Showing papers in "Aeu-international Journal of Electronics and Communications in 2013"
TL;DR: A new image watermarking scheme based on the Redundant Discrete Wavelet Transform (RDWT) and the Singular Value Decomposition (SVD) that showed a high level of robustness not only against the image processing attacks but also against the geometrical attacks which are considered as difficult attacks to resist.
Abstract: Copyright protection and proof of ownership are two of the main important applications of the digital image watermarking. The challenges faced by researchers interested in digital image watermarking applications lie in the creation of new algorithms to serve those applications and to be resistant to most types of attacks, especially the geometrical attacks. Robustness, high imperceptibility, security, and large capacity are four essential requirements in any watermarking scheme. This paper presents a new image watermarking scheme based on the Redundant Discrete Wavelet Transform (RDWT) and the Singular Value Decomposition (SVD). The gray scale image watermark was embedded directly in the singular values of the RDWT sub-bands of the host image. The scheme achieved a large capacity due to the redundancy in the RDWT domain and at the same time preserved high imperceptibility due to SVD properties. Embedding the watermarking pixel's values without any modification inside the wavelet coefficient of the host image overcomes the security issue. Furthermore, the experimental results of the proposed scheme showed a high level of robustness not only against the image processing attacks but also against the geometrical attacks which are considered as difficult attacks to resist.
228 citations
TL;DR: An efficient hybrid image encryption scheme based on a cyclic elliptic curve and chaotic system that overcomes these disadvantages and ascertains efficacy of the proposed encryption scheme.
Abstract: Recently, several image encryption schemes based on chaotic maps have been proposed Nevertheless, most of them hinder the system performance, security, and suffer from the small key space problem This paper presents an efficient hybrid image encryption scheme based on a cyclic elliptic curve and chaotic system that overcomes these disadvantages The new scheme generates an initial keystream based on chaotic system and an external secret key of 256-bit in a feedback manner Then, the generated keystream are mixed with key sequences derived from the cyclic elliptic curve points Thorough encryption performance and security analysis ascertains efficacy of the proposed encryption scheme
114 citations
TL;DR: Experimental results proved that the proposed DWT-based SVD video watermarking method survives attacks based on video characteristics and image processing techniques.
Abstract: This paper presents an efficient, robust, and imperceptible video watermarking technique based on singular value decomposition (SVD) performed in the Discrete Wavelet Transform (DWT) domain. In the proposed DWT-based SVD video watermarking method, the video frames are transformed with the DWT using two resolution levels. The high frequency band HH and the middle frequency bands LH and HL are SVD transformed and the watermark is hidden in them. The proposed DWT-based SVD video watermarking method is characterized by two improvements: (1) a cascade of two powerful mathematical transforms; the Discrete Wavelet Transform (DWT)-based SVD using additive method, and (2) an error correction code is applied and embeds the watermark with spatial and temporal redundancy. The aim of these improvements is to increase robustness against attacks based on video characteristics and the robustness against image processing attacks, realize high security level, protect the watermark against bit errors and obtain good perceptual quality. The proposed DWT-based SVD video watermarking method has been tested in the presence of video and image processing attacks and experimental results proved that the proposed DWT-based SVD video watermarking method survives attacks based on video characteristics and image processing techniques.
102 citations
TL;DR: In this article, the bit error rate (BER) performance and power spectral density of Discrete Fourier Transform (DFT) based OFDM system with wavelet-based OFDM systems were compared.
Abstract: In this paper we have compared the bit error rate (BER) performance and power spectral density of Discrete Fourier Transform (DFT) based OFDM system with wavelet based OFDM system. We also compared the performance of Least Square (LS) and Linear Minimum Mean Square Error (LMMSE) channel estimation technique for wavelet based OFDM system as well as DFT based OFDM system.
62 citations
TL;DR: A novel video watermarking scheme based on visual cryptography and scene change detection in discrete wavelet transform domain is proposed, which can reveal the copyright ownership of the owner's share from the original video based on the frame mean in same scene and the binary watermark.
Abstract: There is wide interest in multimedia security and copyright protection due the explosion of data exchange in the Internet and the extensive use of digital media. We propose a novel video watermarking scheme based on visual cryptography and scene change detection in discrete wavelet transform domain. We start with a complete survey of the current image and video watermarking technologies, and have noticed that majority of the existing schemes are not capable of resisting all attacks. We propose the idea to use different parts of a single watermark into different scenes of a video for generation of the owner's share from the original video based on the frame mean in same scene and the binary watermark, and generation of the identification share based on the frame mean of probably attacked video. These two shares after stacking can reveal the copyright ownership. Experiments are conducted to verify the robustness through a series of experiments. The security requirement of the proposed algorithm is achieved with the visual cryptography.
53 citations
TL;DR: This paper identifies a new digital watermarking approach for copyright protection of video based on wavelet transformation with good performance for transparency and robustness and the robustness of the proposed method against various kinds of attacks including MPEG-4, MPEG-2, and H.264.
Abstract: Due to the replicable nature of video many illegal copies of the original video can be made. So it demands to deliver methods for preventing illegal copying. This paper identifies a new digital watermarking approach for copyright protection of video based on wavelet transformation. First, the motion part of color video is detected by scene change analysis, and then by applying 3D wavelet transformation over detected motion part, 10 sub-bands of wavelet coefficients are obtained. In order to insert the watermark, 3D coefficients of HL, LH and HH with their third level are selected. After all, by using a spread spectrum technique, the watermark is embedded into the selected wavelet coefficients. In extraction step, the original video is not needed, namely, blind detection. So, the resultant watermarking scheme can be used for public watermarking applications, where the original video is not available for watermark extraction. The experimental results show a good performance of the proposed method for transparency and robustness. Furthermore, the robustness of the proposed method against various kinds of attacks such as median filtering, Gaussian noise, frame dropping, frame averaging, frame swapping and lots of lossy compression including MPEG-4, MPEG-2, and H.264 shows the fidelity of our claim.
52 citations
TL;DR: The experimental results show that the proposed algorithm not only guarantees the invisibility and robustness of the watermark, but also has better performance than other methods mentioned in this paper.
Abstract: This paper proposes a novel watermarking algorithm based on the improved compensation of SVD for embedding the color image watermark into the color host image. Firstly, the watermark bit is embedded into 4 × 4 block by modifying the second row first column and the third row first column elements of U component after SVD. Then, the embedded block is compensated by the improved optimization operation for obtaining higher PSNR and larger threshold T . The embedded watermark is extracted from various attacked images by using the relation between the modified elements of U component without resorting to the original data. Moreover, the proposed algorithm overcomes the problem of false positive detection. The experimental results show that the proposed algorithm not only guarantees the invisibility and robustness of the watermark, but also has better performance than other methods mentioned in this paper.
50 citations
TL;DR: Receiver operating characteristics (ROC) curve comparisons with two existing algorithms demonstrate that the proposed robust image hash function outperforms the assessed algorithms in classification performances between perceptual robustness and discriminative capability.
Abstract: Conventional image hash functions only exploit luminance components of color images to generate robust hashes and then lead to limited discriminative capacities. In this paper, we propose a robust image hash function for color images, which takes all components of color images into account and achieves good discrimination. Firstly, the proposed hash function re-scales the input image to a fixed size. Secondly, it extracts local color features by converting the RGB color image into HSI and YCbCr color spaces and calculating the block mean and variance from each component of the HSI and YCbCr representations. Finally, it takes the Euclidian distances between the block features and a reference feature as hash values. Experiments are conducted to validate the efficiency of our hash function. Receiver operating characteristics (ROC) curve comparisons with two existing algorithms demonstrate that our hash function outperforms the assessed algorithms in classification performances between perceptual robustness and discriminative capability.
49 citations
TL;DR: In this paper, a second iteration Sierpinski carpet fractal shape UWB antenna with hexagonal boundary is presented, which covers the frequency band from 3 GHz to 12 GHz (VSWR ≤ 2).
Abstract: In this paper a second iteration Sierpinski carpet fractal shape UWB antenna with hexagonal boundary is presented. The antenna covers the frequency band from 3 GHz to 12 GHz (VSWR ≤ 2). The proposed antenna has the capability to reject 5.15–5.825 GHz band assigned for IEEE802.11a and HIPERLAN/2 which is achieved by embedding a ‘Y’ shaped slot in the radiator that extends to the central conductor of the CPW feed as well. A fabricated prototype is developed where the simulation and experimental results are in good agreement. Measured peak antenna gain varies from 1.25 dBi to 6 dBi within the band. The proposed antenna has a compact size of 33 mm × 32 mm that includes the substrate around the radiating element. Time domain characteristic reveal that the antenna is non-dispersive with a variation of measured group delay within 0.5 ns over the entire band.
45 citations
TL;DR: Both theoretical analysis and experimental results show that the fragile watermarking scheme is not security, and improvement measure is presented to enhance the security of the fragile Watermarking Scheme.
Abstract: In this paper, we analyze the security of a chaotic system based fragile watermarking scheme for image tamper detection proposed by Rawat et al recently Some errors and modification attack against Rawat et al’s scheme are demonstrated Both theoretical analysis and experimental results show that the fragile watermarking scheme is not security Besides, improvement measure is presented to enhance the security of the fragile watermarking scheme
44 citations
TL;DR: In this article, a CPW-feed printed slot antenna with circular polarization characteristics is presented, which is a rectangular slot excited by a 50 Ω CPW line terminated on a trapezoidal shaped tuning stub.
Abstract: A CPW-feed printed slot antenna with circular polarization characteristics is presented in this paper. The basic structure of the antenna is a rectangular slot excited by a 50 Ω CPW line terminated on a trapezoidal shaped tuning stub. Perturbations in the form of circular stubs are applied in the slot to realize circular polarization. The measured impedance bandwidth (S11 < −10 dB) for the initial design is 4.4 GHz (from 2.2 GHz to 6.6 GHz) while the 3-dB axial ratio bandwidth is 1.77 GHz (from 4 GHz to 5.77 GHz) which is 36.23% at the center frequency of 4.88 GHz. The basic structure of the antenna was further modified to enhance the impedance bandwidth to reach well beyond 12 GHz while increasing the ARBW to 44.3% (from 4.3 GHz to 6.75 GHz). The proposed antenna in its final version has a measured peak gain of about 5 dB throughout the useful band and nearly stable radiation pattern.
TL;DR: In this paper, a circuit topology based on accumulate-and-use philosophy has been developed to harvest RF energy from ambient radiations such as those from cellular towers, which can adaptively operate the load depending on the incident radiation levels.
Abstract: A circuit topology based on accumulate-and-use philosophy has been developed to harvest RF energy from ambient radiations such as those from cellular towers. Main functional units of this system are antenna, tuned rectifier, supercapacitor, a gated boost converter and the necessary power management circuits. Various RF aspects of the design philosophy for maximizing the conversion efficiency at an input power level of 15 mu W are presented here. The system is characterized in an anechoic chamber and it has been established that this topology can harvest RF power densities as low as 180 mu W/m(2) and can adaptively operate the load depending on the incident radiation levels. The output of this system can be easily configured at a desired voltage in the range 2.2-4.5 V. A practical CMOS load - a low power wireless radio module has been demonstrated to operate intermittently by this approach. This topology can be easily modified for driving other practical loads, from harvested RF energy at different frequencies and power levels.
TL;DR: A new multiscale texture classifier which uses features extracted from the sub-bands of the RQWT decomposition is proposed in the transform domain and can achieve a high texture classification rate.
Abstract: This article proposes a study of the reduced quaternion wavelet transform (RQWT) which has one shift-invariant magnitude and three angle phases at each scale from digital image analysis application. A new multiscale texture classifier which uses features extracted from the sub-bands of the RQWT decomposition is proposed in the transform domain. The proposed method can achieve a high texture classification rate. The experimental results can demonstrate the robustness of the proposed method and achieve a higher texture classification accuracy rate than a famous wavelet transform based classifier.
TL;DR: In this paper, a two-stage comb decimator with the improved magnitude characteristic was proposed, where multiplierless corrector filters, which are designed using the frequency sampling and IFIR methods, are introduced.
Abstract: This paper presents a novel two-stage comb decimator with the improved magnitude characteristic. Simple multiplierless corrector filters, which are designed using the frequency sampling and IFIR methods, are introduced. The proposed filters compensate the comb passband droop in the wideband passband region and increase the attenuations in the folding bands. Using the multirate identity the filters may be moved to a lower rate. The filter design depends only on the number of the cascaded comb filters and do not depend on the decimation factor M .
TL;DR: In this article, a hexagonal shaped patch with small volume was proposed, and six triangular slots were cut on the ground plane, just below the six corners of the hexagonal radiating patch.
Abstract: In this article, we describe a novel type of defective ground surface (DGS) microstrip antenna that achieves higher gain, multi resonant frequency with compact size. The proposed antenna consists of a hexagonal shaped patch with small volume. Six triangular slots have been cut on the ground plane, just below the six corners of the hexagonal radiating patch. Antenna is circularly polarized one and it has the measured peak gain of 7.2 dBi. The antenna shows multi frequency behavior and more than 57% compactness compare to the conventional hexagonal patch antenna. The simulated results are confirmed experimentally. The proposed antenna is simple in structure compared with the regular stacked or coplanar parasitic patch antennas. It is highly suitable for wireless communications.
TL;DR: It is proved that the Makbol and Khoo scheme was not able to solve the false-positive problem as claimed and should not be used for proof of ownership applications, so the scheme cannot be used.
Abstract: It is shown that the robust blind image watermarking scheme based on Redundant Discrete Wavelet Transform and Singular Value Decomposition proposed by Makbol and Khoo in this AEU journal has a fundamental flaw in its design that undermines the security of its scheme against the false-positive problem. More crucially, this result therefore invalidates the objective of the scheme that is to achieve ownership protection, so the scheme cannot be used. In more detail, an adversary is able to claim ownership of a watermarked image by extracting his watermark from the image, although his watermark has never been inserted into the image in the first place. We then verified the flaw through experimental results and thus, proved that the Makbol and Khoo scheme was not able to solve the false-positive problem as claimed and should not be used for proof of ownership applications. In discussing ways to mitigate the problem, we investigate an approach that would have worked quite efficiently if Discrete Wavelet Transform was used instead of Redundant Discrete Wavelet Transform.
TL;DR: In this paper, a four-layer metal-clad structure was considered as an optical sensor for refractometry applications, which had a negative index material (NIM) as a core layer.
Abstract: A four-layer metal-clad structure was considered as an optical sensor for refractometry applications. The structure had a negative index material (NIM) as a core layer. The structure parameters were chosen for so that the reflectance profile of the proposed structure shows a sharp peak, which is appropriate for sensing applications. The sensor was found to exhibit a considerable angular shift of the reflectance peak for small changes in the refractive index of the analyte, due to the NIM layer.
TL;DR: In this article, some conventional filtering windows are modified and applied to uniform concentric circular antenna arrays (UCCA) for spatial smoothing and sidelobe reduction, where the modified windows are applied to individual rings of the array that will taper the corresponding current amplitudes.
Abstract: In this paper, some conventional filtering windows are modified and applied to uniform concentric circular antenna arrays (UCCA) for spatial smoothing and sidelobe reduction. The modified windows are applied to individual rings of the array that will taper the corresponding current amplitudes. The resulted sidelobe level, beamwidth and stability for amplitude errors are discussed for the different proposed tapering windows where it shows a sidelobe reduction to about 49 dB as in the case of Binomial UCCA while the Hamming window shows the most immunity to tapered amplitude errors.
TL;DR: In this article, a new method for detecting random-valued impulse noise (RVIN) in images is proposed based on similar valued neighbor criterion and the detection of the noisy pixels are realized in maximum four phases.
Abstract: This paper presents a new method for detecting random-valued impulse noise (RVIN) in images. The proposed method is based on similar valued neighbor criterion and the detection of the noisy pixels are realized in maximum four phases. After the corrupted pixels detected in each phase, the median filtering is performed for only these pixels. As such, corrupted pixels are suppressed gradually at the end of the each phase. The performance of the proposed method is evaluated on different test images and compared with ten different comparison filters from the literature. It is shown from simulation results that proposed method provides a significant improvement over comparison filters.
TL;DR: In this paper, a single-input multiple-outputs current-mode analog biquadratic filter based on current controlled current differencing transconductance amplifier (CCCDTA) is presented.
Abstract: In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current controlled current differencing transconductance amplifier (CCCDTA) is presented. The proposed filter uses two CCCDTAs and two grounded capacitors without any external resistors, which is well suited for integrated circuit implementation. The filter simultaneously gives 3 standard transfer functions, namely, lowpass, highpass and bandpass filters with independent control of quality factor and pole frequency by electronic method. By summing of IHP and LLP, the notch filter can be also achieved. Moreover, the circuit has low input and high output impedance which would be an ideal choice for cascading in current-mode circuit. The PSPICE simulation results are included verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.
TL;DR: An energy-efficient multi-layer MAC (ML-MAC) protocol simulated in QualNet 5.2 is presented, designed to achieve low duty cycle, prolonged network lifetime and low number of collisions.
Abstract: Power management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. If the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit. This paper presents an energy-efficient multi-layer MAC (ML-MAC) protocol simulated in QualNet 5.2. This protocol is designed to achieve low duty cycle, prolonged network lifetime and low number of collisions. Sensor nodes in ML-MAC have a very short listening/active time that would reduce the energy consumption during communication. In addition, number of collisions is minimized which saves the energy required to re-transmit corrupted data packets.
TL;DR: Two nature inspired metaheuristics, differential evolution (DE) and harmony search (HS) algorithms are utilized for optimal filter design considering different topologies and manufacturing series.
Abstract: The most crucial design step for analog active filter design is the optimal selection of passive component values due to manufactured constants. Since the search on possible combinations in preferred values for capacitors and resistors is an exhaustive process, it has to be automated with high accuracy within short computation time. In this work, two nature inspired metaheuristics, differential evolution (DE) and harmony search (HS) algorithms are utilized for optimal filter design considering different topologies and manufacturing series. Simulation results show that as global optimization methods both DE and HS minimize the total design error and reduce the elapsed time with respect to previously utilized methods.
TL;DR: The proposed model can be inserted to computer-aided design (CAD) tools in order to have an accurate and fast design, simulation and optimization of microwave circuits including GaAs HEMTs.
Abstract: This paper presents a fast and accurate procedure for extraction of small signal intrinsic parameters of AlGaAs/GaAs high electron mobility transistors (HEMTs) using artificial neural network (ANN) techniques. The extraction procedure has been done in a wide range of frequencies and biases at various temperatures. Intrinsic parameters of HEMT are acquired using its values of common-source S-parameters. Two different ANN structures have been constructed in this work to extract the parameters, multi layer perceptron (MLP) and radial basis function (RBF) neural networks. These two kinds of ANNs are compared to each other in terms of accuracy, speed and memory usage. To validate the capability of the proposed method in small signal modeling of GaAs HEMTs, data and modeled values of S-parameters of a 200 μm gate width 0.25 μm GaAs HEMT are compared to each other and very good agreement between them is achieved up to 30 GHz. The effect of bias, temperature and frequency conditions on the extracted parameters of HEMT has been investigated, and the obtained results match the theoretical expectations. The proposed model can be inserted to computer-aided design (CAD) tools in order to have an accurate and fast design, simulation and optimization of microwave circuits including GaAs HEMTs.
TL;DR: In this article, a miniaturized couple-line-fed planar ultra-wideband (UWB) antenna is proposed, which has a dual band-notched characteristic as well as two integrated monopoles.
Abstract: A miniaturized couple-line-fed planar ultra-wideband (UWB) antenna is proposed, which has a dual band-notched characteristic as well as two integrated monopoles. Narrowband notches are generated at frequencies of 3.5 GHz and 5.5 GHz using independently controlled bent resonators, whereas the monopoles are designed for radiation at 900 MHz and 2.4 GHz. The proposed design is simulated with full wave solvers and verified with measurements. A good agreement is observed between the simulations and measurements for the antenna's return loss, gain and radiation pattern performances.
TL;DR: This paper has used stationary wavelet transform (SWT) as the key idea of the proposed method that makes it possible to investigate all frequency sub-bands and extract multipath disturbance since it is considered to be a low frequency term.
Abstract: GPS positioning issue has been experienced a surge of interest for multipath mitigation in the past few years. Multipath disturbance is a challenging error in high precision GPS positioning particularly in kinematic mode where the moving receiver undergoes different multipath circumstances. Diverse hardware and software approaches have been implemented to reduce this error in both static and kinematic modes. We have proposed an algorithm to alleviate C/A code multipath in kinematic mode. Our proposed scheme falls into software group where wavelet transform (WT) has been used as the main basis. Of course, we have used stationary wavelet transform (SWT) as the key idea of our proposed method that makes it possible to investigate all frequency sub-bands. Consequently, it would be possible to extract multipath disturbance since it is considered to be a low frequency term. After applying SWT to double difference (DD) residuals, the multipath error is extracted and used to correct DD observations. In this paper, we have designed three experiments to study our proposed method efficiency under different conditions in comparison with existing algorithms.
TL;DR: An improved anti-collision technique based on the binary search algorithm that provides same performance in terms of average request's number making the identification process faster, and the expose time of information is then reduced.
Abstract: In this paper, we propose an improved anti-collision technique based on the binary search algorithm. The improvement is achieved thanks to the manner of the requests’ building. This latter reduces considerably the responding tag's numbers and therefore, decreases the probability of bit's collision. Further, the algorithm provides a noticeable advantage for the length of transmitted binary data compared against basic binary search and dynamic binary search algorithms. Besides, it provides same performance in terms of average request's number making the identification process faster, and the expose time of information is then reduced.
TL;DR: An ultra-wideband low noise amplifier design using the dual-resonant broadband matching technique that achieves a 10.2 dB gain with ±0.9 dB gain flatness over a frequency range of 3.1–10.6 GHz and a −3-dB bandwidth of 2.4–11.4 GHz.
Abstract: This paper presents an ultra-wideband low noise amplifier design using the dual-resonant broadband matching technique The proposed LNA achieves a 102 dB gain with ±09 dB gain flatness over a frequency range of 31–106 GHz and a −3-dB bandwidth of 24–116 GHz The measured noise figure ranges from 32 to 47 dB over 31–106 GHz At 65 GHz, the measured IIP3 and input-referred P1dB are +6 dBm and −5 dBm, respectively The proposed LNA occupies an active chip area of 056 mm 2 in a TSMC 018 μm RF-CMOS process and consumes 16 mW from a 18 V supply
TL;DR: A new, precise and time efficient calibration algorithm that combines the reference data collection procedure with the path-loss prediction model is presented, which requires only a few samples to be measured in a given region, and thus significantly reduces the calibration time.
Abstract: Fingerprinting is a popular technology for indoor WLAN based locating systems. Received signal strength information from different access points is used to estimate the location of mobile users. One of the drawbacks of fingerprinting algorithm is the extensive and time-consuming calibration (training) phase, during which the received signal strength measurements from nearby wireless access points are gathered at pre-defined reference spots and stored in a database to build a prior radio signal strength map of the region. In this manuscript, we present a new, precise and time efficient calibration algorithm that combines the reference data collection procedure with the path-loss prediction model. Our algorithm requires only a few samples to be measured in a given region, and thus significantly reduces the calibration time; the rest of the signal strength database is then estimated by using path-loss prediction model. We carefully evaluate the proposed algorithm through a real-world experiment. Field test results show that our new approach reduces the calibration time without harming the location accuracy of the locating system.
TL;DR: In this article, an ultra wideband power divider with bandpass-filtering frequency response has been presented, which can not only divide/combine the power of microwave signals, but also reject unwanted frequency signals to better regulate the UWB performance.
Abstract: A novel ultra-wideband (UWB) power divider with bandpass-filtering frequency response has been presented. The shorted-end coupled lines and the open/short-circuit slotlines are introduced to this presented power divider. An isolation resistor R is located across the slotline for improving the isolation between the output ports of the power divider. Based on even and odd mode analysis, an analytical model of the presented power divider structure has also been proposed. An UWB power divider with passband response has been designed, fabricated, and measured. The measured results verify the predicted attractive features. It can be seen that the presented UWB power divider can not only divide/combine the power of microwave signals, but also reject unwanted frequency signals to better regulate the UWB performance.
TL;DR: A much faster alternative method for determining the spectral characteristics of photonic crystals which eliminates the need of solving an eigenvalue equation is presented.
Abstract: A novel method is presented for determining the dimensional parameters of one-dimensional (1-D) photonic crystals (PCs) with specified bandgap characteristics. Conventionally, the bandgaps are determined by solving an eigenvalue equation on a fine frequency mesh. This approach requires considerable computation time and is therefore not suited for use in the optimization cycles needed in dimensional design. In this paper we present a much faster alternative method for determining the spectral characteristics of photonic crystals which eliminates the need of solving an eigenvalue equation. Examples are given to illustrate the application of the proposed method for determining the dimensional parameters of 1-D PCs with given design specifications.