• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.77-88
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• 2000

In this paper, the 3-mode variable gain high power amplifier for a transmitter of INMARSAT-B operating at L-band(1626.5-1646.5 MHz) was developed. This SSPA can amplify 42 dBm in high power mode, 38 dBm in medium power mode and 36 dBm in low power mode for INMARSAT-B. The allowable errol sets +1 dBm as the upper limit and -2 dBm as the lower limit, respectively. To simplify the fabrication process, the whole system is designed by two parts composed of a driving amplifier and a high power amplifier. The HP's MGA-64135 and Motorola's MRF-6401 were used for driving amplifier, and the ERICSSON's PTE-10114 and PTF-10021 for the high power amplifier. The SSPA was fabricated by the RP circuits, the temperature compensation circuits and 3-mode variable gain control circuits and 20 dB parallel coupled-line directional coupler in aluminum housing. In addition, the gain control method was proposed by digital attenuator for 3-mode amplifier. Then il has been experimentally verified that the gain is controlled for single tone signal as well as two tone signals. In this case, the SSPA detects the output power by 20 dB parallel coupled-line directional coupler and phase non-splitter amplifier. The realized SSPA has 41.6 dB, 37.6 dB and 33.2 dB for small signal gain within 20 MHz bandwidth, and the VSWR of input and output port is less than 1.3:1. The minimum value of the 1 dB compression point gets more than 12 dBm for 3-mode variable gain high power amplifier. A typical two tone intermodulation point has 36.5 dBc maximum which is single carrier backed off 3 dB from 1 dB compression point. The maximum output power of 43 dBm was achieved at the 1636.5 MHz. These results reveal a high power of 20 Watt, which was the design target.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.185-185
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• 2013

반도체 트랜지스터의 집적화 기술이 발달하고 소자가 나노미터 크기로 집적화 됨에 따라 문턱 전압의 변동, 높은 누설 전류, 문턱전압 이하에서의 기울기의 열화와 같은 단 채널 효과가 문제되고 있다. 이러한 문제점들은 비 휘발성 플래시 메모리에서 메모리 윈도우의 감소에 따른 retention 특성을 저하시킨다. 이중 게이트 구조의 metal-oxide-semiconductor field-effect-transistors (MOSFETs)은 이러한 단 채널 효과 중에서도 특히 문턱 전압의 변동을 억제하기 위해 제안되었다. 이중 게이트 MOSFETs는 상부 게이트와 하부 게이트 사이의 capacitive coupling을 이용하여 문턱전압의 변동의 제어가 용이하다는 장점을 가진다.기존의 플래시 메모리는 쓰기 및 지우기 (P/E) 동작, 그리고 읽기 동작이 채널 상부의 컨트롤 게이트에 의하여 이루어지며, 메모리 윈도우 및 신뢰성은 플로팅 게이트의 전하량의 변화에 크게 의존한다. 이에 따라 메모리 윈도우의 크기가 결정되고, 높은 P/E 전압이 요구되며, 터널링 산화막에 인가되는 높은 전계에 의하여 retention에서의 메모리 윈도우의 감소와 산화막의 물리적 손상을 초래하기 때문에 신뢰성 및 수명을 열화시키는 원인이 된다. 따라서 본 연구에서는, 상부 게이트 산화막과 하부 게이트 산화막 사이의 capacitive coupling 효과에 의하여 하부 게이트로 읽기 동작을 수행하면 메모리 윈도우를 크게 증폭시킬 수 있고, 이에 따라 동작 전압을 감소시킬 수 있는 이중 게이트 구조의 플래시 메모리를 제작하였다. 그 결과, capacitive coupling 효과에 의하여 크게 증폭된 메모리 윈도우를 얻을 수 있음을 확인하였고, 저전압 구동 및 신뢰성을 향상시킬 수 있음을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.22-29
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• 2009

In this paper, we developed the 200-Watts SSPA(Solid State Power Amplifier) for the X-band pulse compression solid state radar. The developed X-band SSPA is consists of 3-stage CSA(Corporate Structured Amplifier) modules in pre-amplifier stage, driver-amplifier stage and main-power amplifier stage. The main-power amplifier stage of SSPA designed by balanced type using GaN HEMT with enough power and gain to generate power more than 200-Watts in X-band. The developed SSPA has performance with more than total gain 59dB and output power 200-Watts in condition of frequency range 9.2-9.6GHz, pulse period 1msec, pulse width 100usec and duty cycle 10%. The developed SSPA in this paper can apply to high quality solid state radar system with pulse compression technique.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.22-27
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• 2002

The 25 Watt hybrid MIC SSPA has been developed in the frequency rang from 1.6265 GHz to 1.6465 GHz for uplink of INMARST's earth station. To simplify the fabrication process, the whole system is designed of two parts composed of a friving amplifier and a power amplifier. The Motorolas MRF-6401 is used for driving part, the Motorolas MRF-16006 and MRF-16030 is used the power amplifier. We reduced weight and volume of high power amplifier through arranging the bias circuits in the same housing. The realized SSPA has more than 30 dB for gain within 20 MHz bandwidth, and the voltage standing wave ratios(VSWR) of input and output port are less than 1.7, respectively. The output power of 44 dBm is achieved at the 1 dB gain compression point of 106365 GHz These results reveal a high power amplifier of 25 Watt which is the design target. The Proposed SSPA manufacture techniques in this paper can be applied to the implementation of high power amplifiers for some radars and SCPC.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.62-69
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• 2008

This paper proposes linearization technique that the linearity is improved by controlling IMD between the drive stage and the output stage. From the experimental results of W-CDMA 4FA input signal, this amplifier has ACLR of -48dBc@5MHz offset at 50W average power. Proposed linearization technique provides predistortion effect for using drive amplifier without additional circuit, which is the significant in this paper that it makes up for the weak point of analog predistortion method and feedforward method.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1967-1969
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• 2003

본 논문에서는 무인 주행 저속 전기 자동차 시스템 개발을 위한 적외선 LED 라인트레이서를 제작하였다. 햇빛에 의한 영향을 제거하기 위해 적외선 LED를 펄스(pulse)로 구동시켰으며 흰색선에서 반사된 적외선 신호를 photodiode를 이용하여 감지하였다. 감지된 신호는 증폭단과 Peak Detector를 거쳐 최종적으로 AVR MCU로 입력이 된 후 여러 상황에 따른 차량의 방향을 결정할 수 있도록 알고리즘를 통해 처리하였다. 실험을 통하여 본 논문에서 제작한 라이트레이서 모듈이 원하는 방향으로 동작함을 확인하였다.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.167-172
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• 2006

In this paper, the 25W power amplifier for UHF band radio transceiver has been designed and realized. The power amplifier was composed of drive, power amplifier and control stages. Feedback topology and coaxial line baluns were used for wide band operation. The VDMOS, which has reliable performance for linearity and efficiency, was used for power device and designed to operate as push-pull amplification at Class AB Bias. The power amplifier designed in such a way was found to show stable AM modulation performance when voice signal was detected at the gate stage, with being designed and realized to meet output specifications of commercial air traffic control transmitter.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.710-716
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• 2007

In this paper, I study on the realization of 900 MHz 1 W power amplifier using a harmonic rejection circuit. The proposed harmonic rejection circuit has improved the harmonic rejection characteristic and overcoming the problems related with frequency reproducibility on the microstrip line. The proposed power amplifier, fabricated by the type of hybrid with the epoxy PCB, was composed of driver stage and power amplifier stage with harmonic rejection circuit. The fabricated power amplifier shows -24 dBc and -30 dBc of harmonic rejection characteristic at 2nd and 3rd harmonic compared with that is not used, respectively and it could be replace the filter located between an output stage and an antenna.

• Journal of IKEEE
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• v.25 no.1
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• pp.133-138
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• 2021

We propose a Ku-band three-stack CMOS power amplifier to enhance the output power and efficiency. To minimize the dc power consumption, the driver stage is designed using common-source structure. To obtain high output power and utilize a voltage combining method, the power stage is designed using stack structure. To verify the proposed power amplifier structure, we design a Ku-band power amplifier using 65-nm RFCMOS process which provide nine metal layers. The P1dB, power-added efficiency, and gain are higher than 20 dBm, 23 dB, and 25%, respectively, while the operating frequency is 14 GHz-16 GHz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2241-2248
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• 2011

This paper describes the design of a palette-type 60watt high power amplifier module using gallium nitride(GaN) devices with high power and efficiency performances for WiMAX and LTE systems. The line-up for the high gain amplifier module consists of the pre-amplifier stage with low power and high gain, 8watt GaN driving amplifier stage, and 60watt GaN high power amplifier stage of Doherty structure with two 30watt GaN devices. The obtained gain is 61.4dB with an excellent gain flatness of ${\pm}$0.075dB over 2.5~2.68GHz. GaN devices and the Doherty structure are adopted for the improvement of high efficiency and output power. The measurement for the fabricated high power amplifier module of palette type is performed using the widely known WiMAX signal all over the world. In the example of RRH(remote radio head) application of the fabricated amplifier module, the measured efficiency is 37~38% with the 10watts of modulated output power. It is shown that when the fabricated amplifier module is activated with a digital predistorter(DPD), the measured ACLR is better than 46dBc under the 10watts of modulated output power.