Power divider for harmonically rich waveforms

• US 6,320,478 B1
• Filed: 10/29/1998
• Issued: 11/20/2001
• Est. Priority Date: 10/29/1998
• Status: Expired due to Fees

• Current Assignee: National Aeronautics and Space Administration (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Sims, William Herbert III
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Glenn, Kimberly E
• Application Number:
  US09/182,553
• Time in Patent Office: 1,118 Days
• Field of Search: 333/125, 333/127, 333/128, 333/136, 333/26
• US Class Current: 333/127
• CPC Class Codes: H01P 5/12 Coupling devices having more than two ports H01P5/04 takes precedence

Abstract

A power divider divides an RF signal into two output signals having a phase difference of 180° or a multiple thereof. When the RF signal is a square wave or another harmonically rich signal, the phases of the fundamental and the harmonics have the proper relationship. The divider can be implemented in the form of microstrips on a board, with one of the output microstrips having several bends to provide a different electrical length from the other.

Claims

1. A power divider for dividing a harmonically rich input signal into a first output signal and a second output signal, the power divider comprising:

an input transmission line for transmitting the input signal to a T-point at which the input signal is split into a first portion and a second portion;

a first output transmission line having a length which is a first non-zero integer multiple of approximately λ

/2 of a wavelength of a fundamental frequency of the input signal, the first output transmission line receiving the first portion of the input signal at the T-point for transmitting the first portion while imparting a first phase delay to the first portion of the input signal to form the first output signal; and

a second output transmission line having a length which is a second non-zero integer multiple that is at least twice the value of the first non-zero integer multiple of the first transmission line, the second output transmission line receiving the second portion of the input signal at the T-point for transmitting the second portion while imparting a second phase delay to the second portion of the input signal to form the second output signal;

wherein the first phase delay and the second phase delay have a difference which is a non-zero integer multiple of 180°

, and

the ratio of lengths of said first and second output transmission lines provide that harmonic frequencies output from each of the output transmission lines are in phase with each other.

2. A power divider as in claim 1, wherein the difference is 180°

.

3. A power divider as in claim 1, wherein each of the input transmission line, the first output transmission line, and the second output transmission line is an electrically conductive transmission line;

and

the harmonically rich input signal is a square wave; and

an amplitude of the first output signal is approximately equal to an amplitude of the second output signal.

4. A power divider as in claim 3, wherein each of the input transmission line, the first output transmission line, and the second output transmission line is a coaxial transmission line.

5. A power divider as in claim 3, wherein each of the input transmission line, the first output transmission line, and the second output transmission line is a microstrip line.

6. A power divider as in claim 5, wherein:

the first output transmission line has a first number of bends; and

the second output transmission line has a second number of bends which is different from the first number of bends.

7. A power divider as in claim 3, wherein the length of the first transmission line is approximately λ

/2 of the fundamental frequency of the input signal, and the length of the second transmission line is approximately equal to the wavelength of the fundamental frequency of the input signal.

8. A power divider as in claim 7, wherein the input transmission line, the first output transmission line, and the second output transmission line are formed as part of a stripline assembly.

9. A power divider as in claim 1, wherein the length of the first transmission line is approximately λ

/2 of the fundamental frequency of the input signal, and the length of the second transmission line is approximately equal to the wavelength of the fundamental frequency of the input signal.

10. A power divider as in claim 9, wherein the input transmission line, the first output transmission line, and the second output transmission line are formed as part of a stripline assembly.

11. A power divider as in claim 1, wherein the input transmission line, the first output transmission line, and the second output transmission line are formed as part of a stripline assembly.

12. A method of dividing a harmonically rich input signal into a first output signal and a second output signal, the method comprising:

(a) splitting the input signal into a first portion and a second portion;

(b) imparting a first phase delay to the first portion of the input signal by providing a first transmission line having a length which is a non-zero integer multiple approximately λ

/2 of a wavelength of a fundamental frequency of the input signal to form the first output signal;

(c) imparting a second phase delay to the second portion of the input signal by providing a second transmission line having a length which is a non-zero integer multiple of at least twice the value of the non-zero integer multiple of the first transmission line to form the second output signal;

wherein the first phase delay and the second phase delay have a difference which is a non-zero integer multiple of 180°

, and

the ratio of lengths of said first and second output transmission lines provide that harmonic frequencies output from each of the output transmission lines are in phase with each other.

13. A method as in claim 12, wherein the difference is 180°

.

14. A method as in claim 12, wherein steps (a)-(c) are performed in electrically conductive transmission lines.

15. A method as in claim 14, wherein each of the electrically conductive transmission lines is a coaxial transmission line.

16. A method as in claim 14, wherein all of the electrically conductive transmission lines are formed as one of a microstrip line and a stripline assembly.

17. A method according to claim 12, wherein the length of the first transmission line provided in step (b) is approximately λ

/2 of the fundamental frequency of the input signal; and

the length of the second transmission line provided in step (c) is approximately equal to the wavelength of the fundamental frequency.

18. A method according to claim 17, wherein an amplitude of the first output signal provided in step (b) and an amplitude of the second output signal provided in step (c) are approximately equal.

19. A method as in claim 17, wherein the input transmission line, the first transmission line, and the second output transmission line are all formed as one of a microstrip line assembly and a stripline assembly.

20. A method according to claim 12, wherein an amplitude of the first output signal provided in step (b) and an amplitude of the second output signal provided in step (c) are approximately equal;

and

a frequency of the first output signal and the second output signal are approximately equal.