• JSTS:Journal of Semiconductor Technology and Science
• /
• v.1 no.3
• /
• pp.182-188
• /
• 2001

A solenoid-type MEMS inductor with a quality factor over 10 at 2 GHz has been developed using an electroplating technique. The integrated spiral inductor has a low Q factor due to substrate loss and skin effects. It also occupies a large area compared to the solenoid-type inductor. The direction of flux of the solenoid-type inductor is parallel to the substrate, which can lower the substrate loss and other interference with integrated passive components. To estimate the characteristics of the proposed inductor over a high frequency range, the 3D FEM (Finite Element Method) simulation is used by using the HFSS at the Ansoft corporation. The electroplated solenoid-type inductor is fabricated on a glass substrate step by step by using photolithography and copper electroplating. The fabrication process to improve the quality factor of the inductor is also developed. The achieved inductance varies within a range from 0.5 nH to 2.8 nH, and the maximum Q factor is over 10.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.10
• /
• pp.877-882
• /
• 2016

In this paper, a novel CMOS high Q factor 2-port active inductor has been proposed. The proposed circuit is designed by cascading basic gyrator-C structural active inductors and attaching the feedback LC resonance circuit. This LC resonator can compensate parasitic capacitance of transistor and can improve Q factor over wide frequency range. The proposed circuit was fabricated and simulated using 65 nm Samsung RF CMOS process. The fabricated circuit shows inductance of above 2 nH and Q factor higher than 40 in the frequency range of 1~6 GHz.

• Proceedings of the IEEK Conference
• /
• 2003.07b
• /
• pp.987-990
• /
• 2003

This paper presents a cross-coupled RF VCO with high-Q MEMS-based spiral inductors. Since the use of high-Q inductors is critical to VCO design, MEMS-based spiral inductors with the Q-factor of nearly 22 are used for the RF VCO with an active cascode current source. The RF VCO circuits including spiral inductors have been designed and simulated in GaAs MMIC-MEMS process. The simulation results of the VCO circuits showed the phase noise of -180dBc/Hz at an offset frequency of 500KHz. The RF VCO circuit simulatinon used 2mA DC current and 3.3V supply.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.4 no.2
• /
• pp.83-87
• /
• 2004

Phase noise performance and current consumption of Radio Frequency (RF) Voltage-Controlled Oscillator (VCO) are largely dependent on the Quality (Q) factor of inductor-capacitor (LC) tank. Because the Q-factor of LC tank is determined by on-chip spiral inductor, we designed, analyzed, and modeled on-chip differential inductor to enhance differential Q-factor, reduce current consumption and save silicon area. The simulated inductance is 3.3 nH and Q-factor is 15 at 2 GHz. Self-resonance frequency is as high as 13 GHz. To verify its use to RF applications, we designed 2 GHz differential LC VCO. The measurement result of phase noise is -112 dBc/Hz at an offset frequency of 100 kHz from a 2GHz carrier frequency. Tuning range is about 500 MHz (25%), and current consumption varies from 5mA to 8.4 mA using bias control technique. Implemented in $0.35-{\mu}m$ SiGe BiCMOS technology, the VCO occupies $400\;um{\times}800\;um$ of silicon area.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.2
• /
• pp.541-549
• /
• 2014

In this paper, an extended switched-inductor quasi-Z-source inverter (ESL-qZSI) with high boost voltage inversion ability is presented, which combines the SL-qZSI with the traditional boost converter, as well as improves the switched-inductor cell. Compared with the classic qZSI topologies, the proposed topology reduces the voltage stresses of capacitors, power devices and diodes for the same input and output voltage. Furthermore, the conversion efficiency is improved. The operation principle of the proposed topology is analyzed in details, which is followed by the comparison between the three topologies. In addition, the performance of the proposed topology is verified by simulations and experiments.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.547-548
• /
• 2006

In this paper, cost effective parallel-branch inductor has been proposed and developed in order to increase the quality factor of the conventional spiral inductor. This parallel-branch inductor is composed of only two metals. The presented parallel-branch inductor shows 12% improvement in the quality factor with the same area as the conventional inductor. Also, we improve the parallel-branch inductor for high frequency applications.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.7
• /
• pp.3425-3430
• /
• 2013

The fast-growing market in wireless communications has led to the development of multi-standard mobile terminals. In this paper, a frequency-tunable active RC bandpass filter for multi-standards wireless communication system is designed using an active inductor. The conventional bandpass filter design methods employ the high order filter or high quality factor Q to improve the stopband attenuation characteristics and frequency selectivity of the passband. The proposed bandpass filter based on the high Q active inductor has an improved frequency characteristics. The center frequency and gain of the designed bandpass filter is tuned by employing the tuning circuit. We have performed the simulation using TSMC $0.18{\mu}m$ process parameter to analyze the characteristics of the designed active RC bandpass filter. The bandpass filter with Q=20.5 has 90MHz half power bandwidth at the center frequency of 1.86GHz. Moreover, the center frequency of the proposed bandpass filter can be tuned between 1.86~2.38GHz for the multi-standards wireless communication system using the capacitor of the tuning circuit.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.317-318
• /
• 2006

일반적인 CMOS공정으로는 높은 주파수 대역에서 높은 Q factor를 갖는 인덕터를 구현하는데 어렵고 이에 반해 RF ICs는 갈수록 high Q 를 가지는 인덕터가 요구되고 있다. 이를 LTCC 기판 위에 인덕터를 구현했을 때 높은 주파수 대역에서 성능을 알아보기 위해 모의 실험하였다. 인덕터를 설계하는데 있어서 인덕터 코일의 폭, 코일의 두께와 간격이 인덕터의 성능을 결정짓는다는 것을 고려하였고, MEMS 공정을 이용하여 high Q를 갖는 인덕터를 설계하였다. 인덕터의 전체 크기는 $330{\mu}m\;{\times}\;330{\mu}m$에서 선폭은 $30{\mu}m$, 선간의 간격은 $20{\mu}m$로 기판위에 $80{\mu}m$ 높이로 인덕터를 띄어서 설계하였고, 그리고 이를 LTCC 기판위에 high Q 의 인덕터 구현을 위해 simulation 한 결과가 Q값이 50 정도의 크기를 나타냈다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5B
• /
• pp.985-991
• /
• 2000

In this paper, the optimum structure of 2GHz magnetic thin film planar inductor were designed and fabricated to reduce the inductor area and to maximize the inductance L and quality factor Q of the inductor. The optimum design was performed utilizing Co90Fe10 layer multilayered with SiO2 layers to avoid the eddy-current skin effect and considering new lumped element model. New magnetic thin film inductors operating at 2GHz were fabricated on a Si substrate utilizing photo-lithography and lift-off techniques. The frequency characteristics of L, Q, and impedance in more than fifty identical inductors were measured using an RF Impedance Analyzer(HP4291B with HP16193A test fixture). The self-resonant frequencies(SRF) of the inductors were measured by a Vector Network Analyzer(HP8510). The developed inductors have SRF of 1.8 to 2.3GHz, L of 47 to 68nH, and Q of 70 to 80 near 1GHz. Finally, high frequency, high performance, planar micro-inductor(area=30.8 x 30.8il$^2$) with maximized L and Q were fabricated succefully.

• Journal of the Microelectronics and Packaging Society
• /
• v.16 no.4
• /
• pp.5-8
• /
• 2009

In this paper, a high-quality low-temperature co-fired ceramic (LTCC) solenoid inductor using a solder ball and an air cavity on a silicon wafer for three-dimensional (3-D) system-in-package (SiP) is proposed. The LTCC multi-layer solenoid inductor is attached using Ag paste and solder ball on a silicon wafer with the air cavity structure. The air cavity is formed on a silicon wafer through an anisotropic wet-etching technology and is able to isolate the LTCC dielectric loss which is equivalent to a low k material effect. The electrical coupling between the metal layer and the LTCC dielectric layer is decreased by adopting the air cavity. The LTCC solenoid inductor using the solder ball and the air cavity on silicon wafer has an improved Q factor and self-resonant frequency (SRF) by reducing the LTCC dielectric resistance and parasitic capacitance. Also, 3-D device stacking technologies provide an effective path to the miniaturization of electronic systems.