Get BOOK. Author : Robert C. Microwave pillboxes. Microwave Scanning Antennas. Edited by R. Firstly, given that the ground plane 88 acts as a reflector, the assembly is more directed. Secondly, it is possible to place two pairs of radiating elements as in 84 not shown in a co-located manner. In this regard, a second pair of radiating elements as in 84 is positioned at right angles to the first pair of radiating elements as in 84 with provision of a second hole machined or otherwise formed in the substrate and a second co-axial connector both not shown.
From these modifications, an antenna 14 having an APS configuration is constructed and resistively loaded to achieve a broadband and compact design. Referring to FIGS. Although the total width of the antenna 14 , i. Although the antenna behaviour is significantly improved compared to the first evolved design of FIG. The antenna width is also the same as in the previous design. In the design shown in FIG. As a result, the lossy path, which the current travels before it intercepts a discontinuity, is made longer.
The lossy resistive area 82 is therefore reduced and the total antenna width is reduced, illustratively to 16 mm. As mentioned herein above, different taper profiles other than elliptical e. In this case, the antenna performance will depend on the rate of the flare opening of the radiating element Moreover, as seen on FIG. The antenna geometry illustrated in FIG. Another key advantage resides in the strong forward-region radiation pattern, which makes the antenna 14 a good candidate for cross-polarized card-array arrangements.
Indeed, as described herein above and seen in FIG. Although the present invention has been described hereinabove by way of specific embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims. A micro strip antenna for terminating a transmission line comprising a pair of conductors, said antenna comprising: a planar substrate fabricated from a dielectric material; and.
The antenna of claim 1 , wherein each of said like elements further comprises a dissipating portion on said planar substrate, said dissipating portion comprising an elongate resistive strip interconnected to said conductive strip along an edge at said wide end, said elongate resistive strip of a second constant thickness and comprising second arcuate side edges mutually converging between said wide end and a tip and wherein each of said second arcuate side edges is a differentiable continuation of a respective one of said first arcuate side edges.
The antenna of claim 1 , wherein each of said like elements further comprises an elongate feed positioned lengthwise between said narrow end and said respective one of the pair of conductors, said feed comprising a conductive strip of said constant thickness and having a constant width substantially the same as said narrow end.
The antenna of claim 1 , wherein the transmission line is unbalanced and wherein one of said elements further comprises a balun between said narrow end and the respective one of the pair of conductors. The antenna of claim 1 , wherein each of said pair of first arcuate side edges has a taper profile selected from the group consisting of elliptical and exponential.
The antenna of claim 1 , wherein the micro strip antenna is coplanar and each of said elements are on the same surface of said planar substrate. The antenna of claim 1 , wherein the micro strip antenna is antipoidal and each of said elements are on opposite surfaces of said planar substrate. The antenna of claim 1 , wherein said planar substrate is a printed circuit board and said first element and said second element are formed by depositing a conductive layer on said planar substrate.
A system for detecting the presence of a region having a first dielectric constant within a medium having a second dielectric constant different from the first dielectric constant, said system comprising: a support fabricated from a material having a dielectric constant substantially the same as the second dielectric constant;.
The system of claim 9 , wherein processing said backscatter returns to detect the region comprises analysing said backscatter returns using an image formation algorithm to form an image of the region within the medium, said image. The system of claim 9 , wherein said scanner array is rotationally symmetric. The system of claim 9 , wherein said region is an abnormality, said medium is a fatty tissue and said support comprises a hollow bowl like portion configured to receive the fatty tissue therein.
The system of claim 12 , further comprising a liquid filled impedance matching bag positioned between said hollow bowl like portion and the fatty tissue, the liquid having a dielectric constant substantially equal to the second dielectric constant.
The system of claim 12 , wherein the fatty tissue is a breast of a patient and further comprising a brassiere designed to receive the hollow bowl like portion, said brassiere holding said snuggly against the patient. The system of claim 9 , wherein each of said scanning elements comprises a pair of wideband antennas, each of said antenna pairs comprised of a first antenna arranged orthogonal to a second antenna, wherein said backscatter returns are comprised of co-polarized backscatter returns and cross-polarized backscatter returns and further wherein when said first antenna of each of said antennas pairs is excited by said source of microwave pulses, said analyzer receives said co-polarized backscatter returns via at least one of said first antennas and said cross-polarized backscatter returns via at least one of said second antennas.
The system of claim 12 , wherein said hollow bowl comprises a moveable portion and a fixed portion concentric with said moveable portion about a bowl axis, said fixed portion for positioning between the fatty tissue and said moveable portion, said moveable portion adapted for rotation about said bowl axis and wherein said plurality of scanning elements are imbedded in said moveable portion along an arc extending between a bowl rim and a bowl apex.
The system of claim 16 , further comprising an actuator for rotating said moveable portion about said bowl axis through out a plurality of positions, said actuator under control of said analyzer for selecting a series of said plurality of positions, and further wherein each of said scanning elements emits said microwave pulses and receives said backscatter returns at each of said series of positions.
The system of claim 9 , wherein processing said backscatter returns comprises applying an image formation algorithm to said backscatter returns in order to determine a location of the region and form an image of the region. The system of claim 18 , wherein processing said backscatter returns further comprises removing artefacts from said backscatter returns prior to applying said image formation algorithm. A scanning element for use in a microwave scanning system, comprising: a pair of like substantially flat wideband antennas, each of said antennas comprising a planar substrate fabricated from a dielectric material, a pair of radiating elements arranged on a surface of said substrate and a balun;.
The scanning element of claim 20 , having a bandwidth between 1 GHz and 11 Ghz. The scanning element of claim 20 , wherein said radiating elements are arranged in a bowtie configuration. USP true USB2 en. Uwb microwave imaging system with a novel calibration approach for breast cancer detection.
In vivo attachable and detachable end effector assembly and laparoscopic surgical instrument and methods therefor. Microwave antenna apparatus, systems and methods for localizing markers or tissue structures within a body.
Handheld and portable scanners for millimeter wave mammography and instant mammography imaging. Microwave antenna apparatus, systems, and methods for localizing markers or tissue structures within a body. Systems and methods of 4D electromagnetic tomographic EMT differential dynamic fused imaging. Compressible jaw configuration with bipolar RF output electrodes for soft tissue fusion. Method and apparatus for three dimensional reconstruction of a joint using ultrasound.
Apparatus, systems, and methods for localizing markers or tissue structures within a body. Isolation coupling type waveguide-to-microstrip conversion device and implementation method. Electrosurgical end effector assemblies and electrosurgical forceps configured to reduce thermal spread. Real-time 3-D ultrasound reconstruction of knee and its implications for patient specific implants and 3-D joint injections. EST3 en. Method of transferring rotational motion in an articulating surgical instrument.
USDS1 en. Wide band dipole radiating element with a slot line feed having a Klopfenstein impedance taper. Marconi Aerospace Systems Inc. Advanced Systems Division. EPB1 en. UWB microwave imaging system with a novel calibration approach for breast cancer detection.
Methods of identifying and locating tissue abnormalities in a biological tissue. Li et al. USA en. Gibbins et al. A comparison of a wide-slot and a stacked patch antenna for the purpose of breast cancer detection.
Nilavalan et al. Salvador et al. Microwave method and system to detect and locate cancers in heterogenous tissues. Islam et al. A low cost and portable microwave imaging system for breast tumor detection using UWB directional antenna array. Abbak et al. JPB2 en. Jafari et al. WOA1 en. Wang et al. EPA2 en. Surface identification using microwave signals for microwave-based detection of cancer.
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Investigating a double layer Vivaldi antenna design for fixed array field measurement. The general crosssectional shape of the said thin layer of the second dielectric substance is that of an isosceles triangle which has a small base and a great height and which, if required, may be truncated on the apex side, thus giving it the shape of an elongated trapezium.
The surface waves are propagated parallel to the base of the triangle and are deflected, as by means of a prism. A magnetic field is created in the direction of the altitude of the triangle and the variations of the intensity of this field vary the angle of deflection by the prism. The invention will be better understood on reading the following detailed description with the aid of the accompanying drawings, of which Fig.
The antenna is supposed to have been placed beneath the wing of an airplane, the plate 1 of which constitutes the intrados. A recess 2 is made in this plate for placing the antenna therein, and the latter is fixed to the wing by screws 3. A feeder 4, which is represented in the form of a rectangular guide, connects a microwave transmitter-receiver unit 5 to the antenna.
This feeder is extended by a sectoral horn 6 which has two parallel faces 7 and 8 and two divergent faces 9 and The mouth of said horn is located in a plane which makes a small angle, of a few degrees, with its axis.
It results from the obliquity of the mouth plane of the horn that, among the two parallel faces, one 8 has an extension sharply shorter than the other one 7. A sheet 11 of dielectric substance covers the metallic face 7.
It is in contact with the atmosphere by means of a surface 12 which is the mouth plane of the horn and its thickness with reference to the face 8 of the face 7 decreases from the edge of face 8 to the edge of face 7 of the horn.
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