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| author | drowe67 <[email protected]> | 2023-07-14 10:33:23 +0930 |
|---|---|---|
| committer | GitHub <[email protected]> | 2023-07-14 10:33:23 +0930 |
| commit | 6588e77f38bdebd7adffe091b22e7760d95d0ccb (patch) | |
| tree | e015b6d01db10ff219f5d1cf49eb3dcadb7dbe48 /octave/rf_bpf.m | |
| parent | ac7c48b4dee99d4c772f133d70d8d1b38262fcd2 (diff) | |
| parent | 98992bc3585124981450659394d6f84032b81370 (diff) | |
Merge pull request #1 from drowe67/dr-cleanup
Cleanup
Diffstat (limited to 'octave/rf_bpf.m')
| -rw-r--r-- | octave/rf_bpf.m | 37 |
1 files changed, 0 insertions, 37 deletions
diff --git a/octave/rf_bpf.m b/octave/rf_bpf.m deleted file mode 100644 index e0a39ba..0000000 --- a/octave/rf_bpf.m +++ /dev/null @@ -1,37 +0,0 @@ -% rtlsdr_bpf.m -% -% David Rowe 24 August 2018 -% -% Calculate component values for cascaded HP-LP 2-8 MHz Chebychev filter -% -% From "RF Circuit Design", Chris Bowick, Ch 3 - -1; - -function C = find_C(Cn, fc, R) - C = Cn/(2*pi*fc*R); -endfunction - -function L = find_L(Ln, fc, R) - L = R*Ln/(2*pi*fc); -endfunction - -% 3rd order HP filter, 1dB ripple Cheby, 3MHz cut off, >20dB down at -% 1MHz to nail strong AM broadcast signals, Table 3-7A. Use a Rs=50, -% Rl=50, so Rs/Rl = 1. Note we assume a or phantom load in between -% cascaded HP-LP sections of 50 ohms. - -L1 = find_L(1/2.216, 3E6, 50); -C1 = find_C(1/1.088, 3E6, 50); -L2 = find_L(1/2.216, 3E6, 50); - -printf("L1: %f uH C1: %f pF L2: %f uH\n", L1*1E6, C1*1E12, L2*1E6); - -% 3rd order LPF, 8MHz cut off so >30dB down at 21MHz, which aliases back to 7MHz -% with Fs=28MHz on RTLSDR (14 MHz Nyquist freq). Rs=50, Rl=50, Rs/Rl = 1 - -C2 = find_C(2.216, 9E6, 50); -L3 = find_L(1.088, 9E6, 50); -C3 = find_C(2.216, 9E6, 50); - -printf("C2: %f pF L3: %f uH C3: %f pF\n", C2*1E12, L3*1E6, C3*1E12); |
