Tapped-C transformer calculator
This code returns the tapped_c matching network's elements' values:
--> Q: the required loaded Q of the resonant circuit
--> Xp: either the inductive or capacitive reactance. They are equal at resonance
--> Rp: the equivalent shut resistance of the inductor (Ω)
--> C1: Tapped-C transformer's C1 capacitor (F)
--> C2: Tapped-C transformer's C2 capacitor (F)
--> L: Tapped-C transformer's L inductance (H)
--> IL_dB: insertion loss of the network (dB)
For getting the above values, it requires the following inputs:
--> fc: center frequency of the wanted resonant circuit (Hz)
--> B: bandwidth of the wanted resonant circuit (Hz)
--> Rs: source resistance
--> RL: load resistance
--> Qp: the Q of the inductor
So, the function call is,
[Q,Xp,Rp,C1,C2,L,IL_dB] = tapped_c(fc, B, Rs, Rl, Qp)
It displays the results in the command window, and it saves them a txt in the same folder it has been executed.
---------------------------------------------------------------------------------
Here is an example of a FM band mixer's tapped c transformer:
---------------------------------------------------------------------------------
>> fc = 98e6; % Hz
>> B = 20e6; % Hz
>> Rs = 50: % Ω
>> RL = 1.5e3; % Ω
>> Qp = 75;
>> [Q,Xp,Rp,C1,C2,L,IL_dB] = tapped_c(fc,B,Rs,Rl,Qp);
*************************** Tapped-C resonant matching network ***************************
|
| Initial data:
|
| Center frequency (fc): 98.00 MHz
| Bandwidth (B): 20.00 MHz
| Serial resistance (Rs): 50.00 Ω
| Load resistance (Rl): 1.50 kΩ
| Inductor Q at 98.00 MHz (Qp): 75
|
|
| The Tapped-C transformer's characteristic equations are the following:
|
| Rs' = Rs (1+C1/C2)^2 (1)
| CT = C1C2/(C1+C2) (2)
| Where
| CT is the equivalent capacitance that resonates with L|
|
| First we clear C1/C2 from (1) and we will use (2) in advance to get C1 and C2
|
| Let the system:
|
| Qp = Rp/Xp (3)
| Q = R_total/Xp (4)
|
| Resolving the proposed system,
|
| Xp: 143.06 Ω
| Rp: 10729.59 Ω
|
| Knowing that:
|
| C1 = (C1/C2) * C2 (5)
| Ct = C1||C2 (6)
|
| Then, solving the system above by replacing (5) in (6),
|
| ------------------
| | L : 232.34 nH |
| | C_1: 62.18 pF |
| | C_2: 13.89 pF |
| ------------------
|
| Finally, we calculate the insertion loss of the network,
|
| IL = 20log10(VL_resonant/VL_noResonant) (7)
|
| Solving (7)...
|
| IL = 20log10((ZL*Zc1*(RL + RS))/(RL*RS*ZL + RL*RS*Zc1 + RL*RS*Zc2 + RL*ZL*Zc1 + RS*ZL*Zc1 + RS*ZL*Zc2 + RL*Zc1*Zc2 + ZL*Zc1*Zc2))
|
|
| -------------------
| | IL(dB) : 8.84 |
| -------------------
*******************************************************************************************
Citar como
Gorka Zubia Garea (2024). Tapped-C transformer calculator (https://www.mathworks.com/matlabcentral/fileexchange/75456-tapped-c-transformer-calculator), MATLAB Central File Exchange. Recuperado .
Compatibilidad con la versión de MATLAB
Compatibilidad con las plataformas
Windows macOS LinuxEtiquetas
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!Descubra Live Editor
Cree scripts con código, salida y texto formateado en un documento ejecutable.
Versión | Publicado | Notas de la versión | |
---|---|---|---|
1.0.0 |