Phase-Shift keyed wideband signal against noises detection by quadrature receiver with input band-pass filter

In this paper we consider wideband signal against noise receiving by quadrature correlation receiver with input band-pass filter. We obtain analytical expressions of detection characteristics. We analyzed dependences of correct receiving on delay time, signal-to-noise ratio and input filter bandwidth. It is shown, that maximal probability of signal detection is obtained in case of non-zero delay time of received signal, which depends on filter bandwidth.     

应用于雷达接收机的宽阻带带通滤波器设计

介绍了交指型微带滤波器的基本设计原理,并利用ADS和HFSS软件仿真设计了通带为2.7~3.5 GHz的高陡峭度的宽阻带带通滤波器,并已应用于某雷达接收机。该方法虽然原理上基于传统公式计算、查表,但是充分利用了ADS软件强大的设计功能,直接由指标要求得到近似的尺寸,然后进行优化得到最终设计结果。测试结果表明,该方法可行有效,设计周期短,对雷达接收机滤波器设计有很强的工程指导作用。     

具有输入信号的自适应跟踪滤波器

针对导弹在被动段自由飞行的状态,提出了一种有效的基于输出残差的自适应跟踪滤波器.首先给出了飞行状态方程,其次利用输出残差给出了Kalman滤波增益马尔可夫参量估计,并且得到了Kalman滤波增益估计,解决了自适应跟踪滤波器问题.仿真结果说明了此方法的有效性.     

新型光纤声光可调滤波器的宽带信号放大器设计

为了改进现有宽带信号放大器的设计并优化器件的性能,采用了基于新型声致光纤光栅光路的设计方法,通过对放大器的理论的计算和调试,针对产生声致长周期光纤光栅所需的MHz量级声波信号需要,设计了一个新型射频放大电路.进行了理论分析和实验验证,取得了声致光纤光栅透射光谱中谐振峰的透射深度检验放大电路的性能数据,结果表示:该放大器能够满足产生声致长周期光纤光栅的器件要求,这一结果对大幅改善和优化宽带信号放大器的性能是有帮助的.     

非对称单脊波导带通滤波器的设计

介绍了非对称单脊波导带通滤波器的基本原理,详细描述了准确设计该滤波器的方法,包括耦合尺寸的提取、谐振器尺寸的逼近及电纳斜率参数的获取。给出了X波段实例的详细设计过程及测试结果。     

对称L型缺陷微带结构可调带通滤波器研究

设计了一种由对称L型缺陷微带结构实现的新型频率可调带通滤波器,并给出了相应的等效电路;对具有该结构的单频带带通滤波器的S参数频响特性进行了仿真与分析,并计算了耦合系数;依据上述结构设计制作了一种可调谐的双频带带通滤波器,并对其谐振频率的可调性进行了分析.结果表明:所制滤波器的谐振频率分别为2.4 GHz和3.5 GHz,相对带宽分别为4.63％和4.95％,有效电路尺寸仅为26.0 mm×1.2 mm.该L型缺陷微带结构带通滤波器具有结构简单紧凑、尺寸小、频率选择性好和谐振频率独立可调等优点.     

一种S波段LTCC带通滤波器的改进设计

设计了一种小型化的低温共烧陶瓷(LTCC)滤波器,该滤波器电路由电容耦合的二阶谐振腔组成。设计了该滤波器的三维多层结构,利用组件间的耦合效应,产生一个传输零点,提高了滤波器性能。仿真结果表明,该滤波器中心频率为3.41GHz,相对带宽为5.9%(200MHz),体积为3.8mm×2.8mm×0.8mm,在S波段的通讯,雷达等射频系统有广泛的应用。     

基于缺陷接地结构的超宽带带通滤波器的设计

介绍了一种将阶梯阻抗耦合谐振器和开口谐振环缺陷接地结构相结合的新的超宽带带通滤波器。利用3D场仿真软件,分析了电路的不同支节尺寸对滤波器宽带特性和频率特性的影响,最后给出了一款超宽带滤波器的仿真和实验结果。     

效应实验用的Ka波段正交解调接收机的研制

针对毫米波雷达的复杂电磁环境效应实验研究需求,采用超外差和模拟零中频变频级联的结构,研制了一套Ka波段正交解调接收机。该接收机由低噪声放大器、混频器、中频放大器、正交相位检波器等部分组成。测试表明:该接收机具有大于256 MHz的工作带宽,在整个工作频带内具有1 MHz的瞬时正交解调带宽,可用于开展复杂电磁环境对毫米波雷达接收信号链路影响效应实验的研究。     

The impact of distortions of phase-shift keyed signals with gradual phase change in the receiver input circuits on the signal detection characteristics during the signal reception against the background of noise

This study examines the impact of an input band-pass filter on the reception of phase-shift keyed signals (PSKS) with gradual phase change against the background of noises. In the case under investigation PSKS are received by a correlation receiver during the radar detection of targets. Analytical expressions of the target detection characteristics were obtained for PSKS with random initial phase and the amplitude containing regular and fluctuating components. This study also examines the relationships of the detection characteristics as a function of the input filter band-pass and the interval duration of gradual phase change.     

Wide-band integrated optical receiver with improved dynamic rangeusing a current switch at the input

The front end of optical transmission systems usually consists of a low-noise, wide-band, negative-feedback transimpedance or current amplifier. The dynamic range of current amplifiers can be extended considerably by passing large input currents directly to the output of the amplifier. It is shown that the required current switch does not deteriorate the sensitivity of the receiver. A complete front end, using an external p-i-n photodiode, is integrated in a 2.5-GHz bipolar technology. The receiver has a dynamic range (DR) of 73 dB in a bandwidth of 220 MHz and consumes a supply current of 1.5 mA     

小型化宽阻带微带带通滤波器的设计

提出一种小型化宽阻带微带带通滤波器,采用半波长阶跃阻抗谐振器结构,且在不相邻的谐振器之间引入交叉耦合,从而在滤波器的阻带上产生了2个传输零点,使阻带抑制在3.95~13.27 GHz小于-20 dB,使寄生通带在中心频率的3.92倍处。滤波器的最终尺寸仅为12.2 mm×11.5 mm,即0.21λg×0.2λg,相比于传统的发夹型滤波器,此滤波器的体积减小了63.5%,而且实测的结果与仿真结果达到了较好的一致性。所提出的滤波器具有更宽的带外抑制,更小的尺寸,且设计简单,在工程领域具有实际的应用价值。     

基于第二代电流传输器的二阶带通滤波器设计

设计了一种单端输入单端输出的电流模式带通滤波器,核心部件为用三极管设计的第二代电流传输器（CCⅡ）.电路由两个CCⅡ和一些无源器件构成,通过偏置电流控制其中心频率,实现对信号的带通滤波功能.该滤波器提供了更大带宽下的更高电压增益,解决了电压跟随不理想的问题,且具有更低的无源灵敏度,能广泛应用于无线通讯、射频等高频模拟电路中.使用Hspice软件仿真分析并验证了理论设计的准确性和可行性.     

一种二阶LTCC微波带通滤波器的仿真设计

根据低温共烧陶瓷技术的特点,提出了一种二阶微波带通滤波器的三维结构设计方法,设计的滤波器结构简单、尺寸小、工作频率可调。按照该设计方法,通过电磁仿真软件AnsoftHFSS10设计了一款带通滤波器。结果表明,该滤波器的中心频率为5.2GHz,带宽为0.4GHz,通带内插损小于2.1dB,尺寸为2.5mm×2.2mm×0.4mm,能够满足微波无线通信系统的要求。     

Unsupervised receiver processing techniques for linear space-time equalization of wideband multiple input / multiple output channels

In this paper, we address the problem of unsupervised (blind) space-time equalization of frequency-selective multiple-input multiple-output (MIMO) channels. The motivation behind this work is that in order to provide the high transmission rates that data-demanding applications require, wireless multiple antenna (MIMO) systems will have to operate in wide bandwidths. In such scenarios, frequency selectivity may induce important intersymbol interference (ISI), in addition to the interuser interference (IUI) that each antenna's transmitted stream of data suffers from the other antennas. Under these conditions, channel estimation of the frequency-selective MIMO channel may become a daunting task that ultimately reduces the effective transmission rate. We present a family of globally convergent blind space-time equalization techniques, developed from multiuser kurtosis output-based criteria, which allow the recovery of the MIMO channel inputs without the training overhead that channel estimation typically requires, thus improving the MIMO channel's spectral efficiency.     

Synthesis of a first-order passive complex filter with band-pass/band-elimination characteristics

In this paper, a new passive complex filter is proposed. In the same fashion as the traditional real band-pass filter, the proposed circuit is also designed through the frequency transformation. In order to obtain the prototype complex filter suitable for passive realization, the extended lowpass–highpass transformation or the bilinear lowpass–lowpass transformation different from the well-known frequency shifting method is adopted. These transformations give two filters; however, the final circuits become identical to each other. The proposed circuit has two output terminals. One is the complex band-pass output, and the other is for the complex band-elimination. The proposed circuit includes a capacitor, an autotransformer or an inductor and termination resistors only. Because the proposed circuit has terminating resistors at both of the input and the output sides, it is suitable for high frequency application. As an example, two first-order complex filters which operate in 100 kHz and 10 MHz are designed and their frequency responses are measured. It is shown that the measured frequency responses agree with the theoretical ones through experiment.     

一种具有传输零点的Hairpin带通滤波器设计

本文通过在微带（hairpin）滤波器的谐振器上并联微带开路线，构成了一种新的hairpin带通滤波器。该滤波器在通带附近有一对传输零点，具有良好的频率响应以及频率选择特性。由于这种类型的微带滤波器实现传输零点不需要通过滤波器非相邻谐振器间的交叉耦合来获得，因此，设计过程非常简单。     

Dual-signal receiver structures for simultaneous reception of two BPSK modulated co-channel signals using signal cancellation

In this paper a dual-signal receiver concept is proposed for simultaneous reception of two narrowband Binary Phase Shift Keying (BPSK) modulated co-channel signals, e.g. two desired signals of different strength. The principle of the proposed receiver concept is based on signal separation and cancellation, by decorrelation of the large signal using the estimated data, followed by demodulation of the small signal. A possible implementation of the receiver concept is presented in detail. The Bit Error Rate (BER) for both signals is derived and numerical and simulation results are presented for two receiver structures with different second demodulator: (1) the coherent BPSK demodulator; (ii) the differentially coherent (DPSK) demodulator. The channel is assumed to be an Additive White Gaussian Noise (AWGN) channel without fading. Comparison of the BER performance of the small signal to the optimum result when only AWGN is present, shows that nearly optimum demodulation of the small signal is possible when the signal strength difference is not too small.     

The probability density function for the output of a correlator with band-pass input waveforms

A general expression is obtained for the characteristic function for the output of a correlator with narrow-band inputs. This general expression is applicable to cases in which the input signals are sinusoidal and have arbitrary amplitudes and phases, and in which the noise inputs are partially correlated. The probability density function for the output is obtained for three special cases, one of which corresponds to a situation that often arises in practice. This practical situation is that in which the signal inputs have the same amplitude and phase, and the noise inputs have the same rms value but are uncorrelated.     

微带SIR电容间隙耦合带通滤波器的设计

本文提出了一种新的基于SIR谐振器的微带电容间隙耦合(Capacitive-Gap-Coupled,CGC)带通滤波器结构。首先根据滤波器的低通原型设计、计算了滤波器的参数,并使用微波CAD软件对设计的尺寸进行了优化、仿真。仿真结果表明该类型滤波器的频带响应具有优良的频带响应,二阶谐波通带的中心频率和理论计算一致,通过调整SIR谐振器的阻抗比可以控制二阶谐波中心频率的位置。