This paper presents a 5th-order Chebyshev-I active RC complex filter for multi-mode multi-band global navigation satellite systems （GNSS） RF receivers. An improved passive compensation technique is used to cancel th...This paper presents a 5th-order Chebyshev-I active RC complex filter for multi-mode multi-band global navigation satellite systems （GNSS） RF receivers. An improved passive compensation technique is used to cancel the excess phase lag of the integrators, thus ensuring the in-band flatness of the frequency response over various ambient conditions. The filter has a programmable gain from 0 to 42 dB with a 6 dB step, a tunable center fre- quency at either 6.4 MHz or 16 MHz, and a bandwidth from 2 to 20 MHz with less than 3% frequency uncertainty. Implemented in a 0.18μm CMOS process, the whole filter consumes 7.8 mA from a 1.8 V supply voltage and occupies a die area of 0.4 mm2.展开更多
We propose a passive compensation fiber-optic radio frequency（RF） transfer scheme with a nonsynchronized RF stable source during a round-trip time, which can avoid high-precision phase-locking and efficiently suppre...We propose a passive compensation fiber-optic radio frequency（RF） transfer scheme with a nonsynchronized RF stable source during a round-trip time, which can avoid high-precision phase-locking and efficiently suppress the effect of backscattering only using two wavelengths at the same time. A stable frequency signal is directly reproduced by frequency mixing at the remote site. The proposed scheme is validated by the experiment over a 40 km single mode fiber spool using nonsynchronized common commercial RF sources. The influence of the stability of nonsynchronized RF sources on the frequency transfer is investigated over different length fiber links.展开更多
Renewable power generation is a suitable technology used to deliver energy locally to customers especially in remote regions. Wind energy based on induction generator situates in a foreground position in the total ene...Renewable power generation is a suitable technology used to deliver energy locally to customers especially in remote regions. Wind energy based on induction generator situates in a foreground position in the total energy produced using renewable sources. In the last few decades, a new self- excitation generator was based on multi-stator induction strongly emerges. This article presents a systematic modelling, a detailed analysis and the performance analysis of self-excitation dual stator winding induction generator (SE-DSWIG). The modelling of the SE-DSWIG was done with taking in account the common mutual leakage inductance between stators and the magnetizing inductance, which played a principal role in the stabilization of the output voltage in the steady state. The generator feeds the end user emulated by an inductive-resistive load. In order to simulate the weather conditions’ variation, a step change of the prime mover speed was applied on the SE-DSWIG. A passive series and shunt compensator was used to mitigate the voltage sag and swell appeared in the power system due to wind variation and the lack of reactive power consumed by the inductive load.展开更多
基金Project supported by the Chinese National Major Science and Technology Projects(No.2009ZX01031-002-005)
文摘This paper presents a 5th-order Chebyshev-I active RC complex filter for multi-mode multi-band global navigation satellite systems （GNSS） RF receivers. An improved passive compensation technique is used to cancel the excess phase lag of the integrators, thus ensuring the in-band flatness of the frequency response over various ambient conditions. The filter has a programmable gain from 0 to 42 dB with a 6 dB step, a tunable center fre- quency at either 6.4 MHz or 16 MHz, and a bandwidth from 2 to 20 MHz with less than 3% frequency uncertainty. Implemented in a 0.18μm CMOS process, the whole filter consumes 7.8 mA from a 1.8 V supply voltage and occupies a die area of 0.4 mm2.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.61627817 and 61535006)
文摘We propose a passive compensation fiber-optic radio frequency（RF） transfer scheme with a nonsynchronized RF stable source during a round-trip time, which can avoid high-precision phase-locking and efficiently suppress the effect of backscattering only using two wavelengths at the same time. A stable frequency signal is directly reproduced by frequency mixing at the remote site. The proposed scheme is validated by the experiment over a 40 km single mode fiber spool using nonsynchronized common commercial RF sources. The influence of the stability of nonsynchronized RF sources on the frequency transfer is investigated over different length fiber links.
文摘Renewable power generation is a suitable technology used to deliver energy locally to customers especially in remote regions. Wind energy based on induction generator situates in a foreground position in the total energy produced using renewable sources. In the last few decades, a new self- excitation generator was based on multi-stator induction strongly emerges. This article presents a systematic modelling, a detailed analysis and the performance analysis of self-excitation dual stator winding induction generator (SE-DSWIG). The modelling of the SE-DSWIG was done with taking in account the common mutual leakage inductance between stators and the magnetizing inductance, which played a principal role in the stabilization of the output voltage in the steady state. The generator feeds the end user emulated by an inductive-resistive load. In order to simulate the weather conditions’ variation, a step change of the prime mover speed was applied on the SE-DSWIG. A passive series and shunt compensator was used to mitigate the voltage sag and swell appeared in the power system due to wind variation and the lack of reactive power consumed by the inductive load.
