CC BY
18
UDK 629.783
STUDY OF A CONTROLLABLE STRIP RESONATOR ON A SUSPENDED SUBSTRATE WITH LCD LAYER
N. (V.) Balalaev Scientific supervisor - А. (A.) Leksikov Foreign language supervisor - T. (V.) Strekaleva
Reshetnev Siberian State Aerospace University 31, Krasnoyarsky Rabochy Av., Krasnoyarsk, 660037, Russian Federation
In this study the characteristics of a tunable resonator comprising a layer of liquid crystal as an active medium have been investigated. We have carried out the experiments with two samples of liquid crystal and we have received the value of the relative surgery of resonance frequency 1.8 % at electric voltage under 30 V.
Keywords: relative tuning, resonance frequency, liquid crystals, phase shifter.
ИССЛЕДОВАНИЕ УПРАВЛЯЕМОГО ПОЛОСКОВОГО РЕЗОНАТОРА НА ПОДВЕШЕННОЙ ПОДЛОЖКЕ С ЖК СЛОЕМ
Н. В. Балалаев Научный руководитель - А. А. Лексиков Руководитель по иностранному языку - Т. В. Стрекалёва
Сибирский государственный аэрокосмический университет имени академика М. Ф. Решетнева
Российская Федерация, 660037, г. Красноярск, просп. им. газ. «Красноярский рабочий», 31
Изучены характеристики перестраиваемого резонатора, содержащего слой жидкого кристалла в качестве активной среды. Были проведены эксперименты с двумя образцами жидкого кристалла и получена величина относительной перестройки резонансной частоты 1.8 % при подаче электрического напряжения до 30 В.
Ключевые слова: относительная перестройка, резонансная частота, жидкий кристалл, фазовращатель.
The development of communication systems, radio navigation and radiolocation is impossible without making new controllable microwave devices and upgrading existing ones. There are tunable phase shifters among these devices [1; 2].
Phase shifters represent one of the most important and widespread group of devices, widely applicable in radio communication and radiolocation [3].
The offered construction of a tunable resonator is based on a suspended substrate resonator.
The purpose of the research is designing and investigation of a tunable resonator on the suspended quartz substrate with liquid crystal filling.
The investigation has begun with computer modeling of the tunable resonator on the suspended substrate made of alumina ceramics and quartz with liquid crystal filling with thickness 0.5 mm. It has been carried out using the program for designing radio-frequency and microwave devices - AWR DESIGN ENVIRONMENT 2009 (AWRDE 2009). With the help of the program we have studied influences of screen height, thickness of liquid crystal layer and permittivity of substrates on the relative tuning of resonance frequency. The effects are presented in the fiquresl, 2, 3.
Next, the tunable resonator has been made of quartz substrate. Measurement of its frequency response at backlash filling between substrates with air, spirit, chloroform, tetrachloromethane was carried out, and the calibration dependence has been received.
Секция «Актуальные на учные проблемы в мире (глазами молодых исследователей)»
Figure 1. Dependence of the relative tuning of resonance frequency on the thickness of the liquid crystal layer for the resonators with substrates made of quartz and alumina. The quartz substrate - solid line, the alumina substrate - dashed line
Figure 2. Dependence of the relative tuning of resonance frequency on the height of screens for the resonators with substrates made of quartz and alumina. The quartz substrate- solid line, the alumina substrate- dashed line
Figure 3. Dependence of the relative tuning of resonance frequency on the inductivity of substrates for their different thickness. A solid line - at the thickness of substrates 0.1mm, a small dashed line - at the thickness of substrates 0.3 mm, a large dashed line - at the thickness of substrates 0.5 mm
The experiments with two samples of liquid crystal have been made and value of the relative tuning for resonant frequency 1.8 % has been achieved at electrical voltage 30. That corresponds to the electric field in LC 6x105 V/m (figure 4). We have found the value of the change in liquid crystal MB-1 at permittivity As = 0.15.
-14
-22
iii E.iA 5,H Er& fc il R M)
Frequency. GHz
Figure 4. Tuning of resonance frequency of the second mode at voltage supply. Voltage U = 0 V - solid line, voltage U = 30 V - dashed line
During the experiment being carried out it has been established:
1. Liquid crystals are perspective materials to use in controllable devices though they are very unyielding.
2. The developed design of the tunable phase shifter is promising though it is difficult in manufacturing.
References
1. Lemberg K. V., Serzhantov A. M. Controlled resonant microstrip phase shifter on the electromagnetic substrate // Physics. Tomsk: Tomsk State University. 2012. Vol. 55. № 8/3, p. 106-107 (in Russ).
2. Lemberg K. V., Serzhantov A. M. Study of Controlled LCD microstrip phase shifter // Physics. Tomsk : Tomsk State University. 2010. Vol. 53. № 9 (2), p. 224-225 (in Russ).
3. Velu G., Blary K., Burgnies L., Marteau A. et al. A 360 BST Phase Shifter with Moderate Bias Voltage at 30 GHz // IEEE Transactions on Microwave Theory and Techniques. 2007. Vol. 55, No. 2. P.438-444.
© Balalaev N. (V.), 2015
