1. AEL 1 2015-12-16 Power divider ( Arbitrary Termination Impedance, Arbitrary Power Division ) 2004-21566 유지호

2. AEL 2 2015-12-16 Necessity of the power divider Problems of conventional power dividers Size reduction technique Arbitrary termination Impedance technique Arbitrary power division technique Conclusion Contents

3. AEL 3 2015-12-16 Necessity of the power divider power combining in phase or out of phase

4. AEL 4 2015-12-16 1.Large size at UHF or VHF band. 2.Designed to match 50 Ohm termination. ( Additional matching networks are necessary. - Increase system size ) 3.Symmetry -> Only equal power division ratio. Problems of conventional power dividers

5. AEL 5 2015-12-16 Size reduction technique (1) –> MTT-Trans (1991) A-A’ : symmetrical axis ring hybrid’ scattering matrix Isolation

6. AEL 6 2015-12-16 Size reduction technique (1) –> MTT-Trans (1991) A-A’ : symmetrical axis ring hybrid’ scattering matrix 1.Find S-parameter 2.Isolation : S 31 =S 42 =0 at f=f 0 3.3dB output power division -> |S 21 |=|S 41 | & |S 12 |=|S 32 | Then, obtain

7. AEL 7 2015-12-16 Size reduction technique (1) –> MTT-Trans (1991) 3dB power division & good matching

8. AEL 8 2015-12-16 Size reduction technique (2) –> MTT-S (1989) BUT -> 1. series L : high resistive losses 2. Same termination impedances

9. AEL 9 2015-12-16 Size reduction technique (3) –> MTT-Trans (1994) Reduce series L 1 : Input 2 : +90 output 4 : -90 output 3 : isolation 1 : Input 2 : +90 output 4 : -90 output 3 : isolation series L : 3 개 series L : 1 개

10. AEL 10 2015-12-16 Size reduction technique (3) –> MTT-Trans (1994) Remove series L (1980 ) But limited to equal-power split-ring hybrid

11. AEL 11 2015-12-16 Arbitrary termination impedances (1) –> MTT-Trans (1999) Excitation at port 2 (V) (1)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,

12. AEL 12 2015-12-16 Arbitrary termination impedances (1) –> MTT-Trans (1999) Power division & isolation matching

13. AEL 13 2015-12-16 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

14. AEL 14 2015-12-16 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. 1.The two waves must have a phase shift of 180degree against each other, -> 2.The wave ratio must be b2 : b1 as shown left. Reciprocal 하므로 m=n=p=k & b1:b2=1:1 => conventional ring hybrid

15. AEL 15 2015-12-16 Arbitrary power division & termination impedances (2) –> MTT-Trans (1997) Simulation Result 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 ) Power division Isolationmatching S21=-2.124dB, S41=-4.124dB S43=-2.124dB, S23=-4.124dB S31=-158..656dB, S42=-160.656dB

16. AEL 16 2015-12-16 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

17. AEL 17 2015-12-16 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