• 한국산업정보학회논문지
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• 제19권2호
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• pp.45-49
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• 2014

In this work, a phase shifter radio-frequency integrated chip (RFIC) using a simple all-pass network is presented. As a tuning element of the phase shifter RFIC, tunable capacitors with a multi-layer dielectric of a para-/ferro-/para-electrics using a high tunable BST ferroelectric and a low-loss BZN paraelectric thin film were utilized. In order to evaluate and analyze the fabricated phase shifter RFIC, the same elements such as an inductor and capacitor integrated into it are also fabricated and tested. The designed phase shifter RFIC was fabricated on a quartz substrate in the size of $1.16{\times}1.21mm^2$. As the test results, the maximum phase difference of $350^{\circ}$ is obtained at 15 V and its tuning frequency bandwidth is 90 MHz from 2.72 to 2.81GHz.

• Current Optics and Photonics
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• 제6권6호
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• pp.634-641
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• 2022

A frequency stable and tunable optoelectronic oscillator (OEO) incorporating an optical phase shifter and a phase-shifted fiber Bragg grating (PS-FBG) is designed and analyzed. The frequency tunability of the OEO can be realized by using a tunable microwave photonic bandpass filter consisting of a PS-FBG, a phase modulator. The optical phase compensation loop is used to compensate for the phase variations of the RF signal from the OEO by adjusting an optical phase shifter. Simulation results demonstrate that the output RF signals of the OEO can be tuned in a frequency range of 118 MHz to 24.092 GHz. When the ambient temperature fluctuates within ±3.9 ℃, the frequency drifts of the output RF signals are less than 68 Hz, the side-mode suppression ratios are more than 69.39 dB, and the phase noise is less than -92.49 dBc/Hz at a 10 kHz offset frequency.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.215-218
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• 2002

본 논문에서 마이크로스트립 라인을 사용한 가변 위상 천이기를 제안한다. 인가 전압의 변화에 따라 강유전체의 상대 유전율이 변하는 특성을 이용하여 tunable 특성을 얻었고. 구조는 Au/BSTO/MgO/Au로 설계하였다. 제한 된 면적에서 특정 주파수에서의 위상 편이를 증가시키기 위여 여러 개의 커플링을 연결한 구조를 이용하였고. 금속 도체의 선폭을 줄여 손실을 줄였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.161-164
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• 2002

In this paper, a design technique is introduced for designing a 360-degree linear analog phase shifter at 1.8㎓. Using tunable short-circuit terminated comb-line filters as reactive loads, the circuit gives a very small insertion loss(less than 0.1㏈) and an almost linear phase shifter over the filter bandwidth for the full 360-degree range. We were showed large phase variation with small capacitance variation in the quadrature hybrid coupler using tunable shorted terminated combline filters.

• Journal of electromagnetic engineering and science
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• 제13권2호
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• pp.137-139
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• 2013

A compact metamaterial (MTM)-based tunable phase shifter consisting of four unit cells with a simple DC bias circuit has been designed at 2.4 GHz. The variable series capacitors and shunt inductors that are required to be loaded periodically onto a host transmission line are realized employing only chip variable capacitors (varactors). In addition, the proposed phase shifter requires only one DC bias source to control the varactors, with the matching condition of the MTM line automatically satisfied. The measured phase shifting range is $285.2^{\circ}$ (from $-74.2^{\circ}$ to $211^{\circ}$). The measured insertion loss is approximately 1.5 dB. The circuit/electromagnetic-simulated and measured results are in good agreement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.2014-2016
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• 2004

In order to obtain a low-loss ferroelectric phase shifter, the reflection-type phase shifter with ferroelectric defected ground structure (DGS) resonators has been designed in this paper. The proposed phase shifter is consist of a 3-dB $90^{\circ}$ branch-line hybrid coupler and terminated reflective circuit with tunable ferroelectric DGS resonator. The ferroelectric DGS unit structure can provide high Q resonator characteristic at high frequencies. The design parameters of equivalent circuit for the tunable DGS resonator are derived by using simple circuit analysis method and three-dimensional full wave finite element method. The fabricated phase shifter has an insertion loss of better than 3.4dB at 13.5GHz.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.370-374
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• 2002

This paper describes the design and fabrication of distributed analog phase shifter circuit. The phase shifter consist of coplanar waveguide(CPW) lines that are periodically loaded with voltage tunable (Ba,Sr)TiO$_3$ thin film interdigital(IDT) capacitors deposited by the pulsed laser deposition(PLD) on (001) MgO single crystals. The phase velocity on these IDT loaded CPW lines is a function of applied bias voltage, thus resulting in analog phase shifting circuits. The measured differential phase shift is 48$^{\circ}$ and the insertion loss decreases from -5㏈ to -3㏈ with increasing bias voltage from 0 to 40 V at 100㎐.

• 한국초전도ㆍ저온공학회논문지
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• 제7권1호
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• pp.13-16
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• 2005

High temperature superconductor, $\YBa_2Cu_3O_{7-x}$ (YBCO) and ferroelectric, $\Ba_{0.1}Sr_{0.9}TiO_{3}$ (BST) multilayer thin films were deposited using on MgO(100) substrates pulsed laser deposition. The thin films exhibited only (001) peaks of YBCO and 1357 The HTS thin films demonstrated excellent zero resistance temperature of 92.5 K. We designed and fabricated HTS ferroelectric phase shifter using high frequency system simulator and standard photolithography method, respectively The HTS phase shifter shows a low insertion loss (2.97 dB) and large phase change ($\162^{circ}$) with 40 V do bias at 10 GHz. The HTS phase shifter shows 54 of figure of merit. These results can be applicable to phased anay antenna system for satellite communication services.

• 한국정보통신학회논문지
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• 제6권6호
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• pp.904-908
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• 2002

본 논문에서는 강유전체 기반, 마이크로스트립 라인을 이용하여 13~170Hz에 걸친 넓은 주파수 범위에서 삽입 손실이 2dB 이하, 반사 손실이 10dB 이상인 4-coupled 가변 위상 천이기를 제안한다 특히, 15GHz에서 위상 천이 편이(DPS)는 0V를 인가하였을 때 $89{\circ}$ 이었고, 인가 전압을 150V로 증가시켰을 때 $115{\circ}$ 이었다. 그러므로 위상 천이 편이의 가변성은 $26{\circ}$에 달한다.

• Journal of electromagnetic engineering and science
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• 제6권1호
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• pp.1-9
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• 2006

A sandwich structure of dielectric material and air gap inside a rectangular waveguide is proposed as a fast electrically tunable low-loss phase shifter. As the dielectric material is shifted up and down by piezoelectric actuator and, thereby, the thickness of air gap is changed, the effective dielectric constant of the sandwich structure is varied. Phase shifters based on the sandwich structure with different dielectric materials showed phase shift of $20{\sim}200^{\circ}/cm$ at X-band as the thickness of air gap varied up to $30{\mu}m$. The idea can be extended toward low-loss millimeter wave phase shifters since modem microwave ceramics have been developed to show very low dielectric loss$(tan\;{\delta}{\sim}10^{-4})$.