Curved dipole antenna with center-post amplifier

• US 5,521,610 A
• Filed: 04/26/1995
• Issued: 05/28/1996
• Est. Priority Date: 09/17/1993
• Status: Expired due to Fees

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Rodal, Eric B.
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US08/429,657
• Time in Patent Office: 398 Days
• Field of Search: 343/797, 343/795, 343/701, 343/802, 343/752
• US Class Current: 343/797
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An antenna system embodiment of the present invention comprises a curved dipole antenna stood off at its center by a printed circuit board assembly containing a pre-amplifier. The curved dipole antenna is implemented with a single-sided flexible circuit and is anchored at its four free ends to a sheet metal base for a groundplane. The printed circuit board assembly containing the predetermined amplifier is fixed perpendicular to the sheet metal base and has a tab that engages a slot in the center of the single-sided flexible circuit for electrical connection of a pair of orthogonal dipoles patterned on one side of the flexible circuit.

Claims

1. An antenna system, comprising:

a conductive flat planar base including a groundplane comprised of a solid metal and providing for an electrical ground reference;

a pair of curved dipole antennas disposed orthogonal to one another on an X-shaped insulative substrate and mechanically-anchored by respective electrically-open ends to four points just inside a perimeter of the base with the center of said substrate arid dipole antennas separated from the base, wherein the dipole antennas and said substrate comprise a single-sided flexible printed circuit having a slot proximate to said substrate center; and

an amplifier assembly completely disposed on a support perpendicular to the base between the center of the base and the center of said substrate and providing for amplification of radio signals provided by a connection to the dipole antennas, wherein the amplifier assembly engages said slot and electrically connects to the dipole antennas.

2. The system of claim 1, wherein:

the dipole antennas further include capacitive loads at respective tips for adjusting a response pattern of the antenna system.

3. The system of claim 2, wherein:

the dipole antennas further include a keying means to orient the base and amplifier assembly to the dipole antennas.

4. The system of claim 1, wherein:

the dipole antennas are separated from the base at their respective centers by approximately one-quarter wavelength of a predetermined operating frequency wherein an impedance match between the dipole antennas and the amplifier assembly is obtained.

5. The system of claim 1, wherein:

the dipole antennas are adapted for use at a nominal center frequency of 1575.42 MHz, wherein carrier signals from global positioning system satellites may be received; and

the amplifier assembly supports the dipole antennas at said substrate center aloft from the base by approximately one and one-half inches.

6. The system of claim 1, further comprising:

a non-conductive hemispherical weather dome for enclosing the base, the dipole antennas and the amplifier assembly and comprised of a material substantially transparent to microwave radio signals.

7. An antenna system, comprising:

a conductive flat planar circular base including a groundplane;

a pair of hemispherically-curved dipole antennas disposed orthogonal to one another at their centers on an X-shaped insulative substrate and mechanically-anchored by respective electrically-open ends to four points distributed proximate to a circumference of the base with the center of said substrate and dipole antennas spaced away from the base; and

an amplifier assembly completely disposed on a support perpendicular to the base between the center of the base and the center of said substrate and providing for amplification of radio signals provided by a connection to the dipole antennas;

wherein, the base is comprised of a solid metal and provides for an electrical ground reference;

the dipole antennas and said substrate comprise a single-sided flexible printed circuit having a slot proximate to said substrate center; and

the amplifier assembly engages said slot and electrically connects to the dipole antennas.

8. The system of claim 7, wherein:

the dipole antennas further include capacitive loads at respective tips for adjusting a response pattern of the antenna system.

9. The system of claim 7, wherein:

the dipole antennas further include a keying means to orient the base and amplifier assembly to the dipole antennas.

10. The system of claim 7, wherein:

the dipole antennas are separated from the base at their respective centers by approximately one-quarter wavelength of a predetermined operating frequency wherein an impedance match between the dipole antennas and the amplifier assembly is obtained.

11. The system of claim 7, wherein:

the dipole antennas are adapted for use at a nominal center frequency of 1575.42 MHz, wherein carrier signals from global positioning system satellites may be received; and

the amplifier assembly supports the dipole antennas at said substrate center aloft from the base by approximately one and one-half inches.

12. The system of claim 7, further comprising:

a non-conductive hemispherical weather dome for enclosing the base, the dipole antennas and the amplifier assembly and comprised of a material substantially transparent to microwave radio signals.