Abstract
A communication antenna comprises an electrically conductive base assembly at a lower section of the antenna; a loading coil assembly, at a midsection of the antenna, and electrically connected to the base assembly; and a re-entrant capacitive hat assembly, at an upper section of the antenna, and electrically connected to the loading coil assembly, wherein the re-entrant capacitive hat assembly includes: a hat housing and a support tube longitudinally extending through the hat housing a domed shaped endcap and an insulative bushing.
Claims
1. A communication antenna, comprising: a base assembly at a lower section of the antenna; a rapid tuning module within the lower section of the antenna and electrically connected to the base assembly; a variable inductance loading coil assembly, at a midsection of the antenna, and electrically connected to the base assembly; a re-entrant capacitive hat assembly electrically connected to the variable inductance loading coil assembly, wherein the re-entrant capacitive hat assembly includes: a hat housing; a support tube longitudinally extending through the hat housing; a domed end cap configured to hold, at an end thereof, a whip extension; and a non-electrically conductive spacer insulating the hat housing from the variable inductance loading coil assembly while the support tube is electrically coupled to the variable inductance loading coil assembly.
2. The antenna of claim 1, wherein, the base assembly, the variable inductance loading coil assembly, and the re-entrant capacitive hat assembly can be of various diameters in circumference and are cylindrical in overall shape.
3. The antenna of claim 1, wherein, the base assembly is mechanically and electrically connected to the variable inductance loading coil assembly.
4. The antenna of claim 1, wherein, the coil assembly includes coil windings and a moveable connector disk in contact with the coil windings.
5. The antenna of claim 1, further comprising: an anti-spin groove along a longitudinal axis of a connector disk carrier tube in the variable inductance loading coil assembly; and a set screw in a coil base of the variable inductance loading coil assembly prevents the connector disk carrier tube from rotating around its longitudinal axis.
6. The antenna of claim 1, further comprising: the rapid tuning module is within the lower section and electrically connected to the base assembly, and operatively engaged to the variable inductance loading coil assembly, via a lead screw therein, to provide mechanical adjustments to the variable inductance loading coil assembly.
7. The antenna of claim 1, further comprising: a cable port in the base assembly provides access to data cables contained within the base assembly.
8. The antenna of claim 1, further comprising: an electrical connector in an enclosed space of a support base in the base assembly and configured to power and/or drive a motor in the base assembly and provide programing and data connection to the rapid tuning module.
9. The antenna of claim 1, wherein, the re-entrant capacitive hat assembly includes the dome end cap on the hat housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is an elevated plan view of an exterior of an antenna according to an exemplary aspect of the present disclosure.
(2) FIG. 2 is an elevated plan view in cross section of an antenna according to an exemplary aspect of the present disclosure.
(3) FIG. 3 is a cross-sectional view of a base assembly of an antenna according to an exemplary aspect of the present disclosure.
(4) FIG. 4 is a cross-sectional view of a coil assembly of an antenna according to an exemplary aspect of the present disclosure.
(5) FIG. 5 is a cross-sectional view of a re-entrant capacitive hat assembly of an antenna according to an exemplary aspect of the present disclosure.
(6) FIG. 6 is a partial, enlarged, cross-sectional view of an interfacing area between a base assembly and a coil assembly of FIGS. 3 and 4.
(7) FIG. 7 is a partial, enlarged, cross-sectional view of an interfacing area between a coil assembly and a re-entrant capacitive hat assembly of FIGS. 4 and 5.
(8) FIG. 8 is a partial, enlarged, cross-sectional view of a re-entrant capacitive hat upper cap plug of FIG. 5.
DESCRIPTION OF THE DISCLOSURE
(9) FIGS. 1-8 illustrate the construction and functions of an embodiment of a ruggedized rapid tuning adjustable frequency capable mobile HF antenna with re-entrant capacitive hat in support of frequency hopping and auto tuning modes such as Automatic Link Establishment (ALE) and HF messaging/chat modes according to the present disclosure. Certain aspects of the construction and functions of the ruggedized antenna according to the present disclosure can be the same or similar to corresponding elements of the antenna disclosed in U.S. Pat. No. 9,065,178. Therefore, the ensuing description hereby incorporates by reference the entire disclosure of the '178 patent, and for the sake of brevity and succinctness, may discuss primarily those features of the construction and functions of the presently disclosed ruggedized antenna that distinguish it from the antenna disclosed in the '178 patent.
(10) Referring to FIGS. 1-2, it may be seen that an exemplary embodiment of a ruggedized rapid tuning adjustable frequency antenna 230 with a re-entrant capacitive hat according to the present disclosure may include a metal mast or base assembly 231 at a lower section of the antenna 230, a coil assembly 232 coaxially stacked (i.e., end-to-end) on the base assembly 231 and located at a midsection of the antenna 230, and a re-entrant capacitive hat assembly 503 coaxially stacked on the coil assembly 232 at an upper section of the antenna 230. In an embodiment, the antenna 230 may be cylindrical in overall shape. In an embodiment, each of the base assembly 231, the coil assembly 232, and the re-entrant capacitive hat assembly 503 may be elongated and cylindrical in shape.
(11) In FIG. 3, according to an exemplary embodiment, the mast or base assembly 231 may be electrically connected in series to and mechanically engaged with to the variable inductance loading coil assembly 232. In an embodiment, the base assembly 231 may support coaxially at the upper end thereof the axially aligned, cylindrically shaped loading coil assembly 232. In an embodiment, the elongated base assembly 231 may include a support base 535 at a lower end thereof. A mounting plate 537 may be affixed to the support base 535 (such as by one or more screws 538) to thereby enclose a space within the support base 535. A fiber optic cable port 543 may provide access to the fiber optic data cables contained within the base assembly 231.
(12) In an embodiment, the base assembly 231 may further include a motor 536 (such as a stepper motor) that may be in the enclosed space of the support base 535. An electrical connector 539 (such as a pin connector) may be in the enclosed space of the support base 535 and may be used to power and/or drive the motor 536 and provide programing and data connection to a rapid tuning module 544 described below. A coupler 540 may couple the motor 536 to a lead screw 541 that extends longitudinally within a cylindrical, elongated, electrically conductive base housing 542. In an embodiment, the base housing 542 may be made of aluminum. One end (i.e., lower end) of the lead screw 541 may be fixedly attached to the coupler 540. An opposite end (i.e., upper end) of the lead screw 541 may be operatively engaged with, coupled to, and mechanically connected to the coil assembly 232, as further described below.
(13) In an embodiment, the base assembly 231 may further include a hardware and/or software rapid tuning module 544 (frequency hopping and auto tuning modes such as Automatic Link Establishment (ALE) and HF messaging/chat modes) that may be supported by the mounting plate 537 and be within the base housing 542. One or more screws 545 may be at an upper end of the base housing 542 and enable attachment of the housing 542 to the coil assembly 232, as further described below.
(14) In an exemplary embodiment, the base assembly 231 may have a diameter of about 4 inches and a longitudinal length of about 33 inches. In embodiments, the base assembly 231 may have a diameter of 2 to 4 inches and a longitudinal length of about 16 to 36 inches.
(15) In another embodiment, the base assembly 231 may be the same as or similar to the mast section described in U.S. Pat. No. 9,065,178.
(16) Referring to FIGS. 4 and 6, in an exemplary embodiment, it may be seen that the loading coil assembly 232 of the rugged antenna 230 can have a construction which differs from the loading coil assembly 32 of the antenna 30 disclosed in U.S. Pat. No. 9,065,178. In other embodiments, the coil assembly 232 may have a construction that is the same as or similar to the coil assembly in U.S. Pat. No. 9,065,178.
(17) In FIG. 4, according to an embodiment, the coil assembly 232 may be configured to provide variable inductance in the antenna 230. The elongated, cylindrical coil assembly 232 may include a coil housing 554. The coil housing 554 may be cylindrically shaped, as an example. The coil housing 554 may be made of a high dielectric material, such as plastic. A lower end of the coil housing 554 may be supported by and/or affixed to a coil base 546 of the coil assembly 232, as further described below. An upper end of the coil housing 554 may be supported by and/or affixed to a coil cap 511, as further described below.
(18) In an embodiment, the coil assembly 232 may further include an electrically conductive, elongated, cylindrical helical coil windings 547. The coil windings 547 may be inside the coil housing 554, in an embodiment. The coil windings 547 may extend from an upper end of the coil housing 554 and to the lower end of the coil housing 554, in an embodiment. The number of coil windings 547 may be from about 56 to about 220, in embodiments.
(19) The coil assembly 232 may include, at a bottom end thereof, the coil base 546, in an embodiment. The coil base 546 may be made of an electrically conductive material, such as aluminum. The coil base 546 may be configured, such as at an upper end section thereof, to fit inside the lower end of the coil windings 547 and/or base housing 542 of the base assembly 231, according to an embodiment. Thereby, the coil base 546 may be in conductive contact with the coil windings 547, in an embodiment. The coil base 546, at a bottom end section thereof, may be affixed inside of and/or in conductive connection with the upper end of the electrically conductive base housing 542 by one or more of the screws 545 of the base assembly 231 (FIG. 6).
(20) In an embodiment, the coil assembly 232 may include, at an upper end thereof, the coil cap 511. The coil cap 511 may be configured, such as at a lower end section thereof, to fit inside the upper end of the coil windings 547. Thereby, the coil cap 511 may be in conductive contact with the coil windings 547, in an embodiment. The coil cap 511 may also be supported by and/or affixed to the upper end of the coil housing 554, in an embodiment. The coil cap 511 may be made of an electrically conductive material, such as aluminum.
(21) In combination, the coil base 546, the coil windings 547, the coil housing 554, and the coil cap 511 can provide a hollow cylindrical space 507 located within the coil housing 554 longitudinally extending through the loading coil assembly 232, according to an embodiment.
(22) As shown in FIG. 4, according to an embodiment, the loading coil assembly 232 can include an elongated, cylindrical coil contactor disk carrier tube 322 having a longitudinal bore 513 therein. The coil contactor disk carrier tube 322 has a groove 558 machined along the longitudinal axis whereby a set screw 557 inserted radially through the coil base 546 and penetrates the machined groove of the carrier tube, thereby preventing rotation. This function increases position precision and accuracy of the contactor disk balls on coil winding 547. The coil contactor disk carrier tube 322 may extend from an upper end of the coil windings 547, through the lower end of the coil windings 547, into the coil base 546, and out of a bottom area of the coil base 546, in an embodiment. Thereby, the coil contactor disk carrier tube 322 may be disposed in the upper end of the base housing 542 of the base assembly 231, according to an embodiment.
(23) In FIG. 4, in an exemplary embodiment, the coil assembly 232 may include, at a lower end of the coil contactor disk carrier tube 322, a screw adaptor 548. In an embodiment, the screw adaptor 548 may be configured to fixedly hold therein the upper end of the lead screw 541 of the base assembly 231. Thereby, rotational translation of the lead screw 541 can be converted to longitudinal translation of the coil contactor disk carrier tube 322.
(24) According to an embodiment, the coil assembly 232 may include a conductive gasket 552, such as finger stock, at an upper section of the coil base 546. (FIG. 6). The gasket 552 may extend around the circumferential exterior surface of the coil contactor disk carrier tube 322, in an embodiment.
(25) In FIGS. 4 and 7, according to an embodiment, the coil assembly 232 may include, about the circumferential exterior of the coil contactor disk carrier tube 322, a connector disk 549. The connector disk 549 may be made of an electrically conductive material, such as aluminum, for example. In an embodiment, the connector disk 549 may be affixed at the upper end of the coil contactor disk carrier tube 322. Thus, longitudinal translation of the coil contactor disk carrier tube 322 may be converted to longitudinal translation of the connector disk 549, according to an embodiment. The connector disk 549, according to an embodiment, may include one or more pairs of an electrically conductive contact ball 550 and an electrically conductive compression spring 551. In an embodiment, the compression spring 551 may bias the contact ball 550 radially outward toward and contact the electrically conductive coil windings 547.
(26) Accordingly, the connector disk 549 may provide variable series inductance from the base assembly 231, the coil assembly 232, and the re-entrant capacitive hat assembly 503. Inductance functioning of a connector disk is described in U.S. Pat. No. 9,065,178.
(27) In FIG. 4, according to an embodiment, the coil assembly 232 may include a stiff, strong, reinforced rod 506 disposed axially through the coil contactor disk carrier tube 322. The rod 506 may extend from an upper end of the coil windings 547 and into the coil base 546. Accordingly, the rod 506 may function to minimize torsional and/or bending movement of the coil contactor disk carrier tube 322 and coil assembly 232. In an exemplary embodiment, the reinforced rod 506 can be an elongated solid circular cross-section rod made of fiberglass, having a diameter of 1 inch and a length of 16 inches.
(28) In FIGS. 4 and 7, an upper end of the reinforced rod 506 can be held in a tight interference fit within a blind bore 509 that may extend upwardly into a lower surface 510 of the upper coil cap 511 that can be fastened to an upper transverse annular edge wall 512 with a set screw 516 that may seal the hollow interior space 507 of the coil assembly 232.
(29) As shown in FIG. 7, in an embodiment, the reinforcement rod 506 may extend coaxially downwardly from the upper end cap 511, and axially through the bore 513 of coil contactor disk carrier tube 322. The reinforcement rod 506 may be fastened to the loading coil assembly 232 solely by the interference fit of the upper end of the reinforcement rod within the bore 509 in the upper cap 511, according to an embodiment. The free lower end of the reinforcement rod 506 may be received downwards into the open upper end of the coil contactor disk carrier tube 322, which may be slidably supported on the reinforcement rod 506 through a bore 514 through the thickness dimension of an annular disk-shaped Teflon sleeve 515 fitted within the bore 513 of the coil contactor disk carrier tube 322, according to an embodiment.
(30) In an exemplary embodiment, the loading coil assembly 232 may have a diameter of about 5.5 inches and a length of about 14 inches. In embodiments, the coil assembly 232 may have a diameter of 2 to 6 inches and a longitudinal length of 8 to 20 inches.
(31) The coil assembly 232 may, in certain embodiments, be constructed the same as or similar to the coil tube section described in U.S. Pat. No. 9,065,178.
(32) Referring to FIGS. 1-2, in an embodiment, it may be seen that the antenna 230 can include a re-entrant capacitive hat assembly 503 that is unlike the whip section in U.S. Pat. No. 9,065,178. In an embodiment, the re-entrant capacitive hat assembly 503 may extend upwardly from an upper side of the insulating spacer bushing 500. The re-entrant capacitive hat assembly 503 may include a cylindrical shell-shaped hat housing 505 made of an electrically conductive material. In an example embodiment of the antenna 230, the hat housing 505 of the re-entrant capacitive hat assembly 503 can be of a circular cross-section aluminum tube having an outer diameter of 4 inches, an inner diameter of 3.9 inches, and a length of 34 inches. In embodiments, the re-entrant capacitive hat assembly 503 may have a diameter of 2 to 6 inches and a longitudinal length of 8 to 48 inches.
(33) In FIGS. 2, 5 and 8, according to an embodiment, the re-entrant capacitive hat assembly 503 may include, at an upper end of the hat housing 505, an upper end cap 517. The re-entrant capacitive hat end cap 517 may have a convex, arcuately curved (i.e., dome shaped) upper end face 533, in an embodiment. The upper end cap 517 may be made of an electrically conductive material, such as aluminum. In an embodiment, the upper end cap 517 of the re-entrant capacitive hat assembly 503 may fit conformally within an upper longitudinal end section of a central coaxial bore 518 through the re-entrant capacitive hat housing 505, and may be fastened in conductive contact with the housing 505 by one or a multiplicity of circumferentially spaced-apart screws 520 that are disposed radially through holes 521 in a cylindrical wall of the housing 505, and into bores 522 in a circumferential side wall 523 of the upper end cap 517.
(34) In FIG. 5, the re-entrant capacitive hat assembly 503 may include, at a lower end of and within the hat housing 505, an insulating cylindrically shaped spacer bushing 500 (i.e., a non-electrically conductive spacer) which may operatively interface the coil assembly 232, according to an embodiment. One or more circumferentially disposed screws 553 may affix the hat housing 505 to the bushing 500, according to an embodiment. In an embodiment, the bushing 500 may be configured to prevent electrical conduction between the coil assembly 232 and the bottom end of the re-entrant capacitive hat housing 505, preventing a short between the coil assembly 232 and the re-entrant capacitive hat assembly 503 (i.e., insulating the hat housing 505 from the variable inductance loading coil assembly 232).
(35) As shown in FIG. 7, the spacer bushing 500 may be attached coaxially to an upper side 501 of loading coil assembly 232 and can be axially aligned with the loading coil assembly 232. The spacer bushing 500 can be made of a durable insulating polymer such as Delrin, and in an example embodiment, can have a diameter of about 4 inches and a thickness of about 2 inches. In embodiments, the spacer bushing 500 may have a diameter of 1.5 to 5.5 inches and a longitudinal length of 1 to 5 inches.
(36) In other embodiments, other spacing/electrically conductive insulating means may be disposed between the coil assembly 232 and the re-entrant capacitive hat assembly 503.
(37) In FIGS. 5 and 8, in an embodiment, the re-entrant capacitive hat assembly 503 may include an elongated support tube 524. In an embodiment, the support tube 524 can structurally support the overall hat assembly 503. In an embodiment, the support tube 524 may be an elongated aluminum tube which has externally threaded upper (525) and lower (526) end sections. In an example embodiment of the antenna 230, the re-entrant capacitive hat support tube 524 may have an outer diameter of 1 inch, an inner diameter of 0.75 inch, and a length of 34 inches. As shown in the figures, the upper end section 525 of the re-entrant capacitive hat support tube 524 may be threaded and received in a threaded bore 528 of a boss 529 of re-entrant capacitive hat end cap 517. A circumferential channel 556 of the support tube 524 may encircle an upper end of the bore 528 and the boss 529.
(38) As shown in FIGS. 4-5 and 7, in an embodiment, a lower end section of the support tube 524 of the re-entrant capacitive hat assembly 503 may extend downwardly through a central coaxial hole 530 through the insulating spacer bushing 500. As shown, the lower threaded end section 526 of the re-entrant capacitive hat support tube 524 may be threaded and secured in a blind threaded bore 531 that is centrally located in an upper side 532 of upper coaxial cap 511 of the loading coil assembly 232.
(39) In FIGS. 5 and 8, the re-entrant capacitive hat upper end cap 517 may be configured to hold a whip extension, in an embodiment. The end cap 517 may optionally include a centrally located threaded bore 534 which extends inwardly into the upper end face 533, for receiving a threaded connector 555 to add an optional short whip extension of the antenna. In an exemplary operating mode of the antenna 230 in which a whip is not used, threaded bore 534 may receive a threaded plug (not shown) which has an arcuately curved outer end face that fits flush with curved outer end face 533.
(40) As can be appreciated by those skilled in the art, the re-entrant capacitive hat assembly 503 provides a novel construction and unexpected result/function. Among other things, enabling the antenna to operate at high efficiency even at frequencies at 1.6 MHz and lower, at which the physical length of the antenna is substantially shorter than /4. In an example embodiment of the antenna 230 with re-entrant capacitive hat assembly 503, the antenna was found to have an effective tuning range between 1.6 MHZ to 30 MHZ and above, and usable at frequencies above 150 MHZ.
