• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.49 no.2
• /
• pp.23-30
• /
• 2012

This paper proposes a novel adaptive header-based power gating structure to compensate for the performance loss and the increased wake-up time of the power gating structures induced by the negative bias temperature instability (NBTI) effect. The proposed structure consists of variable width footers based on the two-pass power gating and a new NBTI sensing circuit for an adaptive control. The simulation results of the proposed structure are compared to those of power gating without the adaptive control and show that both the circuit-delay and wake-up time dependence of the power gating structure on the NBTI stress is minimized with only 3% and 4% increase, respectively while keeping small leakage power and rush-current. In this paper, a 45 nm CMOS technology and predictive NBTI model have been used to implement the proposed circuits.

• Journal of Advanced Navigation Technology
• /
• v.3 no.2
• /
• pp.97-107
• /
• 1999

Passive sensors such as Laser Range Finder(LRF) and Forward Looking Infrared(FLIR) camera frequently used for tracking aircraft landing produce the measurements of elevation angle contaminated by large noise due to the exhaust plume disturbance. This results in poor tracking performance if the extended Kalman filter is used for estimation of the range and elevation which are corrupted by the non-Gaussian noise such as plume disturbance. In this paper, an adaptive estimation filter and the extended Kalman filter is combined to produce a combination-type filter. In this approach the adaptive filter is used for the plume-type disturbance noise and the extended Kalman filter is utilized for the measurement of Gaussian type. The proposed combination filter is effective for the trajectory estimation of landing aircraft under the influence of unknown bias and numerical simulations illustrate the performance of the proposed filter.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.2 s.332
• /
• pp.87-92
• /
• 2005

In this paper, adaptive bias circuit and PBG structure have been employed to suppress IMD and improve PAE (Power Added Efficiency) of the power amplifier. It is controlling the gate 'dc' bias voltage with the envelope of the input RF signal. and The PBG structure has been employed on the output port of power amplifier . The proposed power amplifier using adaptive bias circuit and PBG has been improved the IMG by 3 dBc, and the average PAE by $35.54\%$, respectively.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.403-408
• /
• 2008

In this paper, the high efficiency and linearity Doherty power amplifier using DGS and adaptive bias technique has been designed and realized for 2.3GHz WiBro applications. The Doherty amplifier has been implemented us-ing silicon MRF 281 LDMOS FET. The RF performances of the Doherty power amplifier (a combination of a class AB carrier amplifier and a bias-tuned class C peaking amplifier) have been compared with those of a class AB amplifier alone, and conventional Doherty amplifier. The Maximum PAE of designed Doherty power amplifier with DGS and adaptive bias technique has been 36.6% at 34.01dBm output power. The proposed Doherty power amplifier showed an improvement 1dB at output power and 7.6% PAE than a class AB amplifier alone.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.2
• /
• pp.81-86
• /
• 2007

In this paper, the Power Added Efficiency (PAE) and linearity of class-F PA has been improved by using the PBG structure and the application of EER structure, simultaneously. The adaptive bias control circuit has been employed to improve the PAE through the application of EER structure. The PBG structure has been adapted for improving the Linearity by suppressing the harmonics on the output of amplifier. The PAE and the 3rd Inter-Modulation Distortion (IMD) has improved 34.56%, 10.66 dB, compared with those of the conventional Doherty amplifier, respectively.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.8 no.1
• /
• pp.12-17
• /
• 2009

In this paper, We play it for the purpose of study about the power amplifier which applied DGS and adaptive bias circuit structure to general Doherty amplifier for the efficiency of a RF power amplifier and a linearity improvement in the WiBro band. As for the IMD3, 3.4dBc was improved with -26.3dBc when we did the measurement result existing Doherty power amplifier and comparison of the Doherty power amplifier which applied an adaptive bias circuit and the DGS which proposed in this paper, and the mean power efficiency verified what was increased in 37%. Also, we were able to know PAE of 36.6% with output power 34.0dBm in P1dB when magnitude of an input signal was 25.6dBm. we did 6dB back off in output P1dB in order to confirm the ACPR which was a nonlinear characteristic and measured the ACPR. we showed the -34.55dBc which was a value of -34.5dBc or below in the 4.77MHz off-set that was a transmission standard. Therefore, we were able to know that we were satisfied with a spectrum mask standard.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.6 s.121
• /
• pp.584-590
• /
• 2007

In this paper, the efficiency of power amplifier has been maximized by the application of EER structure, and the linearity has been improved by using PBG structure. This paper has proposed a design of power amplifier in class-F to get the PAE, and to control dynamic power using envelope detector. PBG structure gets high-linearity by removing harmonics arisen from the mismatching of matching circuit. The PAE and the 3rd order IMD have been improved 34.64%, 6.65 dB compared with those of conventional Doherty amplifier, respectively.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.4
• /
• pp.49-58
• /
• 2014

A low-swing differential near-ground signaling (NGS) transceiver for low-power high-speed mobile I/O interface is presented. The proposed transmitter adopts an on-chip regulated programmable-swing voltage-mode driver and a pre-driver with asymmetric rising/falling time. The proposed receiver utilizes a new multiple gain-path differential amplifier with feed-forward capacitors that boost high-frequency gain. Also, the receiver incorporates a new adaptive bias generator to compensate the input common-mode variation due to the variable output swing of the transmitter and to minimize the current mismatch of the receiver's input stage amplifier. The use of the new simple and effective impedance matching techniques applied in the transmitter and receiver results in good signal integrity and high power efficiency. The proposed transceiver designed in a 65-nm CMOS technology achieves a data rate of 13 Gbps/channel and 0.3 pJ/bit (= 0.3 mW/Gbps) high power efficiency over a 10 cm FR4 printed circuit board.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.6
• /
• pp.116-126
• /
• 2008

This paper describes the Dual-band WLAN transmitter with 2.4[GHz], 5[GHz]. Dual-band WLAN transmitter was designed at 2.4[GHz] and 5[GHz]. The Dual-band WLAN transmitter has a amplifier which operate at 2.4[GHz] and 5[GHz] frequency and two VCO(Voltage Controlled Oscillator) or VCO has a wide scope of frequency. these problem cause a size and a power consumption, The Dual-band WLAN transmitter module was proposed to solve these. the transmitter was designed to get output signals of IEEE 802.11a's 5.8[GHz] band signal using frequency multiplication way or to act a amplifier about the 2.4[GHz] band signal of IEEE 802.11b/g, according to inputed frequency and bias voltage that a eve using single transmission block. The output spectrum get the improved specification of ACPR of 4[dB], 6[dB], 16[dB] at +11[MHz], +20[MHz], +30[MHz] offset of center frequency compared to no linearization, was satisfied to transmit spectrum mask of IEEE 802.11a wireless Lan.

• Journal of Biomedical Engineering Research
• /
• v.19 no.5
• /
• pp.455-468
• /
• 1998

For the objective interpretation of cerebral metabolic patterns in epilepsy patients, we developed computer-aided classifier using artificial neural network. We studied interictal brain FDG PET scans of 257 epilepsy patients who were diagnosed as normal(n=64), L TLE (n=112), or R TLE (n=81) by visual interpretation. Automatically segmented volume of interest (VOI) was used to reliably extract the features representing patterns of cerebral metabolism. All images were spatially normalized to MNI standard PET template and smoothed with 16mm FWHM Gaussian kernel using SPM96. Mean count in cerebral region was normalized. The VOls for 34 cerebral regions were previously defined on the standard template and 17 different counts of mirrored regions to hemispheric midline were extracted from spatially normalized images. A three-layer feed-forward error back-propagation neural network classifier with 7 input nodes and 3 output nodes was used. The network was trained to interpret metabolic patterns and produce identical diagnoses with those of expert viewers. The performance of the neural network was optimized by testing with 5~40 nodes in hidden layer. Randomly selected 40 images from each group were used to train the network and the remainders were used to test the learned network. The optimized neural network gave a maximum agreement rate of 80.3% with expert viewers. It used 20 hidden nodes and was trained for 1508 epochs. Also, neural network gave agreement rates of 75~80% with 10 or 30 nodes in hidden layer. We conclude that artificial neural network performed as well as human experts and could be potentially useful as clinical decision support tool for the localization of epileptogenic zones.