Compressive Receiver Using a CRLH-Based Dispersive Delay Line for Analog Signal Processing

A compressive receiver (CR) is presented utilizing a composite right/left-handed (CRLH) dispersive delay line (DDL) for analog signal processing applications. The CRLH DDL offers advantages such as arbitrary frequency of operation and wide bandwidth, filling a gap with competing DDL technologies. The presented CR system utilizes an impulse-driven CRLH DDL and mixer inversion for chirp generation required for real-time signal processing. At high frequencies, this eliminates frequency ramp generators. The CR is employed as a frequency discriminator and a tunable delay line with dispersion compensation. The simulation and experimental results fully validate the presented systems as proof-of-concept for high-frequency applications such as real-time Fourier transformers and signal analyzers.      

Composite right/left handed transmission line phase shifter using ferroelectric varactors

A composite right/left handed (CRLH) transmission line (TL) phase shifter, using ferroelectric (Ba/sub 0.25/Sr/sub 0.75/TiO/sub 3/) varactors as tunable element, is presented for the first time. It is theoretically and experimentally demonstrated how the unique features of CRLH TLs, enables a differential phase shift with flat frequency dependence around the center frequency. The experimental prototype is a coplanar design integrated on a high resistive Si substrate. It includes four CRLH T-unit cells and has a physical length of 3850/spl mu/m. The ferroelectric varactors are realized in parallel plate version. Under 15-V dc bias applied over each varactor, the differential phase shift is flat around 17GHz and has an absolute value of 50/spl deg/.     

基于左右手传输线的小型天线设计

基于复合左右手传输线技术研究设计超小型的天线,通过对复合左右手传输线结构的适当调整获得一个零阶谐振天线,此时天线的工作频率不再依赖于天线的几何尺寸,而只与构成左手传输线的电感与电容相关,从而可大大降低天线的几何尺寸。文中基于复合左右手传输线设计了一款小型天线,使其可以工作在ISM频段,能够满足无线局域网(2.4~2.4835GHz)的要求。     

Characteristics of the composite right/left-handed transmission lines

The composite right/left-handed (CRLH) transmission line (TL) is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. The dispersion diagram of the two-dimensional (2-D) CRLH-TL is obtained analytically based on the Bloch-Floquet theory, and the unique phenomenon of infinite guided-wavelength propagation, with nonzero group velocity at a nonzero frequency, is explained. It is shown analytically that when the CRLH TL is "balanced", two eigenfrequencies at the /spl Gamma/ point (/spl beta/=0) of the Brillouin zone (BZ) degenerate at /spl omega//sub /spl Gamma// and a seamless transition from the LH to the RH modes without a bandgap can be achieved. In addition, these phenomena are demonstrated experimentally in the case of a CRLH microstrip line.     

Composite Right/Left-Handed Transmission Line With Wire Bonded Interdigital Capacitor

An enhanced composite right/left-handed (CRLH) transmission line (TL) is presented in this letter. This TL, designed in microstrip technology, is implemented by means of a new improved interdigital capacitor (IDC), the so-called wire bonded IDC (WBIDC). The use of the WBIDC broadens the frequency band where the CRLH TL can be considered as a TL. A conventional 70-Omega CRLH TL (using IDCs) has been compared, by full-wave simulation and measurements, with its enhanced counterpart (using WBIDCs). In addition, this enhanced CRLH TL has been used to design a CRLH diplexer which presents several advantages over standard CRLH coupled lines (using IDCs). The diplexer response has been verified by means of a full-wave electromagnetic solver     

Microstrip Coupled Line Composite Right/Left-Handed Unit Cell

This letter presents a new composite right/left-handed (CRLH) unit cell, which takes advantage of the microstrip coupled line even and odd modes. The new cell does not require vias, it is patterned on a single metal layer, and it has a geometrical circuit model that simplifies the design flow. A novel CRLH transmission line is also proposed. It does not have a cutoff frequency, the operating bandwidth extends from dc to 4 GHz, and it is balanced at the first and second transition frequencies between right- and left-handed bands. The theoretical expectations have been confirmed by EM simulations and measurements.      

Wide-band balun using composite right/left-handed transmission line

A wide-band balun is developed using a composite right/left-handed (CRLH) transmission line (TL) at 2 GHz. It is composed of a Wilkinson power divider and two phase-adjusting transmission lines, namely the CRLH TL and the conventional TL. The input reflection coefficient is better than -10 dB from 1 to 4 GHz. Over the frequency range of 1.24-3.58 GHz, an amplitude imbalance of less than 0.7 dB and a phase error of less than plusmn10deg have been experimentally demonstrated.     

A genetic approach to the synthesis of composite right/left-handed transmission line impedance matching sections

A genetic approach for the synthesis of composite right/left-handed (CRLH) transmission line impedance matching sections is presented. Continuous parameter genetic algorithm (CPGA) is used for the synthesis. Examples for a uniform CRLH transmission line impedance matching section and a nonuniform CRLH transmission line impedance matching section are given.     

基于CRLH的小型化超宽带带通滤波器的研究

提出了基于复合左右手结构传输线(Composite Right/left-handed Structure Transmission Lines.简称CRLH TLs)的小型化超宽带带通滤波器.给出了滤波器的设计结构及其等效电路,仿真表明,该超宽带带通滤波器可在3.2～8.6 GHz的通带范围内插入损耗小于0.7 dB.回损大于17dB.带内群时延小于0.4ns.新的滤波器的尺寸约为中心波导波长的1/3.便于实现结构的小型化.     

CPW‐Fed Arbitrary Frequency‐Switchable Antenna Using CRLH Transmission Line

A novel frequency‐switchable antenna that uses PIN diodes and a composite right‐ and left‐handed transmission line (CRLH TL) is proposed. The CRLH TL provides multi‐order resonance, including a zeroth‐order resonance (ZOR), and its shunt stub determines the ZOR frequency. Thus, the resonant frequency is arbitrarily chosen by lumped chip inductors on the shunt stub. Two prototypes are designed using different chip inductors while maintaining the antenna geometries. Antenna #1 can switch the resonant frequency from 1.8 GHz to 2.3 GHz. Antenna #2 can switch its resonance from 0.9 GHz to 2.3 GHz.     

Enhanced CRLH Transmission Line Performances Using a Lattice Network Unit Cell

A novel topology for the composite right/left-handed transmission line (CRLH TL) is presented. This type of CRLH TLs has the advantage of exhibiting an all-pass behavior and a frequency-independent characteristic impedance, in the so-called balanced case. Moreover, it presents a larger group velocity than its conventional counterpart, thereby allowing for wider bandwidth operation. This letter investigates the fundamental properties of this structure, and demonstrates them by full-wave simulation and measurement results on a practical implementation in parallel stripline technology.      

一种 CRLH 传输线结构的电调移相器设计

基于左右手复合传输线（CRLHTL,Composite Right／Left-Handed Transmission Line）提出了一种加载变容管结构的电调移相器,该移相器由两个电调复合传输线单元级联构成,每个复合传输线单元含3个变容二极管用以实现其相位传播常数以及等效特性阻抗的大范围调配。为方便工程使用,整个移相器6个变容二极管采用单一偏置电压控制,仿真以及最终测试结果均显示,在其工作的S频段内实现了可调相移量大于180°,相对带宽大于10％且回波损耗优于10dB的良好性能。     

频带展宽的复合左右手传输线偶极子天线

针对周期复合左/右手(Composite Right/Left-Handed, CRLH)传输线偶极子天线带宽窄的问题, 提出一种非周期CRLH传输线的天线模型.该模型主要由N个不同尺寸的LC梯形网络单元组成, 实现参差调谐, 改善天线的阻抗匹配, 拓展天线带宽.设计了一种四单元非周期CRLH偶极子天线, 模拟和实验测试结果表明:天线的长度为0.135λ₀时, 满足回波损耗|S₁₁|≤-10 dB的相对阻抗带宽为8.55%, 天线的匹配性能得到了改善.     

Optical fiber recirculating delay line incorporating a fibergrating array

For a practical optical fiber recirculating delay line the maximum notch depth and tunable free spectral range are difficult to achieve because of fixed coupling coefficient and loop length. We present here an optical fiber recirculating delay line incorporating a fiber grating array. In this work, the effect of insertion loss in the delay loop is investigated and used to maximize the notch depth of the frequency response. The tunable free spectral range is obtained from the wavelength dependent loop length introduced by the fiber grating array     

复合左右手微带有源漏波阵列天线

本文通过分析左右手传输线的后向波理论,提出了一种基于复合左右手传输线的有源漏波阵列天线。该天线的有源辐射单元部分采用左右手传输线结构,通过添加有源放大器和移相器,在传输方向上可以实现前后向波束大范围扫描,在组阵方向实现波束相扫,整个阵列实现两维电扫功能。仿真与实验结果吻合良好,表明该设计方法的正确性和可行性。     

Electronically tunable nondispersive magnetostatic wave delay line

An electronically tunable, nondispersive magnetostatic wave delay line consisting of cascaded magnetostatic backward volume waves and magnetostatic surface waves delay lines has been designed and realised. The distinguishing feature of the device is a wide continuously tunable time delay range of ±30% with the central value of 58 ns. An obtained bandwidth for constant time delay is ~300 MHz at a 3.15 GHz centre frequency. A deviation from constant delay is <±5%     

基于多层结构的新型左右手混合传输线

通过利用微带到共面波导的多层耦合结构,设计并制作了一种新型的左右手混合（CRLH）传输线。在该结构中,串联电容可以方便的通过上下两层金属导体之间的耦合加以实现,克服了传统的共面交指电容的电容值有限并且调谐复杂的缺点。同时也研究了判断左手通带的方法,并将该方法应用到所设计的结构中,结果表明该传输线结构具有相对较宽的左手带宽并且在左手通带内匹配良好。     

Pattern Dependence of Data Distortion in Slow-Light Elements

Slow light has been proposed as a potential solution to all-optically tunable delay line. However, a slow-light element may degrade data quality in an optical communication system while decreasing group velocity of optical pulses. In this paper, pattern dependence of signal distortion is identified as a main reason for data degradation, which is caused by narrow-band amplitude and phase responses of the slow-light elements. We define figure of merit involving pulse delay and data degradation to optimize slow-light devices. It is shown that the pattern dependence can be reduced by detuning slow-light devices away from the signal carrier frequency, which allows using narrow-band slow-light techniques to increase normalized delay up to 0.8, with Q improvement of 2 dB.     

基于可调谐激光器的光纤光栅高速解调的时延误差补偿方法

基于可调谐激光器的光纤光栅(fiber Bragg grating, FBG)解调仪用于FBG传感器的远距离、高速测量时,光传输时延会导致显著的波长解调误差。本文设计了一种补偿光传输时延导致的FBG解调误差的方法,可调谐激光器在工作光频率范围内进行高线性度的正向、反向扫描,利用正向、反向扫描过程中的光电探测信号的FBG反射峰差异,对光传输时延导致的波长解调误差进行补偿。试验结果表明,在50 kHz解调频率和100 m连接光纤长度条件下,将光传输时延导致的波长解调误差由2 nm降低到小于10pm。     

Broadband Resonant-Type Metamaterial Transmission Lines

In this letter, it is shown that, contrary to previous assumptions, the broadband characteristics of metamaterial transmission lines are not exclusive of the so called CL loaded composite right/left handed (CRLH) structures. In the balance condition, the typical frequency gap between the left handed (LH) and right handed (RH) transmission bands of these CRLH lines collapses, the characteristic impedance varies smoothly in the vicinity of the transition frequency, and broadband response results. However, through an appropriate design, similar behavior can be obtained in resonant type metamaterial transmission lines, namely transmission lines loaded with complementary split rings resonators. A detailed analysis of the structures, based on the equivalent circuit model is provided, and implications of balancing are pointed out. In this letter, it is clearly demonstrated that broadband balanced CRLH lines can also be implemented by means of the resonant type approach