• ETRI Journal
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• v.25 no.4
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• pp.270-273
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• 2003

This paper presents a simple process to integrate thin-film inductors with a bottom NiFe magnetic core. NiFe thin films with a thickness of 2 to 3${\mu}m$ were deposited by sputtering. A polyimide buffer layer and shadow mask were used to relax the stress of the NiFe films. The fabricated double spiral thin-film inductor showed an inductance of 0.49${\mu}H$ and a Q factor of 4.8 at 8 MHz. The DC-DC converter with the monolithically integrated thin-film inductor showed comparable performances to those with sandwiched magnetic layers. We simplified the integration process by eliminating the planarization process for the top magnetic core. The efficiency of the DC-DC converter with the monolithic thin-film inductor was 72% when the input voltage and output voltage were 3.5 V and 6 V, respectively, at an operating frequency of 8 MHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.11-15
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• 2002

3 V, 2.46GHz Low Noise Amplifier (LNA) have been designed for standard 0.35$\mu\textrm{m}$ CMOS process with one poly and four metal layers. This design includes on-chip biasing, matching network and multilayer spiral inductors. The single-ended amplifier provides a forward gain of 20.5dB with a noise figure 3.35dB, and an IIP3 of -6dBm while drawing 59mW total Power consumption

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.270-273
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• 2003

The design, fabrication, and measured result of a 4.7 GHz differential VCO (Voltage Controlled Oscillator) for a 5.2 GHz WLAN (Wireless Local Area Network) applications is presented. The circuit is designed in a 0.35 mm technology employing three metal layers. The design is based on a fully integrated LC tank using spiral inductors. Measured tuning range is 10% of oscillation frequency with a control voltage from 0 to 3.0 V. Oscillation power of $\square$ 2.3 dBm at 4.63 GHz is measured with 21 mA DC current at 3V supply. The phase noise is $\square$ 104.17 dBc/Hz at 1 MHz offset.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.9
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• pp.28-35
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• 1997

A novel high-Q vertical jinductor for MMICs is proposed and characterized in a wide range of frequencies (DC~10 GHz) using the numerical methods such as the PeEC(partial equivalent element circuit), the FDM (finite difference method) and the MoM (method of moments). Electrical superiority of the vertical inductor to the horizontal is observed in terms of the magnetic flux linkage and the ground screening effect. The veritcal bondwire inductor is designed in consideration of the wire bonding feasibility and the optimum electrical peformance. This structure is also analyzed using the equivalent circuit and compared with the conventional spiral inductors From the calculated results, high Q-factor, inductance, and cut-off frequency are observed to be inherent characteristics of the veritcal bondwire inductor.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.201-204
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• 2007

In this paper, fully embedded and miniaturized diplexer device has been developed and characterized for dual-band/mode CDMA handset applications. The size of the embedded diplexer is significantly reduced by embedding high Q circular spiral inductors and high DK MIM capacitors into a low cost organic package substrate. The fabricated diplexer has insertion losses and isolations of -0.5 and -23 dB at 824-894 MHz and -0.7 and -22 dB at 1850-1990 MHz, respectively. Its size is $3.9mm{\times}3.9mm{\times}0.77mm$. The fabricated diplexer is the smallest one which is fully embedded into a low cost organic package substrate.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1347-1348
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• 2006

기존 반도체공정들이 갖는 리소그래피와 식각 등의 공정단계를 배제하는 direct-write 공정을 이용하여 친환경적인 이점을 가질 수 있는 나선형 인덕터의 구조를 제안하고 주파수 특성을 확인하였다. 인덕터의 구조는 Si를 $300{\mu}m$, $SiO_2$를 $3{\mu}m$으로 하였으며, CU 코일의 폭과 선간의 간격은 LAM 공정과 direct-write 공정을 이용할 수 있도록 각각 $100{\mu}m$으로 설정하여 3회 권선하였다. 인덕터는 200-500MHz 범위에서 3.5nH의 인덕턴스, 4GHz에서 최대 29 정도의 품질계수를 가지며, SRF는 2.6GHz로 시뮬레이션 결과를 얻을 수 있었다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.262-263
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• 2007

In this paper, fully embedded and miniaturized diplexer has been designed, fabricated, and characterized for dual-band/mode CDMA handset applications. The size of the embedded diplexer is significantly reduced by embedding high Q circular spiral inductors and high DK MIM capacitors into low cost organic package substrate. The fabricated diplexer has insertion losses and isolations of -0.5 and -23dB at 824-894MHz and -0.7 and -22dB at 1850-1990MHz, respectively. Its size is 3.9mm$\times$3.9mm$\times$ 0.77mm (height). The fabricated diplexer is the smallest one which is fully embedded into low cost organic package substrate.

• Journal of Magnetics
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• v.6 no.2
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• pp.73-76
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• 2001

A double rectangular spiral type inductor has been fabricated by using FeTaN films. The inductor is composed of internal coils sandwiched by magnetic layers. Characteristics of inductor performance are investigated with an emphasis on planarization of magnetic films. In the absence of the planarization process, the grating topology of the upper magnetic films over the coil arrays degrades the soft magnetic properties and the inductor performance. It also induces a longitudinal magnetic anisotropy with the easy axis aligned to the magnetic flux direction. This alignment prevents the upper magnetic films from contributing to the total induction. Glass bonding is a viable method for achieving a completely planar inductor structure. The planar inductor with glass bonding shows excellent performance: inductance of 1.1 $\mu H$, Q factor of 7 (at 5 MHz), and the current capability up to 100 mA.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.4
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• pp.300-306
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• 2004

This paper reports a novel tunable bandpass filter using two-state switched inductor with direct-contact MEMS switches for wireless LAN applications. In our filter configuration, the switched inductor is implemented to obtain more stable and much larger frequency tuning ratio compared with variable capacitor-based tunable filter. The proposed tunable filter was fabricated using a micromachining technology and electrical performances of the fabricated filter were measured. The filter consists of spiral inductors, MIM capacitors and direct-contact type MEMS switches, and its frequency tunability is achieved by changing the inductance that is induced by ON/OFF actuations of the MEMS switches. The actuation voltage of the MEMS switches was measured of 58 V, and they showed the insertion loss of 0.1 dB and isolation of 26.3 dB at 2 GHz, respectively. The measured center frequencies of the fabricated filter were 2.55 GHz and 5.1 GHz, respectively. The passband insertion loss and 3-dB bandwidth were 4.2 dB and 22.5 % at 2.55 GHz, and 5.2 dB and 23.5 % at 5.1 GHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.284-290
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• 2004

In this paper, two types of thin nim bulk acoustic resonator(TFBAR) ladder filters are desisted and fabricated to analyze the effects of on-wafer inductor integration. To suppress the overmode phenomenon a 1 $\mu\textrm{m}$ thick air-gap is fabricated under the TFBAR and aluminum nitride is used for piezoelectric material, while platinum is employed for the top and bottom electrodes. The Tx filter in a duplexer, which usually has a steeper skirt characteristics o the right side of the passband, is designed with four serial and two shunt resonators, namely, a 4/2 stage. Similarly, the Rx filter is devised with a 3/4 stage to create a mirrored image of the Tx filter passband characteristics. Fabricated on-wafer spiral inductors with underpass reveals the Q factor of 5～9 at 2 ㎓. Inductor integrated filters have approximately 10 to 12 ㏈ out-of-band rejection improvement, when compared to the original filters.