10 research outputs found

    ИЗМЕРИТЕЛЬНЫЙ КОМПЛЕКС ТРЕХМИЛЛИМЕТРОВОГО ДИАПАЗОНА ДЛИН ВОЛН

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    The problems of development as well as methods of construction of measuring devices of 3-mm wavelength range are examined, which allow to provide high degree of accuracy of frequency and power of an input signal measurement. The opportunity and expediency of using the frequency synthesizers, sub-harmonic mixers in heterodyne channel, and logarithmic amplifiers in modulation receiver are shown. The experimental parameters are shown as well as characteristics and parameters of major units of measuring device.Рассмотрены проблемы создания и методы построения измерительных комплексов трехмиллиметрового диапазона длин волн, позволяющих обеспечить высокую точность измерения частоты и мощности входного сигнала. Показана возможность и целесообразность использования синтезаторов частот в гетеродинном тракте субгармонических смесителей и логарифмических усилителей в модуляционном приемнике. Приведены экспериментальные параметры и характеристики основных узлов измерительного комплекса и его параметры

    СИНТЕЗАТОР СВЧ С ПРЯМЫМ ЦИФРОВЫМ СИНТЕЗОМ

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    A synthesizer of frequencies with direct digital synthesis and a frequency multiplier on PLL are developed. Phase noises of an output signal of the synthesizer, noise of a loop of PLL, level of collateral radiations on outputs of the digital synthesizer (frequency of 100 MHz) and the frequency multiplier output on a loop of PLL (frequency of 8 GHz) are probed.Разработан синтезатор частот с прямым цифровым синтезом и умножителем частоты на петле фазовой автоподстройки частоты (ФАПЧ). Исследованы фазовые шумы выходного сигнала синтезатора, шумы петли ФАПЧ, уровень побочных излучений на выходах цифрового синтезатора (частота 100 МГц) и выходе умножителя частоты на петле ФАПЧ (частота 8 ГГц)

    СИНТЕЗАТОР ШИРОКОПОЛОСНЫХ СИГНАЛОВ, СФОРМИРОВАННЫХ МЕТОДОМ ПРЯМОГО ЦИФРОВОГО СИНТЕЗА

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    Development and experimental studies of the generator of wideband signals were conducted by the method of direct digital synthesis. Generator allows for the correction of phasefrequency characteristics of the formed broadband signal. The level of spurious radiation was investigated at the output of the frequency mixer in the transfer of the signal spectrum in the band of UHF.Проведены разработка и экспериментальные исследования формирователя широкополосных сигналов методом прямого цифрового синтеза. Формирователь позволяет обеспечивать коррекцию фазо-частотных характеристик формируемого широкополосного сигнала. Исследован уровень побочных излучений на выходе смесителя сдвига при переносе спектра сигнала в диапазон СВЧ

    ПРИБОР ДЛЯ ИЗМЕРЕНИЯ ПАРАМЕРОВ ВРЕМЕННОГО РАССЕИВАНИЯ РАДИОВОЛН МИЛЛИМЕТРОВОГО ДИАПАЗОНА ПРИ МНОГОЛУЧЕВОМ РАСПРОСТРАНЕНИИ

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    Possibility of temporal characteristics of scattered radiosignals under multipath propagation was analyzed. A scheme of millimeter-length radiowaves transceiver was presented. The feasibility of “window” function using for processing of received signal was shown based on the modelling of the measuring system operation.Рассмотрена возможность измерения временного рассеивания при многолучевом распространении сигналов. Приведена схема построения приемо-передающего устройства миллиметрового диапазона длин волн. Моделирование работы измерительного комплекса показало целесообразность использования оконных функций при обработке принятого сигнала

    ПРИМЕНЕНИЕ РАДИОМЕТРИЧЕСКОЙ СИСТЕМЫ КРАЙНЕ ВЫСОКИХ ЧАСТОТ ДЛЯ ОБНАРУЖЕНИЯ ЗЛОКАЧЕСТВЕННЫХ НОВООБРАЗОВАНИЙ МОЛОЧНЫХ ЖЕЛЕЗ

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    Developed and investigated radiometric system EHF (extremely high frequency) range for the diagnosis of tissue samples affected by carcinoma. EHF system are significantly higher than in the possibility of identifying a lower frequency range, as in UHF band (UHF band) and UHF (ultra high frequency) resolution of 1-3 mm are impossible. It was established that the affected carcinoma tissue samples are 3 dB lower transmittance compared to unaffected tissues. Analysis of the dependency of the harmonic components of the modulation signal passing through the examined tissue samples shows dramatic difference in the behavior of the harmonic components of the frequency domain. This phenomenon appears to altered tissue the presence of slumps that due to the interaction of electromagnetic waves with the tissue samples may be explained by the so-called stochastic resonance effect. Разработана и исследована радиометрическая система диапазона крайне высоких частот для диагностики образцов тканей, пораженных карциномой. Ее возможности существенно превосходят возможности идентификации в диапазонах более низких частот, так как в диапазонах дециметровых волн и сверхвысоких частот разрешение 1–3 мм невозможны. Установлено, что пораженные карциномой образцы тканей имеют на 3 дБ меньший коэффициент прохождения по сравнению с непораженными тканями. Анализ приведенных зависимостей гармонических составляющих модуляционного сигнала, прошедшего через образцы исследуемых тканей, показывает резкое отличие поведения гармонических составляющих в частотной области. Данное явление наблюдается для измененной ткани – наличие резких спадов, что обусловлено взаимодействием электромагнитных колебаний с образцами тканей и может быть объяснено так называемым эффектом стохастического резонанса

    MEASURING DEVICES OF 3-MM WAVE-LENGTH RANGE

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    The problems of development as well as methods of construction of measuring devices of 3-mm wavelength range are examined, which allow to provide high degree of accuracy of frequency and power of an input signal measurement. The opportunity and expediency of using the frequency synthesizers, sub-harmonic mixers in heterodyne channel, and logarithmic amplifiers in modulation receiver are shown. The experimental parameters are shown as well as characteristics and parameters of major units of measuring device

    RF SYNTHESIZER WITH DIRECT DIGITAL SYNTHESIZ

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    A synthesizer of frequencies with direct digital synthesis and a frequency multiplier on PLL are developed. Phase noises of an output signal of the synthesizer, noise of a loop of PLL, level of collateral radiations on outputs of the digital synthesizer (frequency of 100 MHz) and the frequency multiplier output on a loop of PLL (frequency of 8 GHz) are probed

    THE EXPEREMENTIONAL STUDIES OF THE GENERATOR OF WIDEBAND SIGNALS WERE CONDUCTED BY THE METHOD OF DIRECT DIGITAL SYNTHESIS

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    Development and experimental studies of the generator of wideband signals were conducted by the method of direct digital synthesis. Generator allows for the correction of phasefrequency characteristics of the formed broadband signal. The level of spurious radiation was investigated at the output of the frequency mixer in the transfer of the signal spectrum in the band of UHF

    DEVICE FOR MEASURING TEMPORAL CHARACTERISTICS OF MILLIMETER-LENGTH RADIOWAVES SCATTERED UNDER MULTIPATH PROPAGATION

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    Possibility of temporal characteristics of scattered radiosignals under multipath propagation was analyzed. A scheme of millimeter-length radiowaves transceiver was presented. The feasibility of “window” function using for processing of received signal was shown based on the modelling of the measuring system operation

    APPLICATION OF MILLIMETER WAVE′S RADIOMETRIC SYSTEM FOR DETECTION OF MALIGNANT NEW GROWTHS OF MAMMARY GLANDS

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    Developed and investigated radiometric system EHF (extremely high frequency) range for the diagnosis of tissue samples affected by carcinoma. EHF system are significantly higher than in the possibility of identifying a lower frequency range, as in UHF band (UHF band) and UHF (ultra high frequency) resolution of 1-3 mm are impossible. It was established that the affected carcinoma tissue samples are 3 dB lower transmittance compared to unaffected tissues. Analysis of the dependency of the harmonic components of the modulation signal passing through the examined tissue samples shows dramatic difference in the behavior of the harmonic components of the frequency domain. This phenomenon appears to altered tissue the presence of slumps that due to the interaction of electromagnetic waves with the tissue samples may be explained by the so-called stochastic resonance effect
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