Showing papers on "Microstrip published in 2002"

Compact and Broadband Microstrip Antennas

Abstract: Preface. 1. Introduction and Overview. 1.1 Introduction. 1.2 Compact Microstrip Antennas. 1.3 Compact Broadband Microstrip Antennas. 1.4 Compact Dual-Frequency Microstrip Antennas. 1.5 Compact Dual-Polarized Microstrip Antennas. 1.6 Compact Circularly Polarized Microstrip Antennas. 1.7 Compact Microstrip Antennas with Enhanced Gain. 1.8 Broadband Microstrip Antennas. 1.9 Broadband Dual-Frequency and Dual-Polarized Microstrip Antennas. 1.10 Broadband and Dual-Band Circularly Polarized Microstrip Antennas. 2. Compact Microstrip Antennas. 2.1 Introduction. 2.2 Use of a Shorted Patch with a Thin Dielectric Substrate. 2.3 Use of a Meandered Patch. 2.4 Use of a Meandered Ground Plane. 2.5 Use of a Planar Inverted-L Patch. 2.6 Use of an Inverted U-Shaped or Folded Patch. 3. Compact Broadband Microstrip Antennas. 3.1 Introduction. 3.2 Use of a Shorted Patch with a Thick Air Substrate. 3.3 Use of Stacked Shorted Patches. 3.4 Use of Chip-Resistor and Chip-Capacitor Loading Technique. 3.5 Use of a Slot-Loading Technique. 3.6 Use of a Slotted Ground Plane. 4. Compact Dual-Frequency and Dual-Polarized Microstrip Antennas. 4.1 Introduction. 4.2 Some Recent Advances in Regular-Size Dual-Frequency Designs. 4.3 Compact Dual-Frequency Operation with Same Polarization Planes. 4.4 Compact Dual-Frequency Operation. 4.5 Dual-Band or Triple-Band PIFA. 4.6 Compact Dual-Polarized Designs. 5. Compact Circularly Polarized Microstrip Antennas. 5.1 Introduction. 5.2 Designs with a Cross-Slot of Unequal Arm Lengths. 5.3 Designs with a Y-Shaped Slot of Unequal Arm Lengths. 5.4 Designs with Slits. 5.5 Designs with Spur Lines. 5.6 Designs with Truncated Corners. 5.7 Designs with Peripheral Cuts. 5.8 Designs with a Tuning Stub. 5.9 Designs with a Bent Tuning Stub. 5.10 Compact CP Designs with an Inset Microstrip-Line Feed. 6. Compact Microstrip Antennas with Enhanced Gain. 6.1 Introduction. 6.2 Compact Microstrip Antennas with High-Permittivity Superstrate. 6.3 Compact Microstrip Antennas with Active Circuitry. 7. Broadband Microstrip Antennas. 7.1 Introduction. 7.2 Use of Additional Microstrip Resonators. 7.3 Microstrip Antennas with an Air Substrate. 7.4 Broadband Slot-Loaded Microstrip Antennas. 7.5 Broadband Microstrip Antennas with an Integrated Reactive Loading. 7.6 Broadband Microstrip Antennas with Reduced Cross-Polarization Radiation. 8. Broadband Dual-Frequency and Dual-Polarized Microstrip Antennas. 8.1 Introduction. 8.2 Broadband Dual-Frequency Microstrip Antennas. 8.3 Broadband Dual-Polarized Microstrip Antennas. 9. Broadband and Dual-Band Circularly Polarized Microstrip Antennas. 9.1 Introduction. 9.2 Broadband Single-Feed Circularly Polarized Microstrip Antennas. 9.3 Broadband Two-Feed Circularly Polarized Microstrip Antennas. 9.4 Broadband Four-Feed Circularly Polarized Microstrip Antennas. 9.5 Dual-Band Circularly Polarized Microstrip Antennas. Index.

Application of the transmission line theory of left-handed (LH) materials to the realization of a microstrip "LH line"

Abstract: Left-handed (LH) materials, first introduced theoretically in Veselago (1968), have spurred considerable excitement since the demonstration of their practical realizability. The unique properties of these metamaterials, verified by full-wave analysis in Caloz et al. (2001), are promising for a diversity of optical/microwave applications, such as new types of beam steerers, modulators, band-pass filters, superlenses, microwave couplers and antenna radomes. However, the LH structures presented so far are impractical for microwave applications, because of their too narrow bandwidth and too lossy characteristics, and alternative theories are desirable to gain a deeper insight into their behavior. We introduce here a transmission line (TL) approach of LH materials (Caloz et al. 2002), provide a method to realize an artificial lumped-element LH-TL and propose a microstrip implementation of this line.

A design of the novel coupled-line bandpass filter using defected ground structure with wide stopband performance

Abstract: In this paper, a novel three-pole coupled-line bandpass filter with a microstrip configuration is presented. Presented bandpass filters use defected ground structure (DGS) sections to simultaneously realize a resonator and an inverter. The proposed coupled-line bandpass filter provides compact size with low insertion-loss characteristic. Furthermore, a DGS shape for a microstrip line is newly proposed. The proposed DGS unit structure has a resonance characteristic in some frequency band. The proposed coupled-line filter can provide attenuation poles for wide stopband characteristic due to resonance characteristic of DGS. The equivalent circuit for the proposed DGS unit section is described. The equivalent-circuit parameters for DGS are extracted by using a three-dimensional finite-element-method calculation and simple circuit analysis method. A design method for the proposed coupled-line filter is derived based on coupled-line filter theory and the equivalent circuit of the DGS. The experimental results show excellent agreements with theoretical simulation results.

Differentially driven symmetric microstrip inductors

Abstract: A differentially excited symmetric inductor that enhances inductor quality (Q) factor on silicon RFICs is presented. Compared with an equivalent single-ended configuration, experimental data demonstrate that the differential inductor offers a 50% greater Q factor and a broader range of operating frequencies. Predictions from full-wave simulations and a physics-based SPICE-compatible model are validated by experimental measurements on an inductor fabricated in a triple-level metal silicon technology. Application of the symmetric inductor to a cross-coupled oscillator improves output voltage swing and phase noise by 75% and 1.8 dB, respectively (for a given power consumption), while chip area is reduced by 35% compared to conventional inductor equivalents.

Printed ring slot antenna for circular polarization

Abstract: A new design of a microstrip-line-fed circularly polarized printed ring slot antenna is proposed. Circular polarization (CP) radiation of the proposed design is achieved by introducing proper asymmetry in the ring slot structure and feeding the ring slot using a microstrip line at 45/spl deg/ from the introduced asymmetry. The asymmetry introduced in the proposed design is a meandered-slot section and the proposed CP design can be applied to printed square and annular ring slot antennas. Prototypes of the proposed design have been implemented. Experimental results show that good CP radiation performances are obtained and the 3 dB axial-ratio CP bandwidths obtained for the square and annular ring slot antennas are about 4.3% and 3.5%, respectively.

Planar inverted-F antenna including a matching network having transmission line stubs and capacitor/inductor tank circuits

Abstract: A small multi-band planar inverted-F antenna (PIFA) includes a metal radiating element that is physically located above a metal ground plane element, and the space therebetween includes a frequency matching network having a microstrip transmission line that connects an antenna feed to a wireless communications device (WCD) feed. The impedance matching network may include a microstrip impedance transformer whose output provides a 50 ohm connection to the WCD. A number of microstrip stubs are connected to the microstrip transmission line. At least some of the microstrip stubs connect to the microstrip transmission line by way of a LC tank circuit. The LC tanks circuits are responsive to different ones of the multiple frequencies to which the PIFA is responsive, and in this manner the impedance matching network is dynamically reconfigured in accordance with the frequency band currently traversing the microstrip transmission line. The LC tanks circuits include discrete capacitors and inductors. A two-shot molding process is used to make a unitary plastic antenna assembly whose second-shot plastic surfaces are metallized in order to provide the antenna's metal elements, including the microstrip circuit pattern of the impedance matching network.

Microstrip Filters for RF/Microwave Applications [Book Review]

Abstract: Time-Domain Computer Analysis of Nonlinear Hybrid Systems by Wenquan Sui My first thought upon picking up Time-Domain Computer Analysis of Nonlinear Hybrid Systems by Wenquan Sui was wondering just what kind of hybrid he was going to discuss. Dr. Sui’s hybrid world consists of bringing together finite difference time domain (FDTD) electromagnetic simulators with circuit level nonlinear device simulators. In spite of the fact that analyzing even a fraction of a printed circuit board can bring an electromagnetic simulator to its knees, there is a continuing drive to create simulators that will reduce more and more of our problems to a number. The bottom line is that we live in an age where we can join the circuit laws of Kirchoff to the electromagnetic formulations of Maxwell and the nonlinear physics of semiconductors and solve the lot on a desktop computer. Dr. Sui’s book takes on the formidable task of joining FDTD electromagnetic analysis with nonlinear circuit analysis. His treatment is application oriented rather than theoretical or historical. Working at Bell Labs, IBM Microelectronics, and Conexant has obviously motivated Dr. Sui toward the practical side of computer-aided design (CAD). This book appears targeted at the professional who uses CAD or develops CAD programs. Each topic is handled in depth, and the book covers a wide range of subjects quickly. This book is not oriented toward classroom

Parallel coupled microstrip filters with suppression of harmonic response

Abstract: Corrugated coupled microstrip lines are proposed to design planar microwave filters with suppression of spurious response at twice the center frequency (2f/sub o/). The corrugated structure is designed to equalize the phase velocities of the two eigenmodes in the propagation direction. The designed bandpass filters have a wide upper stopband with satisfactory attenuation levels. In addition, the symmetry of the passband response is improved. Measured results of two fabricated circuits show that the idea works very well.

Design of lowpass filters using defected ground structure and compensated microstrip line

Abstract: A method to design lowpass filters (LPF) using defected ground structure (DGS) and compensated microstrip line is presented. Using the extracted equivalent elements of DGS and capacitive microstrip line, an LPF having no open stub, high impedance line, and tee- or cross-junction element, is designed. Only two DGS patterns and one broad microstrip line comprise the LPF Simple structure, small size (half of a conventional LPF), less discontinuities, and high power handling capability are obtained through the proposed LPF.

Bi-directional amplifier module for insertion between microwave transmission channels

Abstract: A waveguide bi-directional amplifier module is illuminated by a downstream illumination source and an upstream illumination source. The illumination sources are coupled to an array having waveguide to microstrip converters that provide for upstream and downstream electrical signals. Switchable amplifiers provide for amplification in both directions for the electrical signals and the converters coherently combine the output of the amplifiers to provide increased power to the electromagnetic wave entering the waveguide.

Phase shifter tunable via apertures in the ground plane of the wave guide

Abstract: A phase shifting element adapted to introduce a variable phase shift to an electromagnetic wave includes a transmission line segment (10), such as amicrostrip line segment (1) or a segment of a waveguide, above a ground plane (or waveguide wall) (2). The ground plane or wall (2) includes at least one aperture (3) positioned below the microstrip line or waveguide segment (1). An electrically conductive tuning plate (4) is provided adjacent the ground plane or wall (2) and is movable, toward or away from the ground plane or wall. Movement of the tuning plate (4) provides adjustement of the phase shift introduced to an electromagnetic wave propagated through the waveguide segment.

Application of defected ground structure in reducing the size of amplifiers

Abstract: This letter presents a new technique to reduce the size of microwave amplifiers using a defected ground structure (DGS). The DGS on the ground plane of a microstrip line provides an additional effective inductive component, which enables a microstrip line with very high impedance to be realized and shows slow-wave characteristics. The resultant electrical length of the microstrip line with DGS is longer than that of a conventional line for the same physical length. Therefore, the microstrip line with DGS can be shortened in order to maintain the same electrical length, matching, and performances of the basic (original) amplifier. To confirm the validity of this idea, two amplifiers, one of which is designed using a conventional microstrip line and the other is reduced using DGS, are fabricated, measured, and compared. The performance of the reduced amplifier with DGS is quite similar to that of the basic amplifier, even though the series microstrip lines with DGS are much smaller than those of the basic amplifier by 53.8% and 55.6% at input and output matching networks, respectively.

Forward coupling phenomena between artificial left-handed transmission lines

Abstract: Coupling phenomena between artificial left-handed (LH) transmission lines are explored on the basis of a transmission line approach of LH materials. A LH forward coupler in the form of an ideal lumped-element ladder network is presented and is shown to exhibit strong forward coupling that increases with decreasing of frequency. A quasi-lumped element microstrip implementation of a LH coupler is proposed. It is demonstrated that this coupler requires a shorter coupling length in comparison with the conventional right-handed coupled-line forward couplers, and hence makes the device much more compact.

Characterization of liquid crystal polymer for high frequency system-in-a-package applications

Abstract: Liquid crystal polymer (LCP) is a promising substrate for electronics packaging. In this paper, the high frequency characteristics of LCP were investigated using a microstrip ring resonator to verify the possibility of applying the material in RF packaging. The relative dielectric constant and the loss tangent have been measured. The radiation loss of the ring is considered to accurately determine the loss tangent. A GaAs MMIC switch circuit was fabricated using LCP as substrate to demonstrate the application of this material for system-in-a-package. From the high frequency measurements, it is shown that LCP has low dielectric constant and low loss tangent in the frequency range from 1 GHz to 35 GHz. It is also found that LCP can be used in system-in-a-package applications.

Broadband and compact multi-pole microstrip bandpass filters using ground plane aperture technique

Abstract: A ground plane aperture technique is developed for effective enhancement of the capacitive coupling factor in a parallel-coupled microstrip line (PCML). By applying a so-called 'short-open calibration' (SOC) scheme in the fullwave method of moments (MoM) algorithm, this PCML with two external lines is characterised by an equivalent J-inverter network with its susceptance and two electrical line lengths. Extracted parameters indicate that the coupling factor appears to be frequency-dependent and its maximum value rises rapidly as the aperture is widened. With the introduction of a single microstrip line section between two identical PCMLs, a broadband and compact multi-pole microstrip bandpass filter is proposed for the first time, and its electrical behaviour is studied and optimised on the basis of its equivalent circuit network. The network-based optimised results are confirmed by an EM simulation of the entire filter layout, featuring ultra-broadband and four-pole bandpass behaviour. Further, a single capacitively loaded line section is utilised to formulate a multi-pole bandpass filter, and its electrical effects are also discussed for filter design. The predicted and measured results confirm attractive properties of the proposed multi-pole filter with BW=60%. |S/sub 11/|<-16 dB and 220% wide upper stop-band.

A novel dual-mode bandpass filter with wide stopband using the properties of microstrip open-loop resonator

Abstract: A novel dual-mode microstrip square loop resonator is proposed using the slow-wave and dispersion features of the microstrip slow-wave open-loop resonator. It is shown that the designed and fabricated dual-mode microstrip filter has a wide stopband including the first spurious resonance frequency. Also, it has a size reduction of about 50% at the same center frequency, as compared with the dual-mode bandpass filters such as microstrip patch, cross-slotted patch, square loop, and ring resonator filter.

Wideband bandpass filter design with three-line microstrip structures

Abstract: A systematic procedure is described for designing wideband bandpass filters based on parallel coupled three-line microstrip structures. It starts with modal analysis of a three-line coupled microstrip circuit. A database of modal eigenvoltage coefficients and modal characteristic impedances for a specified value of substrate ɛr is established. The relation between the circuit parameters of a three-line coupling section and an admittance inverter circuit is derived, so that the filters can be synthesised by a standard procedure. As compared with traditional parallel coupled lines, the proposed three-line design has the following two important features for the design of wideband filters: the tight line spacings of end stages can be greatly relaxed; and the stopband rejections are improved. Four filters with fractional bandwidths from 40% to 70% are fabricated on substrates with low and high dielectric constants. Prediction and measurement results are in good agreement.

Wideband smart antenna theory using rectangular array structures

Abstract: Smart antenna techniques at the base station can dramatically improve the performance of the mobile radio system by employing spatial filtering. The design of a fully spatial signal processor using rectangular array configuration is proposed. Two-dimensional (2-D) spatial filters that can be implemented by microstrip technology are capable of filtering the received signal in the angular domain as well as the frequency domain. Furthermore, it has wideband properties and, hence, eliminates the requirement of different antenna spacing for applications including various carrier frequencies. The desired frequency selectivity of the smart antenna can be combined with compensation of the undesired frequency performance of a single antenna element, and the result is quite satisfactory for practical implementation. In addition, if the elements of the array are not perfectly omnidirectional or frequency independent, we can compensate for these deficiencies in the design algorithm. Two different algorithms for calculating the real-valued weights of the antenna elements are proposed. The first algorithm is more complex but leads to sharper beams and controlled performance. The second method is simpler but has wider beam and lower fractional bandwidth. Some computer simulation results demonstrating the directional beam patterns of the designed beamformers are also presented.

Low-Cost and High-Q Millimeter-Wave Resonator Using Substrate Integrated Waveguide Technique

Abstract: A substrate integrated waveguide (SIW) cavity directly coupled to a planar circuit, i.e. microstrip line or coplanar waveguide, is presented. Different coupling topologies and coupling probes are discussed. Empirical equations to predict the resonance frequencies of the cavity are provided. A temperature stability coupling topology were fabricated and measured. Finally, as an example of potential applications, a filter using two SIW cavities was designed and measured.

Contact flexible microstrip applicators (CFMA) in a range from microwaves up to short waves

Abstract: Contact flexible microstrip applicator (CFMA) is a new light-weight microstrip applicator type for superficial and deep local hyperthermia. Typical specimens are developed for operation at frequencies of 434, 70, 40, and 27 MHz. The main common features of CFMA, namely, their flexibility and light weight, as well as their aperture dimensions slightly depend on the operating frequency. Two antenna types are used in CFMAs: inductive antennas with a radiating plane electrical dipole at microwaves, and coplanar capacitive antennas, providing depression of the normal component of the electrical field in the very high-frequency (VHF) and high-frequency (HF) range. The flexibility of the applicators enables one to conform them with curved surfaces. In a bent state of the applicators there arises a focusing effect of energy deposition in deeper located tissues due to linear polarization of the irradiated electromagnetic (EM) field, inherent in CFMA. All CFMA are integrated with silicon water boluses which serve as a matching element, so as a skin cooling agent. Due to this and to the predominance of the tangential electrical component in the radiated EM field, no fat overheating effects are noticed, as a rule. The aperture of the developed applicators overlap the range 160-630 cm/sup 2/ providing effective heating field sizes (EFSs) 64-400 cm/sup 2/, respectively. The most bulky CFMAs with an aperture of (21/spl times/29) cm/sup 2/ operating at the frequency of 434 MHz weigh 0.8 kg and 2.5 kg at 27 MHz. Phenomenological analysis of the radiating systems, as well as experimental evaluation of the applicators are presented. CFMAs operating at frequencies of 434 and 40 MHz are used in clinical practice. CFMA at 70 and 27 MHz are subjected to laboratory clinical investigations.

A compact-size microstrip spiral resonator and its application to microwave oscillator

Abstract: This letter presents a compact size microstrip spiral resonator and its application to a low phase noise oscillator. This resonator has stopband characteristics to be used in the series feedback oscillator topology. The whole circuit area of the proposed resonator is within 1/10 wavelength, which results in the reduction of the circuit area and cost. A 10-GHz oscillator incorporated with this resonator was designed, fabricated and measured. It shows low phase noise performance of -95.4-dBc/Hz at 100 kHz offset.

A novel phase noise reduction technique in oscillators using defected ground structure

Abstract: A new technique to reduce the phase noise in microwave oscillators is developed using the resonant characteristic of the defected ground structure (DGS). Two kinds of oscillators have been designed and measured for the examination of the reduction of phase noise by the DGS. The first adopts the DGS section under the microstrip line at the gate circuit, while the second has only the conventional microstrip line. Measurement shows reduced phase noise by 10-15 dB in the oscillator with the DGS compared to the conventional one.

Flexible interconnect cable with high frequency electrical transmission line

Abstract: A high speed flexible interconnect cable includes a number of conductive layers and a number of dielectric layers. Conductive signal traces, located on the conductive layers, combine with the dielectric layers to form one or more high speed electrical transmission line structures. The transmission line structure may be realized as a grounded coplanar waveguide structure, a microstrip structure, a stripline structure, or the like. The cable can be coupled to destination components using a variety of connection techniques, e.g., direct bonding to a circuit substrate, direct soldering to a flip chip, mechanical attachment to a component, or integration with a circuit substrate. The cable can also be terminated with any number of known or standardized connector packages, e.g., SMA, GPPO, or V connectors.

Design of defected ground structures for harmonic control of active microstrip antenna

Abstract: Photonic bandgap (PBG) structures are usually periodic structures in which propagation of a certain band of frequencies is prohibited. PBG structures for microwave frequencies are applied in planar circuits such as microstrip line and CPW (coplanar waveguide). In this case, they are more frequently termed defected ground structures (DGS). Most of the research performed on DGS has been based on the equivalent circuit consisting of lumped elements, L and C, extracted from EM simulations (see D. Ahn et al., IEEE MTT, vol.49, 2001). In addition, we also consider radiation effects by including resistance, R, in the equivalent circuit. The general 1D periodic structures with N unit cells are analyzed using an ABCD matrix formulation. The effects of the RLC elements of the unit cell, the spacing between the unit cells, and the cell number, N, are investigated in detail. For a design example, a simple 1D DGS with N=2 is designed for harmonic control through a modeling using transmission line theory. This 1D DGS with N=2 is much simpler than the one proposed by Y. Horii and M. Tsutsmi (see IEEE MGWL, vol.9, no.1. p.1895-8, 1999). The proposed approach enables us to design the required DGS quite easily and quickly.

High frequency printed circuit board via

Abstract: A printed circuit board (PCB) via (42), providing a conductor (56) extending vertically between microstrip or stripline conductors (44, 48) formed on separate layers of a PCB, includes a conductive pad (59) surrounding the conductor (56) and embedded within the PCB (40) between those PCB layers. The pad's shunt capacitance and the magnitudes of capacitances of other portions of the via (42) are sized relative to the conductor's inherent inductance to optimize frequency response characteristics of the via (42).

High frequency circuit module

Abstract: A high frequency circuit module for use in an automotive radar or the like, in which RF circuit parts are mounted on both sides of a hard multilayer dielectric substrate, and a transmission line connecting the RF circuit parts provided on both sides is constructed by a via group including a periodical structure or a via having a coaxial structure perpendicular to faces of the multilayer dielectric substrate. As the multilayer dielectric substrate, a hard multilayer substrate using metallic layers as a microstrip line wiring layer, a DC/IF signal line layer, and grounding metal layers for shielding which are disposed on and under the DC/IF signal line is employed. By using the transmission line achieved by a through via having the periodical structure or the through via having the coaxial structure, an electromagnetic wave propagating in parallel between the grounding conductors is confined.

Millimeter-wave microstrip line to waveguide transition fabricated on a single layer dielectric substrate

Abstract: In this paper, the authors propose a new type of microstrip line to waveguide transition that is fabricated on a single layer dielectric substrate. By controlling the size of a matching element and the length of an inserted microstrip line across a waveguide, impedance matching of the transition can be achieved.

Accurate closed-form expressions for the frequency-dependent line parameters of on-chip interconnects on lossy silicon substrate

Abstract: Accurate closed-form expressions for the complete frequency-dependent R, L, G, C line parameters of microstrip lines on lossy silicon substrate are presented. The closed-form expressions for the frequency-dependent series impedance parameters are obtained using a complex image method. The frequency-dependent shunt admittance parameters are expressed in closed form in terms of the shunt capacitances obtained in the low and high frequency limits. The proposed closed-form solutions are shown to be in good agreement with the electromagnetic solutions.

Equivalent circuit modelling of spiral defected ground structure for microstrip line

Abstract: An equivalent circuit for the microstrip line with a spiral defected ground structure (DGS), which is etched on the metallic ground plane, and a parameter extraction method, are presented. The proposed spiral DGS provides steep rejection characteristics with only one spiral-shaped defect. Experimental results show excellent agreement with simulated results of the equivalent circuit and the validity of equivalent circuit modelling for the spiral DGS.