Abstract: An antenna device for operating in a predetermined frequency band has a resonator section, a semiconductor section and an antenna section. The resonator section includes a first conductor section, a dielectric section, and a second conductor section for specifying a reference potential against each section which is arranged so as to oppose the first conductor section through the dielectric section. A semiconductor section is arranged so as to be sandwiched between the first conductor section and the second conductor section. The antenna section uses the second conductor section as a grounding conductor, is substantially spherical, makes at least its surface electroconductive, and is arranged on the first conductor section.

Abstract: An integrated multi-band antenna has a first radiating conductor, a second radiating conductor spaced from the first radiating conductor, a trap element connected to the first and second radiating conductors, a third radiating conductor with a first feeding point connected to the first radiating conductor, a fourth radiating conductor connected to the second and third radiating conductors, a meandering radiating conductor having two ends which respectively connect a fifth radiating conductor with a second radiating conductor and a sixth radiating conductor parallel to the meandering radiating conductor and a ground portion arranged close to the first radiating conductor and spaced from the fifth radiating conductor. The second, third and fourth radiating conductors resonate at a first frequency bandwidth. The first, second and third radiating conductor and the trap element resonate a second frequency bandwidth.

Abstract: A low profile antenna has a meander length based on the full electrical wavelength of the signal being transmitted or received. The antenna can have either an open-loop structure or a closed-loop structure with a matching network. The low profile enables the antenna to be used in a card for a device such as a personal computer, personal digital assistant, wireless telephone and so on with minimal risk of the antenna breaking off, as compared with a prior art antenna having a higher height and thus more likelihood of being broken from its card.

Abstract: A J-Pole antenna disclosed including: shunt segment extending out of the plane of the J-Pole antenna. A shunt segment extending out of the plane of the J-pole antenna aids in attaching the antenna to a connector and allowing for a reduction in the size of the antenna and connector. The shunt segment also makes the antenna shorter while preserving the same gain and impedance performance as a conventional J-Pole antenna. A connector plate and connector may be used with the antenna having the shunt segment extending out of the plane of the J-Pole antenna. A protective enclosure may be used with the J-Pole antenna and allowing a radiating antenna segment of the J-Pole antenna to extend from the protective enclosure.

Abstract: A multiband antenna with removed coupling includes a radiator formed as a meander line bent zigzag several times and having a gap filling part in at least one area between neighboring meander lines. The gap filling part interconnects the neighboring meander lines. The multiband antenna further includes a ground connected with the radiator and at least one switch element mounted in an area along the longitudinal direction of the radiator and configured to alternately short or open an area of the radiator. Accordingly, two different resonance frequencies can be tuned using the single antenna, and the antenna efficiency can be enhanced by removing the coupling between the resonant frequencies that are tuned through the gap filling.

Abstract: A mobile wireless communications device may include a housing and a multi-frequency band antenna carried within the housing. The multi-frequency band antenna may include a main loop conductor having a gap therein defining first and second ends of the main loop conductor, a first branch conductor having a first end connected adjacent the first end of the main loop conductor and having a second end defining a first feed point, and a second branch conductor having a first end connected adjacent the second end of the main loop conductor and a second end defining a second feed point. A third branch conductor has a first portion within the main loop conductor, and a second portion connected to the second feed point. A tuning branch conductor may have a first end connected to the main loop conductor between the respective first ends of the first and second branches.

Abstract: A low profile antenna has a meander length based on the full electrical wavelength of the signal being transmitted or received. The antenna can have either an open-loop structure or a closed-loop structure with a matching network. The low profile enables the antenna to be used in a card for a device such as a personal computer, personal digital assistant, wireless telephone and so on with minimal risk of the antenna breaking off, as compared with a prior art antenna having a higher height and thus more likelihood of being broken from its card.

Abstract: An antenna of a mobile communication terminal has a plate-shaped dielectric; a conductor line formed to the dielectric and having a leading end connected to a transceiving section of the mobile communication terminal and a terminal end extendingly formed into a shape curved from the leading end and located at a middle part of the plate-shaped dielectric; and an assistance radiator electrically connected to the terminal end of the conductor line and mounted to surround the plate-shaped dielectric. According to the antenna, since there is provided the assistance radiator, it is possible to shorten the length of the antenna while maintaining the overall length of the conductor line to be same and to improve the average radiation gain of the antenna.

Abstract: Various antenna designs that are small and cost effective are disclosed. In one design, the antenna is a bent and folded monopole antenna. In another design, the antenna is a folded and tapped monopole antenna. In yet another design, the antenna is a folded, bent, and tapped monopole antenna. The antennas may be part of a system using two back-to-back symmetric antennas. The antennas may be part of a modem, such as a wireless computer modem or a wireless handset.

Abstract: A patch antenna (10) includes a dielectric substrate (12), a patch conductor (14) and a ground conductor (18) formed on both surfaces thereof. A step (16) is formed on the lower surface of the dielectric substrate, which makes a spacing between the patch conductor and the ground conductor nonuniform in a direction of length of the patch conductor. By making nonuniform the spacing between the patch conductor and the ground conductor in the direction of length of the patch conductor, radiation efficiency and antenna gain are changed in that direction, resulting in asymmetrical directivity.

Abstract: A Planar Inverted-F Antenna (PIFA) device and a method for controlling the PIFA device that can provide optimized frequency characteristics in a multi-frequency environment. The PIFA device is provided with a plurality of shorting pins located at different distances from a feeding pin and an antenna switch capable of selecting one of the shorting pins, or is provided with an antenna switch capable of moving a shorting pin to a preset position, thereby adjusting a distance between the feeding and shorting points. Antenna frequency characteristics can be optimized according to a frequency band used at the current location, and the antenna frequency characteristics can be optimally maintained in the multi-frequency environment at any time.

Abstract: A wideband monopole antenna including an emitter which is embodied in the form of a disc and vertically arranged at a predetermined spacing above an electrically conductive base plane. The disc-shaped emitter includes a modified section initially having a circular or elliptical disc form, with the modified section being limited by a border outline deviating from the circular or elliptical form.

Abstract: Directional wire antennas for use in article or personal tracking and/or inventory monitoring or control systems wherein the antennas are specifically configured to provide a tunable vertical beam angle which is less than their horizontal beam angle. The antennas are modified or non-balanced dipole or monopole structures having non-symmetrical wire legs wherein at least one leg has segments extending angularly in a linear manner in two separate planes. In preferred embodiments the antennas are designed to receive signals from active RFID (radio frequency identification) tags placed on objects to be monitored within confined or defined structures without bleed over of signals from tags placed on objects at different vertical levels of the structure.

Abstract: An on chip diversity antenna switch includes a first switch, a second switch, a third switch, and a fourth switch. The first switch is operably coupled to a pin associated with a first antenna, to a transmit path and to receive a transmit receive (T/R) control signal. The second switch is operably coupled to the pin associated with the first antenna, to a receive path, and to receive the T/R control signal. The third switch is operably coupled to a pin associated with a second antenna, the transmit path, and to receive the T/R control signal. The fourth switch is operably coupled to the pin associated with the second antenna, to the receive path, and to receive the T/R control signal. Based on the T/R control signal, the first or second antenna is coupled to the transmit or receive path via a single switch.

Abstract: The present invention relates to an integrated glass antenna for an automobile, and more particularly, to an integrated glass antenna for an automobile in which an antenna constructed by incorporating a mobile telematics system (MTS) antenna into a radio and television antenna is integrated into a window glass of the automobile. The integrated glass antenna for the automobile with predetermined pattern conductors spaced apart by a predetermined interval from heating wires on a rear window glass of the automobile comprises a radio antenna connected to a radio circuit of the automobile; a television antenna formed to be spaced apart by a predetermined interval from the radio antenna and connected to a television circuit of the automobile; and an MTS antenna formed to be spaced apart by predetermined intervals from the radio antenna and the television antenna, respectively, and connected to an MTS circuit of the automobile.

Abstract: A small-sized mobile radio has a built-in antenna is high enough to enhance the antenna characteristics. In the mobile radio, a base plate is structured by a section (antenna-housing section) including a supply portion and a short-circuiting portion, for example, of an antenna element which affect the antenna characteristics, and a section (circuit-housing section) which is the rest of the base plate. The antenna-housing section is so positioned so as to keep the built-in antenna high enough, that is, to keep the space between the base plate and the antenna element large enough. On the other hand, the circuit-housing section is positioned toward the back of the cabinet to provide room for a display and a key section.

Abstract: An information processing apparatus utilizes a function of a wireless communication card including a control section and a wireless communication section. The apparatus includes a body, and an antenna supported by the apparatus main body. A slot is provided to the body and configured to detachably insert the card therein. A first connector is provided to the apparatus main body, and configured to connect the control section to the body when the card is inserted in the slot. A second connector is provided to the body, and configured to connect the wireless communication section to the antenna in a state where the card is inserted the slot.

Abstract: A dual band antenna (1) includes a printed wiring board (PWB) (20). The PWB has an antenna trace (10) and a grounding plate (30) respectively disposed on opposite surfaces (20a, 20b) of the PWB. The antenna trace includes a radiating arm (100) and a matching means (13). The radiating arm includes a meandering segment (12) and a linking segment (11). The linking segment links two points of the meandering segment, thereby forming a closed loop. Because of the closed loop, the radiating arm has two transmission paths, one longer path, which does not include the linking segment, and one shorter path, which does include the linking segment. The dual band antenna, therefore, is capable of operating at two different frequency bands because of the two paths of the radiating arm.

Abstract: An M-shaped antenna apparatus includes at least two M-shaped antenna elements, a grounding conductor, and a feeding portion. At least two M-shaped antenna elements includes first and second M-shaped antenna elements respectively having first and second resonance frequencies. The first M-shaped antenna element includes a first transmission conductor; a first radiation conductor connected between one end of the first transmission conductor and the grounding conductor; a second radiation conductor connected between a middle portion of the first transmission conductor and the feeding portion; and a third radiation conductor connected between the other end of the first transmission conductor and the grounding conductor. The second M-shaped antenna element includes a second transmission conductor, a fourth radiation conductor, a fifth radiation conductor, and a sixth radiation conductor in a manner similar to that of the first M-shaped antenna element.

Abstract: A wideband double monopole meanderline loaded antenna having a single feed a single feed is disclosed. Equalizing delay lines of the antenna can be manipulated to equalize reactance of the antenna thereby enabling proper impedance matching.

Abstract: An antenna includes a radiation conductor unit constructed with a plurality of radiation conductors having different lengths which extend in parallel to each other from an electricity-supplying conductor and a grounded conductor unit which opposes said plurality of radiation conductor in an approximately parallel manner with a predetermined distance therebetween. The radiation conductor unit and the grounded conductor unit are contained in an insulating casing constructed by a pair of cases which is fixed to each other. The casing is provided with a plurality of projections for positioning the radiation conductor unit and the grounded conductor unit.

Abstract: An antenna includes at least two radiating conductors disposed in parallel and having different lengths, a feeding conductive section connected to the radiating conductors at the same-side ends in the parallel direction of the radiating conductors, and a grounding conductive plate disposed almost in parallel to the radiating conductors. In the antenna, a plurality of resonance points are generated by the plurality of radiating conductors having different lengths, the overall frequency characteristics of the antenna are improved in the frequency bands corresponding to the plurality of resonance points, and the operation frequency band of the antenna is widened.

Abstract: An elongate radiator conformal antenna for portable communication devices is conformed on or in dielectric. The antenna of the present invention is a conformal antenna having an elongate radiator element grounded to a ground plane generally opposite the elongate radiator element, and driven by a feed connected to the elongate radiator element at a point between its connection to the ground plane and its open end. The elongate radiator element and ground plane are conformed with dielectric which, due to its wavelength shortening effect, reduces the required length of the elongate radiator element to less than a quarter wavelength. The dielectric material with which the antenna is conformed and any additional dielectric material between the elongate radiator element and the ground plane is preferably high permittivity and low loss tangent material.

Abstract: The invention relates to small-sized antenna systems, especially planar antenna structures operating on several frequency bands. The antenna structure of the invention comprises a radiating antenna element with at least two lips. Thus, the antenna structure has two basic resonance frequencies, which are defined by the dimensions of the lips of the antenna element, gaps between them, and the other dimensions of the antenna structure. The radiating antenna structure is connected to the ground plane at least at one place. The radiating antenna element comprises at least two connection points, which are used for connecting the feed lines of the transmitter and receiver, and for connecting special tuning elements. The resonance frequencies of the antenna structure may be adjusted by connecting the said tuning elements to the connection points and antenna feed lines so that the antenna structure is operable on more than two frequency bands.

Abstract: A curved inverted-L and F antenna is disclosed. In a preferred embodiment a curved inverted-F antenna 300 comprising a capacitative line 206 and inductive stub 204 is disposed above a correspondingly curved ground plane 308. Preferably, the separation between the capacitative line 206 and ground plane 308 is substantially constant and of the order of one tenth of the wavelength of the operating frequency of the antenna. Suitably the short circuit element of the antenna and the feed track 402 are non-parallel which has the effect of improving the radiated field in a short circuit direction.

Abstract: An antenna adapted for surface deployment is provided. A coaxial feedline, erminated at one end thereof at a feedpoint, has a center conductor and a shield at ground potential. A continuous length of antenna wire having first and second ends is electrically connected at its first end to the center conductor at the feedpoint. A first portion of the continuous length is spooled adjacent the first end. A second portion of the continuous length is deployed from the first portion by means of tension at the second end. The second portion extends to the second end along a substantially straight line away from the first portion. The second portion is typically at least as long as the first portion. The first portion serves as a variable tuning inductor for the antenna as the second portion is deployed therefrom.

Abstract: A printed antenna structure for transmission of radio frequency energy in the gigahertz range that provides good dispersion characteristics and a relatively wide bandwidth using a thin substrate material. The antenna includes a thin printed circuit board having top and bottom surfaces. The bottom surface features an electrically conductive ground plane layer. The top surface features a microstrip feed line structure which is connected to a radiating element. The microstrip feedline extends over the ground plane but the radiating element does not. The radiating element has a main V-shaped segment for coupling radio energy over a wide spatial region, and a tuning stub is sequentially connected to the V-shaped segment. Overall, the printed antenna has an overall shape which resembles a hook in oder to minimize the space occupied on the printed circuit board.

Abstract: U-dipole radiating elements (10) and associated feed conductors (20, 22) are cut or stamped from brass sheet stock. Each U-dipole (10) is then bent up at 90 degrees to the signal distribution conductor (22) which is supported in front of a reflector (12). The U-dipole element (10) includes a first dipole-type conductor segment (14) connected near one end to a feed segment (20) which is the sole signal feed path to the U-dipole element. A second dipole-type conductor segment (16), which is spaced from and parallel to and coextensive with first segment (14), is connected to the other end of the first segment (14). An antenna may include one or more individual U-dipole elements cut from sheet stock and connected to feed points. In a linear array antenna configuration, a group of U-dipole elements (10a-10b) and associated signal feed network components may be cut in a unitary form from a sheet of conductive material and supported in front of a reflector surface.

Abstract: A physically short broad-bandwidth multiband vertical antenna with 50 ohm input impedance and 25 foot square footprint for 160, 80, 40 and 17 meter radio bands. Low ohmic resistance due to the small physical size combined with system impedance transformation and capacitive input coupling provide radiation resistance corresponding to an efficiency of about 85 percent. The 2:1 SWR bandwidth is 50 kHz on 160 meters and 87 kHz on 80 meters. A 30 foot mast, top hat capacitive load, and a plurality of parallel vertical skirt wires depending from the top hat around the mast are electrically connected together at the top of the mast. An impedance transforming multi-tap coil is connected between mast and ground. Skirt wires are in two sets separately fed at their lower ends by separate coaxial cable coupling capacitors for operation on different bands. A 50 ohm feed line, skirt wires, coupling capacitors and impedance transforming coil all have terminal connections on a mast-base insulator.

Abstract: Improved antennas and antenna systems for use in cellular and other wireless communications systems. A folded mono-bow antenna element is provided which has a substantially omnidirectional radiation pattern in a horizontal plane and shows variation in gain in an elevation plane depending upon the size of an associated ground plane. The folded mono-bow antenna element comprises a main bowtie radiating element and parasitic element wherein the main bowtie radiating element and parasitic element are separated by a dielectric material having a dielectric constant preferably less than 4.5 and, in some cases, less than or equal to 3.3. Various antenna arrays and methods of making the same are also provided.

Abstract: An antenna device for surface mounting has a dielectric base plate, a chassis made of an electrically conductive material and attached to the dielectric base plate, a feed electrode and grounding electrodes. The chassis has a planar radiative part facing the upper surface of the dielectric base plate and side walls at its edges. The side walls are provided with slits which separate portions of the side wall into removable parts. The resonance frequency of the antenna device can be adjusted by cutting off and removing one or more of these removable parts of the side walls. These removable parts can be cut off and removed even after the chassis has been attached to the base plate or the antenna device has been mounted to a circuit board.

Abstract: A wireless electronic module includes a folded monopole antenna having an antenna port impedance which is reactive at the RF frequency of operation and which conjugately matches the reactive impedance of the electronic circuit which connects to the antenna port. A grounded shield is interposed between the antenna and the electronic circuit to reduce RF losses at the antenna.

Abstract: A protected antenna apparatus including an elongated tube; a cable having an upper end with a pair of separate bare leads extending therefrom, a lower end with a connector secured thereto, and an intermediate portion extended between the ends; a twin-lead transmission line having a central axis, a free upper end, a lower end with the bare leads extending therefrom and interconnected together, an intermediate location therebetween wherein each lead is connected with one of the bare leads of the cable, and a notch formed on an upper extent of the line at a location between the intermediate location and the upper end to thereby divide one of the leads into two different pieces and thus create a J-pole antenna having a short leg, a long leg, and an impedance matching stub portion therebetween, and wherein the antenna transmits radio signals of a characteristic frequency as a function of the lengths of the legs and the stub portion; and a coupling mechanism for securing the antenna within the tube and along a long

Abstract: The invention provides for antenna apparatus having antenna members extending parallel to a ground plane, which members are L-shaped and can be provided in advantageously miniaturized form. Two such antenna members can be provided on the same ground plane so as to achieve antenna diversity and a switch mechanism is provided for switching between the antenna member in a receive mode, and for switching to only one of the antenna members for operation of the apparatus in a transmit mode. The switch mechanism is arranged to ground a feed connector of the antenna member that is not selected for transmission or reception so as to render that antenna member passive.

Abstract: An antenna mount 31 consisting of a hollow bulging member is formed so as protrude locally from the top of a portable telephone housing 30. A first antenna 10 with an electrical length of .lambda./4 is provided inside the antenna mount so that the base end Q of the first antenna is connected to a feeder cable 15. A second antenna 20 with an electrical length of 3 .lambda./4 is installed parallel to the first antenna 10 at a prescribed distance from the first antenna so that the second antenna can be freely extended from and retracted into the housing 30 via the antenna mount 31 and so that the base end 23 of the second antenna 20 is connected to the earthing means 32 of the housing 30 when the second antenna is extended from the housing 30, thus providing a J-form antenna formed by the first and second antennas 10 and 20. It is desirable that the first and second antennas 10 and 20 each be equipped with an element-shortening means.

Abstract: A dipole antenna for use in motor vehicles is provided. The antenna comprises a primary linear element, a secondary element extending from the distal end of the primary element in a generally perpendicular manner and a tertiary element extending from the primary element intermediate to the distal end and a breakpoint in the primary element. The antenna generally represents an "F" shape and is electrically insulated from ground. Further, the antenna may be closely spaced to a ground plane portion of the vehicle to which the receiving device is grounded, thereby providing a directional antenna useful in a passive entry system.

Abstract: The invention provides a vehicle window glass antenna for transmission and reception of ultrashort waves used for mobile phones and radios for personal or business use. The antenna forms two classes. An antenna under one class comprises a first element consisting of a vertical conductive strip and a horizontal conductive strip connected to an end of the vertical conductive strip, and a second element consisting of a vertical conductive strip and a pair of horizontal conductive strips one of which is connected to an end of the vertical conductive strip of the second element. The horizontal conductive strips of the second element are disposed adjacently above and under the horizontal conductive strip of the first element so as to wrap around an end portion of the first element.

Abstract: An antenna, particularly a mobile telephone antenna mounted onto the window of a motor vehicle. The antenna comprises a H-shaped ground plane turned to the horizontal plane and a vertical radiator essentially perpendicular to it and mounted at a distance from it. On each side of the vertical radiator there is at least one shadow element parallel to the vertical radiator, the said shadow elements being used to adjust the antenna's impedance to the impedance of the connecting cable to be used.

Abstract: An M-type car antenna for traffic information communication systems including an antenna element having a length which is one-half of the wavelength of the radio way used in the information communication systems, and a connector which is connected via an electrostatic coupling to the center-of the antenna element, the impedance matching and feeding being carried out by the connector. In this antenna, the voltage polarity of the connector at the coupling point and that of the center of the antenna element are set to be opposite from each other, and the electric current in the antenna element and that in the connector are set to be in the same direction. Thus, the M-type antenna is compact and easy to manufacture with stable antenna characteristics.

Abstract: An antenna is provided comprising first (11), second (12) and third (13) line elements dispersed on first, second and third consecutive sides of a rectangle (10). The third line element is longer than the first line element by a length approximately equal to the length of the second line element, thereby providing a radiating portion of the third line element. A feed connector (14) is coupled to the first and third line elements, for applying a radio frequency signal to the antenna for radiating from the second line element and from the radiating portion of the third line element.

Abstract: An antenna (105) for receiving radio frequency (RF) signals includes a conductive element (300) having a first electrical length and a first operating impedance and a transmission line (315) having a second electrical length and a second operating impedance for resonating the conductive element (300) at a predetermined operating frequency. A coaxial element (305) having a third electrical length is coupled to the conductive element (300) and the transmission line element (315) for converting the first operating impedance to the second operating impedance. When the conductive element (300) is resonated, the first, second, and third electrical lengths are substantially equal to a quarter wavelength or an odd multiple thereof at the predetermined operating frequency.

Abstract: The invention provides for antenna apparatus having antenna members extending parallel to a ground plane, which members are L-shaped and can be provided in advantageously miniaturized form. Two such antenna members can be provided on the same ground plane so as to achieve antenna diversity and a switch mechanism is provided for switching between the antenna member in a receive mode, and for switching to only one of the antenna members for operation of the apparatus in a transmit mode. The switch mechanism is arranged to ground a feed connector of the antenna member that is not selected for transmission or reception so as to render that antenna member passive.

Abstract: In a circularly polarized wave microstrip antenna 1, a ground conductor 3 and a radiation conductor 2 are provided respectively on one surface and the other surface of a dielectric substrate 4 for feeding electric power to a feeding point P eccentrically provided on the radiation conductor 2. The radiation conductor 2 is provided with at least one projection 21a through 21d for adjusting the axial ratio at a position of an angle of 45.times.(2N+1).degree. (N: Integer) with respect to a reference line passing through a center point O and the feeding point P on the periphery thereof, and is provided with at least one frequency adjusting projection 22a through 22d at a position of an angle of 90 N.degree. (N: Integer) with respect to the reference line.

Abstract: Planar serpentine antennas disclosed include a generally flat, non-conductive carrier layer and a generally flat radiator of a preselected length and arranged in a generally serpentine pattern that is secured to a surface of the carrier layer. One form of the antenna disclosed that is particularly suited for vehicle transceivers and mounting on a vehicle window in a stick-on fashion has a series of change of direction points characterized by a succession of right angle turns and back folds to obtain substantially the greatest length in the smallest surface area. Another form of the antennas disclosed that are particularly suited for AM/FM radios, stereos, etc. have a sinuous pattern with radiator sections in parallel spaced relation to one another and further are connected at opposite ends in curved back folds.

Abstract: A dual polarization antenna for use on an aircraft, preferably a helicopter or the like, permits practical and reliable high frequency radio communications in a severe non line of sight, nap of the earth flight environment. The antenna comprises both a horizontally polarized component and a vertically polarized component. The horizontally and vertically polarized components are formed of an integral element, which has a bend therein so that the two components have an angular orientation with respect to one another. The horizontally polarized component is oriented in a generally horizontal direction and the vertically polarized component is oriented in a generally vertical direction. Ideally, the horizontally and vertically polarized components are oriented as orthogonally to one another as possible, depending upon the airframe application.

Abstract: A tri-band antenna including an center conducting an inner pipe surrounding the center conductor, an outer pipe surrounding the inner pipe and Teflon provided between the inner and outer pipes.

Abstract: A double-folded monopole is used on a linear antenna to produce a traveling-wave distribution of current. The double fold is positioned one-quarter wavelength from the end of the antenna. The resultant antenna has three radiating elements that are orthogonal with respect to each other. The orthogonal folded dipoles each consist of five segments designed so that the currents have comparable magnitudes and are in phase to provide near hemispherical coverage.

Abstract: A radiating element has two superimposed patches separated by a dielectric layer. At least the lower patch has two opposite concave sides to allow space for the feeder conductor to pass to the other patch without increasing the overall dimensions of the element.

Abstract: A circular polarization antenna whose radiation pattern is in the shape of a body of revolution about an axis and has a radiation minimum in the direction of this axis comprises a reflective conductive surface which is essentially in the shape of a body of revolution about the axis. A rectilinear conductive rod extends axially from a first end at the level of and isolated from the conductive surface to a second end and is connected at its first end to an excitation line. A plurality of radiating arms each have a first part extending in an essentially radial plane from the second end of the conductive rod. This first part is electrically connected at its proximal end direct to the conductive rod and is extended at its distal end by a curvilinear rod typically lying on the surface of a sphere centered at the second end and whose general direction is inclined relative to the radial plane.

Abstract: A collapsible `bedspring` monopole antenna is configured to be effectively non-observable in its collapsed condition and, when deployed, remains sufficiently compact to ensure very low observability characteristics, while providing broadband coverage over a wide viewing aperture. The antenna is comprised of a conductor formed as a tapered helix. One end of the conductor is coupled to an antenna feed. The outer end of the helix is looped around on itself to form a circular loop. A plurality of substantially rectilinear `radials` are soldered to distributed locations around its circular loop, so as to extend outwardly and tangentially from the outer perimeter of the loop and provide `top hat` capacitive matching elements. To define the height of the deployed antenna and to electrically short out plural locations of the helix, a plurality of conductive straps are joined to respective spaced apart locations of the helix.