A recent evaluation of the accuracy of the National Physical Laboratory (NPL) primary frequency standard NPL-CsF1 by K Szymaniec et al (2005 Metrologia 42 49–57) reported an overall frequency uncertainty of δν/ν0 = 1 × 10−15. This stated uncertainty includes a correction of a frequency bias of δν/ν0 = 8 × 10−16 ± 3 × 10−16 attributed by the authors to microwave leakage. We believe that the stat...

In WiFi backscatter communication, the frequency shift technique allows a backscattered signal to appear not in channel of carrier but adjacent ones, thus avoiding noisy OFDM-based signals and increasing communication range. Through testbed experiments, we observe that is effective mitigating impact inherent fluctuation signals, particularly bistate communication; however, due weak strength sig...

The generation and evolution process of red shifting in a ultrafast fiber laser with the soliton self-frequency shift are investigated by numerical simulation. And effect different parameters including pump strength, length dispersion fiber, modulation depth saturable absorber initial field on analyzed for first time to our knowledge. By optimizing these parameters, maximum beyond laser's gain ...