Power divider
Download
1 / 17

Power divider ( Arbitrary Termination Impedance, Arbitrary Power Division ) - PowerPoint PPT Presentation


  • 78 Views
  • Uploaded on

Power divider ( Arbitrary Termination Impedance, Arbitrary Power Division ). 2004-21566 유지호. Contents. Necessity of the power divider Problems of conventional power dividers Size reduction technique Arbitrary termination Impedance technique Arbitrary power division technique

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Power divider ( Arbitrary Termination Impedance, Arbitrary Power Division )' - hallam


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Power divider

( Arbitrary Termination Impedance,

Arbitrary Power Division )

2004-21566

유지호


Contents

  • Necessity of the power divider

  • Problems of conventional power dividers

  • Size reduction technique

  • Arbitrary termination Impedance technique

  • Arbitrary power division technique

  • Conclusion


Necessity of the power divider

power combining

in phase or out of phase


Problems of conventional power dividers

  • Large size at UHF or VHF band.

  • Designed to match 50 Ohm termination. ( Additional matching networks are necessary. - Increase system size )

  • Symmetry -> Only equal power division ratio.


Size reduction technique (1) –> MTT-Trans (1991)

A-A’ : symmetrical axis

ring hybrid’ scattering matrix

Isolation


Size reduction technique (1) –> MTT-Trans (1991)

A-A’ : symmetrical axis

ring hybrid’ scattering matrix

  • Find S-parameter

  • Isolation : S31=S42=0 at f=f0

  • 3dB output power division

  • -> |S21|=|S41| & |S12|=|S32|

  • Then, obtain


Size reduction technique (1) –> MTT-Trans (1991)

3dB power division & good matching


Size reduction technique (2) –> MTT-S (1989)

BUT -> 1. series L : high resistive losses

2. Same termination impedances


Size reduction technique (3) –> MTT-Trans (1994)

1 : Input

2 : +90 output

4 : -90 output

3 : isolation

1 : Input

2 : +90 output

4 : -90 output

3 : isolation

series L : 3개

series L : 1개

Reduce series L


Size reduction technique (3) –> MTT-Trans (1994)

Remove series L (1980 )

But limited to equal-power split-ring hybrid


Arbitrary termination impedances (1) –> MTT-Trans (1999)

  • Excitation at port 2 (V)

  • Transmission line Eq

  • node 1&2, node 3&1

  • (2)node Eq

  • node 1, node 2, node 2&GND, nod 2&3

  • (3)3dB power division

  • (4)

So determine optimum load

(1) ~ (4) Then,


Arbitrary termination impedances (1) –> MTT-Trans (1999)

Power division & isolation

matching


Arbitrary power division & termination impedances (2) –> MTT-Trans (1997)

Lossless ->

3 port isolation & 1 port matched ->

S31=0 & excitation for port 1 & put

wave ratio = b1 : b2 = S21 : S41

Under the assumption S31=0, the characteristic admittances Y1, Y4 determined


Arbitrary power division & termination impedances (2) –> MTT-Trans (1997)

  • excitation for port 3

  • The dummy arms Y2 and Y3 makes port 2&4 isolation

  • If isolation is not ideal -> small power flows forward to port 3

  • For these two waves to be isolated from port 1, two conditions must be satisfied.

  • The two waves must have a phase shift of 180degree against each other,

  • ->

  • The wave ratio must be b2 : b1 as shown left.

  • Reciprocal 하므로

m=n=p=k & b1:b2=1:1 => conventional ring hybrid


Arbitrary power division & termination impedances (2) –> MTT-Trans (1997)

Port 1 : n=1 -> 50 Ohm

Port 2 : m=1.1 -> 45.45 Ohm

Port 3 : p=0.7 -> 71.429 Ohm

Port 4 : k=0.8 -> 62.5 Ohm

Power spilt ratio : 2dB ( 20log(b1/b2) =2dB )

Simulation Result

S21=-2.124dB , S41=-4.124dB

S43=-2.124dB , S23=-4.124dB

S31=-158..656dB , S42=-160.656dB

Power division

Isolation

matching


Conclusion

  • Power divider’s size may be reduce

  • ( less than quarter wave line,

  • & lumped element )

  • We can remove matching network with Arbitrary termination Impedance & Arbitrary power division power divider.

  • -> realize small size system


References

  • Three-Port 3-dB Power Divider Terminated by Different Impedances and Its Application to MMIC’s , IEEE MTT Trans. 1999

  • Arbitrary Termination Impedances, Arbitrary Power Division, and Small-Sized Ring Hybrids, IEEE MTT Trans. 1997

  • Miniaturized 3-dB ring hybrid terminated by arbitrary impedances, IEEE MTT Trans. 1994

  • Design of new hybrid-ring, directional coupler using λ/8 or λ/6 sections, IEEE MTT Trans. 1991

  • 180° lumped element hybrid, IEEE MTT-S.1989


ad