Wideband Multifunction Antenna Operating in the Hf Range, Particularly for Naval Installations

• US 20080278407A1
• Filed: 05/18/2006
• Published: 11/13/2008
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: Selex Communications SPA (Leonardo S.p.A.)
• Original Assignee: Selex Communications SPA (Leonardo S.p.A.)
• Inventors: Perelli, Raffaele, Bardati, Fernando, Mattioni, Lorenzo, Colasanti, Giampiero, Falcione, Giovanni, Proia, Manlio, Marrocco, Gaetano, Tognolatti, Piero
• Granted Patent: US 7,839,344 B2
• Time in Patent Office: Days
• US Class Current: 343/900
• CPC Class Codes: H01Q 1/34 Adaptation for use in or on ships, submarines, buoys or torpedoes for subaqueous use H01Q1/04
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A linear antenna for operation in the HF frequency range, particularly for naval communications is disclosed, comprising a radiating arrangement (H1, H2, H3, W1, W2), adapted to be operatively associated with a ground conductor (20) and at least one electrical impedance device (Z1-Z4), characterized in that it includes: a plurality of wire radiating elements with a predominantly vertical extension, forming a first and a second conducting branch (H1, H2) adapted to be operatively coupled to a feed circuit, and a return conducting branch (H3) adapted to be operatively coupled to a ground conductor (20); and a plurality of wire radiating elements with a predominantly transverse extension, forming connecting conducting branches (W1, W2) for connecting the conducting branches (H1, H2) adapted to be coupled to the feed circuit (12), to the conducting branch (113) adapted to be coupled to the ground conductor (20), the radiating elements being positioned in such a way as to form, in a plane in which the antenna lies, two nested closed paths (P1, P2) between the feed circuit (12) and the ground conductor (20), having at least one radiating element in common, and—a plurality of electrical impedance devices (Z1-Z4) interposed along the conducting branches (H1, H2, H3, W1, W2) and adapted to impede the flow of current within corresponding predetermined frequency ranges in such a way as to establish selectively, according to the operating frequency, a plurality of different current paths along the conducting branches (H1, H2, H3, W1, W2), corresponding to a plurality of different electrical and/or geometrical configurations of the antenna (10).

Claims

1. Linear antenna for operation in the HF frequency range, particularly for naval communications, comprising a radiating arrangement (H1, H2, H3, W1, W2), adapted to be operatively associated with a ground conductor (20) and at least one electrical impedance device (Z1-Z4),

characterized in that it includes:

a plurality of wire radiating elements with a predominantly vertical extension, forming a first and a second conducting branch (H1, H2), adapted to be operatively coupled to a radio frequency signal feed circuit (12), and a return conducting branch (H3), adapted to be operatively coupled to a ground conductor (20); and

a plurality of wire radiating elements with a predominantly transverse extension, forming connecting conducting branches (W1, W2) for connecting the conducting branches (H1, H2), adapted to be coupled to the feed circuit (12), to the conducting branch (H3) adapted to be coupled to the ground conductor (20),

the said radiating elements being arranged in such a way as to form, in a plane in which the antenna lies, two nested closed paths (P1, P2) between the feed circuit (12) and the ground conductor (20), having at least one radiating element in common, and

a plurality of electrical impedance devices (Z1-Z4) interposed along the conducting branches (H1, H2, H3, W1, W2) and adapted to impede the flow of current within corresponding predetermined frequency ranges in such a way as to establish selectively, according to the operating frequency, a plurality of different current paths along the said conducting branches (H1, H2, H3, W1, W2), corresponding to a plurality of different electrical and/or geometrical configurations of the antenna (10).

2. Antenna according to claim 1, in which the first conducting branch (H1) and the return conducting branch (H3) connected together form a first, outer, closed path (P1), and the second conducting branch (H2) and the return conducting branch (H3) connected together form a second, inner, closed path (P2), the said paths (P1, P2) having at least part of the return conducting branch (H3) in common.

3. Antenna according to claim 1 or 2, in which the said conducting branches (H1, H2, H3, W1, W2) form, in an operating arrangement of the antenna (10), a vertical plane in which the antenna lies.

4. Antenna according to claim 3, in which the first conducting branch (H1), the second conducting branch (H2) and the return conducting branch (H3) extend parallel to each other in the vertical direction.

5. Antenna according to claim 4, in which the connecting conducting branches (W1, W2) extend in the horizontal direction between the aforesaid vertical conducting branches (H1, H2, H3), in such a way as to form two nested closed paths (P1, P2) of rectangular shape.

6. Antenna according to claim 5, in which the vertical extension of the antenna is in the range from 8% to 10% of the maximum wavelength in the HF band.

7. Antenna according to claim 6, in which the transverse extension of the antenna is in the range from 1% to 2% of the maximum wavelength in the HF band.

8. Antenna according to claim 7, in which the inner rectangular path (P2) has sides whose dimension is half of the dimension of the corresponding sides of the outer rectangular path (P1).

9. Antenna according to any one of claims 2 to 8, in which the said electrical impedance devices (Z1-Z4) are two-terminal reactive circuits with lumped parameters.

10. Antenna according to claim 9, in which the said two-terminal reactive circuits comprise parallel resonant LC circuits.

11. Antenna according to claim 9 or 10, in which the said two-terminal reactive circuits comprise series resonant LC circuits.

12. Antenna according to any one of claims 9 to 11, comprising first impedance devices (Z1) arranged on the outer path (P1), having electrical parameters of a value such that they impede the flow of current in a predetermined first frequency range, being arranged to create in this frequency range a current path comprising, separately, the first conducting branch (H1) and the second conducting branch (H2) connected to the return conducting branch (H3), so that the antenna takes a dipole configuration.

13. Antenna according to any one of claims 9 to 11, comprising second impedance devices (Z4) arranged on the inner path (P2), having electrical parameters of a value such that they impede the flow of current in a predetermined second frequency range, being arranged to create in this frequency range a current path comprising the first conducting branch (H1) connected to the return conducting branch (H3), so that the antenna takes a folded monopole configuration.

14. Antenna according to any one of claims 9 to 11, comprising third impedance devices (Z2, Z3) arranged along the return conducting branch (H3) in the portion common to both paths (P1, P2), having electrical parameters of a value such that they impede the flow of current in a predetermined third frequency range, being arranged to create in this frequency range a current path comprising the first and the second conducting branch (H1, H2) connected to each other, so that the antenna takes a “

whip”

configuration.

15. Antenna according to any one of the preceding claims, in which the impedance devices (Z1-Z4) are arranged to form a distributed impedance matching circuit for each configuration of the antenna.

16. Antenna according to any one of the preceding claims, including a radio frequency signal matching and distribution unit (12) coupled to the said first and second conducting branch (H1, H2) of the radiating arrangement, including:

an impedance step-up transformer circuit (T) referred to the ground conductor (20), having a first terminal coupled to a signal transmission line (L) and a second terminal coupled to the said pair of conducting branches (H1, H2); and

a pair of impedance matching resistors (R1, R2) interposed between the said transformer circuit (T) and the said conducting branches (H1, H2).