Microwave Oscillator Phase Noise Requirement for TD-SCDMA Wireless Communication Systems

In time division synchronous code division multiple access (TD-SCDMA) wireless communication systems, QPSK or 8PSK has been employed to support high data rate services and high efficiency in available bandwidth. The performance of such systems is affected by the phase noise of the microwave local oscillator. The phase noise model of synthesizer and the RF transceiver model for the phase noise effect are proposed for applications of TD-SCDMA systems. The relationship between the power spectral density (PSD) and root mean square (RMS) phase error is given. Then, the error vector magnitude (EVM) performance is analytically evaluated by using the single side band (SSB) phase noise. Theoretical results show agreement with those obtained by measurement data and therefore can be used to derive the TD-SCDMA system performance.

A 10-MHz SOI-Based Face Shear Square Micromechanical Resonator

A 10-MHz face shear(FS) square micromechanical resonator based on silicon-on-insulator(SOI)technology is presented in this paper. In order to examine the improvement of quality factor as well as motional resistance Rx in this structure, the center-stem anchor is employed in this study. The benefit of anchoring the square in the center, which is the nodal point, is that the energy losses through the anchor can be minimized. Hence, a quality factor value of 2.0 million and the motional resistance of 8.2 k can be obtained with an FS mode resonator via finite element(FE) simulation. The results show the significance of the FS mode in this design, not only in its structure but also in its square-extensional mode and Lame-mode. Additionally, an SOI-based fabrication process is proposed to support the design.

A Strong Anti-Jamming Algorithm Based on FPGA for Estimating Loop Delay in Digital Predistortion System

At present what are the key points focused in the research of loop-delay estimation for the digital predistorter in the radio frequency (RF) power amplifier system is reducing its complexity of engineering realization and improving anti-jamming ability and computational speed. Besides, opening up its application scope should be contained. For these targets, a novel method including integer loop delay estimation and fractional part is proposed. The integer part applies amplitude-difference summation function and the fractional one adopts the method of finite impulse response (FIR) linear interpolation. The algorithm finds wide applications. What is more, strong anti-jamming ability and low complexity are also its merits. Simulation results support the above opinion. Digital predistortion (DPD) system based on this algorithm achieves good performance.

Electron-Ion Coupling Mechanism to Construct Stable Output Performance Nanogenerator

Recently,triboelectric nanogenerators(TENGs)have been promoted as an effective technique for ambient energy harvesting,given their large power density and high energy conversion efficiency.However,traditional TENGs based on the combination of triboelectrification effect and electrostatic induction have proven susceptible to environmental influence,which intensively restricts their application range.Herein,a new coupling mechanism based on electrostatic induction and ion conduction is proposed to construct flexible stable output performance TENGs(SOP-TENGs).The calcium chloride doped-cellulose nanofibril(CaCl_(2)-CNF)film made of natural carrots was successfully introduced to realize this coupling,resulting from its intrinsic properties as natural nanofibril hydrogel serving as both triboelectric layer and electrode.The coupling of two conductive mechanisms of SOP-TENG was comprehensively investigated through electrical measurements,including the effects of moisture content,relative humidity,and electrode size.In contrast to the conventional hydrogel ionotronic TENGs that require moisture as the carrier for ion transfer and use a hydrogel layer as the electrode,the use of a CaCl_(2)-CNF film(i.e.,ion-doped natural hydrogel layer)as a friction layer in the proposed SOP-TENG effectively realizes a superstable electrical output under varying moisture contents and relative humidity due to the compound transfer mechanism of ions and electrons.This new working principle based on the coupling of electrostatic induction and ion conduction opens a wider range of applications for the hydrogel ionotronic TENGs,as the superstable electrical output enables them to be more widely applied in various complex environments to supply energy for low-power electronic devices.

Electron-Ion Coupling Mechanism to Construct Stable Output Performance Nanogenerator

Recently,triboelectric nanogenerators(TENGs)have been promoted as an effective technique for ambient energy harvesting,given their large power density and high energy conversion efficiency.However,traditional TENGs based on the combination of triboelectrification effect and electrostatic induction have proven susceptible to environmental influence,which intensively restricts their application range.Herein,a new coupling mechanism based on electrostatic induction and ion conduction is proposed to construct flexible stable output performance TENGs(SOP-TENGs).The calcium chloride doped-cellulose nanofibril(CaCl_(2)-CNF)film made of natural carrots was successfully introduced to realize this coupling,resulting from its intrinsic properties as natural nanofibril hydrogel serving as both triboelectric layer and electrode.The coupling of two conductive mechanisms of SOP-TENG was comprehensively investigated through electrical measurements,including the effects of moisture content,relative humidity,and electrode size.In contrast to the conventional hydrogel ionotronic TENGs that require moisture as the carrier for ion transfer and use a hydrogel layer as the electrode,the use of a CaCl_(2)-CNF film(i.e.,ion-doped natural hydrogel layer)as a friction layer in the proposed SOP-TENG effectively realizes a superstable electrical output under varying moisture contents and relative humidity due to the compound transfer mechanism of ions and electrons.This new working principle based on the coupling of electrostatic induction and ion conduction opens a wider range of applications for the hydrogel ionotronic TENGs,as the superstable electrical output enables them to be more widely applied in various complex environments to supply energy for low-power electronic devices.