Multiband antenna

• US 6,323,820 B1
• Filed: 11/16/2000
• Issued: 11/27/2001
• Est. Priority Date: 03/19/1999
• Status: Expired due to Term

• Current Assignee: Kathrein SE
• Original Assignee: Kathrein-Werke KG. (Kathrein SE)
• Inventors: Haunberger, Thomas
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US09/700,088
• Time in Patent Office: 376 Days
• Field of Search: 343/793, 343/702, 343/905, 343/797, 343/795, 343/822, 343/815, 343/824, 343/834, 343/876
• US Class Current: 343/793
• CPC Class Codes: H01Q 19/10 using reflecting surfaces
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/50 Feeding or matching arrangements for broad-band or multi-band operation
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A multiband antenna has first and second antenna devices for transmitting or receiving. Each device has a dipole structure and associated dipole halves disposed opposite a base plate or reflector by baluns. The antenna devices are provided with a feed from a common antenna input line and a branch circuit. Frequency selective components are respectively associated with the first and second antenna devices. An electrical length of branch lines between a branch point and a feed point on the associated antenna devices having the dipole structure enables the frequency selective components respectively to reject a frequency band range transmitted via another of the first and second antenna devices.

Claims

1. A multiband antenna comprising:

at least first and second antenna devices for transmitting or receiving, said first and second antenna devices each having a dipole structure and associated dipole halves disposed opposite a base plate or reflector by means of baluns;

a feed from a common antenna input line and a branch circuit for each device;

a frequency selective component associated with each of said first and second antenna devices;

said frequency selective components being integrated in the respective antenna devices; and

an effective electrical length of the associated baluns and an electrical length of associated branch lines between a branch point and a feed point on the associated antenna devices having said dipole structure enabling said frequency selective components respectively to reject a frequency band range transmitted via another of said first and second antenna devices.

2. A multiband antenna according to claim 1 wherein the electrical length of the branch line plus the effective length of the baluns have a respective electrical total length whose discrepancy from a value of a formula

3. A multiband antenna according to claim 1 including a shorting element connecting two balun halves of the each device.

4. A multiband antenna according to claim 3 wherein the respective antenna devices are disposed above the reflector by a support device, a height of said support device being greater than the electrically effective length of the balun of the associated antenna device defined by a distance between radiating elements thereof and an associated shorting element.

5. A multiband antenna according to claim 3 wherein the height of the shorting elements with reference to a total distance between the radiating elements of said antenna devices and said reflector is less than 50% of the total height of said support devices for radiating elements of said antenna devices relative to the reflector.

6. A multiband antenna according to claim 3 wherein the shorting elements comprise conductive elements having thicknesses equivalent to a distance between the respectively associated balun halves.

7. A multiband antenna according to claim 3 wherein the shorting elements are soldered in between the two balun halves.

8. A multiband antenna according to claim 3 wherein the shorting elements comprise clamps or screw elements.

9. A multiband antenna according to claim 3 wherein the shorting elements include one or two offsets or angles directed toward one another on the associated balun halves, which are electrically connected to one another.

10. A multiband antenna according to claim 1 including an antenna input line and a branch line being in the form of coaxial cables.