Persons

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The absorbing elements of rectangular and complex form based on homogeneous resistive film are used for building wave guide, coaxial and microstrip attenuators. The decrease of the attenuators sizes leads to problems in the implementation of small and big attenuations, which requires a turn to the absorbing elements based on piece-homogeneous structures. For implementation of a wide range of impairments of radio signals power the topologies of the small size absorbing elements of the wave guide, coaxial and microstrip attenuators, differing from known attenuators elements with the two-layer resistive film by reduced temperature stability and complex manufacturing technology, have been proposed. Such attenuation is achieved using one-layer resistive film with the central region, having either high (cut) or low (conductor) resistivity. The methods for calculation of the proposed absorbing elements based on a strict method of the conformal mappings have been proposed. The obtained relations in the considered particular cases coincide with the well-known ones in literature. The three-dimensional graphs of attenuation dependencies and normalized input impedance from the normalized size of the cut, or the conductor of the central region have been given. Wide possibilities of controlling the output parameters of the absorbing elements have been noted. The performance of the technique has been verified by simulation in the domestic software complex Elcut and by the analysis of real samples of small absorbing elements mounted microstrip attenuator of the proposed topologies.

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Using the methods of finite elements and conformal mappings the analytical models of the low resistance film resistors of the main types of comb (interdigital) structures with arbitrary relations of the specific resistances of resistive and conductive films have been built. In the resultant resistance the resistances of comb-like structure electrodes and connecting electrodes as well as additional resistance associated with the transmission of current from the conductive film to the resistive one and vice versa have been taken into account. The conditions, under which the boundary between the films can be considered as equipotential have been revealed. For this case the calculation has been performed by conformal mappings. The circuit of substitution of the low-impedance comb resistors, used as the current sensors in schemes of stabilization, control, thermal and current protection, has been constructed.

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One of the urgent tasks in the design of hybrid integrated circuits (HIC) is the construction of adapter-attenuators - film absorbing elements providing a wide range of attenuations with specified values of input and output resistances. Known variants of adapter-attenuators based on a homogeneous and piecewise homogeneous resistive film provide (by introducing asymmetry in the dimensions of the input and output contacts, changing the location of a piecewise homogeneous resistive film, introducing dielectric or conductive regions) a resistance transformation coefficient of no more than 3 and 10-12, respectively. In this work, promising topologies of adapter-attenuators for HIC with a close to optimal profile of input and output contacts are proposed, which allow not only to obtain a wide range of transformation coefficients (more than 100), but also to reduce the maximum values of the potential gradient and power density by 10-30 times. The rectangular topology calculations were made using the apparatus of the theory of functions of a complex variable. Modeling of the optimized topology of adapter-attenuators for HIC was carried out by the finite element method implemented in the Elcut software package. The calculated ratios and graphs showing the relationship of attenuation, the transformation coefficient, the gain in the value of the potential gradient and the power density, depending on the ratio of the size of the film element and the resistivity of the resistive films used, have been provided. The features of adapter-attenuators fitting have been considered. The results obtained are especially important for the pulse mode of operation of adapter-attenuators’ film element for HIC.

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The topology of the chip attenuators and adapt-attenuators of attenuation broad range for surface assembling, based on the distributed resistive structures, has been proposed, and their calculation has been executed. The results of the calculations and of the experimental studies both on real samples of the developed items and on their large-scale models have been presented.

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