Showing papers on "Microstrip published in 1995"

Microstrip antennas : the analysis and design of microstrip antennas and arrays

Abstract: Microstrip antennas: the analysis and design of microstrip antennas and arrays , Microstrip antennas: the analysis and design of microstrip antennas and arrays , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Small microstrip patch antenna

Abstract: As stated in Chapter 1, one of the many advantages of microstrip patch technology over its competitors is its low profile and hence small volume. Another key advantage of this printed antenna is the relative ease in which it can be connected to the feed network, as was highlighted in Chapter 2. For these reasons antenna design engineers deduced that microstrip patch antennas could be utilized for applications requiring where there was very limited space to mount the antenna. One such global application is for wireless communication handset terminals.

Dual-band slot-loaded patch antenna

Abstract: A new patch antenna is analysed which provides dual-frequency operation by means of two narrow slots close to the patch radiating edges. The two modes of operations show similar radiating properties. The ratio between the two frequencies can be well controlled within a range varying from 1.6 to 2, by using simple semi-empirical formulas derived from a physical model and tested by using a fullwave analysis. To obtain a more extended range of this frequency ratio, two tuning microstrip stubs are introduced on a back substrate. Satisfactory performances of simultaneous matching when using a single feed point is demonstrated. Several measurements are shown for both the input impedance and the radiation pattern.

Broadband patch antennas

Abstract: Part 1 General background: microstrip structures waves on microstrips microstrip lines significant advantages main design problems. Part 2 Microstrip antennas: patch resonators antenna feeds simple models broadbanding. Part 3 SSFIP principle: description of structure material properties design principles examples of realization. Part 4 Theoretical developments: Maxwell's equations potentials and wave equations free space Green's function boundary conditions stratified Green's function method of moments mixed potential integral equation finite size antenna. Part 5 Dual polarization antennas: definitions scattering matrix dual polarization circular polarization. Part 6 Antenna arrays: periodic arrays broadside arrays shaped beams. Part 7 Fabrication techniques: the substrate metallization photolithographic process feed layout design. Part 8 Measurement techniques: circuit measurements antenna measurements substrate properties near fields.

Design and performance of a microstrip reflectarray antenna

Abstract: Microstrip reflectarray antennas present an alternative to conventional directive antennas in that they are flat, inexpensive, easy to install and manufacture, conformal to the mounting surface, easy to package, and they possess high power and beam steering capabilities. For the first time, a comprehensive, experimentally verified design procedure for the microstrip reflectarray is presented. In this design procedure, the microstrip reflectarray has been shown to be an effective linear array capable of beam switching and dual polarization. The design procedure also allows the array to be fed from a feed-horn offset at any given angle to the plane of the array. The design procedure is well suited for CAD programs. >

Bandpass characteristics of new dual-mode microstrip square loop resonators

Abstract: A new type of dual-mode microstrip square loop resonator is proposed for the design of compact microwave bandpass filters. The associated characteristics of mode splitting are described. A novel bandpass filter, consisting of such a dual-mode resonator having a 1.2% bandwidth at 1.52 GHz was designed and fabricated. The measured filter performance is presented.

Bandwidth study of microstrip reflectarray and a novel phased reflectarray concept

Abstract: A microstrip reflectarray is a flat reflector antenna that can be conformally mounted onto its supporting structure without consuming a significant amount of real estate and without adding significant mass. The article concentrates on the bandwidth study of a form of reflectarray that uses identical patches with different-length transmission delay lines attached to compensate for the spatial phase delays. This antenna suffers from one major shortcoming, its limited bandwidth. A new concept of mechanically phased reflectarray is also presented.

Micro-patch antenna connected to circuits chips

Abstract: An antenna apparatus comprises: a first chip having: a substrate; a ground film on the substrate; a dielectric film on the ground film; a micro-patch antenna on the dielectric film; a microstrip line extending from the micro-patch antenna; and an in/output microstrip line on the dielectric film; a second chip having a circuit for effecting an operation with the antenna; and a connecting portion for fixing the second chip to the first chip by providing mechanical and electrical connection (flip-chip bonding) between the circuit and the microstrip line and between the circuit and the in/output microstrip line. The substrate comprises a silicon, a GaAs substrate, or a dielectric substrate. The antenna may be provided on the bottom surface of the substrate and be provided on a third substrate also connected by the flip-chip bonding wherein the second chip and the antenna is connected using a through hole. Instead of the through hole, the antenna is coupled to the circuit portion electromagnetically. The substrate may have a hollow portion and the second chip may be accommodated in the hollow portion and the antenna may be provided on a third chip covering the second chip.

Planar antenna array and associated microstrip radiating element

Abstract: The invention relates to radio technology, more specifically to strip antenna arrays used for the direct reception of satellite television broadcasts. The problem addressed by the invention is that of producing a simple, reliable and efficient planar antenna array for receiving signals of differing polarisations, and of producing a microstrip radiating element with double circular polarisation which is highly efficient across a broad frequency band. The proposed planar antenna array is designed as a multiple-layer structure consisting of the following elements arranged one below the other: a dielectric cover (1) with reflecting elements on its inner surface; a conductive layer (5) with a plurality of radiating apertures (4); a dielectric sheet (9) on which are arranged exciter elements and two power circuits for the reception/transmission of signals of differing polarisation; and a screen layer (7). The planar antenna array is also provided with an output waveguide arranged centrally, with two pairs of output probes configured at a right angle in the waveguide cross-section. The proposed microstrip radiating element consists of the following elements arranged one below the other: a conductive layer with radiating aperture; a dielectric sheet on which is mounted an exciter element; and a screen layer. The exciter element is formed by two probes configured at a right angle, a loop arranged on the line bisecting the right angle between the probes, and the conductive region situated at a distance from the point of intersection of the probe axes.

Planar microwave and millimeter-wave lumped elements and coupled-line filters using micro-machining techniques

Abstract: Planar microwave and millimeter-wave inductors and capacitors have been fabricated on high-resistivity silicon substrates using micro-machining techniques The inductors and capacitors are suspended on a thin dielectric membrane to reduce the parasitic capacitance to ground The resonant frequencies of a 12 nH and a 17-nH inductor have been increased from 22 GHz and 17 GHz to around 70 GHz and 50 GHz, respectively We also report on the design and measurement of a new class of stripline filters suspended on a thin dielectric membrane Interdigitated filters with 43% and 5% bandwidth have been fabricated and exhibit a port-to-port 07 dB and 20 dB loss, respectively, at 14-15 GHz The micro-machining fabrication technique can be used with silicon and GaAs substrates in microstrip or coplanar-waveguide configurations to result in planar low-loss lumped elements and filters suitable for monolithic integration or surface mount devices up to 100 GHz >

Design and Characterization of Two-Junction Tuning Circuits for Submillimeter SIS Mixers

Abstract: We report on the continuing development of submillimeter quasi-optical slot antenna SIS mixers which use two-junction tuning circuits [1]. The mixers use 10 kA/cm2 Nb/Al-Oxide/Nb junctions and Nb wiring, and have generated DSB receiver noise temperatures around 5hv/kB to 700 GHz, and 16hv/kB (620 K) at 798 GHz. We present Fourier-transform spectrometer (FTS) measurements and heterodyne measurements on several such devices. In general, the measured response at frequencies below the gap of Nb is in good agreement with the predicted performance. Introduction SIS mixers with Nb-trilayer tunnel junctions offer excellent performance at frequencies below 800 GHz, and should perform competitively at frequencies as high as 1.4 THz [2-5]. Our goal is to develop a suite of ultra-low-noise SIS mixers which cover frequencies from = 400 GHz to more than I THz. At frequencies below the Nb gap (< 700 GHz), existing devices perform quite well [6], but further improvements in noise temperatures remain important. In addition, it is quite useful to be able to predict device performance given the design parameters. One can then optimize the device design for a particular frequency band, and confirm that we indeed understand the physics of the device. Progress in the design and operation of devices in this frequency range is presented below. At frequencies above the Nb gap, RF photons can break Cooper pairs, resulting in greater signal loss and higher receiver noise temperatures. The loss is particularly important in the slender microstrip lines used to resonate the junction capacitance and to transform the antenna impedance down to the RF junction impedance. However, the actual coupling of radiation into Nb junctions above the gap should still be reasonably efficient -more than 30% at 800 GHz [7]. In addition to RF loss, one is also affected by increased dispersion at frequencies near the gap. The Nb microstriplines have therefore been carefully designed to ensure the desired bandpass is achieved. We demonstrate for the first time that all-Nb SIS receivers can have substantially better performance than GaAs Schottky receivers for the astronomically important CI ( P2 — P 1 ) and CO (7-6) transitions near 810 GHz. Receiver Configuration Since waveguide mixers become difficult to construct at short submillimeter wavelengths, we have adopted a quasi-optical approach. Here, lenses take the place of waveguide horns, and the incoming radiation is collected by a planar antenna on the SIS mixer substrate [8]. This offers several other advantages, such as on-chip broad-band silt a SS 114 SSE WA Wa Sta MX Dewar 120 Mylar Window SIS Mixer 295 IQ 77 K Mylar Load Bearnsplitter ICI 1= NZ IC =1 HEN1T Amplifier Polyethylene Lens

High performance circularly polarized microstrip antenna

Abstract: A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array (20) of at least four microstrip radiator elements (22a-22d), each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider (30) impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45° angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

A Ka-band circularly polarized high-gain microstrip array antenna

Abstract: In this article, the development of a circularly polarized microstrip array with 28 dBic of gain at 32 GHz is presented. Two primary objectives of this development are minimizing the microstrip array's insertion loss and maintaining a reasonable frequency bandwidth (3%). The parallel/series feed technique for the array's power distribution circuit and the sequential rotation method for the element arrangement are employed to meet these objectives. >

High-power HTS microstrip filters for wireless communication

Abstract: The performance of narrowband microstrip filters with low insertion loss and high power-handling capabilities made from YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) high-temperature superconducting (HTS) thin films is presented. Results are shown for two different designs that were chosen to optimize the power-handling capability. Both filters have a 2-GHz center frequency and 5 poles that incorporate coupled resonators with 10-/spl Omega/ internal impedances. They were made on 5-cm-diameter LaAlO/sub 3/ substrates. Both designs use parallel-coupled feed lines to avoid current crowding, The first design includes backward- and forward-coupled filters, has 1% bandwidth, and has handled over 25 watts of input power at 10 K with less than 0.25 dB compression. The second design has 1.2% bandwidth and uses only forward-coupled resonators. The dissipation loss is less than 0.2 dB at 45 K and it has a third-order intercept of 62 dBm. Another similar filter handled 36 watts of power at 45 K with less than 0.15 dB compression across the passband. We have developed a technique to visualize the power dissipation of the filter by observing the bubbles created by the filter when submerged in liquid helium, showing areas with local defects or where the current distribution is at its peak value. We also discuss several planar high-power filter issues, including material selection and fabrication, device configuration trade-offs, filter structure optimization, and design approaches to maximize power-handling capacity.

Slot excitation of the dielectric disk radiator

Abstract: Dielectric disk radiators which are excited by a narrow slot in the ground plane of a microstrip line are investigated. The resonance frequencies of the dielectric disk for the HEM/sub 11/ mode are computed numerically in the complex frequency plane. From the later results, the actual resonance frequency and the Q-factor are obtained. The dielectric disk is made of a high dielectric constant ceramic material with /spl epsivsub r/=22. The radiation patterns and reflection coefficients are measured and presented for several slot lengths and dielectric disk dimensions. The radiation patterns are also computed assuming a magnetic current element, which models the slot and excites the HEM/sub 11/ mode. Good agreement is obtained between the computed and measured results. The results presented here also demonstrate the viability of this type of antenna, which has high dielectric constants an efficient radiator provided the proper mode is excited. >

Monolithic planar RF inductor and waveguide structures on silicon with performance comparable to those in GaAs MMIC

Abstract: The monolithic inductors and transmission lines on Si substrate with very high Q factor, low insertion loss, and high resonant frequency, are achieved by using very thick polyimide (10 /spl mu/m) as dielectric material, and thick Al (4 /spl mu/m) metalization system. This structure is made on the finished conventional standard two layer metalization BiCMOS wafer. For 10 nH inductor, 6 GHz resonant frequency, maximum Q factor of 5.5 at 1.2 GHz, and 1.2 dB insertion loss at 3 GHz are obtained, which are very comparable to those available in GaAs MMIC, These inductors can be used as RF choke as well as matching element. Transmission lines are also fabricated using this technology. The S/sub 21/ of coplanar waveguide with 1 mm length is -0.2 dB at 4 GHz, and that of microstrip line is -0.3 dB. It is expected that, using these passive elements, Si RF IC can be designed up to several GHz with performance comparable to GaAs MMIC.

Development of new microstrip pseudo-interdigital bandpass filters

Abstract: A new type of miniaturized microstrip bandpass filter with pseudo-interdigital structure without via hole grounded resonators is described. A very compact filter of this type, having a size smaller than quarter-wavelength by quarter-wavelength at a midband frequency of 1.1 GHz was designed and fabricated. The measured and simulated results are presented. >

Design of microwave filters by inverse scattering

Abstract: A new design method for planar microwave filters based on the theory of inverse scattering is presented. The method results in filters with a continuously changing profile, for example a nonuniform microstrip line with continuously varying width. Filters designed by this method are shown to possess some distinct advantages in realization and performance over other common techniques. The design method is presented in detail, and efficient numerical algorithms to solve the design equations that arise are discussed. A wideband 4 pole Chebyshev bandpass filter was designed, constructed, and tested, to prove the design method. This is the first demonstration of a microwave filter designed using inverse scattering. >

Mixed potential integral equation technique for hybrid microstrip-slotline multilayered circuits using a mixed rectangular-triangular mesh

Abstract: In this paper, a mixed potential integral equation (MPIE) formulation for hybrid microstrip-slotline multilayered circuits is presented. This integral equation is solved with the method of moments (MoM) in combination with Galerkin's method. The vector-valued rooftop functions defined over a mixed rectangular-triangular mesh are used to model the electric and magnetic currents on the microstrip and slotline structures. An efficient calculation technique for the quadruple interaction integrals between two cells in the system matrix equation is presented. Two examples of hybrid microstrip-slotline circuits are discussed. The first example compares the simulation results for a microstrip-slotline transition with measured data. The second example illustrates the use of the simulation technique in the design process of a broadband slot-coupled microstrip line transition. >

Transponder employing modulated backscatter microstrip double patch antenna

Abstract: A reader interrogates a transponder attached to a remote object. The transponder includes a microstrip patch antenna having two segments connected together by a switch, each segment being one-half wavelength, the antenna being a full wavelength at the frequency of the interrogating signal. In response to a control signal, the switch is opened and closed, thereby coupling and decoupling the two segments of the microstrip antenna. When the switch is in the closed position, the two segments are out-of-phase with one another, thereby producing a maximum reflected signal. When the switch is in the open position, the two segments act in concert to produce a minimum backscattered signal. The backscatter signal is thus modulated in accordance with the control signal and is received at the reader where it is subsequently decoded to identify the remote object.

Microstrip antenna with solar cells for microsatellites

Abstract: A microstrip antenna designed for microsatellites with solar cells on the surface has been developed. High-gain antennas require a large surface area of the microsatellite, which reduces the area available for solar cells. By installing high-gain antenna arrays consisting of these microstrip antennas, the area required for solar cells is not reduced because the microstrip antenna has solar cells on its surface. >

Three-dimensional passive circuit technology for ultra-compact MMICs

Abstract: A novel passive circuit technology of a three-dimensional (3-D) metal-insulator structure is developed for ultra-compact MMICs. By combining vertical passive elements, such as a wall-like microwire for shielding or coupling, and a pillar-like via connection with multilayer passive circuits, a 3-D passive circuit structure is formed to implement highly dense and more functional MMICs. O/sub 2//He RIE for forming trenches and holes in a thick polyimide insulator, low-current electroplating for forming gold metal sidewalls in the trenches or holes, and ion-milling with a WSiN stopper layer for patterning the gold metal are used to produce such a structure. The complete 3-D structure provides miniature microstrip lines effectively shielded with a vertical metal-wall, a miniature balun with low-loss vertical wall-like microwires, and inverted microstrip lines jointed with pillar-like vias through a thick polyimide layer. This technology stages next-generation ultra-compact MMICs by producing various functional passive circuits in a very small area.

Study of gain enhancement method for microstrip antennas using moment method

Abstract: The moment method is used to determine the radiation and impedance properties of microstrip patch antennas in multilayered material configurations. The resonance conditions for the layer structure which allow for high gain are studied. The gain, the impedance, the beamwidth, and the bandwidth are discussed. >

Low thermal impedance integrated circuit

Abstract: A frontside ground plane (306) integrated circuit with backside contacts (312) plus optional passive components such as microstrip (308) and capacitors The frontside ground plane provides direct heat dissipation from active junctions such as heterojunction and field effect transistors

Microstrip flexible printed wiring board interconnect line

Abstract: An RF flexible printed wiring board transmission line for connecting strip transmission line microwave assemblies without the use of coaxial connectors and coaxial cables. The flexible transmission line includes a thin flexible dielectric ribbon, having on one side a ground plane layer and on the other side a microstrip conductor strip. Plated through holes at the ends of the flexible line provide access to both the ground plane and conductor strip on the same side of the flexible line, to facilitate interconnection of the microwave assemblies to the flexible line. The flexible line operates at microwave frequencies with little or no radiation leakage.

Microstrip patch antennas using very thin conductors

Abstract: A microstrip patch antenna has a first conductive layer (4) adjacent a dielectric substrate (6). The first conductive layer (4) has a thickness of less than one skin depth of the material of the first conductive layer. A second conductive layer (8) acts as the ground plane for the first conductive layer. A feed network which may comprise a second dielectric substrate (10), microstrip feedline (12) and aperture (14) aligned with the first conductive layer feeds the radiating patch of the first conductive layer.

Canonical microstrip filter using square open-loop resonators

Abstract: A configuration for the realisation of canonical microstrip elliptic function narrow-band bandpass filters is proposed. The new filter configuration consists of two identical arrays of microstrip square open-loop resonators, The two resonator arrays are approximately placed on the same plane so as to allow nonadjacent electric and magnetic couplings to be realised and adjusted. A theoretical investigation has confirmed the feasibility.

System and method for calibrating a ferroelectric phase shifter

Abstract: A ferroelectric phase shifter for shifting the phase of a radio frequency F) signal. The phase shifter includes a conductor line, a ground plane and a ferroelectric element between the conductor line and the ground plane to form a microstrip circuit through which the RF signal propagates. The ferroelectric element has a dielectric constant that can be varied as a function of a DC voltage applied to the ferroelectric element wherein the speed of the RF signal propagating through the ferroelectric element is a function of the dielectric constant. The phase shifter further includes a DC voltage source connected across the conductor line and the ground plane. The DC voltage source applies a variable DC voltage to the ferroelectric element in response to a control signal thereby to vary the dielectric constant of the ferroelectric element. The phase shifter further includes a controller circuit operating at a test frequency having a synchronous detector for detecting changes in the dielectric constant of the ferroelectric element. The controller circuit provides the control signal to the DC voltage source to vary the applied DC voltage as a function of the detected changes. In this manner, changes in the dielectric constant over time are compensated for and the phase shift is maintained substantially constant.

Narrowband lumped-element microstrip filters using capacitively-loaded inductors

Abstract: Coupling between microstrip resonators decreases very slowly as a function of the resonator separation. Therefore, it is difficult to realize narrowband filters (e.g., <0.1% fractional bandwidth) in reasonably sized microstrip form due to the very weak coupling values required. In this paper, we report a class of lumped-element filters that uses capacitively-loaded inductors to give frequency-dependent inductance values. A novel frequency transformation technique is used in the design process. Using this approach, filter bandwidth is determined by the inductance slope of frequency-dependent inductors, dL/d/spl omega/. Large coupling capacitance, thus small coupling element separations, can still be used in narrowband microstrip filters to keep the filter layout compact. We present a 5-pole, 0.27% bandwidth YBa/sub 2/Cu/sub 3/O/sub 7/ high-temperature superconducting thin film microstrip prototype filter at 900 MHz, which has 1.2 dB insertion loss and 20 dB return loss. It was designed with the coupling capacitors of a 1% bandwidth filter, and then transformed to a 0.27% fractional bandwidth using an appropriate inductance slope parameter, dL/d/spl omega/. Measurement showed good agreement with theory.

New uniplanar transitions for circuit and antenna applications

Abstract: New uniplanar microstrip-to-slotline, microstrip-to-coplanar strips (PS) and microstrip-to-coplanar waveguide (CPW) transitions for MIC/MMIC and slotline antennas for phased array applications are described. Such transitions are compact and suitable to be used in an open environment inside a package or a multichip module. The transitions share the concept of using a balun which consists of two microstrip lines connected to a slotline through a pair of coupled microstrips. In this paper, the transitions are studied theoretically using the Finite Difference Time Domain (FDTD) technique and measured experimentally using an HP8510C Network Analyzer. For a back-to-back microstrip-to-slotline transition, an insertion loss of less than 1.3 dB per transition is achieved over a 49% bandwidth with a minimum of 0.6 dB around the design frequency.