Complete Filter Specification Checklist
| Parameter | Source | Pass Criterion | RF View Method |
|---|---|---|---|
| Center frequency f₀ | S21 peak | f₀_spec ± Δf | BW Marker reads f₀ |
| Passband IL | S21 at f₀ | < IL_max | Single marker at f₀ → read S21 |
| Passband ripple | S21 within BW | < ripple_max | Delta marker min-to-max within BW |
| 3 dB bandwidth | S21 | BW_min to BW_max | BW Marker |
| Input return loss S11 | S11 | > RL_min | BW Marker on S11 with RL_min threshold |
| Output return loss S22 | S22 | > RL_min | Same as S11 |
| Stopband rejection (TX) | S21 at f_TX | > reject_min | Single marker at f_TX |
| Stopband rejection (other) | S21 at f_other | > reject_min | Multiple markers at all stop freqs |
| Group delay ripple | Group delay | < GD_ripple_max | Delta marker on GD plot |
| Shape factor | S21 | BW₋₄₀/BW₋₃ < SF_max | BW Marker at −3 dB and −40 dB |
Step-by-Step Verification Procedure
- Load filter .s2p → S21 dB view
- BW Marker → reads f₀, IL, 3dB BW → record all values
- Move single marker to TX band center → read S21 rejection
- Move marker to other stopband frequencies → record each
- Switch to S11 view → BW Marker at −14 dB threshold → reads VSWR<1.5 bandwidth
- Switch to Group Delay → delta marker over passband → record GD ripple
- Compare all recorded values against specification table → mark Pass/Fail
Documentation Template
Filter: Murata SFECF1G8CB0A0A (LTE Band 3 RX SAW) Date: 2025-01-15, Unit: S/N 12345, Condition: 25°C, 50Ω Parameter Spec Measured Pass? f₀ 1843 MHz 1844 MHz ✓ IL (max) 2.5 dB 1.83 dB ✓ 3dB BW (min) 70 MHz 75.2 MHz ✓ S11 RL (min) 10 dB 14.7 dB ✓ TX rejection (min) 50 dB 52.3 dB ✓ GD ripple (max) 100 ns 82 ns ✓ ALL PASS: Yes
RF View Filter Verification: Load filter .s2p → systematically check all spec parameters using BW Marker, single markers, delta markers, and Group Delay view. Export measurement summary to CSV for documentation. Free on Android.