A new digital controller for a single-phase boost power factor correction (PFC) converter operating at a discontinuous conduction mode (DCM), is presented to achieve high input power factor over wide input voltage and load range. A method of duty cycle modulation is proposed to reduce the line harmonic distortion and improve the power factor. The loop regulation scheme is adopted to further improve the system stability and the power factor simultaneously. Meanwhile, a novel digital pulse width modulator (DPWM) based on the delay lock loop technique, is realized to improve the regulation linearity of duty cycle and reduce the regulation deviation. The single-phase DCM boost PFC converter with the proposed digital controller based on the field programmable gate array (FPGA) has been implemented. Experimental results indicate that the proposed digital controller can achieve high power factor more than 0.99 over wide input voltage and load range, the output voltage deviation is less than 3V, and the peak conversion efficiency is 96.2% in the case of a full load.

Tracking capsule endoscope location is one of the promising applications offered by implant body area networks (BANs). When tracking the capsule endoscope location, i.e., continuously localize it, it is effective to take the weighted sum of its past locations to its present location, in other words, to low-pass filter its past locations. Furthermore, creating an exact mathematical model of location transition will improve tracking performance. Therefore, in this paper, we investigate two tracking methods with received signal strength indicator (RSSI)-based localization in order to solve the capsule endoscope location tracking problem. One of the two tracking methods is finite impulse response (FIR) filter-based tracking, which tracks the capsule endoscope location by averaging its past locations. The other one is particle filter-based tracking in order to deal with a nonlinear transition model on the capsule endoscope. However, the particle filter requires that the particle weight is calculated according to its condition (namely, its likelihood value), while the transition model on capsule endoscope location has some model parameters which cannot be estimated from the received wireless signal. Therefore, for the purpose of applying the particle filter to capsule endoscope tracking, this paper makes some modifications in the resampling step of the particle filter algorithm. Our computer simulation results demonstrate that the two tracking methods can improve the performance as compared with the conventional maximum likelihood (ML) localization. Furthermore, we confirm that the particle filter-based tracking outperforms the conventional FIR filter-based tracking by taking the realistic capsule endoscope transition model into consideration.

Ultra-wideband pulse radar exhibits high range resolution, and excellent capability in penetrating dielectric media. With that, it has great potential as an innovative non-destructive inspection technique for objects such as human body or concrete walls. For suitability in such applications, we have already proposed an accurate permittivity estimation method for a 2-dimensional dielectric object of arbitrarily shape and clear boundary. In this method, the propagation path estimation inside the dielectric object is calculated, based on the geometrical optics (GO) approximation, where the dielectric boundary points and its normal vectors are directly reproduced by the range point migration (RPM) method. In addition, to compensate for the estimation error incurred using the GO approximation, a waveform compensation scheme employing the finite-difference time domain (FDTD) method was incorporated, where an initial guess of the relative permittivity and dielectric boundary are employed for data regeneration. This study introduces the 3-dimensional extension of the above permittivity estimation method, aimed at practical uses, where only the transmissive data are effectively extracted, based on quantitative criteria that considers the spatial relationship between antenna locations and the dielectric object position. Results from a numerical simulation verify that our proposed method accomplishes accurate permittivity estimations even for 3-dimensional dielectric medium of wavelength size.

In this paper, we propose a time and memory efficient Ultra Wide Band Short Range Radar (UWB SRR) system for measuring relative target velocities of up to 150km/hr. First, for the proposed detector, we select the required design parameters for good performance. The parameters are the number of coherent integrations, non-coherent integrations, and FFT points. The conventional detector uses a Fast Fourier Transform (FFT) to extract the range and velocity of the target simultaneously. Therefore, it requires high computation effort, high FFT processing time, and a huge amount of memory. However, the proposed pulse radar detector first decides the target range and then computes the target velocity using FFT sequentially for the decided range index. According to our theoretical and simulation analyses, the FFT processing time and the memory requirement are reduced compared to those of the conventional method. Finally, we show that the detection performance of the proposed detector is superior to that of the conventional detector in a background of Additive White Gaussian Noise (AWGN).

In this paper, we propose a method for deciding the parameters to satisfy the experiment values, and also checked the effectiveness of this method based on Kramers-Kronig (K.K.) relation. In our proposed method, we are expressed as matrix the Sellmeier's formula, and are solved the simulatenaous equation until the satisfied the experiment value. Numerical results are given for the influence of pulse responses using the medium constants which can be found by proposed method. Also, numerical technique of pulse responses is employed the fast inversion of Laplace transform (FILT).

Conventional CPM signals employ information sequence with time-unlimited phase shaping pulse (PSP) to achieve power and bandwidth efficient transmission. On the contrary, information sequence using time-limited PSP was believed to produce power-wasting data-independent discrete spectral lines in CPM spectra, and was suggested to be avoided. In this paper, we revisit this problem and adopt the time-limited PSP to replace the one with time-unlimited, it turns out to have an alternative solution to the CPM scheme. We first modify the spectral computing formula for the CPM with time-limited PSP (or CPM-TL) from conventional CPM formula and show that the discrete spectral lines appeared in the power density spectrum of CPM-TL signals can be diminished or become negligible by appropriately choosing PSP. We also show that this class of CPM can use any real number modulation index (h) and the resultant trellis structure of CPM guarantees the maximum constraint length allowed by the number of states in the MLSD receiver. Finally, the energy-bandwidth performance of CPM using time-limited PSP is investigated and compared with conventional CPM with time-unlimited PSP. From numerical results we show that, under the same number of states in the MLSD receiver and bandwidth occupancy, this subclass of CPM could outperform the conventional CPM up to 6dB coding gain, for h<1, in many cases.

In this paper, penetration phenomenon of an early-time (E1) high altitude electromagnetic pulse (HEMP) into dispersive underground multilayer structures is analyzed using electromagnetic modeling of wave propagation in frequency dependent lossy media. The electromagnetic pulse is dealt with in the power spectrum ranging from 100kHz to the 100MHz band, considering the fact that the power spectrum of the E1 HEMP rapidly decreases 30dB below its maximum value beyond the 100MHz band. In addition, the propagation channel consisting of several dielectric materials is modeled with the dispersive relative permittivity of each medium. Based on source and channel models, the propagation phenomenon is analyzed in the frequency and time domains. The attenuation levels at a 100m underground point are observed to be about 15 and 20dB at 100kHz and 1MHz, respectively, and the peak level of the penetrating electric field is found 5.6kV/m. To ensure the causality of the result, we utilize the Hilbert transform.

The optimal design of an extrapolated impulse response (EIR) filter (in the mini-max sense) is a non-linear programming problem. In this paper, the optimal design of the EIR filter by the semi-infinite programming (SIP) is investigated and an iterative technique for optimally designing the EIR filter is proposed. The simulation experiment validates the effectiveness of the SIP technique and the proposed iterative technique in the optimal design of the EIR filter.

This paper reports an advanced millimeter-wave radar system to enable detection of vehicles and pedestrians in wide areas around the radar site such as an intersection. We focus on a pulse coding scheme using complementary codes to reduce range sidelobe for discriminating vehicles from pedestrians with high accuracy. In order to suppress sidelobe increase created by RF circuit imperfections, a π/2 shift pulse modulation method with a complementary code pair cycle is presented. Moreover, in order to improve the angular resolution, a high-resolution direction of arrival estimation involving Tx beam scanning is presented. Experiments on a prototype confirm its range sidelobe suppression exceeds 40dB and its angular resolution is 5° for two human's separation at the distance of about 10m in an anechoic chamber. In a trial intersection experiment, a pedestrian detection rate of 95% was achieved at the false alarm rate of 10% in the range from 5m to 40m. The results prove the system's feasibility for future automotive safety application.

A complete 4-level pulse amplitude modulation (4-PAM) serial link transceiver including a wide frequency range clock generator and clock data recovery (CDR) is proposed in this paper. A dual-loop architecture, consisting of a frequency locked loop (FLL) and a phase locked loop (PLL), is employed for the wide frequency range clocks. The generated clocks from the FLL (clock generator) and the PLL (CDR) are utilized for a transmitter clock and a receiver clock, respectively. Both FLL and PLL employ the identical voltage controlled oscillators consisting of ring-type delay-cells. To improve the frequency tuning range of the VCO, deep triode PMOS loads are utilized for each delay-cell, since the turn-on resistance of the deep triode PMOS varies substantially by the gate-voltage. As a result, fabricated in a 0.13-µm CMOS process, the proposed 4-PAM transceiver operates from 1.5 Gb/s to 9.7 Gb/s with a bit error rate of 10-12. At the maximum data-rate, the entire power dissipation of the transceiver is 254 mW, and the measured jitter of the recovered clock is 1.61 psrms.

Ultra-wideband pulse radar is a promising technology for the imaging sensors of rescue robots operating in disaster scenarios, where optical sensors are not applicable because of thick smog or high-density gas. For the above application, while one promising ultra-wideband radar imaging algorithm for a target with arbitrary motion has already been proposed with a compact observation model, it is based on an ellipsoidal approximation of the target boundary, and is difficult to apply to complex target shapes. To tackle the above problem, this paper proposes a non-parametric and robust imaging algorithm for a target with arbitrary motion including rotation and translation being observed by multi-static radar, which is based on the matching of target boundary points obtained by the range points migration (RPM) algorithm extended to the multi-static radar model. To enhance the imaging accuracy in situations having lower signal-to-noise ratios, the proposed method also adopts an integration scheme for the obtained range points, the antenna location part of which is correctly compensated for the estimated target motion. Results from numerical simulations show that the proposed method accurately extracts the surface of a moving target, and estimates the motion of the target, without any target or motion model.

This paper presents a 20 GHz push-push VCO realized by a 10 GHz super-harmonic coupled quadrature oscillator for a quadrature 60 GHz frequency synthesizer. The output nodes are peaked by a tunable second harmonic resonator. The proposed VCO is implemented in 65 nm CMOS process. It achieves a tuning range of 3.5 GHz from 16.1 GHz to 19.6 GHz with a phase noise of -106 dBc/Hz at 1 MHz offset. The power consumption of the core oscillators is 10.3 mW and an FoM of -181.3 dBc/Hz is achieved.

We propose a new fine Doppler frequency estimator using two fast Fourier transform (FFT) samples for pulse Doppler radar that offers highly sensitive detection and a high resolution of velocity. The procedure of fine Doppler frequency estimation is completed through coarse frequency estimation (CFE) and fine frequency estimation (FFE) steps. During the CFE step, the integer part of the Doppler frequency is obtained by processing the FFT, after which, during the FFE step, the fractional part is estimated using the relationship between the FFT peak and its nearest resultant value. Our simulation results show that the proposed estimator has better accuracy than Candan's estimator in terms of bias. The root mean square error (RMSE) of the proposed estimator has more than 1.4 time better accuracy than Candan's estimator under a 1,024-point FFT and a signal-to-noise ratio (SNR) of 10 dB. In addition, when the FFT size is increased from 512 to 2,048, the RMSE characteristics of the proposed estimator improve by more than two-fold.

This letter proposes an iterative learning control with advanced output data (ADILC) scheme using an estimation of the impulse response for non-minimum phase (NMP) systems, whose model is unknown, except for the relative degree and the number of NMP zeros. Although the ADILC has a simple learning structure that can be applied to both minimum phase and NMP systems, at least a partial model should be known in order to apply ADILC. Considering this fact, in this letter, we propose a new ADILC method based on the estimation of the impulse response for NMP systems whose model is unknown. An estimation method for the learning matrix and an ADILC scheme are presented for NMP systems.

Pulse coupled neural network (PCNN) is a new type of artificial neural network specific for image processing applications. It is a single layer, two dimensional network with neurons which have 1:1 correspondence to the pixels of an input image. It is convenient to process the intensities and spatial locations of image pixels simultaneously by applying a PCNN. Therefore, we propose a modified PCNN with anisotropic synaptic weight matrix for image edge detection from the aspect of intensity similarities of pixels to their neighborhoods. By applying the anisotropic synaptic weight matrix, the interconnections are only established between the central neuron and the neighboring neurons corresponding to pixels with similar intensity values in a 3 by 3 neighborhood. Neurons corresponding to edge pixels and non-edge pixels will receive different input signal from the neighboring neurons. By setting appropriate threshold conditions, image step edges can be detected effectively. Comparing with conventional PCNN based edge detection methods, the proposed modified PCNN is much easier to control, and the optimal result can be achieved instantly after all neurons pulsed. Furthermore, the proposed method is shown to be able to distinguish the isolated pixels from step edge pixels better than derivative edge detectors.

A method for the specification of weighting functions for a spaceborne/airborne interferometric synthetic aperture radar (SAR) sensor for Earth observation and environment monitoring is introduced. This method is based on designing an optimum mismatched filter which minimizes the total power in sidelobes located out of a specified range region around the peak value point of the system point-target response, i.e. impulse response function under the constraint imposed on the peak value. It is shown that this method allows achieving appreciable improvement in accuracy performance without degradation in the range resolution.

Ultra-wideband (UWB) pulse radar has high range resolution and permeability in a dielectric medium, and has great potential for the non-destructive inspection or early-stage detection of breast cancer. As an accurate and high-resolution imaging method for targets embedded in a dielectric medium, extended range points migration (RPM) has been developed. Although this method offers an accurate internal target image in a homogeneous media, it assumes the permittivity of the dielectric medium is given, which is not practical for general applications. Although there are various permittivity estimation methods, they have essential problems that are not suitable for clear, dielectric boundaries like walls, or is not applicable to an unknown and arbitrary shape of dielectric medium. To overcome the above drawbacks, we newly propose a permittivity estimation method suitable for various shapes of dielectric media with a clear boundary, where the dielectric boundary points and their normal vectors are accurately determined by the original RPM method. In addition, our method iteratively compensates for the scattered waveform deformation using a finite-difference time domain (FDTD) method to enhance the accuracy of the permittivity estimation. Results from a numerical simulation demonstrate that our method achieves accurate permittivity estimation even for a dielectric medium of wavelength size.

As technology scales to 45 nm and below, the reliability of VLSI declines due to small delay defects, which are hard to detect by functional clock frequency. To detect small delay defects, a method which measures the delay time of path in circuit under test (CUT) was proposed. However, because a large number of FFs exist in recent VLSI, the probability that the resistive defect occurs in the FFs is increased. A test method measuring path delay time including the transmission time of FFs is necessary. However, the path measured by the conventional on-chip path delay time measurement method does not include a part of a master latch. Thus, testing using the conventional measurement method cannot detect defects occurring on the part. This paper proposes an improved on-chip path delay time measurement method. Test coverage is improved by measuring the path delay time including transmission time of a master latch. The proposed method uses a duty-cycle-modified clock signal. Evaluation results show that, the proposed method improves test coverage 5.2511.28% with the same area overhead as the conventional method.

Capacitive feedback VCOs use capacitors that are connected from the output node to the gate of the tail transistor that acts as a current source. Using such feedback results in modulating the current that is used by the oscillator and therefore changes its cyclostationary noise properties which results in a lower output phase noise. This paper presents a mathematical study of capacitive feedback VCOs in terms of stability and phase noise enhancement to confirm stability and to explain the enhancement in phase noise. The derived expression for the phase noise shows an improvement of 4.4 dB is achievable by using capacitive feedback as long as the VCO stays in the current limited region. Measurement results taken from an actual capacitive feedback VCO implemented in a 65 nm CMOS process also agrees with the analysis and simulation results which further validates the given analysis.

As an application of low electric field to biomedical engineering, this paper attempts to study the dose-effect of biological effects caused by msPEF with experiments on HeLa cells. MTT assay was used to trace the cell electroporation and examine cell viability. It is observed that with the increasing electric field intensity and pulse numbers, IRE effects will occur successively.