Microstrip resonators on anisotropic substrates

The spectral domain method is applied to study shielded microstrip resonators printed on anisotropic substrates. A Green's function that takes into account the dielectric anisotropy effects is derived through a fourth-order formulation. Galerkin's method is then applied to form the characteristic equation from which the resonant frequency of the microstrip resonator is numerically obtained. Results for a microstrip situated on an isotropic substrate are used to validate the theory     

Microstrip rectangular resonators on ferrimagnetic substrates

The resonant frequency, bandwidth, efficiency and resonant length of a rectangular microstrip resonator on a ferrimagnetic substrate are derived theoretically and are computed for a typical ferrite substrate. The computed values are compared with those of a similar microstrip antenna on a dielectric substrate.     

Microstrip filters using new compact resonators

Compact two-pole and four-pole passband filters in 900 MHz frequency band using novel square microstrip resonators are presented. The measured filters' responses demonstrate the feasibility of selective filters using these new resonators     

Microstrip resonators having reduced radiation loss

The radiation loss of several forms of microstrip resonator is considered with a view to determining a form which retains as far as possible the advantages of compactness and easy fabrication of the half-wave o.c. resonator, but having reduced radiation loss. A new form of resonator, of U shape or `hair-pin? configuration, is proposed, and theoretical and experimental confirmation of its low radiation is described.     

一种新型U型槽宽频微带天线

提出一种新型的低剖面宽带开槽微带天线。该天线通过U型槽加载,从而产生新的谐振点,达到展宽带的目的。采用HFSS软件对提出的天线模型进行仿真优化,结果显示,该天线在12.83 GHz、15.06 GHz两个频点产生谐振,天线阻抗带宽达到940 MHz和770 MHz     

一种U型开槽的平面倒置F型双频微带天线

提出一种新型U型开槽的平面倒置F型双频微带天线(PIFA)，该天线利用单馈点同轴线馈电，辐射贴片尾端折叠的设计方式，其结构实现了微带天线在无线通信中小型化双频段工作的要求。利用著名的ANSOFF公司的仿真软件HFSS8．0(High Frequency Structure Simulator)进行仿真设计和优化，最终仿真设计了一副适用于GSM900MHz／DCS1800MHz通信系统的微带天线。     

Microstrip resonators with extended range of capacitive tuning

The analysis of different step-impedance microstrip resonators with extended range of the capacitive frequency tuning has been performed. The specified resonators are capable of operating in a wide wave range, including the meter and centimeter radio waves. The resonance equations were obtained and the problem of separating the oscillation modes was considered, and distinctive features of these resonators were established. Recommendations are made regarding the use of the specified resonators at different frequencies (VHF-band, K-band). It is shown that the use of step-impedance resonators and ferroelectric capacitors having the relative variation of capacitance C _max/C _min = 2.2 in the frequency range of 20GHzand higher makes it possible to achieve the tuning bandwidth as large as 28%.     

Microstrip dual-band bandstop filter of defected ground structure and stepped impedance resonators

This article presents a compact microstrip dual-band bandstop filter (BSF), in which one λ_g/4 defected ground structure (DGS) pair is utilised to realise one stopband while two stepped impedance resonators (SIRs) help obtain another stopband and suppress the spurious harmonics. The design strategies and the equivalent circuits are introduced in detail. The measured results indicate 43.8% and 18.7% fractional bandwidth in the two stopbands (2.4 GHZ and 5.2 GHz) respectively, and the return loss is greater than 15 dB in the whole passband. In addition, size reduction can be conveniently achieved by adjusting the length of the SIRs and DGS.     

Microstrip dual-band bandpass filter with independently tunable passbands using varactor-tuned stub loaded resonators

In this paper, a dualband bandpass filter with independently tunable passband is proposed. Two half-wavelength resonators with shunt stub have been placed side by side, fed with a common input-output microstrip line to achieve the individual tunability without affecting other passband. For tuning resonance frequency, varactor diodes are used at the ends of the half wavelength resonators and also at the end of the shunt stubs. Proper shunt stub length and width are derived numerically in such a way that only one control voltage is required in each passband. Measured results show that lower passband can be tuned in a frequency range from 1.78 to 1.96 GHz, whereas the upper passband varies from 2.27 to 2.39 GHz individually. H shaped DGS is integrated below the input-output feed lines to suppress higher order harmonics up to 21 GHz with more than 19 dB attenuation.     

Microstrip antennas

Microstrip antennas consist of a planar resonant radiating element parallel to, but separated, from a ground plane by a thin dielectric substrate (t ll lambda). These antennas are very thin and consequently rugged and easy to mount. They may be fed from the back through the ground plane or from the edge by depositing microstrip lines on the dielectric substrate. Several varieties of microstrip antennas are discussed in this paper. Design procedures are given for both linearly and circularly polarized antennas. Measured patterns are presented for antennas from UHF throughCband.     

Microstrip antennas

Microstrip antennas have been one of the most innovative topics in antenna theory and design in recent years, and are increasingly finding application in a wide range of modern microwave systems. This paper begins with a brief overview of the basic characteristics of microstrip antennas, and then concentrates on the most significant developments in microstrip antenna technology that have been made in the last several years. Emphasis is on new antenna configurations for improved electrical performance and manufacturability and on advances in the analytical modeling of microstrip antennas and arrays     

Microstrip Characteristic Impedance

A recent paper by Bianco et al. gives five definitions of microstrip characteristic impedance which do not have the same frequency dependence. This paper shows that the most widely used definition can be based on wave-impedance and is a unique unambiguous characteristic impedance for microstrip, consistent with characteristic impedance definitions of other waveguiding structures.     

一种微带魔T

文中详细介绍了一种微带一微槽双重接头的作用机理,并在微带一微槽过渡接头和魔T的设计中得到证实,表明它可在微波集成电路中有广泛的应用.     

Microstrip antenna technology

A survey of microstrip antenna elements is presented, with emphasis on theoretical and practical design techniques. Available substrate materials are reviewed along with the relation between dielectric constant tolerance and resonant frequency of microstrip patches. Several theoretical analysis techniques are summarized, including transmission-line and modal-expansion (cavity) techniques as well as numerical methods such as the method of moments and finite-element techniques. Practical procedures are given for both standard rectangular and circular patches, as well as variations on those designs including circularly polarized microstrip patches. The quality, bandwidth, and efficiency factors of typical patch designs are discussed. Microstrip dipole and conformal antennas are summarized. Finally, critical needs for further research and development for this antenna are identified.     

Finite-aperture waveguide-laser resonators

A general theory of finite-aperture waveguide-laser resonators is developed which represents the external reflectors by matrices which couple linearly polarized waveguide modes having the same azimuthal symmetry. The theory allows the determination of resonator efficiency, resonator frequencies, and laser near- and far-field patterns. Computations of the coupling loss for the fundamental waveguide mode as a function of mirror curvature, separation, and aperture are in good agreement with recent infinite-aperture calculations in the limit of large apertures and indicate three low-loss configurations: 1) large radius of curvature mirrors close to the guide; 2) "large" radius of curvature mirrors centered at the guide entrance: and 3) generally smaller curvature mirrors separated by half their curvature from the guide entrance. The importance of higher order waveguide modes in determining laser output power and far-field patterns is demonstrated experimentally and compared to theoretical predictions. Design guidelines for the construction of high-efficiency CO2, CO, and He-Ne waveguide-laser resonators are summarized in tabular form.     

Losses in Microstrip

Expressions are derived for the conductor loss in microstrip transmission lines. The formulas take into account the finite thickness of the strip conductor and apply to the mixed dielectric system. Good agreement with experimental data is obtained for rutile and alumina substrates.     

Microstrip loss calculations

Loss calculations have been performed for microstrip lines by relating the longitudinal component of current to the charge distributions obtained without the substrate. Comparison with experiment shows good agreement.     

Microstrip array technology

Past and present technological developments in microstrip antenna arrays are summarized. Emphasis is on exploring the potential of such arrays for satisfying the requirements of advanced military and commercial applications.     

微带巴伦设计

根据微带耦合线的准TEM模参数 ,推导出相同耦合线Marchand巴伦须满足的导纳方程 ,讨论了改善巴伦性能的方法———电容补偿法。ADS仿真结果表明 :采用最佳条件选取的耦合线 ,巴伦的反射系数接近最小 ,传递系数接近最大 ;采取电容补偿后 ,可进一步改善巴伦的性能。最后给出宽边耦合线巴伦的实验结果。结果表明 :可用上述导纳方程设计巴伦耦合线的参数。