В работе представлены результатыисследования метода, который позволяет увеличить полосу частот электрически малой антенны с помощью “нефостеровской цепи”на основе операционного усилителя. Были получены графики, которые позволяют оценить входное реактивное сопротивление и полосу частот электрически малой антенны с представленным методом расширения полосы частот. / The paper presents the results of a study of the method, which makes it possible to increase the frequency band of an electrically small antenna by means of a "Non-foster circuit"with operational amplifier. The graphs were obtain, which allow estimating the input reactance and the bandwidth of an electrically small antenna with the method of bandwidth extension represented.

В работе представлены результатыисследования метода, который позволяет увеличить полосу частот электрически малой антенны с помощью “нефостеровской цепи”.Также были представлены классические методы расширения полосы частот антенны с помощью индуктивности и колебательного контура, чтобы сравнить их эффективность с исследуемым методом. Были получены графики, которые позволяют оценить входное реактивное сопротивление и полосу частот электрически малой антенны со всеми представленными методами расширения полосы частот. / The paper presents the results of a study of the method, which makes it possible to increase the frequency band of an electrically small antenna by means of a "Non-foster circuit". Also, classical methods for extending the frequency band of the antenna with the help of inductance and a vibrational circuit were presented to compare their effectiveness with the method being studied.

Frequency reference oscillator is a critical component of modern radio transceivers. Currently, most reference oscillators are based on low-frequency quartz crystals that are inherently bulky and incompatible with standard micro-fabrication processes. Moreover, their frequency limitation (<200MHz) requires large up-conversion ratio in multigigahertz frequency synthesizers, which in turn, degrades the phase-noise. Recent advances in MEMS technology have made realization of high-frequency on-chip low phase-noise MEMS oscillators possible. Although significant research has been directed toward replacing quartz crystal oscillators with integrated micromechanical oscillators, their phase-noise performance is not well modeled. In addition, little attention has been paid to developing electronic frequency tuning techniques to compensate for temperature/process variation and improve the absolute frequency accuracy. The objective of this dissertation was to realize high-frequency temperature-compensated high-frequency (>100MHz) micromechanical oscillators and study their phase-noise performance. To this end, low-power low-noise CMOS transimpedance amplifiers (TIA) that employ novel gain and bandwidth enhancement techniques are interfaced with high frequency (>100MHz) micromechanical resonators. The oscillation frequency is varied by a tuning network that uses frequency tuning enhancement techniques to increase the tuning range with minimal effect on the phase-noise performance. Taking advantage of extended frequency tuning range, and on-chip temperature-compensation circuitry is embedded with the sustaining circuitry to electronically temperature-compensate the oscillator. Finally, detailed study of the phase-noise in micromechanical oscillators is performed and analytical phase-noise models are derived.