Synthesis of transfer functions by dependent sources

A new procedure is given for the synthesis of nth-order voltage transfer functions by two dependent current sources as active elements. In the letter, by using a simple voltage-divider circuit configuration, the problem of the synthesis of transfer functions has been transformed to the synthesis of driving-point admittance functions.     

Synthesis of transfer functions by signal-flow graphs

A new procedure is given for the synthesis of voltage transfer functions. It is shown that the well known circuits of Lovering and Brugler can also be derived easily by this method. It is also indicated that a simplification can be obtained in the RC:-RC decomposition method. which is in the proposed procedure.     

Deembedding of lossy Foster networks

Data-processing procedures are described, which should be useful for measurement of the radiation Q factors of small antennas such as microstrip patch antennas or dielectric-resonator antennas. Typical values of radiation Q factors are quite low, of the order of ten or even smaller. Two equivalent Foster-type networks are proposed, modified for the presence of losses: one for the single resonance behavior, and another for the dual resonance behavior. The individual network elements are determined by optimization. A least squares procedure is described that can provide a good estimate for the starting values of the optimization.     

Synthesis of biquad transfer functions using modified continued fraction expansion and NICs

A new method for synthesizing second-order transfer functions is proposed. The method utilizes the negative immitance converter (NIC) as the active device. To generate the necessary passive elements (R and C), and to determine their manner of interconnection, a modified form of Cauer's continued fraction expansion is used. The synthesis procedure is illustrated by some examples and experimental results.     

Realization of second-order transfer functions with switched-capacitor networks

A flexible switched-capacitor synthesis procedure realizing second-order z-domain voltage-transfer functions is given. The active networks generated by this technique consist of capacitors, switches and operational amplifiers.     

Determining elements of lossy ladder networks

An algorithm for determining the Stieltjes continued-fraction expansion of driving-point function from its Taylor-series expansion has been suggested. This algorithm can be used to determine the elements of lossy ladder networks with advantage when the driving point function is represented in time domain by state variables.     

Scattering by two-dimensional lossy, inhomogeneous dielectric andmagnetic cylinders using linear pyramid basis functions and pointmatching

A volume integral equation approach is used to calculate the scattering characteristics of lossy, inhomogeneous, arbitrarily shaped, two-dimensional dielectric and magnetic bodies. The scatterer is divided into triangular patches, which simulate curved and piecewise linear boundaries more closely than circular cylinder cells. Linear pyramid basis functions are employed to expand the unknown total electric field at the triangle nodes. The enforcement of the boundary conditions by point matching at the nodes converts the electric field integral equation to a matrix equation. Example cases are run and compared to previous moment methods and exact solutions, and this method shows good agreement. This method requires only one unknown per node in dielectric and magnetic material, which is a significant reduction in unknowns and matrix storage compared to traditional methods. By duality, this method can be used at either transverse electric or transverse magnetic polarization     

A new lossy compression algorithm for wireless sensor networks using Bayesian predictive coding

Wireless Networks - Wireless sensor networks (WSNs) generate a variety of continuous data streams. To reduce data storage and transmission cost, compression is recommended to be applied to the data...     

Analysis of worst-case gain for Nth-order transfer functions realised by cascaded 2nd-order networks

Given the s-plane tolerance domains of the poles and zeros of a filter transfer function, a method is presented of finding, by computer, the worst-case limits of the corresponding gain function in a given frequency range.     

Realisation of transfer functions using one amplifier

A new procedure is described for the realisation of a voltage transfer function C(s) by an earthed RC network incorporating a finite-gain amplifier. The method is applicable, barring a few minor restrictions, to a general G(s), and can realise zeros of transmission on the positive real axis.     

Synthesis of arbitrary digital transfer functions using allpass-based structures derived via LBR two-pair extraction procedure

The implementation of a digital filter transfer function with all transmission zeros on the unit circle is developed via the synthesis of an appropriate allpass function. The synthesis procedure is based on the LBR-extraction approach. The resulting structure is in the form of a doubly terminated cascade of lossless (LBR) two-pairs, with each two-pair realizing a single real or a pair of complex transmission zeros. The Concepts of complete and partial 1 removals, and 1 shifting are introduced and utilized during the synthesis process. The resulting structures have several properties in common with the Gray and Markel lattice filters, but do not require tap coefficients for numerator realization. The building blocks used in this paper are similar to those in certain wave-digital filters and orthogonal filters.Work supported in part by NSF Grant Number ECS 82-18310 and in part by NSF Grant Number ECS-8508017.     

Realization of transfer functions using differential-input operational amplifiers

A new active RC synthesis procedure for the transfer functions using signal-flow graphs is presented. Examples are given to illustrate the synthesis procedure.     

Efficient simulation of interconnect networks withfrequency-dependent lossy transmission lines

Accurate and efficient moment generation methods are important when using moment matching based circuit reduction techniques for the simulation of transients on transmission line networks. A modified matrix exponential method is presented for fast computation of the moments associated with frequency-dependent lossy transmission lines. Numerical examples are given which demonstrate the improved performance of the proposed method with respect to existing techniques     

On-demand transmission of 3D models over lossy networks

Three-dimensional (3D) meshes are used intensively in distributed graphics applications where model data are transmitted on demand to users’ terminals and rendered for interactive manipulation. For real-time rendering and high-resolution visualization, the transmission system should adapt to both data properties and transport link characteristics while providing scalability to accommodate terminals with disparate rendering capabilities. This paper presents a transmission system using hybrid unequal-error-protection and selective-retransmission for 3D meshes which are encoded with multi-resolutions. Based on the distortion-rate performance of the 3D data, the end-to-end channel statistics and the network parameters, transmission policies that maximize the service quality for a client-specific constraint is determined with linear computation complexity. A TCP-friendly protocol is utilized to further provide performance stability over time as well as bandwidth fairness for parallel flows in the network. Simulation results show the efficacy of the proposed transmission system in reducing transmission latency and providing smooth performance for interactive applications. For example, for a fixed rendering quality, the proposed system achieves 20–30% reduction in transmission latency compared to the system based on 3TP, which is a recently presented 3D application protocol using hybrid TCP and UDP.     

Qualitative analysis for recurrent neural networks with linear threshold transfer functions

Multistable networks have attracted much interest in recent years, since multistability is of primary importance for some applications of recurrent neural networks where monostability exhibits some restrictions. This paper focuses on the analysis of dynamical property for a class of additive recurrent neural networks with nonsaturating linear threshold transfer functions. A milder condition is derived to guarantee the boundedness and global attractivity of the networks. Dynamical properties of the equilibria of two-dimensional networks are analyzed theoretically, and the relationships between the equilibria features and network parameters (synaptic weights and external inputs) are revealed. In addition, the sufficient and necessary conditions for coexistence of multiple equilibria are obtained, which confirmed the observations in with a cortex-inspired silicon circuit. The results obtained in this paper are applicable to both symmetric and nonsymmetric networks. Simulation examples are used to illustrate the theory developed in this paper.     

Natural modes of partitioned networks in analysis and synthesis of transfer functions

The letter describes a relatively rapid computational method of finding the natural modes of four-pole networks by partitioning and using a modification of potential-analogue type of computation in application to natural modes of the parts of the network obtained by partitioning. The method described may be regarded as an extension of the bisection method applicable to symmetrical networks. It lends itself well to iterated networks, yielding accurate results also for lossy networks and physically realisable impedances of termination.     

Interpolation of head-related transfer functions using spherical fourier expansion

A new interpolation algorithm for Head-Related Transfer Function (HRTF) is proposed to realize 3D sound reproduction via headphones in arbitrary spatial direction. HRTFs are modeled as a weighted sum of spherical harmonics on a spherical surface. Truncated Singular Value Decomposition (SVD) is adopted to calculate the weights of the model. The truncation number is chosen according to Frobenius norm ratio and the partial condition number. Compared with other interpolated methods, our proposed approach not on...     

Realization of rational transfer functions using tapered RC lines

A procedure for realizing a rational transfer function using any tapered RC line, its dual, and an ideal gyrator is given. The effect of the nondual behavior of the lines is also examined.     

Synthesis using active constant-resistance 3-terminal networks

A method of independent control over the polynomial coefficients of a transfer function is described. It employs 3-terminal constant-resistance networks and a unity-gain voltage amplifier. The constant-resistance building blocks are realised using gyrators and n.i.c.s, in addition to resistors and capacitors.