Температурная коррекция широкополосных детекторов мощности на основе низкобарьерных диодов

The article is devoted to investigation of microwave power converter temperature dependence caused by changes in the current-voltage characteristic of diodes. The analytical expressions are given for such diode parameters as junction resistance and diode saturation current that allow to estimate temperature influence on diode detector output voltage. This paper presents a comparison of two methods, i.e. correlation based on a terminological method that works in con-junction with an arithmetic-logical mechanism. The first method implies that the temperature stabilizes by use of identical pair of diodes one of which compensates for temperature-induced changes of the second diode junction resistance. The second method involves formation of correction factors that allow performing temperature correction of measurement results in a wide range of capacities. Based on the conducted temperature tests of microwave power meters with the use of a temperature sensor in the microwave unit, the thermal correction algorithm was implemented. It allows to reduce the changes in the readings from ±15 to ±1.5%. Data from the results of experimental studies that can be used in measuring microwave equipment of various types. The results of experimental studies of detectors based on low-barrier diodes ZB-28 with a boundary speed exceeding 100 GHz and a tangential sensitivity of 1 nW are presented.Исследуется температурная зависимость сверхвысокочастотных преобразователей мощности. Приведены аналитические выражения сопротивления перехода и тока насыщения диода, позволяющие оценить степень влияния температуры на выходное напряжение диодных детекторов. Выполнено сравнение двух способов температурной коррекции. Известный способ заключается в достижении температурной стабилизации за счет использования идентичной пары диодов, один из которых компенсирует изменение сопротивления перехода второго диода при изменении температуры. В настоящей статье предложен альтернативный способ, заключающийся в формировании поправочных коэффициентов, позволяющих проводить температурную коррекцию результатов измерений в широком диапазоне мощностей. Представлены результаты экспериментальных исследований детекторов на основе низкобарьерных диодов ZB-28 с граничной частотой свыше 100 ГГц и тангенциальной чувствительностью 1 нВт. На основе температурных испытаний измерителей мощности СВЧ с использованием термодатчика реализован алгоритм термокоррекции, позволивший уменьшить изменение мощности с ±15 до ±1.5 %. Полученные результаты свидетельствуют о том, что предложенный способ температурной коррекции широкополосных детекторов мощности с использованием показаний термодатчиков может успешно применяться в измерительном СВЧ-оборудовании различного типа

Temperature Correction of Broadband Power Detectors Based on Low-Barrier Diodes

The article is devoted to investigation of microwave power converter temperature dependence caused by changes in the current-voltage characteristic of diodes. The analytical expressions are given for such diode parameters as junction resistance and diode saturation current that allow to estimate temperature influence on diode detector output voltage. This paper presents a comparison of two methods, i.e. correlation based on a terminological method that works in con-junction with an arithmetic-logical mechanism. The first method implies that the temperature stabilizes by use of identical pair of diodes one of which compensates for temperature-induced changes of the second diode junction resistance. The second method involves formation of correction factors that allow performing temperature correction of measurement results in a wide range of capacities. Based on the conducted temperature tests of microwave power meters with the use of a temperature sensor in the microwave unit, the thermal correction algorithm was implemented. It allows to reduce the changes in the readings from ±15 to ±1.5%. Data from the results of experimental studies that can be used in measuring microwave equipment of various types. The results of experimental studies of detectors based on low-barrier diodes ZB-28 with a boundary speed exceeding 100 GHz and a tangential sensitivity of 1 nW are presented

Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives

A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the aromatic arms is rotated around the C-N bond. At temperatures below −40 °C, the VT NMR spectra in DMF-d7 are in a slow exchange regime, and the signals of two conformers can be elucidated. At temperatures above 100 °C, the VT NMR spectra in DMSO-d6 are in a fast exchange regime, and the averaged spectra can be measured. The ratio of symmetric and asymmetric conformers in DMF-d7 varies from 14:86 to 50:50 depending on the substituents. The rotational barriers of symmetric and asymmetric conformers in DMF-d7 were measured for all compounds and are in the interval from 11.7 to 14.7 kcal/mol. The ground-state energy landscapes of the studied compounds, obtained by DFT calculations, show good agreement with the experimental rotational barriers. The DFT calculations reveal that the observed chemical exchange occurs by the rotation around the C(1,3,5-triazine)-N bond. Although some of the compounds are potentially tautomeric, the measured absorption and emission spectra do not indicate proton transfer neither in the ground nor in the excited state

Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives

A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the aromatic arms is rotated around the C-N bond. At temperatures below −40 °C, the VT NMR spectra in DMF-d7 are in a slow exchange regime, and the signals of two conformers can be elucidated. At temperatures above 100 °C, the VT NMR spectra in DMSO-d6 are in a fast exchange regime, and the averaged spectra can be measured. The ratio of symmetric and asymmetric conformers in DMF-d7 varies from 14:86 to 50:50 depending on the substituents. The rotational barriers of symmetric and asymmetric conformers in DMF-d7 were measured for all compounds and are in the interval from 11.7 to 14.7 kcal/mol. The ground-state energy landscapes of the studied compounds, obtained by DFT calculations, show good agreement with the experimental rotational barriers. The DFT calculations reveal that the observed chemical exchange occurs by the rotation around the C(1,3,5-triazine)-N bond. Although some of the compounds are potentially tautomeric, the measured absorption and emission spectra do not indicate proton transfer neither in the ground nor in the excited state