Proceedings of the IEEE

A new adaptation algorithm designed for real-time data processing in large antenna arrays is presented. The algorithm is used to determine the set of filter coefficients (weights) which minimizes the mean-square error in a multidimensional linear filter. The algorithm forms an estimate of the target signal, which is assumed to be of interest, in the presence of interfering noises. It is assumed th... View full abstract»

This paper sets forth a rather general analysis pertaining to the performance and synthesis of generalized tracking systems. The analysis is based upon the theory of continuous Markov processes, in particular, the Fokker-Planck equation. We point out the interconnection between the theory of continuous Markov processes and Maxwell's wave equations by interpreting the charge density as a transition... View full abstract»

Trapped energy resonators and transducers have attained a considerable importance in quartz crystal technology both as single-frequency resonators for the control of crystal oscillators and as drivers for the monolithic crystal filter which appears likely to have a wide use as a channel filter for the separation of voice frequency channels for long-distance carrier systems, microwave radio, and su... View full abstract»

This paper calculates the error at the output of a digital filter using floating-point arithmetic operations due to roundoff accumulation and input quantization. Expressions are derived for the mean square error for each of the three canonical forms of realization: direct, cascade, and parallel. Upper bounds that are useful for a special class of filters are given. The theoretical result is found ... View full abstract»

For electromagnetic propagation in linear dispersive media, two definitions of energy transport velocity may be introduced. The first is the transport velocity of total stored energy density, and it was first discussed by Brillouin. This concept does not distinguish different forms of energy, but considers only the total. It is equal to the group velocity for the case of a lossless dispersive medi... View full abstract»

Light-modulator displays can be built so that an unexcited element delivers either maximum or minimum light to the observer. For scanned displays, the duty factor for an individual element is in general less than unity, so that the contrast available from the display will be less than the contrast from an individual element considered in isolation. If the display is so arranged that unenergized el... View full abstract»

A technique for the manufacture of flexible compressible transducers is presented based on the use of piezoelectric ceramic powder dispersed in a silicone rubber medium. Potential applications are discussed. View full abstract»

The probability of peak sidelobe level of a random array is obtained for any given probability density of element positions. The method is based on the sampling theorem for band-limited functions. These results are applicable to small as well as large arrays. In the case of large arrays, they coincide with those obtained earlier by Lo through a different argument. In addition, this method shows th... View full abstract»

The possible values of the number of messages generated by an information source which can be encoded into complete tree codes for successive coding alphabet sizes 2, 3, 4,..., D are derived. Properties and relations for the smallest such values are given. View full abstract»

It is shown that the components of gate leakage current of a MOSFET used in a previously described unity gain buffer amplifier may be reduced to a minimum under static and dynamic conditions. Modified packaging and novel biasing techniques can minimize both extrinsic and intrinsic components of gate leakage current at the input to the amplifier. View full abstract»

The performance of the synchronized analog integrate-and-dump filter is compared with an equivalent digital implementation. Degradation in the output SNR of the digital filter due to sampling is computed. A first order prefilter is assumed and quantization noise is neglected. View full abstract»

The U. S. Navy Navigation Satellite System and the Geodetic SECOR satellite system both employ two widely separated carrier frequencies to permit an error correction to be made for ionospheric refraction. It is shown that this same two-frequency technique can be employed within the narrow bandwidth of a VHF communications satellite repeater to permit ranging signals transmitted through the repeate... View full abstract»

An application of the high power/energy density available from a focused laser beam is presented as a means of transferring an ink-like substance from a substrate onto a recording medium. This technique will permit wide-band recording with instant readout. View full abstract»

A microwave phase stabilization feedback circuit used with injection-locking increases the locking range of a Gunn oscillator and reduces the voltage fluctuations in the bias circuit. View full abstract»

A series representation is derived for a class of bivariate probability density functions. The representation uses orthonormal sets generated by the first-order density functions. View full abstract»

A high-voltage thin-film FET, with a voltage gain of at least 40, is described. The I-V characteristics-of these units are not predicted by conventional thin-film transistor theory. View full abstract»

A new instability problem associated with numerical integration of circuit equations is pointed out. A change of state variables is shown as a means of avoiding the problem. View full abstract»

A new method of near-logarithmic companding is proposed. The method consists of first uniformly quantizing each sample and then processing the resulting binary number digitally. This is in contrast to the usual scheme of first compressing the input and then uniformly quantizing it. The method presented here is extremely simple to implement and requires no arithmetic operations. The inverse transfo... View full abstract»

Simple formulas for quick and easy calculation of the transfer characteristics of a specific kind of ladder network have been developed starting from the Fibonacci relationship of the network. Examples calculating the characteristics are also given. View full abstract»

A formula and an iterative algorithm are given for converting a continued fraction into a rational function. View full abstract»

Thin-film transistors were made on polycrystalline CdSe-CdTe semiconducting films prepared by flash evaporation of mixed CdSe and CdTe powders. View full abstract»