PBG Structure Research Articles

High linearity and high power added efficiency power amplifier by employing adaptive bias and PBG structure

AbstractIn this article, adaptive bias circuit and PBG structure have been employed to achieve high power added efficiency (PAE) and high third‐order intermodulation (IM3) suppression in power amplifier simultaneously. The dc bias voltage of the gate in FET has been controlled by envelope of the input signal. The PBG structure has been employed to suppress IM3 on the output port of the power amplifier. The PBG structure was optimized to suppress the second harmonics of the amplifier. IM3 and PAE of the proposed power amplifier using adaptive bias circuit and PBG structure has been improved by 2.73 dBc, and by 35.54%, respectively. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 443–446, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22158

Characteristics of Planar PBG Structures with a Cover Layer

Planar kind of photonic bandgap structures are compatible with the integrated circuits technology, and can be used in microstrip circuits and antennas design. While the characteristics of the structure with a cover layer is not considered yet. For the practical applications of photonic bandgap materials, such as antenna arrays, a radome must be used to prevent the antenna from the damage of wind, snow and rain. So the effect of the radome is very important to the design procedure of the PBG based circuits and antennas. Here the effect of cover layer to the PBG structure has been studied, including different dielectric constant and different thickness. Some experiments have been done to verify the theoretical analysis.

A Novel PBG Planar Inverted-F Antenna for Wearable System

In this paper, a novel PBG planar inverted-F antenna (PIFA) is presented. The PBG structure which is stuck on the back of the Teflon substrate (εr = 2.65) can suppress the surface waves effectively, the simulated impedance bandwidth of the novel PBG PIFA is 27.5% (1.984 GHz–2.621 GHz), increased 2.1% than that of the regular PIFA, and the resonant frequency is decreased at the same time. It can be proved that the size of the antenna is reduced 10.6%. The measured impedance bandwidth is 40%, and it shows that the novel PBG PIFA is more effective and useful. The simulated radiation patterns at the two principle planes of the novel PBG PIFA are narrower than that of the regular PIFA, so the performance of the antenna is improved. The novel PBG PIFA can be applied in some wireless communication systems such as the WLAN2.4 and Bluetooth wireless technology system etc.

Coherent Analysis for Electromagnetic Solitons in PBG Structure of Square Lattice

Coherent X-point solitons is investigated on the basis of dynamic variational formulation in two dimensional PBG structure of square lattice. Nonlinear coupled Schrödinger equations are derived through the action principle. The coherent interaction of soliton parameters and the relevant coherent coupled potential are also investigated. The bound state of solitons can arise due to the negative coupled potential. Moreover the first order analysis indicates that standing wave characteristic for relative interval arises in the direction of transmission.

Rectangular increasing distance spiral slots (RIDSS) PBG applied to MEMS frequency-reconfigurable antenna design

A frequency-reconfigurable antenna with rectangular increasing distance spiral slots (RIDSS) PBG, which is controlled by two microelectromechanical systems (MEMS) switches, is presented. The antenna can work at four states (in the 32–36-GHz band) with different configurations of the switches. The RIDSS PBG structure can restrain the leakiness of RF energy through DC control of the feed lines of the switches. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 394–395, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21179

Harmonic suppression by photonic bandgap on CPW‐fed loop‐slot antenna

AbstractA conventional CPW‐fed loop‐slot antenna, incorporating a PBG structure in the feeding network, is presented. Experimental results show that the PBG structure with cross‐shaped lattices exhibits a well behaved band‐stop characteristic; furthermore, the impedance bandwidth of the proposed antennas also becomes wider than that of the conventional CPW‐fed slot antenna. In this design, the impedance bandwidth can reach 1320 MHz, which is about 60% with respect to the central frequency of 2200 MHz. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 154–156, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20077

Influence of a PBG Structure on the Bandwidth of a Microstrip Antenna

In this work the influence of a PBG structure on the bandwidth of a microstrip antenna is verified. Such structure is located in different forms to relation with the antenna patch (above, below and by a combination of these). Then, the thickness of PBG layer is varied. With this, it is possible to get some results for the bandwidth and efficiency of the antenna, mainly when this antenna is inverted by the PBG structure. The analysis of the problem is made by FD-TD method with ABC using UPML.

Influence of a PBG Structure on the Bandwidth of a Microstrip Antenna

Influence of a PBG Structure on the Bandwidth of a Microstrip Antenna

Novel bandpass filter using tapered PBG cells

AbstractA novel bandpass filter using tapered PBG cells is designed and implemented. With the tapered PBG structure inserted between the top layer of two hairpin resonators with symmetric feed‐line tapping and a ground‐plane bottom layer, the passband characteristics are excited and, moreover, a transmission zero on the higher passband edge is produced. The novel bandpass filter using tapered PBG cells demonstrates the frequency characteristics with a central frequency f0 = 2.9 GHz, a 3‐dB bandwidth (FBW) of 9%, and insertion loss S21 of −2.8 dB. Good agreement between the experimental and simulation results is obtained. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 66–68, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20048

An improved analysis of one‐dimensional PBG structure using the ADI‐FDTD method

AbstractIn this paper, an improved finite‐difference time‐domain (FDTD) algorithm is proposed in order to eliminate the restraint by the Courant–Friedrich–Levy condition. The new algorithm is developed based on an alternating‐direction implicit (ADI) approach. In this method, the conventional time step is divided into two time sub‐steps and each of their difference errors can be remedied. It thus has a high efficiency in the case when a long time is spent to reach a stable status, and this situation usually appears in periodical structures such as PBG structures. A numerical example of one‐dimensional (1D) PBG materials is considered to demonstrate the availability and efficiency of this scheme. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 348–352, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11057

Analysis of Bi-anisotropic PBG Structure Using Plane Wave Expansion Method

An algebraic eigenvalue problem for analyzing the propagation characteristics of electromagnetic waves inside the PBG Structure consisting of complex medium is established by using Bloch theorem and plane wave expansion. Two eigen-solvers are employed. One is matrix-based and another is iterative. Calculated results show that both methods are effective for 2-D PBG structure, but the iterative eigen-solver is more attractive in both CPU-time and memory requirement. A sample of 2-D PBG structure, with Chiral medium as host and air cylinders arranged in triangular lattice as inclusion, is analyzed using both methods. It is found that the introduction of chirality increases the band gap width significantly.

ANALYSIS OF BI-ANISOTROPIC PBG STRUCTURE USING PLANE WAVE EXPANSION METHOD - ABSTRACT

An algebraic eigenvalue problem for analyzing the propagation characteristics of electromagnetic waves inside the PBG Structure consisting of complex medium is established by using Bloch theorem and plane wave expansion. Two eigen-solvers are employed. One is matrix-based and another is iterative. Calculated results show that both methods are effective for 2-D PBG structure, but the iterative eigen-solver is more attractive in both CPU-time and memory requirement. A sample of 2-D PBG structure, with Chiral medium as host and air cylinders arranged in triangular lattice as inclusion, is analyzed using both methods. It is found that the introduction of chirality increases the band gap width significantly.

３次元積層ＰＢＧ構造を使用したミリ波アクティブ集積アンテナアレイ

In this report, the implementation and characterization of a millimeter wave Active Integrated Antenna Array is demonstrated, utilizing second harmonics for the MMIC oscillator with the multiple 3D printed PBG structure by etching. The 3D PBG structure is laminated by 2D PBG structure. The PBG was designed by computer program based on the FDTD method. The PBG structure works to suppress the leaked fundamental wave and makes improve performance of the Active Integrated Antenna Array.

A novel fractal microstrip PBG structure

AbstractA novel fractal microstrip PBG structure is proposed. It is realized by replacing the etched rectangular holes in a ground plane with a Sierpinski carpet. A dual‐stopband characteristic not related to harmonics is observed. Different numbers of iterations of Sierpinski carpet are studied experimentally. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 136–138, 2002.

ＰＢＧ構造基板を用いたマイクロ波平面回路の試作および数値解析による検討

Recently, the demand of information and telecommunication systems has been growing rapidly. In order to realize these systems with small, lightweight and multi-function capabilities, planar circuit and antenna technology have been used. However, these technologies have problems such as low gain and surface wave loss. Photonic band-gap technology is believed to be a promising new solution to these problems. In this paper, simulation results using the FDTD method for photonic band-gap structure on a microwave and a millimeter wave circuit substrate made by etching are presented. The analysis of a Microstrip line and a millimeter wave active integrated antenna with PBG structure are also presented.

A novel PBG structure for a microwave integrated circuit and a planar antenna in a telecommunication system.

Applications of the novel artificial microwave crystal, PBG, made by etching were demonstrated for the circuit as well as for the antenna. The PBG was designed using a computer program based on the FDTD method. From observation of experimental data, the improvement of the microwave and millimeter-wave circuit and of the planar antenna by combining the PBG technique were confirmed.

Photonic bandgap structures used as filters in microstrip circuits

The application of photonic bandgap structures (PBG's) as substrates in microstrip circuits has been investigated. The effects of substrate thickness, microstrip transmission line location, and length of the PBG structure were studied using a finite-difference time-domain (FDTD) simulation and experimental measurement. A low-pass filter with a very wide high-frequency rejection bandwidth was constructed from a serial connection of many different PBG structures.

Broad-band power amplifier using dielectric photonic bandgap structure

Two class AB GaAs field-effect transistor (FET) power amplifiers have been designed and fabricated in the 4.4-4.8 GHz range. In the first case, a dielectric PBG line was incorporated in the design to tune the second harmonic. In the second case, a 50-/spl Omega/ line is used with no harmonic tuning. The PBG structure allows broad-band harmonic tuning and is inexpensive to fabricate. A 5% improvement in power-added efficiency was achieved at the design frequency of 4.5 GHz, in both simulation and measurement.