Comments on "Simple and accurate formula for the resonant frequency of the equilateral triangular microstrip patch antenna"

For original paper by Kumprasert and Kiranon see IEEE Trans. Antennas Propagat., vol.42, p.1178-9 (1994 August). Discusses the calculation of the resonance frequencies and provides some corrected calculations.     

Effective side length formula for resonant frequency of equilateral triangular microstrip antenna

A novel and accurate expression is obtained by employing the differential evolution algorithm for the effective side length (ESL) of the equilateral triangular microstrip antenna (ETMA). This useful formula allows the antenna engineers to accurately calculate the ESL of the ETMA. The computed resonant frequencies (RFs) show very good agreement with the experimental RFs when this accurate ESL formula is utilised for the computation of the RFs for the first five modes.     

Simple tunable dual-band microstrip patch antenna

A novel technique for designing a tunable dual-band microstrip patch antenna is proposed. Dual-band operation is easily achieved by loading a microstrip patch antenna with one varactor diode placed on a small gap between a square patch and a parasitic strip. It is observed from the measured result that the proposed antenna shows a wide tuning range at the two resonant frequencies.     

Improved formulae for the resonant frequencies of triangular microstrip patch antennas

In this article, an improved formula for the effective side length (a _eff) of the equilateral triangular patch antenna is presented. The computed resonant frequencies for the first five modes, using this formula, are compared with the available experimental and theoretical results in the literature. It is shown that the proposed formula has better accuracy than other available expressions. Moreover, the 30°–60°–90° and 30°–30°–120° triangular patch antennas are studied. Specifically, improved formulae for the effective dielectric constant of these patches are derived.     

On the resonant frequencies of the triangular patch antenna

The appropriate correction factor to use in the resonant frequency formula of an equilateral triangular patch antenna obtained from the cavity model with perfect magnetic walls is discussed.     

The formula for computing the resonant wavelengths of composite microstrip antenna

The fundamental model resonant wavelength of a composite microstrip antenna is analyzed with Rayleigh-Rits method, the numberial examples are compared with experimental results, the measured data verify the theoretical values.     

An improved formula for the resonant frequencies of the triangularmicrostrip patch antenna

An improved version of a formula due to J.S. Dahele and K.F. Lee (ibid., vol.AP-35, p.100-101, Jan. 1987) is presented for predicting the resonant frequency of a triangular microstrip patch antenna. Using a different effective length and the actual substrate permittivity, the technique previously used for the case of a circular disk is modified to produce greater accuracy than previously reported in the literature. This method consistently predicts resonant frequencies more accurately through the first five resonances     

Theoretical and experimental studies of the resonant frequencies ofthe equilateral triangular microstrip antenna

A critical study of the resonant frequency of the equilateral triangular patch antenna is presented. The contributions include: (1) comparison of the previous experimental data of J. S. Dahele and K. F. Lee (see ibid., vol.AP-35, no.1, p.100-1, 1987) with moment method results; (2) new measurements and moment method results for ϵ_r=10.5 and comparison with Gang's hypothesis; (3) verification of the relationship among the various modes by measurements and by the moment method; and (4) a curve fitting formula yielding the resonant frequency of the lowest mode, which is within 1% of the value obtained from moment method analysis     

Approximate expression for the resonant frequency of a rectangular patch antenna

An approximate expression is derived for the resonant frequency of a rectangular patch antenna. It shows explicitly the dependence of the resonant frequency on the characteristic parameters of the antenna. Accuracy of the expression is established by comparing the theoretical results with available measured results.     

Compact triangular microstrip antenna

Loading a triangular microstrip antenna with a shorting pin can significantly reduce the antenna size at a given operating frequency. Experimental results of such a triangular microstrip antenna are presented. Variations of the resonant frequency of the triangular microstrip patch with different shorting-pin positions are given, and comparisons of the compact and conventional triangular microstrip antennas are also presented and discussed     

Edge effects for resonance frequency of covered rectangular microstrip patch antenna

Edge effects using the variational method are calculated and included in the resonance frequency calculations of a rectangular patch antenna covered with a dielectric superstrate. These are compared with the reported experimental results and those based on available theoretical expressions. The calculations are found to more closely agree with reported experimental values.<>     

基于显卡的微带天线谐振频率神经网络建模

谐振频率是微带天线(Microstrip Antennas,MSA)设计过程中最重要的一个参数.针对粒子群神经网络(Particle Swarm Optimization-Neural Network,PSO-NN)对矩形MSA谐振频率建模所面临的计算时间过长以及模型精度不高等问题,提出一种基于图形处理单元(Graphic Processing Unit,GPU)技术的并行处理解决方案.该方法使用粒子与线程一一对应的并行策略,通过并行处理各个粒子的计算过程来加快整个粒子群的收敛速度,从而减少NN的训练时间.在统一计算设备架构下对矩形MSA谐振频率进行了PSO-NN建模,数值计算结果表明:相对于CPU端串行PSO-NN,GPU端并行PSO-NN在寻优稳定性一致的前提下取得了超过300倍的计算加速比;在GPU端大幅增加粒子数,能在运行时间增加极为有限的情况下大幅降低建模的网络误差.     

Small microstrip patch antenna

A novel small microstrip patch antenna is presented. The probe-fed circular microstrip patch incorporates a single shorting post which significantly reduces the overall size of the antenna. Experimental and theoretical impedance behaviour and radiation characteristics of the modified patch are given. Very good agreement between experiment and theory was achieved     

Broadband microstrip patch antenna

The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband     

Cylindrical-rectangular microstrip patch antenna for circularpolarization

The circular polarization condition for a rectangular microstrip patch antenna on a thin cylindrical substrate is investigated. The theoretical study is based on the modal-expansion theory, which is valid for the thin-substrate case. Numerical results for the aspect ratio of the cylindrical-rectangular patch, the optimal feed point for minimum voltage standing wave ratio and the 3-dB bandwidth for circularly polarized radiation are analyzed. Effects of the curvature on the circular polarization condition are also discussed     

New computation of the resonant frequency of a tunable equilateraltriangular microstrip patch

A new dynamic permittivity expression is formulated to be used in the cavity analysis to determine the resonant frequency of an equilateral triangular microstrip patch. The proper sidelength extension expressions are given for low and high substrate permittivity cases. Better accuracy with respect to the moment method and other previous models is obtained for various structural parameters and operational modes. The proposed computation is also extended for the analysis of the two-layer structure in order to determine the air-gap tuning effect on the resonant frequency     

A novel single feed frequency and polarization reconfigurable microstrip patch antenna

In this paper, a novel single feed frequency and polarization reconfigurable microstrip patch antenna is presented. This antenna mainly comprises of a corner truncated square patch with a rectangular ring slot, eight PIN diodes and six conductive pads. Four PIN diodes are placed symmetrically in the rectangular ring slot to bridge the gap and to switch the frequency between WLAN bands resonating at 5.2G Hz and 5.8G Hz. Four PIN diodes connect the corner truncated square patch to parasitic triangular conductors. PIN diodes are used to switch the polarization between linear, right hand circular and left hand circular at each frequency. When compared to conventional patch, the proposed design provides a size reduction of 12% at 5.2G Hz, and 30% at 5.8G Hz. The simulated reflection coefficient and radiation patterns are presented and compared with the experimental data. This antenna finds applications for modern wireless communication system.     

基于神经网络集成的微带天线谐振频率建模

谐振频率是微带天线设计过程中最重要的一个参数,直接决定设计的成败.提出基于十进制粒子群优化(DePSO)算法和二进制粒子群优化(BiPSO)算法的选择性神经网络集成方法,通过粒子群优化(PSO)算法合理选择组成神经网络集成的各个神经网络,使个体间保持较大的差异度,减小"多维共线性"和样本噪声的影响.为有效保证PSO算法的粒子多样性,在迭代过程中加入混沌变异策略.仿真试验表明:混沌PSO算法可以有效提高神经网络集成的泛化能力,基于混沌PSO算法的选择性神经网络集成所建立的微带天线的谐振频率模型好于此问题的已有结论.     

Wideband dual-polarised microstrip patch antenna

A dual-polarised microstrip antenna capable of achieving a wide bandwidth, a high isolation, low cross-polarisation levels and low backward radiation levels is presented. The H-shaped coupling aperture is used. For wide bandwidth and easy integration with active circuits, it uses the aperture-coupled stacked microstrip square patches. Measured return loss exhibits a bandwidth of over 20.9%, and isolation is better than 36 dB over the bandwidth. Cross-polarisation levels and the front-to-back ratio are better than 22 and 21 dB, respectively     

Stacked H-shaped microstrip patch antenna

A small H-shaped microstrip patch antenna (MPA) with enhanced bandwidth is presented. The H-shaped antenna is first studied by a transmission line model and then is fully analyzed with a MoM code. A stacked patch configuration is proposed to increase the narrow bandwidth, radiation efficiency and directivity. The stacked H-shaped MPA is studied using Chu's fundamental limit for electrically small antennas.