TPMS Wire Antenna Engineering Guide for 315MHz and 433MHz Sensors
A practical engineering guide to bent-wire UHF antennas for TPMS sensors, from material and forming tolerance to enclosure detuning, RF validation, and automotive reliability.
Quick assessment
The visible part is consistent with a CNC-formed bent-wire UHF radiator. Final material and frequency must be confirmed by drawings and RF measurements.
A compact TPMS antenna must be tuned inside the complete sensor with its PCB ground, battery, housing, valve, potting, and matching network.
Decision factors
- Electrical length and free-end position control resonance.
- Material conductivity, temper, plating, solderability, and springback affect loss and consistency.
- Battery, PCB ground, housing, valve, and potting detune the antenna.
- A good S11 result alone does not prove radiation efficiency or communication range.
- 315MHz and 433MHz variants require separate verification.
- Vibration, centrifugal loading, corrosion, and joint fatigue must be validated.
Engineering decision matrix
| Review area | Recommended action | Validation evidence |
|---|---|---|
| Material and forming | Lock alloy, diameter, plating, developed length, bend radii, angles, and end position. | Material certificate, dimensional capability, optical inspection, and springback study. |
| Integration and clearance | Define feed, fixing method, PCB ground, battery, enclosure, valve, and potting boundaries. | Assembly drawing, controlled clearance inspection, and movement check under load. |
| RF matching | Tune the assembled sensor and evaluate impedance, S11, efficiency, gain, polarization, and TRP. | VNA data, chamber report, communication range, and packet reliability. |
| Reliability and production | Validate environment and correlate critical dimensions with RF performance. | Temperature, vibration, shock, centrifugal, corrosion, aging, and periodic RF sampling records. |
Verification workflow
- Measure developed length, bend angle, radius, coplanarity, feed point, and free-end position.
- Test S11 and impedance on the assembled sensor with a controlled fixture.
- Verify efficiency, gain, TRP, polarization, range, and packet reliability for each frequency variant.
- Repeat RF tests after temperature cycling, vibration, shock, centrifugal, humidity, and corrosion exposure.
- Use production sampling to correlate geometry with resonant frequency and radiated performance.
Quality and implementation risk
Uncontrolled material substitution, springback, enclosure detuning, weak joints, or an RF gate based only on S11 can produce unstable range, early field failures, and large batch variation.
Information needed for project review
- Target frequency and destination market.
- Antenna drawing, material, diameter, plating, and dimensional tolerances.
- PCB ground, battery, housing, valve, potting, and feed geometry.
- RF targets for S11, efficiency, gain, TRP, range, and packet reliability.
- Environmental and production acceptance requirements.
Engineering conclusion
Treat the wire shape, enclosure, battery, PCB ground, matching network, feed, and fastening method as one antenna system. Dimensional stability is necessary, but assembled RF evidence is the final acceptance gate.
For a project-specific review, provide the target frequency, antenna drawing, enclosure boundary, and RF acceptance criteria.
Submit TPMS antenna requirementsResource Scope and Project Inputs
This module helps readers convert website guidance into reviewable RFQ and project inputs for XSD Precision engineering communication.
Who This Resource Is For
TPMS sourcing, service, channel and engineering teams confirming OE numbers, vehicle year and market, frequency, programmable-sensor coverage and vehicle relearn validation boundaries.
Project Inputs
OE number, vehicle year, target market, 315MHz / 433MHz frequency, programming tool, sensor sample, activation/read results and relearn conditions.
How XSD Precision Uses This Information
The website explains decision logic, input checklists, validation paths and collaboration methods. Vehicle programs, test records, software details, quality records and project confirmation materials are reviewed through direct project communication.