• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.408-413
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• 2011

In this paper, a real-coefficient approach to Adaptive Frequency Sampling (AFS) technique is developed for efficient equivalent circuit modeling of RF components. This proposed method is advantageous than the vector fitting technique and the conventional AFS method in terms of fewer samples leading to a lower order of a rational function on a given data and to a direct conversion to an equivalent circuit for PSPICE(Personal Simulation Program with Integrated Circuit Emphsis) simulation, respectively. To validate the proposed method, the distributed equivalent circuit of a presented multi-layered RF low-pass filter is obtained using the proposed real-coefficient AFS, and then comparisons with EM simulation and circuit simulation for the device under consideration are achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.96-99
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• 2001

In this paper, we present the simulation results of the multi-layer VCO(Voltage Controlled Oscillator), which is composed of the resonator, the oscillator and the buffer circuit. using EM simulator and nonlinear RF circuit simulator. EM simulator is used for obtaining the EM(Electromagnetic) characteristics of the conductor pattern as well as designing the multi-layer VCO. Obtained EM characteristics were used as real components in nonlinear RF circuit simulation. Finally the overall VCO was simulated using the nonlinear RF circuit simulator. The material for the circuit pattern was Ag and the dielectric was DuPont 951AT, which will be applied for LTCC process. The structure is constructed with 4 conducting layer. Simulated results showed that the output level was about 4.5[dBm], the phase noise was -104[dBc/Hz] at 30[kHz] offset frequency, the harmonics -8dBc, and the control voltage sensitivity of 30[MHz/V] with a DC current consumption of 9.5[mA]. The size of VCO is $6{\times}9{\times}2mm$(0.11[cc]).

• 한국정보기술학회 영문논문지
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• 제10권1호
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• pp.37-43
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• 2020

This paper presents analysis of passive metal interconnection of the LNA block in CMOS integrated circuit. The performance of circuit is affected by the geometry of RF signal path. To investigate the effect of interconnection lines, a cascode LNA is designed, and circuit simulations with full-wave electromagnetic (EM) simulations are executed for different positions of a component. As the results, the position of an external capacitor (C_ex) changes the parasitic capacitance of electric coupling; the placement of component affects the circuit performance. This analysis of interconnection line is helpful to analyze the amount of electromagnetic coupling between the lines, and useful to choose the signal path in the layout design. The target of this work is the RF LNA enabling the seamless connection of wireless data network and the following standards have to be supported in multi-band (WCDMA: 2.11~ 2.17 GHz, CDMA200 1x : 1.84~1.87 GHz, WiBro : 2.3~2.4GHz) mobile application. This work has been simulated and verified by Cadence spectre RF tool and Ansoft HFSS. And also, this work has been implemented in a 0.13um RF CMOS technology process.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.68-71
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• 2021

In this paper, GaN-SBD devices with excellent breakdown voltage and frequency characteristics for use in high-power microwave wireless power transmission has been modeled for PSpice circuit simulation. The RF-DC conversion circuits were simulated and compared with a commercial Si-SBD device. Although the modeled GaN-SBD devices had lower RF-DC conversion efficiency compared to Si-SBD at 2.4 and 5.8 GHz, it was confirmed through PSpice circuit simulations that they can be used sufficiently according to the required application circuit in a high power situation.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.416-423
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• 2012

Ansoft HFSS와 Serenade를 사용하여, 적층형 저역통과필터(LPF)와 RF 다이오드 스위치를 설계하였다. RF diode switch의 등가회로를 참고한 시뮬레이션은 송신모드 (Transmit mode)일 때 다이오드를 인덕터(Inductor)로 등가 회로화 하였고, 수신모드(Receive mode) 일때는 다이오드를 커패시터(Capacitor)로 변환하여 시뮬레이션 하였다. 적측형 RF diode 설계는 소자 와 수축률 변화를 고려하여 수행하였다.

• 한국전자파학회논문지
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• 제11권6호
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• pp.976-983
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• 2000

본 논문은 MRI용 RF 코일로 널리 사용되고 있는 Birdcage type의 RF 코일을 FDTD 방법을 이용해서 해석, 설계하였다. 기존의 저자장(1T, 1.5T) MRI용 RF 코일의 해석 방법은 코일의 공진 주파수를 얻기 위해서 LC 등가 회로를 사용하였으며 코일 내부의 필드 분포를 얻기 위하여 Biot-Savart 법칙을 이용한 방법이 널리 사용되어 왔다. 그러나 3T이상의 고주파에서 동작하는 RF 코일의 해석에는 위의 방법이 커다란 오차를 일으킬 수 있다. 따라서 본 논문에서는 고주파 해석이 가능한 전파 (Full Wave) 해석 방법인 FDTD 방법을 이용하여 3T MRI용 RF 코일을 해석하고 설계하였다. 또한 FDTD 방법을 이용하여 본 논문에서 실제 제작된 Birdcage type과 Spiral type RF 코일에 적용하여 이 방법의 타당성을 실험적으로 검증하였으며 Spiral type의 RF 코일이 B1 field 균일도면에서 Highpass Birdcage type보다 우수함을 수치 해석적으로 검증하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권3호
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• pp.198-206
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• 2011

This paper presents a new programmable compensation circuit (PCC) for a System-on-Chip (SoC). The PCC is integrated with $0.18-{\mu}m$ BiCMOS SiGe technology. It consists of RF Design-for-Testability (DFT) circuit, Resistor Array Bank (RAB) and digital signal processor (DSP). To verify performance of the PCC we built a 5-GHz low noise amplifier (LNA) with an on-chip RAB using the same technology. Proposed circuit helps it to provide DC output voltages, hence, making the RF system chain automatic. It automatically adjusts performance of an LNA with the processor in the SoC when it goes out of the normal range of operation. The PCC also compensates abnormal operation due to the unusual PVT (Process, Voltage and Thermal) variations in RF circuits.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.27-30
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• 2007

This paper deals with an equivalent circuit model for RF passive components. Rational functions are obtained from the frequency responses of EM simulation by using Foster canonical partial fraction expressions. The Vector Fitting(VF) and the Adaptive Frequency Sampling(AFS) scheme are also implemented to obtain the rational functions. A passivity enforcement algorithm is applied to ensure the stability of the equivalent circuit model. In order to verify the schemes, S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure with 3 slots in ground.

• 정보통신설비학회논문지
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• 제8권1호
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• pp.1-5
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• 2009

In this paper, we propose a method that applies Vector Fitting (VF) technique to the equivalent circuit model for RF passive components. These days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI/SI (Power Integrity/Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time consuming task. Therefore equivalent circuit model using RF passive component is important. VF schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.281-284
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• 2009

In this paper, we propose a method that applies Adaptive Frequency Sampling(AFS) technique to the equivalent circuit model for RF passive components. Thes days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI(Power Integrity)/SI(Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time comuming task. Therefore equivalent circuit model using RF passive component is important. AFS schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit moldel is compared to those of EM simulation in case of the microstrip line structure.