• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.335-339
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• 2003

This Paper describes the design and the simulation results of the RF CMOS Class-E Power Amplifier for a 2.4GHz ISM band. This circuit is composed two connected amplifiers. where Class F amplifier drives Class E amplifier. The proposed circuit can reduce the total power dissipation of the driving stage and can work with higher efficiency. The power amplifier has been implemented in a standard 0.25$\mu\textrm{m}$ CMOS technology and is shown to deliver 100mW output Power to load with 41％ power added efficiency(PAE) from a 2.5V supply.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.83-88
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• 2007

The reliability characteristics of class-E RF power amplifier are studied, based on the degradation of MOSFET electrical characteristics. The class-E power amplifier operates as a switch mode operation to achieve high efficiency. This operation leads to high voltage stress when MOSFET switch is turned-off. The increase in threshold voltage and decrease in nobility caused by high voltage stress leads to a drop in the drain current. In the class-E power amplifier the effects caused by the degradation of MOSFET drain current is a drop of the power efficiency and output power. But the small inductor in the class-E load network allows the reliability to be improved. After $10^{7}\;sec$. the drain current decreases 46.3% and the PAE(Power Added Efficiency) decreases from 58% to 36% when the load inductor is 1mH. But when the load inductor is 1nH the drain current decreases 8.89% and the PAE decreases from 59% to 55%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.1-11
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• 2009

In this paper, a new 1 kW power amplifier with high efficiency and high stability in a RF generator is designed and fabricated for plasma applications. The efficiency of power amplifier is improved by using class-E amplifier that consists of one push-pull MOSFET and high current drive IC instead of class-C amplifier composed of several single ended MOSFET. Switchable damper that allows selecting three different modes of amplifiers for considering efficiency and stability is added into the amplifier for plasma applications. Stable region of an early electronic discharge section is extended to VSWR of 4.5:1 compared to conventional VSWR of 3.8:1 through using switchable damper. The dimension of the amplifier is also reduced to 30 % of conventional amplifier. The 80 % efficiency of power amplifier with switchable damper is obtained the output power of 1 kW in operating frequency of 13.56 MHz. In comparison of conventional power amplifier for plasma applications, 13 % efficiency is improved.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.556-561
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• 2016

This paper describes implementation of a 13.56 MHz, 5 kW RF high power generator for ISM band applications. This RF generator consists of four LDMOS modules of 1.25kW class-AB push-pull power amplifier with drive amplifier and its outputs are combined by using Wilkinson type transmission-line transformers. Its generator has a high efficiency and output power better than linearity. In order to discharge power transistor heats, we used on water cooled copper plate. Also, these have a composite circuit of combiner and low-pass filter and safety circuit to detector over and reflected power. The RF generator has achieved a efficiency of 79 % at 5.33 kW of saturated power level experimentally.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.10
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• pp.24-31
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• 1997

A new design method of stable RF power amplifier using 3dB coupled line is proposed in this thiesis. The proposed method of broadband matching consist of resistive matching circuits at low frequency and lossless matching circuits at microwave band. This design method increase the stability of an amplifier and is suitable for interstage matching. When high power amplifier is designed using this method for PCS base transceiver station, the measured resutls show thst the gain of 18.5dB, and 9W (39.5dBm) output power. We use motorola's MRF6401 for medium power and MRF 6402 for large power and cascaded them.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.183-186
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• 1999

A 900 71Hz RF band-pass amplifier for wireless communication systems is designed and fabricated. HSPICE simulation results show that the amplifier can achieve a tunable center frequency between 880 MHz and 920 MHz. The gain of designed amplifier is 19 dB at Q=88, and the power dissipation is about 61 mW under 3 V power supply by using the spiral inductor with negative-7m circuit and center frequency tunning circuit. The designed band-pass amplifier is implemented by using 0.6 um 2-poly-3-metal standard CMOS process.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.15-21
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• 1999

A new design of RF automatic gain control amplifier with low phase shift attenuator is proposed. By using the RF AGC amplifier, the output level of amplifier becomes to be constant. The error is 0.1dB. In addition, for arbitrary RF input power, it is possible to design the gain of amplifier to be fixed. If the constant gain is maintained, it is more reliable to make wanted IMD(Intermodulation Distortion) characteeristic amplifier.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.1
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• pp.1-9
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• 2017

In this paper, ETRI's $0.25{\mu}m$ GaN MMIC process is introduced and the fabricated results of X-Band 3 W power amplifier MMIC are discussed. The one-stage X-Band 3 W power amplifier MMIC using the $0.25{\mu}m$ GaN MMIC devices has been designed and fabricated. From the fabricated GaN MMIC, the characteristics of the $0.25{\mu}m$ GaN MMIC process and devices are evaluated and analyzed. The X-band power amplifier MMIC shows output power of 3.5 W, gain of 10 dB, and power-added efficiency of 35 %.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.807-815
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• 2019

In this paper, we design a power amplifier to support quad-band in wireless communication devices using RF CMOS 180-nm process. The proposed power amplifier consists of low-band 0.9, 1.8, and 2.4 GHz and high-band 5 GHz. We proposed a structure that can support each input matching network without using a switch. For maximum linear output power, the output matching network was designed for impedance conversion to the power matching point. The fabricated quad-band power amplifier was verified using modulation signals. The long-term evolution(LTE) 10 MHz modulated signal was used for 0.9 and 1.8 GHz, and the measured output power is 23.55 and 24.23 dBm, respectively. The LTE 20 MHz modulated signal was used for 1.8 GHz, and the measured output power is 22.24 dBm. The wireless local area network(WLAN) 802.11n modulated signal was used for 2.4 GHz and 5.0 GHz. We obtain maximum linear output power of 20.58 dBm at 2.4 GHz and 17.7 dBm at 5.0 GHz.

• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.209-215
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• 2003

In this paper. We tested and fabricated the error amplifier for the 15 Watt linear power amplifier for the IMT-2000 baseband station. The error amplifier was comprised of subtractor for detecting intermodulation distortion, variable attenuator for control amplitude, variable phase shifter for control phase, low power amplifier and high power amplifier. This component was designed on the RO4350 substrate and integrated the aluminum case with active biasing circuit. For suppression of spurious, the through capacitance was used. The characteristics of error amplifier measured up to 45 dB gain, $\pm$0.66 dB gain flatness and -15 dB input return loss. Results of application to the 15 Watt feedforward Linear Power Amplifier, the error amplifier improved with 27 dB cancellation from 34 dBc to 61 dBc IM$_3$.