• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.51 no.9
• /
• pp.493-498
• /
• 2002

Double-side linear pulse motor(DSLPM) has more advantages than single-side linear pulse motor because noise and vibration can be considerably decreased by countervailing the normal forces, which is generated between two stators and mover. However, DSLPM has more complicated magnetic flux path and layout of stator pole toot/mover tooth rather than single-side linear pulse motor In this paper, DSLPM is designed and fabricated by considering the air gap magnetic density, shape of tooth and slot. In order to verify the characteristics of DSLPM, the air gap magnetic flux density is analyzed by 2D FEM and the magnetic flux path is analyzed by 3D FEM. Also the static thrust forces is obtained with the analyzed results.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.6
• /
• pp.255-262
• /
• 2001

This paper deals with characteristic analysis method of the slotless type Permanent Magnet Linear Synchronous Motor(PMLSM) using the space harmonic method. Analysis models of the PM and the armature current are described by the magnetization configurations taking into account the 2D and 3D distribution. In 3D analysis, the thrust and normal force can be calculated more accurately, because it can consider the z component flux density which is impossible in 2D analysis. In order to verify the validity of the proposed method, the results of the analytic method are compared with not only the experimental ones but ones of Finite Element Method(FEM).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.241-242
• /
• 2010

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.3C
• /
• pp.234-240
• /
• 2002

A power amplifier with AlGaAs/InGaAs/GaAs HBT's has been developed for customer premise equipments of the quasi millimeter-wave frequency-band broadband wireless local loop(BWLL) system. Parameters of the linear and nonlinear equivalent circuits for a common base HBT have been extracted by a fitting method. The amplifier has been designed through the linear and nonlinear circuit simulations and fabricated on a ceramic substrate for a hybrid IC. The amplifier has produced a 25.5-dBm output power with 35% power-added efficiency(PAE) at 24.4 GHz and achieved a 7.5-dB linear power gain at 24.8 GHz. In 24.25 ∼24.75 GHz band, the amplifier has exhibited a saturated output over larger than 22 dBm and PAE higher than 25%.

• Earthquakes and Structures
• /
• v.10 no.3
• /
• pp.629-643
• /
• 2016

Among all the natural disasters, earthquakes are the most destructive calamities since they cause a plenty of injuries and economic losses leaving behind a series of signs of panic. The present study highlights the moment-curvature relationships for the structural elements such as beam and column elements and Non-Linear Static Pushover Analysis of RC frame structures since it is a very simplified procedure of non-linear static analysis. The highly popular model namely Mander's model and Kent and Park model are considered and then, seismic risk evaluation of RC building has been conducted using SAP 2000 version 17 treating uncertainty in strength as a parameter. From the obtained capacity and demand curves, the performance level of the structure has been defined. The seismic fragility curves were developed for the variations in the material strength and damage state threshold are calculated. Also the comparison of experimental and analytical results has been conducted.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.10
• /
• pp.90-99
• /
• 2009

In this paper, we proposed the new class-E frequency multiplier design that include the highest efficient characteristics. The proposed frequency multiplier is designed for 5.8[GHz] output using the frequency multiplier about 2.9[GHz] input signal. And studying in this paper is for the design and the implementation of the class E frequency multiplier. For the result, the maximum highest efficient characteristics 32[%] which is with output power 24.5[dBm] and 8.5[dB], is shown with frequency multiplier for the 2.9/5.8[GHz] class E. And we applied the linear method to the implemented class E frequency multiplier. As a result, the output spectrum for the linear is upgrade to 12[dB], 12[dB], 13[dB] of the ACPR characteristics on the +11[MHz], +20[MHz], +30[MHz] offset frequency in the center frequency. The result is satisfied with the 3.83[%] of the lineared EVM for the 64-QAM modulated method with the 54[Mbps] transmission velocity. In this paper, we show that the good compensation result of the linearity and the efficiency through the digital pre-linear method of the distortion with the frequency multiplier. Therefore, we suggested the frequency multiplier method are applying to WLAN, cellular, PCS, WCDMA, and etc.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.8B
• /
• pp.1341-1347
• /
• 2000

For the DRT satellite transponder system, BER and total SNR to be required in the earth terminal are evaluated under the condition of HPA nonlinearity in the FBJ(full-band jamming) or PBJ(partial-band jamming) of uplink and downlink. In case that the satellite Inter bandwidth( Ws) is same to the earth terminal bandwidth($W_r$),in conditions of uplink JSR 10[dB], downlink JSR 10[dB] and processing gain 30[dB], linear transponder system shows that uplink SNR needs to be 14.2[dB] to achieve the total SNR 10[dB] requirement in downlink SNR 14[dB]. However, Nonlinear transponder system with OBO(output backoff) 2[dB] requires 20.1 [dB] uplink SNR. From the above results, the nonlinearity of HPA in the satellite transponder causes the degradation of BER performance so that it is of interest to consider the power increase.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.12
• /
• pp.556-561
• /
• 2002

In this paper, a discrete-time variable structure controller for linear time-varying sampled-data systems with disturbances is proposed. The proposed method guarantees that the system state if globally uniformly ultimately bounded (G.U.U.B), and the ultimate bound is shown to be the order of T, O(T), where T is a sampling period.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.22 no.6
• /
• pp.97-102
• /
• 1985

A new microwave transmission line frequency discriminator in MIC is described, which is composed of a branch-line hybrid 3dB coupler, a λ/2-short stub and a λ/4-opcn stub. It is experimentally verified that the discriminator is linear in a 400 MHz bandwidth at center frequency 4.94 GHz and has return loss more than 15dB in that range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.8 no.6
• /
• pp.558-567
• /
• 1997

Linear power amplifier modules with high-efficiency have been developed for PCS handy phone. These modules were designed using extracted large-signal models of MESFETs and harmonic balance simulation. The modules are intended for low-tier and high-tier at the operation frequency range of 1750 ~ 1780 MHz. For low-tier module, the output power and $IMD_3$ were 23.2 dBm and 31 dBc, respectively, at power-added efficiency of 34% with the supply drain bias of 3.6 V. For high-tier module, the output power and $IMD_3$ were 272.2 dBm and 31 dBc, respectively, at power-added efficiency of 33% with the supply drain bias of 4.2 V. These linear power amplifier modules are suitable for PCS handy phone.