Switchable N-way power divider/combiner

• US 5,872,491 A
• Filed: 11/27/1996
• Issued: 02/16/1999
• Est. Priority Date: 11/27/1996
• Status: Expired due to Term

• Current Assignee: KMW USA Incorporated (KMW Incorporated)
• Original Assignee: KMW USA Incorporated (KMW Incorporated)
• Inventors: Kim, Duk Yong, Chang, Ik Soo
• Primary Examiner(s): Pascal, Robert J.
• Assistant Examiner(s): Ham, Seungsook
• Application Number:
  US08/757,503
• Time in Patent Office: 811 Days
• Field of Search: 333/101, 333/1, 333/105, 333/108, 333/124, 333/125, 333/127, 333/128, 333/136, 330/51, 330/124 D
• US Class Current: 333/101
• CPC Class Codes: H01P 1/10 for switching or interrupting in systems using reflection or reradiation of radio, acoustic or other waves G01S7/034
• CPC Class Codes: H01P 5/16 Conjugate devices, i.e. devices having at least one port decoupled from one other port

Abstract

An improved Wilkinson-type power divider/combiner possessing switching capabilities for selectively controlling operative modes of its constituent dividing/combining channels is disclosed. The switchable power divider/combiner includes N first switches connecting N input/output transmission lines to a common junction and N second switches connecting N isolation resistors coupled to the N input/output transmission lines to a common node. The operating mode of the power divider/combiner can be controlled by activating each pair of the first and second switches to a closed or open switch position. The impedance values of the dividing/combining channel transmission lines are adjusted to provide the optimal impedance matching in both N-way and (N-1)-way operating modes. The resulting switchable power divider/combiner is capable of providing efficient power combining and distribution in a low-loss, phase-balanced manner in both N-way and (N-1)-1 way modes. When one of the signal-processing channels in the dividing/combining system fails, the power divider/combiner is switched to the (N-1)-way mode to provide continuing operation of the system without any degradation in the signal characteristics.

Claims

1. A power divider/combiner operable over a range of radio frequencies, comprising:

a common transmission line, one end of said common transmission line defining a common junction;

N input/output transmission lines, where N is an integer greater than 1, one end of each said input/output transmission line defining one of N input/output junctions;

N first switchable transmission line arrangements, each said first switchable transmission line arrangement including a first transmission line having one end coupled to a corresponding one of said N input/output junctions, each said first switchable transmission line arrangement further including a first switch disposed between the other end of said first transmission line and said common junction, said first switch adapted for making electrical connection between the other end of said first transmission line and said common junction in a closed switch position and breaking electrical connection between the other end of said first transmission line and said common junction in an open switch position;

N resistors, one end of each said resistor coupled to a corresponding one of said N input/output junctions;

N second switchable transmission line arrangements, each said second switchable transmission line arrangement including a second transmission line having one end coupled to the other end of a corresponding one of said N resistors, said second switchable transmission line arrangement further including a second switch disposed between the other end of said second transmission line and a common node, said second switch adapted for making electrical connection between the other end of said second transmission line and said common node in said closed switch position and breaking electrical connection between the other end of said second transmission line and said common node in said open switch position; and

control means coupled to said first switch of each said first switchable transmission line arrangement and said second switch of each said second switchable transmission line arrangement for selecting one of said first and second switch positions.

3. The invention of claim 1, wherein each said second switchable transmission line arrangement electrically connected between the other end of said corresponding resistor and said common node in said closed switch position of said second switch is substantially an integer multiple of a half-wavelength long at a selected frequency within the operating frequency range.

11. The invention of claim 1, wherein said second switch of each said second switchable transmission line arrangement in said open switch position is adapted to be disassociated from said common node such that no portion of said second switch is in electrical contact with said common node.

12. The invention of claim 11, wherein said first switch of each said first switchable transmission line arrangement and said second switch of each corresponding said second switchable transmission line arrangement are adapted for being actuated simultaneously so that said first switch and said corresponding second switch are always in the same switch position.

13. The invention of claim 1, wherein each said first switchable transmission line arrangement electrically connected between said common junction and said corresponding input/output junction in said closed switch position of said first switch is substantially a quarter-wavelength long at a selected frequency within the operating frequency range.

14. The invention of claim 13, wherein each said first switchable transmission line arrangement is substantially an odd integral multiple of a quarter-wavelength long at said selected frequency.

15. The invention of claim 11, wherein:

said common transmission line and said N input/output transmission lines have a substantially same characteristic impedance equal to a selected impedance Z₀ ;

each said first switchable transmission line arrangement electrically connected between said common junction and said corresponding input/output junction in said closed switch position of said first switch has a substantially same characteristic impedance Z, where Z is an impedance value between Z₀ and √

NZ₀ ; and

each said resistor has a substantially same resistance R₀ equal to said selected impedance Z₀.

16. The invention of claim 15, wherein said characteristic impedance Z is an impedance value between √

NZ₀ and √

N-1Z₀.

17. The invention of claim 16, wherein said characteristic impedance Z is substantially equal to (√

N+√

N-1)Z₀ /2.

23. The invention of claim 1, wherein each line in the second switchable transmission line arrangement is substantially an integral multiple of a half-wavelength long at a selected frequency.

2. A power divider/combiner operable over a range of radio frequencies, comprising:

a common transmission line, one end of said common transmission line defining a common junction;

N input/output transmission lines, where N is an integer greater than 1, one end of each said input/output transmission line defining one of N input/output junctions;

N first switchable transmission line arrangements, each said first switchable transmission line arrangement including a first transmission line having one end coupled to a corresponding one of said N input/output junctions, each said first switchable transmission line arrangement further including a first switch disposed between the other end of said first transmission line and said common junction, said first switch adapted for making electrical connection between the other end of said first transmission line and said common junction in a closed switch position and breaking electrical connection between the other end of said first transmission line and said common junction in an open switch position;

N second transmission lines, each second transmission line coupled between each successive pair of N connecting nodes to form a ring;

N switchable resistor arrangements, each said switchable resistor arrangement including a resistor having one end coupled to a corresponding one of said N input/output junctions, each said switchable resistor arrangement further including a second switch disposed between the other end of said resistor and a corresponding one of said N connecting nodes, said second switch adapted for making electrical connection between the other end of said resistor and said corresponding connecting node in said closed switch position and breaking electrical connection between the other end of said resistor and said corresponding connecting node in said open switch position; and

control means coupled to said first switch of each said first switchable transmission line arrangement and said second switch of each said switchable resistor arrangement for selecting one of said first and second switch positions.

4. The invention of claim 2, wherein each said second transmission line is substantially an integer multiple of one-wavelength long at a selected frequency within the operating frequency range.

18. The invention of claim 2, wherein each said first switchable transmission line arrangement electrically connected between said common junction and said corresponding input/output junction in said closed switch position of said first switch is substantially a quarter-wavelength long at a selected frequency within the operating frequency range.

19. The invention of claim 18, wherein each said first switchable transmission line arrangement is substantially an odd integral multiple of a quarter-wavelength long at said selected frequency.

20. The invention of claim 2, wherein:

said common transmission line and said N input/output transmission lines have a substantially same characteristic impedance equal to a selected impedance Z₀ ;

each said first switchable transmission line arrangement electrically connected between said common junction and said corresponding input/output junction in said closed switch position of said first switch has a substantially same characteristic impedance Z, where Z is an impedance value between Z₀ and √

NZ₀ ; and

each said resistor has a substantially same resistance R₀ equal to said selected impedance Z₀.

21. The invention of claim 20, wherein said characteristic impedance Z is an impedance value between √

NZ₀ and √

N-1Z₀.

22. The invention of claim 21, wherein said characteristic impedance Z is substantially equal to (√

N+√

N-1)Z₀ /2.

5. A power divider/combiner operable over a range of radio frequencies, comprising:

a common transmission line having a characteristic impedance equal to a selected impedance Z₀, one end of said common transmission line defining a common junction;

N input/output transmission lines, where N is an integer greater than 1, each said input/output transmission line having a substantially same characteristic impedance equal to said selected impedance Z₀, one end of each said input/output transmission line defining one of N input/output junctions;

N first switchable transmission line arrangements, each said first switchable transmission line arrangement including a first transmission line having one end coupled to a corresponding one of said N input/output junctions, each said first switchable transmission line arrangement further including a first switch disposed between the other end of said first transmission line and said common junction, said first switch adapted for making electrical connection between the other end of said first transmission line and said common junction in a closed switch position and breaking electrical connection between the other end of said first transmission line and said common junction in an open switch position, each said first switchable transmission line arrangement electrically connected between said common junction and said corresponding input/output junction in said closed switch position of said first switch is substantially a quarter-wavelength long at a selected frequency within the operating frequency range and has a substantially same characteristic impedance Z where Z is an impedance value between Z₀ and √

NZ₀ ;

N resistors having a substantially same resistance R₀ equal to said selected impedance Z₀, one end of each said resistor coupled to a corresponding one of said N input/output junctions and the other end of each said resistor connected to a corresponding one of N connecting nodes;

N second switchable transmission line arrangements, each said second switchable transmission line arrangement including a second transmission line being inserted between each pair of N connecting nodes to form a ring, said each second switchable transmission line arrangement further including a second switch disposed between the other end of said each resistor and the corresponding one of said N connecting nodes; and

control means coupled to said first switch of each said first switchable transmission line arrangement and said second switch of each said second switchable transmission line arrangement for selecting one of said first and second switch positions.

6. The invention of claim 5, wherein said characteristic impedance Z is an impedance value between √

NZ₀ and √

N-1Z₀.

7. The invention of claim 6, wherein said characteristic impedance Z is substantially equal to (√

N+√

N-1)Z₀ /2.

8. The invention of claim 7, wherein said selected impedance Z₀ is 50 ohms.

9. The invention of claim 5, wherein each said first switchable transmission line arrangement is substantially an odd integral multiple of a quarter-wavelength long at said selected frequency.

10. The invention of claim 5, wherein said first switch of each said first switchable transmission line arrangement in said open switch position is adapted to be disassociated from said common junction such that no portion of said first switch is in electrical contact with said common junction.