APPENDIX A
Example of a Solenoid Design
The design of a solenoid inductor was described in Chapter 2. An example for a 100-nH solenoid design where the Q is evaluated at 200 MHz is shown below using the program SOLENOID where the bold type indicates user inputs. After initial values for the solenoid are given, the form length and number of integral turns are modified, but the form diameter remains unchanged. The interwire capacitance, C, the self-resonant frequency, Fres, and the Q are calculated.
Frequency in Hz for Q calculation = 200.E6
Geometry -> Inductance, type <G>
Inductance -> n, the number of turns, type <L>
L
Desired inductance, L (H), initial form Length,
Form Diameter - inches, Initial value for no. turns
100.E-9, 0.5, 0.1, 20
Number of turns = 13.00000
AWG = 21.0 Wire Diameter = .284625E-01
Final Length = .576708E+00 inches
Pitch = .44362E-01 Wire Diameter = .28462E-01 in.
Turn Diameter = .12846E+00 in. Form Diameter = .10000E+00 in.
L = .10002E+00 µH
C = .203350E+00 pF Fres = .111600E+04 MHz
Q = .649760E+02 at F = .200000E+03 MHz