Frequency-selective Devices Research Articles

The Resonistor: A frequency selective device utilizing the mechanical resonance of a silicon substrate : R. J. Wilfinger, P. H. Bardell and D. S. Chabra. IBM J. Res. Dev.12, No. 1, January (1968)

The Resonistor: A frequency selective device utilizing the mechanical resonance of a silicon substrate : R. J. Wilfinger, P. H. Bardell and D. S. Chabra. IBM J. Res. Dev.12, No. 1, January (1968)

The Resonistor: A Frequency Selective Device Utilizing the Mechanical Resonance of a Silicon Substrate

This communication describes an approach to tuned monolithic circuitry which utilizes the mechanical resonance of a silicon substrate. The proposed device is compatible with monolithic technology and will operate from a few hundred cycles to hundreds of kilocycles. The basic device consists of a silicon cantilever mechanically deflected by electrically induced thermal expansion. Diffused silicon piezo-resistive elements are used to detect stress in the cantilever and provide an electrical output. Maximum stress and electrical output occur when the cantilever is driven at its mechanical resonant frequency.

A frequency selective device utilizing the mechanical resonance of a silicon substrate

A frequency selective device utilizing the mechanical resonance of a silicon substrate

High Data Rate SHF Communication Receiver

This paper describes an SHF receiver capable of demodulating analog or digital information rates of up to 50 Mc/s. The receiver is a dual conversion superheterodyne design having a first IF of 1660 Mc/s and a second IF of 445 Mc/s. The model was developed as part of an Air Force contract to study and evaluate design techniques aimed at increasing reliability of aerospace SHF communication equipment. Semiconductor circuitry is used throughout, in addition to numerous deposited thin film circuits for reliability enhancement. The second IF amplifier design is unique in that all circuit components, with the exception of the semiconductors, are deposited, whereas more conventional microelectronics approaches to date have employed externally connected, discrete-component, frequency-selective devices, such as tunable IF coils or filter networks.

A frequency selective device utilizing the mechanical resonance of a silicon substrate

A frequency selective device utilizing the mechanical resonance of a silicon substrate

A new method of synthesis of reactance networks

In the insertion-loss design method for filters, compensating networks and other frequency-selective 4-terminal devices, the final step is the synthesis of a network of coils and capacitors which possesses a set of characteristic functions of frequency, in the form of one of several alternative kinds of matrix, previously deduced from the desired overall frequency behaviour. The present paper is chiefly concerned with this step.Practical experience has shown that the most satisfactory way of synthesizing a complicated network is to use a chain of sub-networks connected in cascade. For such a synthesis the most convenient matrix is the so-called “chain matrix,” since the chain matrix of a chain of networks is simply the product of the individual chain matrices. Conversely, a specified chain matrix can be synthesized by factorizing it into sub-matrices, each of sufficiently small degree to allow of direct synthesis, and then connecting all the corresponding networks in cascade.In previous methods of factorizing a given chain matrix it has always been necessary to split off small network sections one at a time. In the present method sections of arbitrary size can be split off in each stage. The importance of this is that the larger the size of section to be directly synthesized, the greater is the likelihood of being able to avoid coupled coils in the design.The method depends on a new theorem of a novel and far-reaching character concerning reactance and impedance functions. In proving and discussing this, reference has to be made to certain properties of such functions which are of great importance in themselves but have not hitherto been presented in a connected manner. Accordingly, a systematic treatment of these is first given, including a number of results believed to be new.A possible extension of the method, potentially of considerable value, to general dissipative networks is indicated.