieve this information and extract the main signal characteristics. This strategy of using 1-bit acquisition with a digital tester channel has already been exploited in previous works and dedicated algorithms have been developed for the analysis of AM and FM-modulated signals [6], or to perform phase-noise characterization of signals in the IF frequency band [7,8]. However, it is worth noting that these algorithms have been developed based on an oversampled acquisition.…”

Section: Testing Strategymentioning

confidence: 99%

Power Measurement and Spectral Test of ZigBee Transmitters from 1-bit Under-sampled Acquisition

2019 IEEE European Test Symposium (ETS)

Azaïs

Latorre

et al. 2019

This paper presents a low-cost solution to perform power and spectral measurements on RF signals. More specifically, we target RF modulated signals such as 2.4 GHz signals delivered by ZigBee transmitters. The solution is based on 1-bit under-sampled acquisition of the RF signal, acquisition that can be realized using a standard digital ATE channel. The captured binary sequence is then fed to a dedicated postprocessing algorithm, which (i) extracts amplitude and phase variations and (ii) reconstructs the RF signal. From the reconstructed signal, it is possible to perform power and spectral measurements. The different steps of the post-processing algorithm are detailed in the paper. The validity of the technique is demonstrated through both simulations and hardware measurements.

“…A dedicated postprocessing algorithm is then applied in order to retrieve I and Q data in the code domain, and therefore verify the DSSS sequence encoded in the RF signal. This strategy of using 1-bit acquisition has already been exploited in previous works to perform phase-noise characterization of signals in the IF frequency band [12,13]. Dedicated post-processing algorithms have been developed that provide retrieval of the phase noise information present in the IF signal after oversampling.…”

Section: B Proposed Techniquementioning

confidence: 99%

“…The presence of phase noise in the carrier has been investigated. For this, we have used the model described in [12] to introduce 1/f 2 phase noise with a level of about -80dBc/Hz at a frequency offset of 100kHz. The impact of phase noise is not directly visible in the modulated RF signal, but can be observed on the Costas loop response, as shown in Figure 21.…”

Section: ) Iq Balancementioning

confidence: 99%

Low-Cost Digital Test Solution for Symbol Error Detection of RF ZigBee Transmitters

IEEE Trans. Device Mater. Relib.

Azaïs

Latorre³

et al. 2019

 Abstract-This paper presents a low-cost approach for testing RF ZigBee transmitters using only a standard digital ATE. The proposed solution permits to implement symbol error detection. The approach is based on 1-bit under-sampled acquisition of the RF signal (2.4GHz OQPSK-modulated signal with half sine pulse shaping). A dedicated post-processing algorithm is then applied, which (i) extracts the phase information from the captured binary sequence, (ii) reconstructs the RF modulated signal and (iii) performs the demodulation. The different steps of the postprocessing algorithm are detailed in this paper. The robustness of the post-processing algorithm to various imperfections, both in the signal under test and in the acquisition equipment, are investigated with numerical simulations. Finally, experimental results obtained with NXP ZigBee transceiver fully validate the ability of the proposed method to retrieve the symbol sequence present in the RF modulated signal using the simple binary capture.