Mutual coupling between rotated horns in a ground plane

Two formulations are presented for the mutual admittance of rotated rectangular apertures in a ground plane. One extends an earlier solution, and the other is a third-order asymptotic formula that is shown to be accurate when the apertures satisfy the Rayleigh distance criterion. These formulations are combined with a conventional mode-matching approach to study coupling between rotated horns. Results are presented for both coupling formulations, and these demonstrate excellent agreement with experiment for coplanar pyramidal and sectoral horns     

Modeling the power and ground effects of BGA packages

Ground bounce noise and power supply noise are the major concerns in the electrical design of ball grid array (BGA) packages, therefore accurate models of the package's ground and power structures are needed for circuit simulators. This innovative new software is targeted for the engineer who, at his laptop PC, can rapidly generate accurate power and ground electrical models of an entire BGA package. Using the accepted approximation equations of Grover and Walker [1973 and 1990], the program was designed to be fast and portable contrasting other methods of modeling in which such attributes were sacrificed for greater accuracy. Operation consists of entering the available data, and in just minutes retrieving a parameter listing and two sub-circuit models simultaneously, one circuit for power and one for the ground of the package. The values of inductance and capacitance generated by the program closely match those generated by Grover, Walker, and Caggiano [1995, 1997]. The listing can be used as an evaluation tool for a specific package (e.g., during a design review when critical information is needed quickly) while the circuit models can be used in a simulation program with integrated circuit emphasis (SPICE) circuit simulation of the integrated circuit (IC). These separate models, designed with as few components as possible in order to reduce the complexity of the SPICE topology while still maintaining accuracy, can be either incorporated with signal package models or can be simulated alone     

Study of the ground bounce caused by power plane resonances

We describe Delta-I noise caused by power plane resonances in multilayer boards. First, we study the effect of power plane resonances on the ground bounce of the system by performing finite-difference time-domain (FDTD) simulations. We simulate the voltage fluctuations at one point of the printed circuit board (PCB) due to a current surge between the power planes in a different point. Next, two methods to prevent this ground bounce effect are investigated. The first method consists of adding lumped capacitances to the design. The effect of one large capacitor is compared to the effect of adding a “wall” of smaller capacitors. A second approach is to isolate the chips by etching a slot around the sensitive integrated circuits (ICs) and connecting both sides by a small inductor. Both methods provide excellent protection against power plane resonances     

Composite effects of reflections and ground bounce for signal line through a split power plane

The signal propagating along a microstrip line over a slot on the power plane will suffer from composite effects of reflected noise by a discontinuity in signal return path and ground bounce between power and ground planes. A new equivalent circuit model is proposed and simulations are performed for multilayer structures to characterize these composite effects. An experimental setup is devised to demonstrate significant coupling between signal lines due to the slot-induced ground bounce. Favorable comparison between the simulation and measured results validates the proposed equivalent circuit model and analysis approach.     

Mutual coupling between circular waveguide-fed apertures in a rectangular ground plane

A method is presented whereby the infinite ground plane analytical model for the self- and mutual admittances of waveguide-fed apertures can be supplemented (using the geometrical theory of diffraction) to include the edge effects of a rectangular ground plane. TheH-plane coupling between twoTE_{11}mode excited circular apertures is calculated and compared with measurements.     

电磁带隙结构在抑制电源层上噪声的应用

本文在阐述电磁带隙结构的基础上,从理论上分析其原理,结合印制电路板电源层存在的瓶颈,即目标阻抗随着设计频率的不断上升而变得越来越难控制。电磁带隙结构最早应用在天线结构中,而本文引用到PCB板电源完整性的设计中来达到抑制高频谐振的目的,并且通过Slwave建模仿真验证了其正确性。     

Accurate power supply and ground plane pair models [for MCMs]

In this paper, we derive a theory and method for the use of two-dimensional (2-D) discrete transmission lines (TL's) or discrete coupled transmission lines (CTL's) in modeling power supply and ground planes accurately. If the stray coupling between power or local ground and global ground is not significant, the discrete TL's model is used. Otherwise the discrete CTL's model is used. An arbitrarily shaped plane pair is discretized into a 2-D TL or CTL array by an automatic mesh algorithm. The equivalent distributed circuit, including skin loss effect at high frequencies, represents this power ground plane pair. The theory is extended to be applicable to a generic multiple dielectric layer structure. The model computation results are in excellent agreement with S parameter measurements for practical frequency ranges, including the first major resonant nulls and peaks. The null or peak of the S parameter frequency response represents the test port interaction with the resonant standing wave of these planes at that frequency. The resultant S parameter data of these models can be condensed into a simpler N port equivalent circuit to represent a larger hierarchical power and ground plane network for fast simulation     

Analysis and suppression of SSN noise coupling between power/ground plane cavities through cutouts in multilayer packages and PCBs

The authors introduced a model of simultaneous switching noise (SSN) coupling between the power/ground plane cavities through cutouts in high-speed and high-density multilayer pack-ages and printed circuit boards (PCBs). Usually, the cutouts are used in multilayer plane structures to isolate the SSN of noisy digital circuits from sensitive analog circuits or to provide multiple voltage levels. The noise-coupling model is expressed in terms of the transfer impedance. The proposed modeling and analysis results are compared with measured data up to 10 GHz to demonstrate the validity of the model. It is demonstrated that the cutout is the major gate for SSN coupling between the plane cavities, and that substantial SSN coupling occurs between the plane cavities through the cutout at the resonant frequencies of the plane cavities. The coupling mechanism and characteristics of the noise coupling, from which a method of suppression of the SSN coupling evaluated was also analyzed and discussed. Proper positioning of the cutout and the devices at each plane cavity achieves significant noise suppression at certain resonant frequencies. The suggested suppression method of the SSN coupling was successfully proved by frequency domain measurement and time domain analysis.     

Analysis of power delivery network constructed by irregular-shaped power/ground plane including densely populated via-hole

The high speed and low power trend has imposed more and more importance on the design of the power distribution network (PDN) using multilayer printed circuit boards (PCBs) for modern microelectronic packages. This paper presents a fast and efficient analysis methodology in frequency domain for the design of a PDN with a power/ground plane pair, which considers the effect of irregular shape of the power/ground plane and densely populated via-holes. The presented method uses parallel-plate transmission line theory with equivalent circuit model of unit-cell grid considering three-dimensional geometric boundary conditions. Characteristics of PDNs implemented by perforated planes including a densely populated via-hole structure is quantitatively determined based on full-wave analysis using the finite-difference time-domain (FDTD) periodic structure modeling method and full-wave electromagnetic field solver. Using a circuit simulator such as popularly used SPICE and equivalent circuit models for via-hole structure and perforations, the authors have analyzed input-impedance of the power/ground plane pair. Since the presented method gives an accurate and fast solution, it is very useful for an early design of multilayer PCBs.     

Net and partial inductance of a microstrip ground plane

A knowledge of the net inductance of the ground plane can aid in the analysis and investigation of printed circuit board emissions. In this paper, we present a method, based on the concept of partial inductance, to determine the net inductance of the ground plane associated with a microstrip line. This method is based on a previously derived expression for the current density on the ground plane. We show calculations for the net, self-partial, and mutual-partial inductance of the ground plane for various trace geometries of practical interest. We also illustrate how the classical transmission line inductance of a microstrip line can be obtained from the concept of partial inductance. Comparisons to different experimental results are also given     

A helical-beam antenna without a ground plane

The helical-beam antenna (a.k.a. axial-mode helix), which the author devised in 1946, was fed via a ground plane. This arrangement has proven very satisfactory for many applications. Now, almost 50 years later, he presents a version in which the ground plane is replaced by one or more loops. This design is well suited for pole mounting. It has less wind resistance, and presents a much-cleaner appearance, while providing equivalent performance to a helix with ground plane. The new version retains the broadband and non-critical nature of the ground-plane helix to a marked degree     

Skywave propagation over a multisection plane ground

The ground-loss profile along the path of a skywave for a sectionally homogeneous ground is investigated by means of the compensation theorem. A recurrence procedure, which is suitable for numerical work, has been satisfactorily tested against recent experimental results concerning m.f. skywave propagation over a path in South-East England, extending to 300 wavelengths from the shore.     

Influence of a floating plane on effective ground plane inductancein multilayer and coplanar packages

The impact of a floating metal layer on the effective ground plane inductance has been investigated in both multilayer (ground planes) and coplanar (ground conductors) packages. For the multilayer case, both thick and thin film geometries were examined, and the results were compared to a thin film coplanar configuration. It was seen that the floating plane actually increases the ground plane inductance in the multilayer case and decreases the ground plane inductance in the lead frame case. Examining the current density in the floating and ground plane and the ground's partial self-inductance and ground-signal partial mutual inductance give a detailed explanation for this phenomenon     

An electromagnetic crystal power substrate with efficient suppression of power/ground plane noise on high-speed circuits

An electromagnetic crystal power substrate (ECPS) in a high-speed circuit package is proposed for suppressing the power/ground planes noise (P/GPN) and the corresponding electromagnetic interference (EMI). The ECPS is simply realized by periodically embedding the high dielectric-constant rods into the conventional package substrate between the continuous power and ground planes. With a small number of embedded rods and low rod filling ratio, the proposed ECPS design can efficiently eliminate the noise of 30dB in average within several designed stopbands. In addition, the radiation or EMI resulting from the P/GPN is also significantly reduced over 25dB in the stopbands. The excellent noise and EMI suppression performance for the proposed structure are verified both experimentally and numerically. Reasonably good consistency is seen.     

A novel power plane with super-wideband elimination of ground bounce noise on high speed circuits

A novel L-bridged electromagnetic bandgap (EBG) power/ground planes is proposed with super-wideband suppression of the ground bounce noise (GBN) from 600Mz to 4.6GHz. The L-shaped bridge design on the EBG power plane not only broadens the stopband bandwidth, but also can increase the mutual coupling between the adjacent EBG cells by significantly decreasing the gap between the cells. It is found the small gap design can prevent from the severe degradation of the signal quality for the high-speed signal referring to the perforated EBG power plane. The excellent GBN suppression performance with keeping reasonably good signal integrity for the proposed structure is validated both experimentally and numerically. Good agreement is seen.     

A novel uniplanar compact photonic bandgap power plane with ultra-broadband suppression of ground bounce noise

A novel /spl pi/-bridged photonic bandgap (PBG) power/ground planes is proposed with ultra-broadband suppression of the ground bounce noise(GBN) in the high-speed printed circuit boards. The S-parameters of the proposed low-period structures show that the novel uniplanar compact photonic bandgap (UC-PBG) structures could omni-directionally suppress the GBN in RF/analog circuits and digital circuits. The high omnidirectionally suppressions of the GBN for the proposed structure are validated both experimentally and numerically in the noise bandwidth from 300MHz to 6GHz, almost the whole noise band.     

Remote detection of a thin slit in a thick ground plane

A method for detecting a thin slit in a thick ground plane is discussed. The method is based upon detecting the slit resonances which occur when the thickness of the ground plane is approximately an integer order of half-wavelengths. A theoretical model for the scattering from a two-dimensional slit by a short current element is also described. Both theory and experiment display the slit resonances.     

Broadband probe-fed patch antenna with a W-shaped ground plane

A new design of a broadband probe-fed patch antenna with a W-shaped ground plane is presented. The W-shaped ground plane is obtained by bending the conventional planar ground plane into an inverted V-shape, seen in the resonant direction of the patch antenna and then adding proper flanges at the two straight edges of the bent ground plane. The proposed design is applicable to the patch antenna with a planar radiating patch with a thin air substrate. With the use of the proposed W-shaped ground plane, the required probe-pin length in the substrate remains small, although the effective substrate thickness is significantly increased, resulting in a much wider operating bandwidth. Also, by choosing proper dimensions of the W-shaped ground plane, the antenna gain for frequencies over the obtained wide bandwidth is enhanced, compared to the conventional patch antenna with a planar ground plane. In addition, the cross polarization is also reduced for the proposed design and the cross-polarization level (XPL) in the H-plane pattern can even be better than that of a conventional probe-fed patch antenna with a thin air substrate     

TM-wave radiation from grooves in a dielectric-covered ground plane

This article describes the radiation characteristics from multiple rectangular grooves in a dielectric-covered ground plane. The theoretical far-zone radiation pattern is compared with the measured data at 10 and 11 GHz using a wavenumber conversion procedure