Bao Jingfu

Impulsive Control for Fractional-Order Chaotic Systems

We propose an impulsive control scheme for fractional-order chaotic systems. Based on the Takagi–Sugeno (T-S) fuzzy model and linear matrix inequalities (LMIs), some sufficient conditions are given to stabilize the fractional-order chaotic system via impulsive control. Numerical simulation shows the effectiveness of this approach.

Three-way Doherty power amplifier with uneven power drive

The basic operation principle of the three-way Doherty power amplifier is described. For the experimental verification, a 2.14 GHz three-way Doherty power amplifier using LDMOS devices with a power ratio of 1:2:2 is implemented and tested using WCDMA signal. In the design, we assign more input power to the peaking2 and peaking1 power amplifiers, so the three-way Doherty power amplifier has an uneven power drive. The test data prove that, the three-way Doherty power amplifier with uneven power drive has higher efficiency than the classical two-way Doherty power amplifier when the input signal has a high peak-to-average power ratio.

Impulsive control of nonlinear systems with time-varying delays

A whole impulsive control scheme of nonlinear systems with time-varying delays, which is an extension for impulsive control of nonlinear systems without time delay, is presented in this paper. Utilizing the Lyapunov functions and the impulsive-type comparison principles, we establish a series of different conditions under which impulsively controlled nonlinear systems with time-varying delays are asymptotically stable. Then we estimate upper bounds of impulse interval and time-varying delays for asymptotically stable control. Finally a numerical example is given to illustrate the effectiveness of the method.

Geological disaster monitoring system based on WSN and GSM dual-network integration technology

According to time-consuming, difficulty and network building complication problem for traditional geological disaster monitoring methods, on the basis of the study of wireless sensor network (WSN) and Zigbee standard protocol, the paper presents a real-time and online geological disaster monitoring system architecture applied WSN and mobile communication network (GSM) dual-network integration technology. It has realized hardware and software design of the system architecture that provides an excellent project reference for China to build the ubiquitous networks of mobile communication network and sensor network integration.

An Memory polynomial model for power amplifiers

In this paper, an envelope Memory polynomial (MP) model is introduced to describe dynamic input -output characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.

An 0.5–6GHz ultra-wideband low noise amplifier design

In this letter, the design of a compact, two-stage, low noise, unconditionally stable, amplifier from 0.5 to 6 GHz is discussed. To achieve its wide-band characteristics, a novel matching mechanism is proposed, which consists of lumped-elements and micro-strip lines. The amplifier is designed around the HEMT FHX35LG and the PHEMT ATF-54143. The negative feedback technique is also adopted to border the frequency band, and the software ADS is used to optimize design and the whole matching network. In the covered band, the amplifier provides more than 18 dB gain, gain-flatness of less than ±1 dB, noise figure of less than 3.5 dB, linear output power (P−1dB) of more than 20 dBm.

A S-band colpitts VCO for fast hopping frequency synthesizer

This paper analyzed the basic theory of voltage controlled oscillator as well as the mathematical expression of hopping time in frequency synthesizer. The impaction of the oscillator gain of VCO on the hopping time is discussed consequently. Finally, a S-band colpitts VCO is designed and simulated in ADS and a novel type of mixed simulation method which can provide better accuracy is provided.

An analysis of self-heating and collector-current-collapse on RF power transistor

This paper examines the influences of the self-heating behavior of Silicon-on-Insulator (SOI) MOSFET transistors and multi-finger Hetero-junction Bipolar Transistors (HBT) on a range of primitive Radio Frequency Integrated Circuits (RFIC) cells. In addition to the more well-known self-heating effect (SHE), Collector Current Collapse effects (CCCE) are examined. Particular emphasis is given to the impact of these effects on drain current mismatch due to localized temperature differences. Simulations and analyses are presented for a simple cascode amplifier stage. Anomalies due to self-heating are also clearly visible in the small-signal characteristics of the cascode stage. The paper demonstrates how circuit-level simulations can be used to predict undesirable nonisothermal operating condition during the design stage.

Optimum Design of the Adaptive Predistortion Power Amplifier For WCDMA RF Subsystem

In this paper, an adaptive predistortion RF power amplifier for repeater subsystem is introduced. With an optimum gate bias voltage of the power amplifier, ACPRs of 12 and 13.5 dB are improved for the cases of the upper and lower channels. It delivers a Pout of 33 dBm with an ACPR of -50 dBc in the implementation. The characteristic of the adaptive predistortion RF power amplifier with two loops performed excellent under various conditions, such as vary input power levels, temperature, and operating frequency channels

Simulation Design of a Low-Noise Amplifier for 3.1-10.6 GHz Ultra-Wideband Wireless Receivers

An ultra-wideband (UWB) hybrid low noise amplifier (LNA) is presented. The topology is a two-stage amplifier including a bandpass Chebychev LC filter and a source-follower buffer. The bandpass filter works as input matching network to give an acceptable reflection coefficient and a small amount DC power. Gain flatness is achieved mainly by the two transistors with matching network between stages. And the slight source negative feedback inductors are designed to facilitate input impedance and noise matching. The proposed UWB amplifier is implemented with gallium arsenide (GaAs) field effect transistors and a Rogerss substrate (RO4003). The LNA gives 18.2 dB gain flatting, a minimum noise figure (NF) of 1.2 dB, input and output reflection coefficient better than - 12 dB within 2 dB from 3.1 to 10.6 GHz