A1313AN-0001GGH=P3: Measured Q, L and Frequency Analysis
These numbers matter because Q and L determine insertion loss, bandwidth, and tuning resolution for RF networks; a 72 Q at VHF implies modest loss and predictable reactance for many tuning and matching tasks. This article gives a data-driven analysis of measured Q, inductance, and frequency behavior for A1313AN-0001GGH=P3, explains measurement methods, interprets circuit impact, and offers practical selection and test guidance.
Background: Component Overview and Performance Significance
This component is a small surface-mount adjustable inductor designed for compact VHF applications. Typical nominal inductance is around 50 nH with a manufacturing tolerance (often ±10–20%). Reported typical Q values are in the mid-double-digits in the VHF band, and the usable frequency range is commonly given from tens of MHz up toward a few hundred MHz before Self-Resonant Frequency (SRF). The package is SMD, low-profile, and intended for PCB mounting.
Key Specifications at a Glance
Key specifications: nominal L ≈ 50 nH (tolerance per datasheet), typical Q values mid-50s to mid-70s depending on frequency and mounting, and recommended operating band in the VHF region up to where SRF approaches. The term adjustable inductor applies because the part is tuned during production or assembly to reach target L; designers should verify L and Q on their own board because packaging and pads influence performance.
Typical RF Applications and Performance Constraints
Common uses include tuning networks, small VHF filters, input matching for automotive infotainment RF front-ends, and resonant elements in tank circuits. Q factor constrains selectivity and insertion loss: a lower Q increases filter loss and widens bandwidth. Example impacts: a narrowband filter requiring 1 dB insertion loss may need Q > 80 at center frequency; an impedance match for a high-Q resonator demands stable L within tolerance to avoid detuning.
Measured Q: Equipment, Method, and Raw Results
Q factor measurements were performed with a two-port VNA configured for 20–120 MHz sweeps. Q factor is reported as unloaded Q derived from S21 resonance or from series RLC extraction using measured S11/S21 and standard conversion.
Measurement Setup
- •Two-port VNA, 401 points
- •IF Bandwidth: 1 kHz
- •Source Power: 0 dBm
- •SOLT Calibration + De-embedding
Interpretation
A Q of ~72 at 100 MHz indicates moderate loss—acceptable for many matching networks but marginal for very narrowband filters. If the design needs
| Frequency (MHz) | Measured L (nH) | Measured Q Factor | Visual Q Trend |
|---|---|---|---|
| 20 | 52 | 85 |
|
| 50 | 51 | 78 |
|
| 100 | 50 | 72 |
|
| 120 | 48 | 60 |
|
Inductance (L) and Frequency Response: Observed Behavior
Measured inductance tracks nominal ~50 nH with a slight downward drift at higher frequencies due to internal winding capacitance and skin effect. The Self-Resonant Frequency (SRF) was estimated from the impedance magnitude peak and phase reversal near ~240–300 MHz; above SRF, the part becomes capacitive.
L Value & Tolerance
L ≈ 50 nH nominal, ±10–20% variability between units. Expect a 5–10% effective L decrease near 100–120 MHz from parasitic effects. Record L as L@f (e.g., 50 nH @ 100 MHz).
Matching & Filter Design
Rule of thumb: keep operating frequency below 0.6–0.7× SRF for stable inductive action. If operating closer, compensate with network design to avoid unexpected matching shifts.
Measurement Best Practices and Sources of Error
PCB layout and mounting significantly affect measured L and Q. Pad geometry, solder fillet volume, nearby ground pours, and test-fixture launch inductance add or subtract effective inductance and introduce loss.
- Oversized ground clearance causing parasitic capacitance shifts.
- Long launches and inconsistent solder joints lowering the Q factor.
- Inadequate de-embedding of the test fixture.
Practical Recommendations & Troubleshooting
Selection Guidance
Choose A1313AN-0001GGH=P3 when you need a compact SMD adjustable inductor with medium-high Q at VHF and a nominal L around 50 nH. Ensure SRF > 1.4× operating band.
Troubleshooting Flow
- Isolate board effects on a reference fixture.
- Inspect and reflow solder joints.
- Shorten launches or alter pad geometry.
- Check sample variance across different lots.
Summary
- ✓ Measured Q Behavior: Q ≈ 72 at 100 MHz indicates moderate-low loss suitable for VHF matching; confirm on final PCB production.
- ✓ Nominal L: ≈ 50 nH with small frequency-dependent decrease; always report L@f and SRF in documentation.
- ✓ Caveats: Layout, soldering, and de-embedding are critical for reproducibility of both L and Q data.
