Analysis of Frequency Behavior of Microstrip Lines on Anisotropic Substrates With Slots In Ground Plane (original) (raw)
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Cross-hatching of PCB grounds refers to a process in which certain ground planes appear as copper lattices; regular openings are placed at regular intervals. Nowadays, the efficacy of ground hatching on rigid PCBs is minimal. However, it is becoming essential for flexible hybrid electronics. Utilizing hatched grounds for flexible applications could offer some benefits. Hatched grounds can perform dual roles, act as ground surfaces, and offer structural support. Hatched grounds are more durable for bending and stretching applications. Also, hatched grounds are desirable in terms of material conservation. In this paper, we focus on studying how hatched grounds affect the RF performance of a straight microstrip line. Simulations show that cross-hatched grounds with more than 50% filling produces good radio-frequency performance. We will study the effect hatching pattern as well as the density of the hatching on the RF performance of the microstrips. The theoretical modeling is consider...
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We have studied the behavior of the microstrip lines on lossy biaxial anisotropic dielectric substrates. A spectral-domain moment method is used with the Galerkin testing procedure to determine the dispersion characteristics of single and coupled lines. Modes of both even and odd symmetries are included. It is found that the anisotropy of the substrate has a significant influence on the propagation characteristics. The theory is verified by comparison with previously published data.
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IEEE Transactions on Microwave Theory and Techniques, 1977
Afrstract-A method is described for enlcrdating the dynamical (frequency-dependent) properties of varions microstrip discontinuities such as unsymmetrical crossings, T junctions, right-angle bends, impedance steps, and filter elements. The method is applied Ito an unsymmetrical T junction with three different linewidths. Using a wavegnide model with frequency-dependent parameters, a field matching method proposed by Kiihn is employed to compute tlhe scattering matrix of the strictures. The elements of the scattering mntrix calculated in this way differ from those derived from static methods by a bigher frequency dependence, especially for frequencies near tlhe cutoff frequencies of the higher order modes on the microstrip lines. The theoretical results are compared with measurements, and theory and experiment are fonnd to correspond closely.
International Journal of RF and Microwave Computer-Aided Engineering, 2003
mm is inset 19.25 mm from the center of a patch edge. The coaxial aperture has radius 1.75 mm. The resonant frequency, resistance, and reactance were measured as 1.55 GHz, 128.1 ⍀, and 48.6 ⍀, respectively. A circular capacitor patch is added. The probe is now penetrating the radiating patch and is connected to the center of the capacitor patch. The radius of the hole in the radiating patch is 2 mm. The impedance was calculated for a range of structures. Four different antenna elements were fabricated and measured. For the fabricated structures the distance between the patch and the capacitor patch is 3.4 mm. The measured resonant frequency in all cases stayed at 1.55 GHz, as expected. In Figure 3, the resonant impedance is given for several distances d 2 between the radiating and capacitor patch and for capacitor patch diameters ranging from 5 to 35 mm. The agreement is very good for the resistance. A small shift is seen in the reactance. It is probably due to the use of the approximate slot model. It is clearly seen that the inductance of the probe can be canceled out by selecting the configuration with zero inductance and 50 ⍀ resistance. This allows the bandwidth to be broadened considerably. IV. CONCLUSION A network model is given for the calculation of the effect of a top capacitor patch on the impedance of a microstrip antenna. The main advantages of the procedure are that it is a very fast a posteriori procedure, it is easily implemented, and it gives full physical insight. Therefore, it is a very practical tool for antenna designers that want to use the concept of capacitive feeding.
A method for analysis of multilayer coupled transmission lines with and without defected microstrip structure (DMS) excited by an external electromagnetic wave is presented. The structure is first decomposed into coupled transmission-line sections and crosstalk regions, then a lumped circuit model for the crosstalk region and the DMS section is presented, and the forced terms associated with the incident wave are calculated. Finally, by using the modal decoupling method, the unknown modal coefficients and subsequently voltages and currents are obtained.
Defected ground and patch-loaded planar transmission lines
IET Microwaves, Antennas & Propagation, 2009
Two new structures, defected slotline and patch-loaded coplanar waveguide (CPW), are introduced and quasi-static geometrical models for them and for the defected ground structures in microstrip and in CPW configurations are developed, combining those structures with the patch-loaded slotline and the stepped impedance resonators (SIRs) in a microstrip; and thus, a unified approach for the realisation of series and parallel stubs in different planar transmission line configurations is presented. Complementarity between the different structures has been investigated. It has been found that an identical dumbbell-shaped defect and a SIR in a microstrip are complementary to each other. Consequently, a new technique is developed to compensate for the effect of a defect in the ground of a microstrip. All theoretical predictions have been confirmed with both EM simulations and measurements.