LTCC Filter Overview
LTCC (Low Temperature Co-fired Ceramic) filters integrate multiple dielectric layers with embedded conductors, resonators, and capacitors in a small package. They offer excellent performance from DC to 30+ GHz with tight dimensional tolerances and stable temperature characteristics.
LTCC Filter Properties
| Property | LTCC Filter | Typical Value |
|---|---|---|
| Frequency range | 100 MHz – 30+ GHz | Wide range |
| Insertion loss | Low (high-Q resonators) | 0.5–2.5 dB |
| Dielectric constant εr | Fixed by material (5–30) | εr ≈ 7–10 typical |
| Temperature stability | Very good (ceramic) | <±20 ppm/°C |
| Size | Very compact (multilayer) | 1.0×0.5 mm to 3.2×2.5 mm |
LTCC Filter S-Parameter Analysis
- Load LTCC filter .s2p file from manufacturer
- S21 dB → BW Marker → reads passband center, IL, 3dB BW
- Note: LTCC filters often show flat passband (low Chebyshev ripple) due to 3D resonator Q
- Group Delay: check passband flatness — LTCC can achieve very flat GD
- S11, S22 match: LTCC often shows better return loss than SAW due to integration
- Temperature check: load .s2p at −40, 25, 85°C — expect very small f₀ shift (<±10 MHz)
LTCC vs Alternative Technologies at 5 GHz
| Metric | LTCC | BAW | Discrete LC |
|---|---|---|---|
| Size (BPF 5 GHz) | 2×1.2mm (small) | 1.1×0.9mm (smallest) | 3×2mm+ (large) |
| IL at 5 GHz | 0.8 dB | 1.2 dB | 1.5 dB |
| Integration | Embedded: L, C, R possible | Filter only | Separate components |
RF View LTCC Analysis: Load LTCC filter .s2p for full analysis — BW, IL, group delay, temperature stability. LTCC filters typically show excellent flat group delay — confirm with RF View Group Delay view. Free on Android.