- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE International Symposium on Phased Array System & Technology (PAST) - Waltham, MA, USA (2019.10.15-2019.10.18)] 2019 IEEE International Symposium on Phased Array System & Technology (PAST) - A Low Profile Tightly Coupled Antenna Array with 80?° Scanning for Multifunctional Applications
摘要： This paper presents an all-digital phase-locked loop (AD-PLL) using a voltage-domain digitization realized by an analog-to-digital converter (ADC) instead of adopting a traditional time-to-digital converter (TDC) which usually suffers from a tradeoff in resolution and power consumption. It consists of an 18 bit class-C digitally controlled oscillator (DCO), a 4 bit comparator, a digital loop filter (DLF), and a frequency-locked loop (FLL). Implemented in 65 nm CMOS technology, the proposed PLL reaches an in-band phase noise of ?112 dBc/Hz and an RMS jitter of 380 fs at a carrier frequency of 2.2 GHz. A figure of merit (FoM) of ?242 dB was achieved with a power consumption of only 4.2 mW.
关键词： sub-sampling,analog-to-digital converter (ADC),voltage-domain,All-digital phase-locked loop (AD-PLL),frequency synthesizer,CMOS,low-power
更新于2025-09-19 17:13:59
-
[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - High-resolution frequency and phase control of a terahertz laser
摘要： We report on the high-resolution frequency and phase control of a terahertz (THz) quantum cascade laser (QCL). The 2.0 THz QCL is locked to a stable microwave reference frequency via an all-fibre infrared frequency comb. The frequency of the QCL is controlled by optical injection and the phase is independently controlled by introducing a phase-lock loop that provides electronic feedback to the QCL, forming an optical injection phase locked loop (OIPLL). By implementing this, (1) the instrument limited linewidth of the locked QCL was <1Hz (2) for a fixed frequency, the phase of the THz QCL relative to the microwave reference frequency can be controlled within a range 0.3(cid:2).
关键词： optical injection phase locked loop,phase control,quantum cascade laser,frequency control,terahertz
更新于2025-09-16 10:30:52
-
Heterodynes Laser-Doppler-Vibrometer mit gekoppelten Diodenlasern zur Schwingungsanalyse von SAW-Filtern / Heterodyne laser-Doppler vibrometer with frequency-offset-locked diode lasers for vibration analysis of SAW filters
摘要： Heterodyne interferometers measure vibration amplitudes at frequencies > 100 MHz with defined measurement uncertainty in contrast to homodyne methods. The low efficieny of Bragg cells for frequency shifting > 409 MHz impedes the application of heterodyne interferometers for the Gigahertz range. In this paper, we present an automated measurement system for the aquisition of operting deflection shapes of microsystems with a laser-Doppler-vibrometer microscope, in which an optical phase-lock loop controls the frequency offset of two diode lasers and, therefore, determines the carrier frequency. Our measurement system provides a vibration-amplitude resolution in the picometer range for vibration frequencies from 10 MHz to 700 MHz. The measurement capability for the absolute amplitude and phase of the vibration is exemplary shown with a vibration analysis of a surface-acoustic-wave filter.
关键词： MEMS testing,heterodyne laser-Doppler vibrometry,Heterodyne interferometry,phase-locked loop
更新于2025-09-16 10:30:52
-
AIP Conference Proceedings [AIP Publishing INTERNATIONAL SYMPOSIUM ON GREEN AND SUSTAINABLE TECHNOLOGY (ISGST2019) - Perak, Malaysia (23–26 April 2019)] INTERNATIONAL SYMPOSIUM ON GREEN AND SUSTAINABLE TECHNOLOGY (ISGST2019) - Single - phase phase locked loop with DC offset and noise rejection capability for photovoltaic inverters in distributed generation
摘要： Green and sustainable energy could not be realised without stable and reliable grid. When green energy such as photovoltaic (PV), is injected to the grid, it requires accurate synchronization (voltage, frequency and phase angle). This can be done via phase locked loop (PLL). The performance of the conventional PLL is poor due to steady-state error. Moreover, it fails to operate under weak grid condition, i.e., with dc offset and with noise. Although many PLLs have been proposed in the literature to eliminate the steady-state error, the performance of the PLLs under weak grid condition is still poor. In this paper, a new PLL is proposed to eliminate the DC offset and noise. The results show that the proposed PLL is able to completely eliminate the perturbation of 30 % DC bias, 0.095 W of noise, with a settling time of 150 ms. 10% of magnitudes of low order 3rd, 5th and 7th harmonics are also reduced considerably. Furthermore, the under shoot of the estimated frequency waveform is reduced up to 8 Hz. With the proposed PLL, the green energy can be harvested without any grid stability concerns.
关键词： photovoltaic inverters,phase locked loop,DC offset,noise rejection,distributed generation
更新于2025-09-16 10:30:52
-
Collaborative Fault Detection for Large-scale Photovoltaic Systems
摘要： The synchronous reference frame phase-locked loop (SRF-PLL) is widely used for synchronization applications. However, it suffers from a poor performance under unbalanced and distorted grid conditions. To improve the filtering capability of SRF-PLL, moving average filter (MAF) is incorporated into its control loop at the cost of a slow transient response of PLL in recently published literature. To further improve their dynamic performance without compromising the disturbance rejection capability and stability, a novel PLL based on quasi-type-1 PLL structure is proposed in this paper. A complex notch filter is incorporated into the QT1-PLL to eliminate the fundamental frequency negative sequence voltage component. The window length of MAF in QT1-PLL is reduced. And MAF is responsible for rejecting the rest of harmonics. Parameter design guidelines are suggested to obtain the minimum settling time for both phase jump and frequency jump. The proposed PLL provides a faster transient response with higher stability margins. The effectiveness of the proposed PLL is confirmed through simulation and experimental results and comparison with advanced PLLs.
关键词： Phase-locked loop (PLL),complex-vector filter,synchronization,moving average filter (MAF)
更新于2025-09-16 10:30:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Optical Repetition Rate Stabilization Techniques of Ultrafast Yb Doped All Fiber Oscillator
摘要： High intensity lasers usually based on OPCPA technology [1] require stable and precisely controlled repetition rate of the oscillator. Common method of repetition rate control is based on movable mirrors mounted on piezoelectric stages in free space [2]. This method has some disadvantages such as sensitivity to changes of ambient conditions and requirement for high voltage driving of piezo actuators. Different approach of fiber laser repetition rate control, which helps to overcome these shortcomings, is based on refractive index modification [3] instead of geometrical oscillator length change. In this work we demonstrate all-fiber concept of precise repetition rate control of an ultrafast ytterbium oscillator passively mode-locked using semiconductor saturable absorber mirror (SESAM). Refractive index change in Er-doped fiber core induced by pump laser power change allowed to lock repetition rate of oscillator to external clock frequency using phase-locked loop (PLL) electronics.
关键词： Refractive Index Modification,Ultrafast Yb Doped All Fiber Oscillator,Optical Repetition Rate Stabilization,Phase-Locked Loop
更新于2025-09-12 10:27:22
-
Carrier Frequency Offset Estimation for BPSK Signals in Coherent Optical Communications
摘要： In this paper, a algorithm which is used for carrier frequency offset (CFO) estimation is proposed in coherent optical communications system with binary phase-shift keying (BPSK) modulation. The proposed algorithm utilizes the frequency divider to broaden the range of the estimation algorithm. In a 5-GBaud coherent BPSK system, simulation results show that when 12dB signal-to-noise ratio (SNR) and 512 samples are utilized, a 8 frequency divider can expand the range of the frequency offset estimation from [-0.5GHz, +0.5GHz] to [-4GHz, +4GHz] and the CFO estimation error can be obtained less than 5MHz. The paper presents a novel algorithm that features the large estimation range for carrier frequency offset while estimation error is not enlarged. The experimental results verified the effectiveness of the proposed algorithm.
关键词： costas optical phase-locked loop,BPSK modulation,carrier frequency offset estimation,frequency divider,Coherent optical communication
更新于2025-09-12 10:27:22
-
A Compact Quick-Start Sub-mW Pulse-Width-Controlled PLL with Automated Layout Synthesis using a Place-and-Route Tool
摘要： This paper demonstrates the design ?ow of a quick-start pulse-width-controlled PLL with automated layout synthesis using a place-and-route tool. The quick-start PWPLL converts the internal state into an analog-digital mixed signal called soft-thermometer-code (STC) and stores them into memory before PWPLL is turned o? in order to enhance the start-up in the next turn-on. Our chip fabricated with TSMC 65nm shows 220ns settling time (13 reference clock cycles), 858μW power consumption under 1V nominal supply voltage with 59μm × 58μm silicon area. The measurement results demonstrate that the design-automated PLL realizes the FoM of ?221.7dB, which is roughly the same value as that of the manually-designed one with the same target speci?cation.
关键词： layout automation,pulse-width-controlled PLL,quick start,Phase locked loop,place and route
更新于2025-09-12 10:27:22
-
[IEEE 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT) - Charlotte, NC, USA (2019.10.6-2019.10.9)] 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT) - Novel Direct Power Control Strategy for Single-Phase Photovoltaic Inverters
摘要： In the design of inverter controllers, a phase-locked loop (PLL) is usually used to synchronize the inverter output with power grids. However, the adoption of PLL may increase the complexity of the controller. In addition, the accuracy of the PLL can be impacted if the power quality of the power grid is distorted, and the inaccurate PLL output can degrade the performance of the controller. To overcome these issues, a number of non-PLL control strategies have been studied for the single-phase PV inverter. In this work, a novel non-PLL direct power control strategy (DPC) for single-phase H-bridge SVPWM photovoltaic (PV) inverters are proposed. In this strategy, instantaneous real and reactive power are calculated respectively by using voltage and current components with specific frequencies. Then a maximum power point tracker (MPPT) technique is integrated with the strategy to maximize PV generation. Simulation results demonstrate the effectiveness of the proposed strategy.
关键词： phase-locked loop,single-phase H-bridge inverter,Direct power control,SVPWM,photovoltaic generation
更新于2025-09-11 14:15:04
-
Implementation of a pulse-type laser detection and ranging system based on heterodyne detection for long-range measurement with high repetition rate
摘要： This paper presents the implementation of a pulse-type LAser Detection And Ranging (LADAR) system based on heterodyne detection for long-range measurement. A pulse-type LADAR based on an intensity direct-detection is certainly simple and mature, but it requires a high peak-power laser and a low-noise avalanche photodiode for long-range measurement, which restricts the scope of the application due to the weight, power consumption, and cost of the laser and the photodetector. In this work, heterodyne detection using a PIN photodiode is implemented to increase receiver sensitivity instead of using a low-noise avalanche photodiode. An optical phase-locked loop is adopted to generate an optical local oscillator signal for heterodyne detection. The proposed heterodyne detection scheme achieves a minimum detectable signal level of ?52.6 dBm at a bandwidth of 1.2 GHz, and it is adopted in a pulse-type LADAR system for long-range measurement. The pulse-type LADAR system can measure a distance of 2.77 km at a repetition rate of 40 kHz, and it demonstrates great advantages for realizing real-time 3D imaging for long-range measurement with a high frame rate.
关键词： LADAR,optical phase-locked loop,long-range measurement,heterodyne detection,high repetition rate
更新于2025-09-11 14:15:04