Abstract: A shortened multi-band antenna includes in-line dipoles, selected elements of which having shielded meanderline chokes to be able to switch from an extended dipole at the lower VHF frequencies to a shortened dipole for the UHF band. Additionally, the staggered asymmetric meanderline configuration permits overall size reduction, whereas antenna construction includes an intermediate fiberglass layer over which conductive foil is placed for tuning and for parasitic radiator purposes to improve the gain of the UHF dipole in the upper regions of the band at 450 megahertz. Additionally, at the low end of the 30 megahertz band a sleeve is positioned between the base of the lowest dipole element and ground, with the sleeve provided with two parallel RLC circuits tuned to different bands to improve VSWR at the low end of the VHF band and to eliminate unwanted nulls.

Abstract: A lossless broadband dipole antenna of length L having three collinear parts including a central part and two external parts. The parts are separated by slits, with a first feeding point for the antenna being located at a first end of one of the external parts nearest the slits, and a second feeding point being located at a second end of the other external part nearest the slits. The two feeding points of the antenna at the slits are arranged at a distance d from each other along the length L of the antenna, d/L being chosen such that d L = 0.37 ± 0.04 .

Abstract: A shortened multi-band antenna includes in-line dipoles, selected elements of which having shielded meanderline chokes to be able to switch from an extended dipole at the lower VHF frequencies to a shortened dipole for the UHF band. Additionally, the staggered asymmetric meanderline configuration permits overall size reduction, whereas antenna construction includes an intermediate fiberglass layer over which conductive foil is placed for tuning and for parasitic radiator purposes to improve the gain of the UHF dipole in the upper regions of the band at 450 megahertz. Additionally, at the low end of the 30 megahertz band a sleeve is positioned between the base of the lowest dipole element and ground, with the sleeve provided with two parallel RLC circuits tuned to different bands to improve VSWR at the low end of the VHF band and to eliminate unwanted nulls.

Abstract: The present invention relates to a broadband lossless dipole antenna which is supplied at two supply points (M1, M2, S1, S2) which are symmetrically positioned along the length L of the antenna and at such a distance from each other that d L = 0 , 37 ± 0 , 04.

Abstract: Antenna assembly 100 to be worn by a user includes a low-band dipole antenna (310) and at least one high band dipole antenna (312, 612). The high-band dipole antenna is comprised of a high-band dipole feed (102, 602) interposed at a location along a length of a low-band dipole element (105, 110). The high-band dipole feed divides the first low-band dipole element into a first high-band dipole element (128) and a second high-band dipole element (130). One of the high-band dipole elements (130) is formed as a flexible electrically conductive sleeve. An RF control device (308) is provided for selectively directing RF energy in a high-band to the high-band dipole feed (102), and for selectively directing RF energy in a low-band to the low-band dipole feed (202). A transmission line (113) extends from the RF control device (308) to the high-band dipole feed (102).

Abstract: A multi-feed dipole antenna and method. Provides a volumetrically efficient antenna with wide radiation pattern bandwidth and wide impedance bandwidth that are relatively independent. Driving the antenna at multiple locations provides for a half wavelength dipole antenna with a wider frequency range than any other known fat dipole of similar volume. The apparatus is constructed from brass or any other suitable metal without requiring dielectric loading and without requiring direct coupling on the outside of the tubes. The apparatus utilizes a parasitic center tube with two end tubes that are driven by a collinearly mounted metal rod that is driven from the midpoint. Insulators hold the parasitic tube to the end tubes. The parasitic tube allows for induced currents to flow on the surface of the tube which allow for operation of the dipole over a wide frequency range.

Abstract: A microwave antenna assembly is disclosed. The microwave antenna assembly includes a feedline having an inner conductor, an outer conductor and an inner insulator disposed therebetween and a radiating portion including a dipole antenna having an operative length and an inductor. The inductor is adapted to adjust the operative length of the dipole antenna based on the frequency of the microwave energy supplied to the dipole antenna.

Abstract: In one example, an antenna is disclosed comprising a first, outer conductor, at least one inner conductor within the first outer conductor, and a second outer conductor surrounding the first outer conductor. The second outer conductor may define a plurality of holes therethrough. The at least one inner conductor may comprise a plurality of inner conductors. At least two of the plurality of inner conductors may be connected to each other in series, across a capacitor. At least two of the plurality of inner conductors may be connected to each other in parallel, across a capacitor. The at least one inner conductor may be sufficiently surrounded by the first outer conductor to shield the inner conductor from receiving a radiofrequency signal.

Abstract: In one embodiment, wafer-scale antenna module is provided that includes: a substrate having a first surface and an opposing second surface; a plurality of conductive contact regions extending from the first surface into the substrate towards the second surface; active circuitry formed in the substrate adjacent the second surface, the active circuitry electrically coupled to the conductive contact regions; an insulating layer adjacent the first surface, the insulating layer forming a plurality of vias arranged corresponding to the plurality of conductive contact regions, each via forming an opening at the corresponding conductive contact region; and a plurality of antennas formed on the insulating layer corresponding to the plurality of vias; wherein each via contains an electrical conductor to electrically couple the corresponding contact region to the antenna corresponding to the via, whereby a resulting separation between the driving circuitry and the antennas aids an electrical isolation of the driving cir

Abstract: A flat antenna includes a substrate, a first antenna module having a first grounding unit, a first radiating unit, a first feeding unit and a second radiating unit, and a second antenna module having a second grounding unit, a third radiating unit, a second feeding unit and a fourth radiating unit. The second antenna module is disposed abreast with the first antenna module. The first and the second grounding units, and the first and the third radiating units are disposed on a first surface of the substrate. The first and the second feeding units, and the second and the fourth radiating units are disposed on a second surface of the substrate. The first, the second, the third and the fourth radiating units, which have a first, a second, a third and a forth openings respectively, are electrically connected with the first grounding unit, the first feeding unit, the second grounding unit and the second feeding unit.

Abstract: A multi-feed dipole antenna and method. Provides a volumetrically efficient antenna with wide radiation pattern bandwidth and wide impedance bandwidth that are relatively independent. Driving the antenna at multiple locations provides for a half wavelength dipole antenna with a wider frequency range than any other known fat dipole of similar volume. The apparatus is constructed from brass or any other suitable metal without requiring dielectric loading and without requiring direct coupling on the outside of the tubes. The apparatus utilizes a parasitic center tube with two end tubes that are driven by a collinearly mounted metal rod that is driven from the midpoint. Insulators hold the parasitic tube to the end tubes. The parasitic tube allows for induced currents to flow on the surface of the tube which allow for operation of the dipole over a wide frequency range.

Abstract: A compact SATCOM antenna is provided having an LNA integrated into the radiator body which may be mounted to a handheld satellite radio and articulated with respect to the radio to assume a wide variety of positions for communication with a geosynchronous satellite.

Abstract: A wideband antenna comprised of two or more conductive segments that are parasitically coupled.

Abstract: A thinner portable wireless telephone with a thinner built-in antenna. An antenna unit is composed of a first radiating conductor and a second radiating conductor. The second radiating conductor having about half electrical length of the first radiating conductor is arranged so as to correspond the first radiating conductor from its center to one end in parallel. In addition, one ends of the first and second radiating conductors are electrically connected and power is supplied to around the center of the first radiating conductor and the other end of the second radiating conductor. Only electric current flowing on the external surfaces of the antenna unit causes radio waves. As a result, the space between the first and second radiating conductors can be narrowed, thus making it possible to construct a thinner antenna unit. Thus a portable wireless apparatus can be made thinner.

Abstract: A method of manufacturing a dipole antenna comprises the steps of forming first and second radiating elements on the surface of a flexible substrate, the radiating elements including respective feed points for making operative electrical contact with a feed line including corresponding first and second feed conductors. The radiating elements are arranged on the substrate such that, in use, an input impedance of the dipole antenna is substantially matched to a characteristic impedance of the feed line over a selected frequency band. The flexible substrate is then formed into a substantially cylindrical shape. The resulting antenna comprises an integral dipole antenna member having radiating elements disposed on a surface of a substantially cylindrical substrate. The antenna avoids the need to separately manufacture the radiating elements, and subsequently to assemble the elements to form a dipole antenna.

Abstract: An ultra-broadband antenna system is disclosed. The antenna system is a single tubular antenna structure comprising an asymmetrical dipole fed with a biconical dipole. The biconical dipole covers the high frequency spectrum, while the asymmetrical dipole covers intermediate frequencies. The invention further relates to a combination of the two dipole structures such that together they act as a monopole to cover the low frequency spectrum. A first RF connector attaches to the asymmetrical dipole and the biconical dipole, and a second RF connector excites the combination of the two dipoles as one large monopole. A choke minimizes interference between the asymmetrical/biconical dipoles and the monopole. The resulting frequency span is greater than 500:1, providing operation over the range of 20 MHz to 10 GHz.

Abstract: A compact SATCOM antenna is provided having an LNA integrated into the radiator body which may be mounted to a handheld satellite radio and articulated with respect to the radio to assume a wide variety of positions for communication with a geosynchronous satellite.

Abstract: A vertically polarized traveling wave antenna is omnidirectional, bottom-mounted, and bottom-fed. A robust center coax provides a self-supporting mechanical structure. Multiple dipoles are capacitively coupled to the coax in quads, with a first two dipoles placed on opposite sides of the center coax and spaced by a quarter wavelength along the coax from the second two, which couple at right angles to the first two. This matched-layer spacing cancels the reactive components of the impedances of the dipoles. Beam tilt is readily incorporated over a wide range by adjusting layer spacing to add phase taper. All dipoles are oriented parallel to the coax axis, with opposite “hot” (center coupled) dipole elements oriented oppositely to each other. A radiated signal thus has rotating phase, when viewed from above, but is vertically polarized at each azimuth. A lightweight radome, provided for weather protection, is not needed for structural integrity.

Abstract: An antenna assembly has a lower break assembly and an upper break assembly. Both have a center fed transmission line within a conductive tube, and both are mutually connectable for connecting the transmission lines to each other at a junction. When connected, the lower break assembly and upper break assembly form one pole of a center-fed dipole radiator without significant signal loss through the junction.

Abstract: A dual-band antenna (1) includes a first antenna (2) and a second antenna (3). The first antenna includes a u-shaped first dipole half (11) and an n-shaped second dipole half (12). The first dipole half is disposed above the second dipole half with a space therebetween and the two dipole halves are mirror imaged. The second antenna includes a u-shaped third dipole half (21) and an n-shaped fourth dipole half (22). The first and the third dipole halves are crossly connected with each other at bottom. The second and the fourth dipole halves are crossly connected with each other at top.

Abstract: A mobile antenna includes a center-fed, broadband, dipole radiator, and a coupler assembly for mounting the dipole radiator to a mount. A power matching circuit is connected between the dipole radiator and the coupler assembly to maintain an effective balance of current distribution and impedance in conductive elements of the antenna.

Abstract: A broadband antenna comprises an upper section with an open sleeve dipole radiator to receive and/or transmit signals in a high frequency band.

Abstract: A dual-band antenna (1) includes a first antenna (2) and a second antenna (3). The first antenna includes a first dipole half (11) and a second dipole half (12). The first dipole half is disposed above the second dipole half with a space therebetween and the two dipole halves are corresponding to each other in a lengthwise direction. The second antenna includes a coaxial cable (4) including an inner conductor feeding the first antenna and comprising an exposed extending section (40) acting as a radiating portion of the second antenna, and a ground patch (5) electrically connected with the second dipole half.

Abstract: An antenna includes a differential transmission line and a center conductor, where the center conductor is at least partially contained within the differential transmission line and at least partially protruding therefrom. A first conductive flat element is connected to the center conductor and a flat meander-line structure is integral with the first conductive flat element. In addition, a second conductive flat element is integral with the flat meander-line structure.

Abstract: The coaxial dipole antenna of the present invention has a ground tube made of metal and a coaxial cable. The ground tube has a hollow containing part that the coaxial cable passes through, and an end of the ground tube has a clamping part. The clamping part has a first clamping slice to clamp a jacket of the coaxial antenna and a second clamping slice to clamp a metallic mesh of the coaxial cable. Such coaxial dipole antenna can transmit energy with the coaxial cable. The elements of the coaxial dipole antenna are combined with each other by pressing. Therefore, the coaxial dipole antenna can be manufactured by automation, the product thereof can be increased, and the quality thereof can be controlled.

Abstract: An integrated dual antenna system for Global Positioning System (GPS), Local Area Augmentation System (LAAS), ground based subsystem surface mounted (pole/tower/platform/other) and coaxially stacked (over and under). The dual antenna and receiver system is specifically designed and tuned to receive only the direct GPS satellite ranging signals while highly rejecting the ground multipath (indirect) signals. The upper antenna is a Right Hand Circularly Polarized (RHCP) omni-directional High Zenith Antenna (HZA) with dual obstruction lights and dual air terminals. The lower antenna is an electrically long vertically polarized omni-directional linear phased array having a very sharp horizon cut off and is a Multipath Limiting Antenna (MLA). When the two antennas (MLA and HZA) are mounted together they become the Integrated Multipath Limiting Antenna (IMLA). Interoperability is assured by high RF isolation between antennas.

Abstract: Provided is an ultra-wideband dipole antenna. In one embodiment, the antenna comprises a first outer sleeve, an intermediate sleeve surrounded by the first outer sleeve, a second outer sleeve above the first outer sleeve, a conductive interconnection interconnected the outer sleeves, and an inner coaxial conductor surrounded by the intermediate sleeve. A distance between the first outer sleeve and the intermediate sleeve can be changed for adjusting the generated capacitance for obtaining a required impedance matching in the resonance mode of an antenna operating bandwidth and an ultra-wideband characteristic. The antenna is particularly suitable for operating in a frequency range of 2.1 GHz to 11.7 GHz.

Abstract: A multiband antenna has a lower radiator and several upper radiators, all of which are spaced from each other and disposed on the same longitudinal axis. The lower radiator and the upper radiators form a dipole radiator that resonates in a lower frequency band. The upper radiators form a dipole radiator that resonates in a higher frequency band. Multiple isolation circuits in the upper radiators resonate at different frequencies within the lower frequency band.

Abstract: A multiband antenna has a dipole radiator that resonates in a lower frequency band, and a stacked dual dipole radiator that resonates in a higher frequency band. An isolation circuit, tuned to block signals in the higher frequency band, is connected between one end of the stacked dual dipole radiator and the lower frequency dipole radiator to isolate the higher frequency band from the lower frequency band.

Abstract: Low cost moldable antennas and methods of forming the antennas are described. Elements of the antennas are conductive loaded resin-based material having a conducting wire center. The conducting wire center can be single strand, multi-strand, insulated, or non-insulated wire. The conductive loaded resin-based material comprises micron conductor fibers, micron conductor powders, or in combination thereof homogenized within a base resin host wherein the ratio of the weight of the conductor fibers, conductor powders, or combination thereof to the weight of the base resin host is typically between about 0.20 and 0.40. The micron conductive fibers or powders can be stainless steel, nickel, copper, silver, carbon, graphite, or plated particles or fibers, or the like. The conducting metal wire can be copper, nickel, stainless steel, silver, or the like.

Abstract: A multiband antenna has a lower conductive tube and three or more upper conductive tubes, all spaced from each other and disposed on the same longitudinal axis. A transmission line extends within the lower conductive tube to a first feed point and a second transmission line extends within the lower conductive tube and one or more of the upper conductive tubes to a second feed point. The lower and upper conductive tubes form a dipole radiator centered on the first feed point. The upper conductive tubes form a dipole radiator centered on the second feed point. One or more isolation circuits resonate in only one frequency band for signals transmitted along one of the transmission lines.

Abstract: A cost efficient multi-band antenna, for use with non-harmonically related frequency bands, for example dual Wi-Fi frequency bands. An antenna element extends away from a ground plane. A sleeve positioned coaxial about the antenna element is spaced apart from the antenna element and the ground plane. Dimensions, spacing and dielectric constants of the antenna element, sleeve and any dielectric spacers are selected to tune the antenna to the desired frequency bands. Further, the ground plane may be the radiating element of, for example a GPS module or SDAR antenna to create a triple frequency band antenna assembly.

Abstract: An antenna for generating radiation includes a primary E-field generating circuit and a secondary E-field generating circuit. The primary E-field generating circuit generates a primary E-field in response to a source RF signal being applied to the antenna. The secondary E-field generating circuit generates a secondary E-Field, disposed apart from the primary E-field, in response to the source RF signal and develops an H-field that is in time phase with the primary E-field. This causes the antenna to develop a radiation resistance as an indication of radiation.

Abstract: The invention relates to an antenna of colinear type. It comprises a radiating portion comprising: three substantially rectilinear conductive wire elements that are mutually parallel, comprising a central conductor and two lateral conductors; and 2N radiating zones constituted by alternating first radiating zones and second radiating zones: each first radiating zone further comprising a cylindrical conductive element whose axis coincides with said central wire element and which is electrically connected to both of said lateral wire elements; and each second radiating zone further comprises two cylindrical conductive elements whose axes coincide substantially respectively with the lateral wire elements, said cylindrical elements being electrically connected to said central wire element.

Abstract: An antenna includes a dipole feed, a first dipole element connected to and extending outwardly from the dipole feed, a transmission line extending from the dipole feed in an opposite direction, and a flexible electrically conductive sleeve surrounding the transmission line and connected to and extending outwardly from the dipole feed. The electrically conductive sleeve may thus serve as a second dipole element and as a balun for the antenna. The antenna may by removably fastened to a garment of the user by at least one fastener, and the antenna may be connected to a radio also carried by the user. To enhance broadband performance, the dipole feed may include a broadband matching network, and the antenna may include a noise filter coupled to the transmission line adjacent an end of the flexible electrically conductive sleeve opposite the dipole feed.

Abstract: A double frequency antenna for transmitting and receiving radio signals includes a first substrate and a second substrate. The first substrate has a first surface and a second surface opposing each other. The first surface has a first radiation section to radiate a corresponding first frequency. The second surface has a first ground section. The second substrate has four L-shape corners, and a first surface and a second surface opposing each other. The first surface has a second radiation section to radiate a corresponding second frequency. The second surface has a second ground section.

Abstract: A combined directional beam and omnidirectional antenna comprises a unitary structure having a plurality of antennas being configured and oriented to achieve both directional beam coverage and omnidirectional beam coverage.

Abstract: A multi-band sleeve dipole antenna including a generally axially disposed elongate inner conductor having first and second ends and arranged to be connected at the first end thereof to a modulated signal source, a generally axially disposed intermediate conductor disposed generally coaxially with respect to the inner conductor and arranged to be connected to ground, a generally axially disposed first outer sleeve conductor disposed generally coaxially with respect to the inner conductor and to the intermediate conductor and a generally axially disposed second outer sleeve conductor having a first and second ends disposed generally coaxially with respect to the inner conductor and to the intermediate conductor.

Abstract: A dual-frequency broadband antenna mainly comprises a dipole antenna set and an inductive shield, in which a positive and a negative pole are substantially two cup-like tubular hollow poles spaced out from a distance apart equal to ¼&lgr; of a high frequency band approximately; and the inductive shield is a tube made of an insulating material, having a open end. The dipole antenna set is assembled in a cavity of the inductive shield without contacting the inner rim of the latter.

Abstract: A broadband dual-frequency tablet antenna comprises a set of dipole antennas, a baseplate, and an inductive investing-piece, in which a positive and a negative pole of the antenna-set disposed on the baseplate are composed of cambered narrow straps, respectively; the pole length is set about ¼&lgr; (wavelength) of a low-frequency band while the space between poles is set about ¼&lgr; (wavelength) of a high-frequency band; and the construction including the antenna and the baseplate is entirely invested in the inductive investing-piece. During application, by adjusting the cambered shape of the poles respectively, width of the narrow straps, interval between the narrow straps, and cooperating with inductance of the investing-piece, the harmonic bandwidth of said antenna could be widened to hence obtain the broadband dual-frequency function of the tablet antenna.

Abstract: The present invention relates to a collinear antenna structure. The structure comprises a dipole antenna, a coil, and a set of stacked radiator, wherein the length of the dipole antenna is ½&lgr;, the ground end and the signal end of the dipole antenna are connected to a coaxial cable, the length of the cable line is less than ¼&lgr;, one end of the cable line is connected in series to the top of the signal end, wherein the stacked radiator comprising at least two parallel radiators in series, the length of each radiator is ½&lgr;, the distance between the two radiators is about 1.0 to 4.0 mm, one of the stacked radiator is axially connected in series to the other end of the coil, thus forming the structure of the antenna.

Abstract: A broadband dual-frequency tablet antenna comprises a set of dipole antennas, a baseplate, and an inductive investing-piece, in which a positive and a negative pole of the antenna-set disposed on the baseplate are composed of cambered narrow straps, respectively; the pole length is set about ¼&lgr; (wavelength) of a low-frequency band while the space between poles is set about ¼&lgr; (wavelength) of a high-frequency band; and the construction including the antenna and the baseplate is entirely invested in the inductive investing-piece. During application, by adjusting the cambered shape of the poles respectively, width of the narrow straps, interval between the narrow straps, and cooperating with inductance of the investing-piece, the harmonic bandwidth of said antenna could be widened to hence obtain the broadband dual-frequency function of the tablet antenna.

Abstract: A dual-frequency broadband antenna mainly comprises a dipole antenna set and an inductive shield, in which a positive and a negative pole are substantially two cup-like tubular hollow poles spaced out from a distance apart equal to ¼&lgr; of a high frequency band approximately; and the inductive shield is a tube made of an insulating material, having a open end. The dipole antenna set is assembled in a cavity of the inductive shield without contacting the inner rim of the latter.

Abstract: A parallel fed colinear dipole array antenna for broadcasting and receiving a signal of a selected wavelength. The antenna comprises a plurality of elongate dipole antennas attached end-to-end in a linear array. A power divider divides and transmits a signal in parallel to each of the dipole antennas. The linear spacing of the dipoles is correlated with the dimensions of the dipoles and the selected wavelength, such that the signals of the dipole antennas interfere with each other when broadcast, so as to focus signals which propagate substantially perpendicularly to the linear array, and to diminish other signals.

Abstract: A substance structure of a dual-band dipole antenna, it consists of: an internal conductor, which is formed by a lead coated with an internal insulation layer; an external conductor, which is formed by a grounding layer coated or coiled to the said internal insulation layer, and an external insulation layer coated to the grounding layer; and a metal tube with a tip connected with the external conductor; thus, by means of the exposed end section of the internal conductor that is diverged into two branches, a dual-band dipole antenna is accomplished.

Abstract: A substance structure of a dual-band dipole antenna, it consists of: an internal conductor, which is formed by a lead coated with an internal insulation layer; an external conductor, which is formed by a grounding layer coated or coiled to the said internal insulation layer, and an external insulation layer coated to the grounding layer; and a metal tube with a tip connected with the external conductor; thus, by means of the exposed end section of the internal conductor that is diverged into two branches, a dual-band dipole antenna is accomplished.

Abstract: The present invention relates to a collinear antenna structure. The structure comprises a dipole antenna, a coil, and a set of stacked radiator, wherein the length of the dipole antenna is ½&lgr;, the ground end and the signal end of the dipole antenna are connected to a coaxial cable, the length of the cable line is less than ¼&lgr;, one end of the cable line is connected in series to the top of the signal end, wherein the stacked radiator comprising at least two parallel radiators in series, the length of each radiator is ½&lgr;, the distance between the two radiators is about 1.0 to 4.0 mm, one of the stacked radiator is axially connected in series to the other end of the coil, thus forming the structure of the antenna.

Abstract: A whip antenna with switchable operative length provides seven band coverage from 30 to 90 MHZ. A coaxial choke section below a fixed upper antenna element is used for the highest frequency band. A series of four coaxial line sections are switchably coupled below the choke section to increase its operative length for operation in bands of successively lower frequency. One or more lumped constant non-coaxial transmission line sections are switchably coupled below the coaxial line sections for operation in the two lowest frequency bands. Dipole level gain is provided with low reflections loss. Increased height gain is provided by height of operative antenna elements employed at higher frequency bands.

Abstract: A multi-band sleeve dipole antenna including a generally axially disposed elongate inner conductor having first and second ends and arranged to be connected at the first end thereof to a modulated signal source, a generally axially disposed intermediate conductor disposed generally coaxially with respect to the inner conductor and arranged to be connected to ground, a generally axially disposed first outer sleeve conductor disposed generally coaxially with respect to the inner conductor and to the intermediate conductor and a generally axially disposed second outer sleeve conductor having a first and second ends disposed generally coaxially with respect to the inner conductor and to the intermediate conductor.

Abstract: A slotted coaxial antenna design that accomplishes simultaneous UHF and either VHF broadcast, is disclosed. This design combines a DTV channel broadcast system, where the radio frequency signals are in the UHF band (i.e. slotted coaxial UHF antenna), with an NTSC broadcast system where the radio frequency is in the low and mid VHF band (i.e. circularly polarized VHF antenna), using a common antenna aperture.