A low current GaAs MMIC down conversion mixer has been
designed for cellular band applications. The mixer exhibits conversion gain
of 6~9 dB with a small LO power of -5 dBm. Total current disspation of the
mixer is less than 5 mA with 5V drain bias voltage.
GaAs MMIC Foundary를
이용한 BS Tuner 설계
김영웅, 박인우,
곽명현, 이영재, 배종대, 정웅, 마동성, 김범만
Abstract
A BS Tuner IC for DBS receiver has been designed using
KUKJE GaAs Foundary Library. Its mixer adopts common gate configuration
to achieve easy of input impedance matching and good isolation between two
input signals. The VCO operates from 1.4GHz to 2.5GHz(oscillation frequency)
with varactor tuning voltage raging from 5V to 28V. The IC delivers a conversion
gain of more than 6dB from 950MHz to 2GHz satellite for the extended satellite
TV band application under a single 5V supply voltage.
SABM 공정으로 개발된
X-band AlGaAs/GaAs HBTs
이준우, 김우년,
서영석, 김범만, 정영래, 서화창, 정웅, 마동성
Abstract
자기 정열 베이스 공정 기법에 의해 AlGaAs/GaAs HBTs를
제작하였다. 자기 정열 수율을 향상시키기 위하여 크롬을 에미터 금속 위에 증착시켜
건식 식각 마스크로 사용하는 공정과 intrinsic 에미터 바로 위에 금을 도금하는
공정을 개발하여 HBT의 DC/RF 및 열적 특성을 크게 향상시켰다. 제작된 HBT는
20~40의 에미터 공통 전류 이득과 30V 및 14V의 컬렉터 베이스의 항복전압을
나타내었고 베이스와 컬렉터 접합의 이상계수는 각각 1.10~1.45와 1.02~1.17로
매우 우수하였다. On-wafer S-parameter 측정으로부터 계산된 3umX20um 에미터
크기의 에미터 공통 HBT는 #19394 소자의 경우 Jc=40kA/cm2의 전류 밀도에서 ft=41GHz, fmax=51GHz의 결과를 얻었고 #19294 소자에서는
Jc=60kA/cm2의 전류
밀도에서 ft=63GHz, fmax=45GHz의 결과를 얻었다.
HBT의 비선형 intermodulation
상쇄 효과
김우년, 이준우, 김영식,
김범만
Abstract
This paper examines cancellation effects of intermodulation
components generated by nonlinear elements of heterojunction bipolar transistors(HBT's).
We have calculated the third order intercept point(IP3) using Volterra Series
analysis technique. The simulation shows that the output current distortion
components generated by the emitter current source and those generated by
the collector current source cancel each other almost exactly.
레이다 송수신 모듈용
X-band 14W 전력증폭기 연구
임준열
, 노태문, 김범만
Abstract
This paper shows the design and testing of X-band(8.9-9.5GHz)
SSPA which is useful for radar transmitter/receiver module. The SSPA consists
of 5 stages; the first 2stages were of it was designed by harmonic balancing
method and the other stages were designed by load-pull method. Wilkinson
power combiner/devider was used for last stage. We got the SSPA output characteristics
from measurement as below. The SSPA has 32dB gain, over 41.5dBm output power
and about 21% power added effiency.
AlGaAs Emitter Depletion
Ledge를 이용한 HBT의 Base 표면전류 감소
김지영, 신진호, 이준우, 인병욱, 김민석, 김우년, 박경석, 김범만
Abstract
In AlGaAs/GaAs HBT, base current consists of bulk current
and surface current. Current gain of HBT can be improved by reductin of
surface current. Surface recombination current occurs at the extrinsic surface
of base and the surface current can be reduced using depleted AlGaAs layer
passivation technique. We efficiently reduce the surface current by a factor
of 1/2.78~1/5 using the passivation technique, thereby improving current
gain by a large amount.
AlGaAs/GaAs 이중 접합
트랜지스터의 저주파 잡음의 감축
신진호, 정유진, 이준우, 김지영, 김민석, 김범만
Abstract
We have investigated the low-frequency noise characteristic
of AlGaAs/GaAs heterojunction bipolar transistors(HBT's) with different
emitter-base(E-B) structure and surface passivation technique. It is shown
that the use of electrically abrupt E-B junction can greatly reduce the
extrinsic GaAs base surface recombination current which is the dominant
low-frequency noise source in HBT's. The noise corner frequency of the abrupt
HBT without surface passivation is about 9 kHz, which is comparable to that
of Si BJT. At the same collector current density at f=10Hz, the HBT with
abrupt E-B junction has about 15dB lower 1/f noise level than HBT with graded
E-B junction. This clearly demonstrates the effectiveness of using an electrically
abrupt E-B junction for reducing the 1/f noise of HBT. By applying a ledge
passivation, we can further reduce 1/f noise of abrupt HBT by 2~5dB. For
the passivated HBT, the noise corner frequency is reduced to 3kHz. The surface
recombination noise is no longer a dominant noise source for the passivated
HBT and the device noise characteristics are a lot more repeatable.
AlGaAs/GaAs HBT에서 Surface
Recombination에의한 전류이득의 Frequency Dispersion
인병욱, 이준우, 노태문, 김영식, 김범만
Abstract
We studied the surface rcombination related frequency
dispersion of current gain in AlGaAs/GaAs HBTs for the first time. If the
measurement frequency is higher than the characteristic frequency(fo) of
the surface-states, surface-state occupancy will be unable to follow the
signal, and, therefore, the surface recombination current component will
be vanished. The surface recombination current-to-total base current ratio
(delta(ib)s/delta(ib))
is about 0.47 below 100 MHz (AE=300X20um2),
and the transition frequency is between 100 MHz and 3 GHz. Above 3 GHz,
the ratio is zero. These results indicate that the current gain of HBT is
dispesive. This effect must be included in HBT equivalent circuit model.
MESFET 채널전류 측정용
펄스 I-V 시스템
노태문, 김영식, 서영석,
박위상, 김범만
Abstract
A new pulse I-V measurement set-up to determine the channel
current of microwave MESFETs is described. This set-up is capable of I-V
measurement using pulsewidth of 500 nanoseconds under actual bias. In the
two-tone test, the simulation results with a large-signal MESFET model using
the channel current data have been found to be in good agreement with the
measured data.
AlGaAs/GaAs SABM 이종
접합 바이폴라 트랜지스터의 고주파 잡음 특성
허득현, 이준우, 신진호, 김민석, 김영식, 김범만
Abstract
The minimum noise figures of SABM HBTs were measured.
The fabricated HBTs showed excellent noise performances. Under low dc bias
of 2V(Vce) and 0.8mA(Ic), the 4umX10um emitter size HBT showed a minimum
noise figure(NFmin) of 0.9dB with associated gain(Gass) of 16.45dB at 2.5GHz.
It correspondsto a figure of merit Gain/(Fmin*Pdc) ratio of 11.4[1/mW].
This high performance obtained from these HBTs at very low dc bias makes
them very attractive for prtable wireless communication low noise amplifiers.
900MHz대 휴대폰용 MMIC
혼합기의 설계 및 제작
김영웅, 조웅식,
정기웅, 김범만
Abstract
This paper describes a GaAs monolithic microwave integrated
cicuit(MMIC) series-connected FET active mixer(cascode mixer) at 900MHz
Cellular-band that is designed for portable telecommunication applications
using LG MMIC Foundary. From 869MHz to 894MHz (RF frequency) this mixer
performs as follows: conversion gain is between 2dB and 3.5dB with an LO
power of 0dBm, isolation between LO and RF ports is better than 30dB,TOI(Third
Order Intercept) is better than 30dBc. The circuit was manufactured using
a 0.5um GaAs MESFET process without substrate-through viaholes. Total chip
size is 1.2mmX2mm.
6-18GHz 대역 MMIC 1W
전력 증폭기 설계
허원혁, 임준열,
노태문, 김범만
Abstract
This paper describes a GaAs mmonolithic microwave integrated
circuit(MMIC) 1watt power amplifier design at 6-18GHz. It is designed for
broadband signal conversion sing Ratheon Library. From 6GHz to 18GHz band,
the simulation result shows that output power is 29.4dBm-31.4dBm, efficiency
is better than 10%, gain is better than 15dB, flatness is also better than
10% except at mid band region. The circuit was laid out using 0.25um GaAs
MESFET process with substrate-through viaholes. Total chip size is 3.5mmX6.5mm.
HBT 대신호 모델링
김영식, 서영석, 김범만
Abstract
A large signal model of 2X3umX20um AlGaAs/GaAs HBT including
self heating effect is developed. In this model, hybrid-pi configuration
is used to extract ac parameters through the optimization of S-parameters
measured at various bias conditions. Thermal parameters are extracted from
pulsed I-V and temperature dependent forward gummel data. The model proposed
showed a good agreement with measured data and model data even at a low
current level.
고효율 3W급 TRS 단말기용
전력증폭기 모듈의 구현
노태문, 박상욱,
김상희, 김범만, 박위상
Abstract
A high-efficient power amplifier module has been developed
for TRS cellular phone. It is fabricated in a hybrid integrated circuit
using thin film process. To improve thermal property, an alumina substrate
was utilized. At the operating frequency range of 719-734 MHz with the output
power of 34.5 dBm and Vdd=7.2V, the power added efficiency and the large
signal gain were 58% and 28.5 dB, respectively, and the harmonic powers
were below -40 dBc. In comparison with other modules using MOSFETs and BJTs,
the size of the module is small (16X11 mm2) and the efficiency and gain are higher. This power amplfier
module is suitable for TRS cellular application.
PCS 휴대단말기용 전력증폭기의
구현
노태문, 박상욱, 이승학, 박위상,
김범만
Abstract
A linear power amplifier module has been developed for
PCS handy phone. It os fabricated in a hybrid integrated cicuit using thin
film process. To iprove thermal property and circuit accuracy, an alumina
substrate was utilized. The module is two stage topology using OKI GaAs
MESFETs. At the operation frequency range of 1750 - 1780MHz with the output
power of 27.22dBm and Vdd=4.2V, the 3rd order intermodulation distortion
and power-added efficiency were -31dBc and 33%, respectively. In this condition,
the large signal gain and harmonic power were 21dB and below -26dBc, respectively.
This linear pwer amplifier module is suitable for PCS handy phone.
위성 수신 튜너용 MMIC
혼합기의 설계 및 제작
김영웅, 오승건,
곽명현, 김범만
Abstract
A series-connected FET active mixer(cascode mixer)that
is designed for BS(broad satellite) tuner using Kukje GaAs MMIC Foundary.
The active FET model parameters are extracted from the pulsed I-V measurement
at quiescent bias points. This model includes the frequency dispersion effects
due to traps. The mixer has a conversion gain 7.53-10.8dB over the frequency
from 950 to 2050MHz. Isolation is better than 26dB between LO and RF ports.
Total current dissipation of the MMIC chip is less than 7mA with 3V drain
bias voltages and total chip size is 1.2mmX1.8mm
접합부 온도 효과를 고려한
AlGaAs/GaAs HBT의 대신호 전류원 모델링
서영석, 김영식, 노태문, 김범만
Abstract
AlGaAs/GaAs HBT를 위한 정 전류원 모델과 이에 대한 등가회로
파라메터를 추출하는 방법을 제안한다. 제안한 모델은 단자전류를 표시하기 위해
9개의 파라메터를 가지고 있다. 이들 파라메터에 대해 어떤 조정 과정도 필요치
않은 직접적인 추출 방법을 제안한다. 이 방법은 기존의 방법에서 사용하는 Gummel-Plot를
사용하지 않고 측정한 DC-IV 곡선을 이용한다. 이 모델은 물리적으로 의미있는
파라메터로 표시되며 측정된 DC-IV 곡선을 잘 예측한다.
X-밴드 5-bit 디지털 변위기의
구현
한기천, 허원혁, 정유진, 김범만
Abstract
A microwave hybrid PIN diode phase shifter at 8.9-9.2
GHz frequency band is designed, fabricated and rf-tested. A loaded line
type is used for the 11.25 degree, 22.5 degree, and 45 degree bits and a
switched line type for the 90 degree and 180 dgree bits. The measured results
show that the phase error and average insertion loss are less than +-2 degree
and 4.3dB respectively. and
선형성이 우수한 PCS용의
저항성주파수 혼합기
강상훈, 김범만
Abstract
A resistive mixer is designed and realized for PCS application.
Conversion gain is 5dBm and NF is 3.5dB at LO power 4dBm. It shows high
linearity and power handling capability. RF input 1dB compression point
was -5.5dBm and two-tone IIP3 was 4.6dBm. LO to RF, LO to IF isolations
are more than 40dB at the frequency band.
저잡음 AlGaAs/GaAs 이종접합
바이폴라 트랜지스터를 이용한 2GHz VCO
정유진, 신진호, 서영석, 강상훈, 정민철, 김범만
Abstract
A low phase noise voltage controlled oscillator(VCO)
based on HBT was realized. The HBT's were optimized for low 1/f noise characteristics
using the ledge passivation technique. Large signal model including bias-dependent
1/f noise sources have been extracted. Using the model, VCO was designed
and realized. The center frequency of the VCO was 2GHz and the sweep range
was 700MHz. The phase noise was about -109dBc/Hz at 100kHz offset.
AlGaAs/GaAs HBT의 High
Frequency Noise Sources 분석
김민석,
김범만
Abstract
AlGaAs/GaAs HBT의 각 noise source가 Fmin에 미치는 영향을
Hawkin's model을 이용하여 분석하였다. Fmin의 분석 결과 HBT의 dominant source는
base current and collector current shot noise sources이었다. HBT의 output
noise 크기뿐만 아니라 전류에 따른 변화 경향까지 shot noise sources에 의하여
결정되었다. Shot noise sources 사이의 correlation은 noise modeling과정에서
직간접적으로 반드시 고려되어야 하며, correlation과 shot noise sources사이의
cancellation으로 인하여 전류에 따른 Fmin의 변화에서 Fmin이 최소가 되는 전류가
결정된다. Base 저항은 thermal noise에 기여하는 것보다도 shot noise sources를
증폭하여 output noise의 특성을 나쁘게 하는 것을 알 수 있었다.
레이다 송수신 모듈용
10W 전력증폭기 제작
임준열, 김범만
Abstract
본 논문에서는 동작 대역이 X-band인 레이다 송수신 모듈에
쓰이는 전력증폭기를 설계, 제작하였다. 증폭기는 전체 4단으로 구성되어 있으며,
전력구동단과 전력증폭단으로 나누어 설계, 제작하였다. 전력구동단은 2단으로
제작되었으며, 출력 전력 1W, 전력이득 10dB의 특성을 가졌다. 전력증폭단 역시
2단으로 설계, 제작되었으며, 출력 전력 10W 이상, 전력 이득 10dB였다.
X-band 5bit 디지탈 변위기의
구현
한기천, 김범만
Abstract
본 연구에서는 레이더 송수신 모듈에 사용되는 5bit 위상
변위기를 개발하였다. 8.9GHz~9.5GHz의 주파수 대역을 가지는 이 위상변위기는
Alumina기판 위에 Micropen을 사용하여 제작되었으며 PIN*HPND-4028) Diode를
사용하였다. 11.25 degree, 22.5 dgree, 45 degree는 부하선로 방식을 사용하였고
90 degree, 180 degree는 가변선로 방식을 사용하여 설계하였다. 제작된 전체
5bit 변위기의 크기는 1.2X5 cm2이고 위상오차는 +-3 degree 미만, 전체 삽입손실은 4dB미만, 입출력
정합은 평균 15dB 이하의 측정 결과를 얻었다.
DBS Tuner용 Down Converter
강상훈, 김영웅, 김범만, 곽명현, 마동성
Abstract
We have made an MESFET MMIC down converter for DBS tuner
application. It covers 0.91GHz~1.83GHz band and shows more than 8.33dB conversion
gain. LO SSB phase noise is -71dBc at 10kHz offset. OIP3 is 9.8dBm.
RF Frequency에서의 MOSFET
Modeling
김병수, 김범만, 박성호,
이용희
Abstract
We have made a RF frequency band MOSFET model based on
BSIM3v3. This model can accurately express Vds-Ids curve and Vgs-Ids curve
at the same time. And small signal parameter can be predicted using this
model.
MESFET 채널 전류의 비선형
성분 모델링
이재혁, 김영식, 양영구,
남중진, 김범만
Abstract
The nonlinear componenets of MESFET channel currnent
were modeled by extracting high order Talyor series coefficients. MESFET
channel current can be expanded in a Taylor seried including high order
terms which represent nonlinearity. We used low frequency, about 60 MHz,
two tone signal as source signal to MESFET and measured hamornic components
of output power. From this measurements, we extracted Taylor series coefficients
up to 3rd order using Volterra analysis. Extracted coefficients of channel
current model were compared with those of Pedro's channel current model
showing small differences.
