• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.454-460
• /
• 2019

In this paper, a watt-level 2.4-GHz RFCMOS linear power amplifier (PA) with pre-distortion method using variable capacitance with respect to input power is demonstrated. The proposed structure is composed of a power detector and a MOS capacitor to improve the linearity of the PA. The pre-distortion based linearizer is embedded in the two-stage PA to compensate for the gain compression in the amplifier stages, it also improves the output P1dB by approximately 1 dB. The simulation results demonstrate a 1-dB gain compression power of 30.81 dBm at 2.4-GHz, and PAE is 29.24 % at the output P1dB point.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.4
• /
• pp.401-410
• /
• 2014

This paper presents a high-efficiency concurrent dual-band Class-E power amplifier(PA) that is based on a multi-harmonic matching network(MHMN). The proposed MHMN controls the impedance at 1.3 GHz, 2.1 GHz, and their second and third harmonics, respectively, by using transmission lines only rather than switches or lumped components. The dual-band Class-E PA is implemented using Avago ATF-50189 GaAs p-HEMT. The PA exhibits a measured output power of 27.1 dBm and 25.7 dBm, a power gain of 6.1 dB and 4.7 dB, and a drain efficiency of 71.2 % and 60.1 % at 1.3 GHz and 2.1 GHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.5
• /
• pp.686-693
• /
• 2001

In this paper, a new carrier complex power series which represents nonlinear transfer function of high power amplifier is derived. Using this transfer function, the nonlinear transfer function of predistortive circuit for linearizing the distortion effect of a HPA(High Power Amplifier) is derived and fabricated. A measured gain and $P_{1dB}$ of the fabricated HPA in IMT-2000 basestation transmitting band are 34.06 dB and 35.4 dBm. The predistortive circuit using inverse carrier complex power series is fabricated and operated with HPA. The predistortive HPA improves C/I(Carrier to Intermodulation) ratio of HPA by 17.01 dB(@Pout=25.43 dBm/tone) with 2-tone at 2.1375 GHz and 2.1425 GHz.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1599-1600
• /
• 2006

In this paper, a small size, $7{\times}6\;mm^2$, Low Noise Amplifier(LNA) using LTCC process was fabricated with multi-layer structure for 2.4GHz wireless LAN. The measured results demonstrate that the bandwidth is 130 MHz, and the operating frequency is from 2.39GHz to 2.52GHz. The power gain is above 7.3 dB in the operating frequency range and the gain flatness is 0.5 dB. The maximum S11 is -4 dB and the maximum S22 is -7.5 dB. The noise figure is less than 1.83 dB. The measured power gain, S11 and S22 were had poorer performance than the simulation results. The reason for this discrepancy is that the input and output matching was not performed exactly. However, the noise figure of the LTCC low noise amplifier is better than simulation result. It is found that it is possible to fabricate a LTCC low noise amplifier in a small size.

• Journal of IKEEE
• /
• v.24 no.4
• /
• pp.1093-1097
• /
• 2020

This work describes the design and characterization of a Ku-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) for satellite communication applications. The device technology used relies on 0.25 ㎛ gate length gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (PHEMT) of wireless information networking (WIN) semiconductor foundry. The developed Ku-band PHEMT MMIC power amplifier has a small-signal gain of 22.2~23.1 dB and saturated output power of 34.8~35.4 dBm over the entire band of 13.75 to 14.5 GHz. Maximum saturated output power is a 35.4 dBm (3.47 W) at 13.75 GHz. Its power added efficiency (PAE) is 30.6~37.83% and the chip dimensions are 4.4 mm×1.9 mm. The developed 3 W PHEMT MMIC power amplifier is expected to be applied in a variety of Ku-band satellite communication applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.7
• /
• pp.620-626
• /
• 2015

In this paper, a 2~6 GHz wideband GaN power amplifier MMIC is designed and fabricated using a second-order all-pass filter for input impedance matching and an LC parallel resonant circuit for minimizing an output reactance component of the transistor. The second-order all-pass filter used for wideband lossy matching is modified in an asymmetric configuration to compensate the effect of channel resistance of the GaN transistor. The power amplifier MMIC chip that is fabricated using a $0.25{\mu}m$ GaN HEMT foundry process of Win Semiconductors, Corp. is $2.6mm{\times}1.3mm$ and shows a flat linear gain of about 13 dB and input return loss of larger than 10 dB. Under a saturated power mode, it also shows output power of 38.6~39.8 dBm and a power-added efficiency of 31.3~43.4 % in 2 to 6 GHz.

• Journal of IKEEE
• /
• v.26 no.4
• /
• pp.722-727
• /
• 2022

In this paper, we present the design and characterization of a power amplifier (PA) monolithic microwave integrated circuit (MMIC) in the X-band. The device is designed using a 0.25 ㎛ gate length AlGaN/GaN high electron mobility transistor (HEMT) on SiC process. The developed X-band AlGaN/GaN power amplifier MMIC achieves small signal gain of over 21.6 dB and output power more than 46.11 dBm (40.83 W) in the entire band of 9 GHz to 10 GHz. Its power added efficiency (PAE) is 43.09% ~ 44.47% and the chip dimensions are 3.6 mm × 4.3 mm. The generated output power density is 2.69 W/mm². It seems that the developed AlGaN/GaN power amplifier MMIC could be applicable to various X-band radar systems operating X-band.

• Journal of electromagnetic engineering and science
• /
• v.15 no.4
• /
• pp.232-238
• /
• 2015

This work describes the development of a D-band (110-170 GHz) signal source based on a SiGe BiCMOS technology. This D-band signal source consists of a V-band (50-75 GHz) oscillator, a V-band amplifier, and a D-band frequency doubler. The V-band signal from the oscillator is amplified for power boost, and then the frequency is doubled for D-band signal generation. The V-band oscillator showed an output power of 2.7 dBm at 67.3 GHz. Including a buffer stage, it had a DC power consumption of 145 mW. The peak gain of the V-band amplifier was 10.9 dB, which was achieved at 64.0 GHz and consumed 110 mW of DC power. The active frequency doubler consumed 60 mW for D-band signal generation. The integrated D-band source exhibited a measured output oscillation frequency of 133.2 GHz with an output power of 3.1 dBm and a phase noise of -107.2 dBc/Hz at 10 MHz offset. The chip size is $900{\times}1,890{\mu}m^2$, including RF and DC pads.

• Journal of electromagnetic engineering and science
• /
• v.17 no.4
• /
• pp.178-180
• /
• 2017

This study presents a 2-20 GHz monolithic distributed power amplifier (DPA) using a $0.25{\mu}m$ AlGaN/GaN on SiC high electron mobility transistor (HEMT) technology. The gate width of the HEMT was selected after considering the input capacitance of the unit cell that guarantees decade bandwidth. To achieve high output power using small transistors, a 12-stage DPA was designed with a non-uniform drain line impedance to provide optimal output power matching. The maximum operating frequency of the proposed DPA is above 20 GHz, which is higher than those of other DPAs manufactured with the same gate-length process. The measured output power and power-added efficiency of the DPA monolithic microwave integrated circuit (MMIC) are 35.3-38.6 dBm and 11.4%-31%, respectively, for 2-20 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.2
• /
• pp.262-265
• /
• 2012

In this paper, a Ka-band 8 W power amplifier module with WR-28 waveguide input and output ports is implemented and measured using four 2 W power amplifier modules and 4:1 waveguide power combiners with high isolation of 25 dB at 35 GHz. The 2 W power amplifier modules are fabricated using waveguide-to-microstrip transitions and show output power of 32.5~33.3 dBm and power gain of 26.9~28.7 dB at 35 GHz. Four 2 W power amplifier modules are combined through 4:1 waveguide power combiners with resistive septum and the combined power shows 39.0 dBm(8 W) under 6 V drain bias and 39.6 dBm(9.1 W) under 6.5 V drain bias at 35 GHz.