GMSK Demodulator Implementation for ESA Deep-Space Missions

This paper discusses a new implementation of a Gaussian minimum-shift keying (GMSK) modulator and demodulator on the European Space Agency (ESA)'s common deep-space receiver-the Intermediate Frequency Modem System (IFMS), which is a software radio based platform. The GMSK demodulator is needed for ESA's deep-space and near-Earth missions, starting with the Herschel-Planck satellites in 2008. The implementation requirements and hardware restrictions from the IFMS lead to the need for a significant simplification versus the optimum demodulation approach. In part, this can be achieved by using a demodulator based on the Laurent decomposition, yet further simplifications and changes to obtain a feasible implementation were necessary. The presented GMSK demodulator was directly implemented on the existing IFMS receiver without requiring any hardware changes. Measurements with the demodulator showed only a marginal technical degradation in the order of 0.1-0.3 dB for the chosen approach. Furthermore, for testing purposes, a GMSK modulator was implemented on the same platform.     

A Common Receiver Architecture for ESA Radio Science and Delta-DOR Support

The need to support radio science experiments and enhance navigation accuracy for the currently flying deep-space missions of the European Space Agency (ESA) has triggered the development of suitable tools in the agency's deep-space stations. This paper describes the modifications implemented in the ESA standard receiver, the Intermediate Frequency and Modem System (IFMS), for the above goals. These modifications were possible due to the highly flexible architecture of the IFMS. Results obtained in the area of radio science research and delta differential one-way ranging tracking are also presented.     

Dual- and Triple-Mode Branch-Line Ring Resonators and Harmonic Suppressed Half-Ring Resonators

Ring resonators have been widely used for various applications. Dual-mode ring resonators have also been investigated due to their applicability to multifrequency mode requirement. In this paper, dual-mode ring resonators using a branch line are designed along with a systematic approach. Triple-mode branch-line ring resonators are also designed adding two branch lines to the ring resonator. Adding more branch lines, multimode resonators can be realized based on the design procedure developed here. The location of the branch lines determines the additional resonant frequencies other than the fundamental resonant frequency generated by the enclosing ring. Furthermore, half-ring resonators working at 2.5 GHz are proposed for suppressing multiple harmonics (second and third harmonics) and providing size reduction with employment of various physical configurations. Equalizing the even- and odd-mode phase delays, harmonics are suppressed effectively in the design of half-ring resonators. Double half-ring resonators with a long opening gap are investigated to continuously decrease the resonant frequency. An open-loop structure provides flexible design and lowers the resonant frequency. Two dual-mode ring resonators and one triple-mode ring resonator are simulated and fabricated along with three different half-ring resonators     

Design of Miniature Planar Dual-Band Filter Using Dual-Feeding Structures and Embedded Resonators

A new dual-band planar filter has been proposed. It is shown that the two transmission bands can be excited and designed using proposed resonators which combine different sizes of open-loop resonators. The main resonators control the low-band resonant frequency and the sub resonators control the high-band resonant frequency. With dual-feeding structures added, the performances of the filter such as frequency selectivity and insertion loss are much improved. The embedded resonators structure can further miniaturize the dimensions of the overall structure. The proposed dual-band filter will find applications in wireless communication circuits     

Characteristics of single and coupled rectangular resonators in suspended substrate stripline

A rigorous spectral-domain analysis is carried out to determine the resonant frequency characteristics of resonators in a general suspended substrate stripline. The resonant frequency characteristics of single as well as coupled rectangular resonators are computed. An important observation for resonators in broadside-coupled suspended substrate stripline is that the even- and odd-mode resonant frequencies are considerably different.     

Precision fabrication techniques and analysis on high-Q evanescent-mode resonators and filters of different geometries

High-Q evanescent-mode resonators and filters are realized by both silicon micromachining and layer-by-layer polymer processing. Capacitively loaded cavities can be reduced to a size much smaller than a wavelength, but still have a much higher unloaded Q than lumped elements. The loaded resonators are utilized for reduced-size filters with a low insertion loss enabled by the relatively high-Q factor. The small fabrication tolerances of silicon micromachining and polymer stereolithography processing enable the realization of highly loaded evanescent-mode resonators and filters. A 14-GHz resonator micromachined in silicon has a volume of 5 mm /spl times/ 5 mm /spl times/ 0.45 mm, representing a resonant frequency reduction of 66.8% compared to an empty cavity of the same dimensions. The polymer-based fabrication is used to create resonators of different three-dimensional geometries with Q's up to 1940 and frequency reductions up to 49.9%. An insertion loss of 0.83 dB is measured in a 1.69% bandwidth filter created by polymer processing with a frequency reduction of 47% compared to an unloaded cavity. The frequency sensitivity to fabrication tolerances of these structures is also analyzed.     

Microwave resonators with dual-mode oscillations

Analysis of microwave resonators with dual-mode oscillations is conducted. A new type of resonators is discovered in which dual-node oscillations are observed. It represents a half-wave resonator with a short-circuit in the middle part. The length of such a resonator is twice less than the length of a widely used ring resonator. It is shown that in resonators of the loop type combined frequency tuning of dual-mode oscillations is accomplished using capacity and inductance. In the loop-type resonators with a stub frequency tuning of dual-mode oscillations is accomplishing with two capacities synchronously changing their values according to a specific law. Resonance equations are obtained.     

Investigation of the noise characteristics of oscillators based on composite acoustic resonators

It is shown that composite acoustic resonators are promising microwave frequency-control components. It is found that, for a detuning from a carrier frequency exceeding 1 kHz, the phase noise of an oscillator stabilized by a composite resonator is lower than that of oscillators with surface-acoustic-wave crystal resonators and with AT-cut crystal resonators.     

纳机械谐振器的非线性特性分析

纳机械谐振器有几百兆甚至更高的工作频率,本文利用达芬方程作为纳机械谐振器的动力学方程,用数值方法求解了电磁驱动纳机械谐振器的动态特性,计算表明谐振器有明显的非线性特性,与国外已有的实验结果相符合,该分析方法可以为纳机械混频器设计提供参考。     

Study on Planar Whispering Gallery Dielectric Resonators. II. A Multiple-Band Device

The basic theory underlying the realization of simple multiple-band non-homogeneous dielectric resonators, whose spectral response is the overlap of single-resonator frequency bands, is developed exploiting a general approach discussed in the previous companion paper. The limit frequencies of the proposed devices, given only by the dielectric properties of the involved materials, can differ in principle by several decades. Experimental confirmations have been obtained on a composite structure built up with teflon and polyethylene; as predicted by the theory, the overall band includes frequencies which range about from 20 GHz to more than 400 GHz, when high frequency resonances are selectively excited. The localization of the higher frequency radiation between the positive steps of the dielectric constant, which is the basic properties of these non-homogeneous resonators, has been experimentally verified by mapping the electromagnetic field intensity. Possible applications of multiple-band Whispering Gallery dielectric resonators are finally outlined.     

基于SAW谐振器无源无线传感器编码方法研究

为简化声表面波(SAW)传感器的编码过程,提出了一种基于SAW谐振器的编码方法,通过多个不同中心谐振频率的SAW谐振器分别连接不同的负载阻抗进行传感器的编码。设计了传感器的具体结构,建立了传感器的等效电路模型,利用ADS仿真软件对中心谐振频率分别为868MHz和915MHz的2个SAW谐振器组成的传感器进行仿真,结果表明,SAW谐振器外接1pF与4pF的阻抗,其谐振频率差可达200³00kHz。根据仿真结果,设计制作了不同编码的2个传感器,一个不外接阻抗,一个外接10pF的阻抗,测试谐振频率差别可达39.75300kHz。根据仿真结果,设计制作了不同编码的2个传感器,一个不外接阻抗,一个外接10pF的阻抗,测试谐振频率差别可达39.75⁴0.2kHz,因此,SAW谐振器外接不同阻抗时谐振频率的差异明显,基于SAW谐振器与外接阻抗的传感器编码方法是可行的。     

电容式RF MEMS谐振器

介绍了应用于通信领域的电容式RF MEMS谐振器及其在通信系统小型化中的优势。对电容式微机械谐振器进行了综合分析,包括基本工作过程分析、基本参数的理论分析及等效电路的分析。介绍了目前几种常用结构的谐振器,包括梳状谐振器、梁式谐振器及盘式谐振器的工作过程和谐振频率的发展空间。重点分析了谐振器的电容间隙及锚这两个重要的结构参数对谐振器性能的影响。最后,对电容式微机械谐振器存在的问题作了总结,对其发展趋势做出展望。     

High-Q HF microelectromechanical filters

IC-compatible microelectromechanical intermediate frequency filters using integrated resonators with Q's in the thousands to achieve filter Q's in the hundreds have been demonstrated using a polysilicon surface micromachining technology. These filters are composed of two clamped-clamped beam micromechanical resonators coupled by a soft flexural-mode mechanical spring. The center frequency of a given filter is determined by the resonance frequency of the constituent resonators, while the bandwidth is determined by the coupling spring dimensions and its location between the resonators. Quarter-wavelength coupling is required on this microscale to alleviate mass loading effects caused by similar resonator and coupler dimensions. Despite constraints arising from quarter-wavelength design, a range of percent bandwidths is still attainable by taking advantage of low-velocity spring attachment locations. A complete design procedure is presented in which electromechanical analogies are used to model the mechanical device via equivalent electrical circuits. Filter center frequencies around 8 MHz with Q's from 40 to 450 (i.e., percent bandwidths from 0.23 to 2.5%), associated insertion losses less than 2 dB, and spurious-free dynamic ranges around 78 dB are demonstrated using low-velocity designs with input and output termination resistances of the order of 12 kΩ     

Magnetically Controlled Millimeter Waveband Filter Based on Disk Resonator Chain

Numerical calculation of transmission spectra of the chain of disk resonators has been executed by FDTD method. Two dielectric and the semiconductor disk resonators form the chain of disk resonators. The tensor constitutive parameters of semiconductor resonator can be varied with magnetic field. The optimal range of magnetic field, providing the most effective tuning the resonance frequency of the resonators chain, is defined. The numerical values of the tuning the frequency-selective parameters of structure under study are obtained.     

Tunability limitations of microwave resonators tuned by several capacitances and inductances

Tunability limitations of resonators that consist of transmission line sections and are tuned by several capacitances and inductances are established. The limitations are common for lossy and lossless resonators. It is shown that an increase in the number of tuning elements does not lead to increasing frequency ratio. It is proved that combined tuning is more effective that tuning by one-type elements. This tuning makes possible continuous variation of the resonance frequency in a wide range exceeding a decade.     

单基三电极石英晶体谐振器频率-温度特性研究

设计了一种新型的单基三电极石英晶体谐振器，并在大气环境条件下测试分析了这种谐振器的频率-温度特性，验证了其频率-温度特性与已有的单基单电极谐振器的频率-温度特性基本一致，曲线为三次曲线。在相同激励及环境条件下，在同一基片上设置多对电极时，各对电极构成的谐振器的频率-温度特性基本相同。根据这种相似特点，将同一基片上不同电极对应的谐振器的振动频率进行差频补偿，可有效地抑制温度对谐振器振动频率的影响。这种谐振器所采用的差频补偿方法可为石英谐振器相关特性的进一步开发利用提供依据。研究了这种结构的石英晶体谐振器的晶片表面处理（是否抛光）及边沿形状（是否倒边）对其频率-温度特性的影响。实验结果表明，对单基多电极石英晶体谐振器的晶片表面进行抛光并对边沿进行倒边处理后，谐振器的稳定性得到了有效的改善，性能得到了优化。     

单基三电极石英晶体谐振器频率-温度特性研究

设计了一种新型的单基三电极石英晶体谐振器,并在大气环境条件下测试分析了这种谐振器的频率-温度特性,验证了其频率-温度特性与已有的单基单电极谐振器的频率-温度特性基本一致,曲线为三次曲线。在相同激励及环境条件下,在同一基片上设置多对电极时,各对电极构成的谐振器的频率-温度特性基本相同。根据这种相似特点,将同一基片上不同电极对应的谐振器的振动频率进行差频补偿,可有效地抑制温度对谐振器振动频率的影响。这种谐振器所采用的差频补偿方法可为石英谐振器相关特性的进一步开发利用提供依据。研究了这种结构的石英晶体谐振器的晶片表面处理(是否抛光)及边沿形状(是否倒边)对其频率-温度特性的影响。实验结果表明,对单基多电极石英晶体谐振器的晶片表面进行抛光并对边沿进行倒边处理后,谐振器的稳定性得到了有效的改善,性能得到了优化。     

Tunable Microwave Resonators Using Magnetostatic Wave in YIG Films

The purpose of this paper is to review the status of magnetostatic wave (MSW) resonators and to describe, in detail. the theory of operation of the recently developed straight-edge resonators. These resonators are based on magnetostatic waves propagating in high Q cavities fabricated in thin ferrimagnetic films. The resonance frequency of these resonators can be tuned via a bias magnetic field. The theory of propagation of magnetostatic wave devices in periodic arrays will be briefly described followed by a detailed overview of the different configurations for MSW resonators. Three distinct classes of resonators will be discussed 1) resonators based on array reflectors (deposited metals and etched grooves) will be described in detail; 2) guided-wave ring resonators will be discussed; and 3) the theory of operation and design criteria for the straight-edge resonators will be described. Each class will be evaluated, pointing out the advantages and drawbacks, and whenever applicable, the power handling properties and the phase noise performance will be given.     

Tunable Solidly Mounted Thin Film Bulk Acoustic Resonators Based on BaxSr1−xTiO3 Films

Electrically tunable solidly mounted thin film bulk acoustic resonators based on Ba_xSr_1-xTiO₃ films are reported for the first time. The films are acoustically isolated from the silicon substrate by a Bragg reflector stack. Applying DC bias induces piezoelectric effect and an acoustic resonance at approximately 4 GHz. Under 10 V applied DC bias the resonance frequency of the resonators based on Ba_0.25Sr_0.75TiO₃ films is tuned 1.2% to lower frequencies. The Q-factor of these resonators is approximately 120, and the electromechanical coupling coefficient is 0.5%. The resonant frequency of the BaTiO₃ based resonators shifts upwards 1.3% under 10 V DC bias, and the -factor is approximately 30, with an electromechanical coupling coefficient of 6.2%.     

Open Complementary Split Ring Resonators (OCSRRs) and Their Application to Wideband CPW Band Pass Filters

In this letter, open complementary split ring resonators (OCSRRs) are introduced for the first time. Such resonators are the dual counterparts of the open split ring resonators (OSRRs), introduced in 2004 by some of the authors, and consist on a pair of concentric hooks etched on a metal layer in opposite orientation. It is shown in the letter that OCSRRs can be modeled by means of an LC parallel resonant tank and that this particle roughly exhibits half the resonance frequency of the complementary split ring resonator (CSRR), hence being electrically very small. The interest of these resonators is illustrated through their application to a wideband coplanar waveguide band pass filter.