Analysis and design of the mixing chamber in a flat ejector

An analysis is made of the laws which govern isothermal flow in the mixing zone of an ejection chamber with a longitudinal pressure gradient. The proposed method of calculations has been verified experimentally.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 21, No. 6, pp. 1060–1067, December, 1971.     

Fast iterative methods for phase-only synthesis of antenna arraypattern nulls

Two iterative methods for arbitrary antenna array pattern null phase synthesis are presented. The problem is solved in RMS approximation and is reduced to minimisation of non-negative functionals by element excitation phases. The methods are based on its numerical-analytical minimisation by one phase or by two phases on each iteration     

Class of Optimal Polynomial Window Functions for Spectral Analysis of Signals

Journal of Communications Technology and Electronics - The problem of synthesis of low-order polynomial window functions with an arbitrarily specified decay rate of spectral lobes (optimal with...     

The phase-only shaping and adaptive ing of an amplitude pattern

An efficient phase-only control method is reported for shaping a given antenna array amplitude pattern and simultaneously placing adaptive s in unknown interference directions. The method iteratively minimizes a functional (that incorporates constraints imposed on the desired pattern shape and power measured at the array output) with respect to phases of the array element excitations and to the phase of the given amplitude pattern by a coordinate-by-coordinate (single-coordinate) method that finds the minimum along each coordinate by a closed-form formula using three power measurements per one iteration. The method shows fast convergence, is stable to phase shifter errors, and complies with the digital phase control. Results of computer modeling are provided.     

Finite array antenna, scattering, and transmission-line analysisusing the FFT

An efficient unified approach to the solution of a wide class of electromagnetic problems involving finite structures-including analysis of finite-array antennas (both transmission and reflection), scattering problems, and calculation of transmission-line eigenwaves-is presented. This approach is based on the fact that these problems can be described by the same mathematical tool, namely, convolution-type systems of linear algebraic equations (systems with matrices having a Toeplitz type of structure). Efficient methods are proposed for solving them     

Estimating aperture efficiency

It is shown that for a wide class of aperture distributions, the aperture efficiency can be related to the ratio between the beamwidth of this distribution and that of the uniform one. A heuristic rule for estimating the aperture efficiency of elliptic and rectangular tapered apertures is introduced. It is shown that, if the beamwidth is given (i.e., the aperture size is unconstrained), the maximum directivity is provided by a tapered, rather than uniform amplitude distribution.     

A Family of Optimal Window Functions for Spectral Analysis with the Spectrum Sidelobe Falloff Rate Multiple of 12 dB per Octave

Journal of Communications Technology and Electronics - A synthesis problem is solved for low-order windows with the sidelobe spectrum falloff rate equal to 12n decibel per octave (dB/oct), where n...     

Synthesis of spectrum of packet of radio pulses by phase-onlycontrol

An iterative fast-convergent phase-only method for shaping the amplitude spectrum of a packet of radio pulses is developed. Its efficiency is verified by a numerical experiment