1 / 35

Impedance Matching (2)

Impedance Matching (2). Outline. Three Element Matching Motivation Pi Network T Network Low Q or Wideband Matching Network Impedance Matching on Smith Chart Two-Element Three-Element Matching Multi-Element Matching Genesis. RV=4.424 Ohms. Component Q= 4.73. Circuit Q.

talon-pena
Télécharger la présentation

Impedance Matching (2)

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Impedance Matching (2)

  2. Outline • Three Element Matching • Motivation • Pi Network • T Network • Low Q or Wideband Matching Network • Impedance Matching on Smith Chart • Two-Element • Three-Element Matching • Multi-Element Matching • Genesis

  3. RV=4.424 Ohms Component Q=4.73

  4. Circuit Q Q of Vin/VS=102.2/(125.4-83.1)=2.416 Circuit Q is different from component Q! Q of Vout/VS=98/(117.6-73.4)=2.21

  5. Four Combinations of L-Match RL>RS RS>RL

  6. Split a Pi Network into Two L Networks

  7. Virtual Resistor Virtual Resistance must be smaller than source resistance! (Blocks DC) RS>RL RL>RS

  8. Design a Pi-Match • RS=100 Ohms • RL=1000 Ohms • Resonant Frequency: 100 MHz • Q2=15 • R2/R=(Q22+1)/(Q12+1) (See attached) Q1 Q2

  9. Calculation Design Sequence: Q1, Q2 RV L2, C2 L1, C1

  10. Pi-Match Schematic

  11. Use Pi-Match to Produce Matching at 100 MHz

  12. T-Match

  13. T-Match RL>RS RS>RL

  14. Calculation in Matlab

  15. Schematic Q1=10 Q2=4.472 RV=1050 Ohms

  16. Vin/VS

  17. Review of Smith Chart • Adding an inductor in series • Adding a capacitor in series • Adding a capacitor in parallel • Adding an inductor in parallel

  18. Adding an Inductor in Series Insertion of a series inductor to an impedance moves the impedance upward, causing a rotation clockwise along a constant circle of resistance

  19. Adding a Capacitor in Series Insertion of a seriescapacitor to an impedance move impedance downward, causes a rotation counterclockwise along a constant circle of resistance

  20. Adding a Shunt Capacitance Insertion of a shunt capacitor causes a rotation clockwise along a constant circle of admittance

  21. Adding a Shunt Inductance Insertion of a shunt inductor causes a rotation counter clockwise along a constant circle of admittance

  22. Example Design a matching network with a source impedance of 25+15j Ohm and output impedance of 100+25j Ohms.(We need to have match the source and load to their complex conjugates)

  23. Starting Smith Chart (source) (load)

  24. Four Combinations of L-Match (Series L causes clockwise Movement on constant R on smith chart… …) (The only one) RL>RS RS>RL

  25. C=39.46 pF; L=156.35 nH

  26. Constant Q Q of series impedance=ratio of reactance to resistance

  27. Constant Q Circle

  28. Example 4-4 Constant Q of 15 Q=15 The end of large terminating resistor will determine the Q.

  29. Example 4-4 (Adding a Series L) Get the admittance circuit with a series L

  30. Example 4.4 Get back with the center of chart with a shunt cap.

  31. Example 4-4 (Q=15)

  32. Compare the Smith Chart Design with Calculation in Matlab

  33. Example 4.8 • Design a T network to match Z=15+15j Ohm source to a 225 Ohm load at 30 MHz with a loaded Q of 5.

  34. Example 4.8 Get on Constant Q=5 curve

More Related