• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1108-1111
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• 2015

In this paper, a ${\times}49$ frequency multiplier based on a ring oscillator and a multi-push multiplier is presented. The proposed ${\times}49$ frequency multiplier consists of two ${\times}7$ frequency multipliers and these multiplier is connected by injection-locking technique. Each ${\times}7$ frequency multiplier consists of a ring oscillator with 14-phase output signal and 7-push frequency multiplier requiring 14-phase input. The proposed ${\times}49$ frequency multiplier provides 2.78~2.83 GHz output signal with 56.7~57.7 MHz input signal. This operation frequency is defined that the output power difference between the carrier and the spur is above 10 dB. The proposed chip consumes 13.93 mW.

• Earthquakes and Structures
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• v.8 no.1
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• pp.205-224
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• 2015

A new method for designing moment resisting concrete frames failing in a global mode is presented in this paper. Starting from the analysis of the typical collapse mechanisms of frames subjected to horizontal forces, the method is based on the application of the kinematic theorem of plastic collapse. The beam section properties are assumed to be known quantities, because they are designed to resist vertical loads. As a consequence, the unknowns of the design problem are the column sections. They are determined by means of design conditions expressing that the kinematically admissible multiplier of the horizontal forces corresponding to the global mechanism has to be the smallest among all kinematically admissible multipliers. In addition, the proposed design method includes the influence of second-order effects. In particular, second-order effects can play an important role in the seismic design and can be accounted for by means of the mechanism equilibrium curves of the analysed collapse mechanism. The practical application of the proposed methodology is herein presented with reference to the design of a multi-storey frame whose pattern of yielding is validated by means of push-over analysis.