Micro-coaxial cable sits in a narrower part of our factory mix — about 15% of production volume, but a larger share of the technically demanding work. As a micro coaxial cable manufacturer, these are the ultra-fine coax assemblies you find inside WiFi and 5G modules, medical endoscopes, AR/VR headsets, and high-speed test equipment. We build primarily with I-PEX MHF family connectors (MHF I through MHF 4), Hirose U.FL and W.FL, and Murata MM8130 / MM8430 series. Wire AWG runs from 40 to 50. MOQ starts at 100 sets, first samples in 7–10 days.
What Is a Micro-Coaxial Cable?
A micro-coaxial cable is an ultra-fine version of a standard coaxial cable, with center conductor, dielectric insulation, shield braid, and outer jacket all compressed into a diameter typically 0.5 mm to 1.5 mm overall. The extreme size reduction allows routing inside tight enclosures — mobile device chassis, medical probe heads, camera modules — where standard RG178 or RG316 coax simply wouldn’t fit.
Despite the size, these cables have to maintain controlled impedance and low signal loss at high frequencies. Key parameters:
- Characteristic impedance — typically 50 Ω for RF and antenna work, 75 Ω for video or specific signaling. Tolerance is ± 3 Ω to ± 5 Ω depending on application.
- Center conductor — silver-plated or tin-plated copper, solid or stranded. AWG 40 to 50. Material affects insertion loss at high frequencies.
- Dielectric — foam PE, solid PFA, or FEP. Choice of dielectric determines velocity of propagation and frequency handling.
- Shield — tinned copper braid, aluminum foil, or both. Braid coverage typically 90% + for good EMI and RF isolation.
- Return loss (S11) and VSWR — critical for RF applications. We measure this on first article builds when the client spec calls for it.
Micro-coax is different from the differential pair cables used in LVDS or eDP work. It carries single-ended RF or high-speed single-ended digital signals. For differential signaling at high speeds, designers typically choose twin-axial or twin-axial micro-coax pairs.
Micro-Coaxial Connector Families We Build With
The micro-coax connector landscape is dominated by three manufacturers. Choosing the right series matters because cable-to-connector frequency matching affects performance:
- I-PEX MHF series — the industry workhorse for mobile and embedded RF. MHF I (original) works to 6 GHz, MHF II to 15 GHz, MHF III to 15 GHz with improved mating, MHF 4 to 15 GHz in ultra-compact form, MHF 4L is the low-profile variant. MHF 4 and MHF 4L have become standard in current smartphones and WiFi 6/6E modules.
- Hirose U.FL and W.FL — U.FL is the de facto standard micro-coax connector in countless products dating back 20+ years. Rated to 6 GHz. W.FL is Hirose’s newer ultra-compact variant rated to 40 GHz, used in 5G millimeter-wave applications.
- Murata MM8030 / MM8130 / MM8430 — Japanese-designed alternatives often cross-referenceable with I-PEX or Hirose. MM8130 is a common WiFi module connector; MM8430 targets higher-frequency 5G applications.
- SMA, SMP, and SMPM on the other end — many assemblies terminate in standard RF connectors for testing, instrumentation, or board-edge interfacing.
We stock common MHF 4 and U.FL variants for fast turnaround and source less-common pin configurations on 1–2 week lead times.
Micro-Coaxial Cable Specifications We Support
| Parameter | Range |
|---|---|
| Wire AWG | 40 AWG to 50 AWG |
| Overall Diameter | 0.5 mm to 1.5 mm |
| Characteristic Impedance | 50 Ω ± 3 Ω (standard RF), 75 Ω available |
| Frequency Range | DC to 40 GHz (depends on connector + cable combination) |
| Center Conductor | Silver-plated or tin-plated copper, solid or stranded |
| Dielectric | Foam PE, solid PFA, FEP |
| Shield Coverage | 90%+ braid, plus aluminum foil on request |
| Connector Types | I-PEX MHF I/II/III/4/4L, Hirose U.FL/W.FL, Murata MM series, SMA, SMP, SMPM |
| Cable Length | 30 mm to 500 mm typical (longer on request) |
| Operating Temperature | -40 °C to +105 °C (standard), higher with PFA dielectric |
| Bend Radius | 5× to 8× cable diameter minimum |
| Compliance | RoHS, REACH, UL 1354 plenum rating on specific builds |
| MOQ | 100 sets standard, lower for prototypes |
For specialized requirements — phase-matched pairs, very high VSWR specifications, or frequencies above 40 GHz — contact us directly. These are doable but require additional engineering review.
Typical Applications
Our micro-coax production splits across six main application areas, with each having its own technical priorities:
WiFi, Bluetooth, and 5G antenna cables. By volume, the largest single use. These connect the radio module to the internal antenna inside laptops, IoT devices, smart appliances, and drones. MHF 4 and U.FL dominate here. Specifications focus on insertion loss and connector retention during device assembly.
Medical endoscopes and imaging probes. Ultra-fine coax carries signals from miniature image sensors inside endoscope tips back to the processing console. Cable diameters go down to 0.5 mm to fit inside the endoscope lumen. These programs run ISO 13485 workflow and use biocompatible jacket materials. We accomodate specific autoclave and sterilization requirements per the client’s device class.
AR/VR headsets. Tight-space interconnects carrying signals between display drivers, camera modules, and main PCBs inside the headset housing. Here the challenges are both RF performance and mechanical reliability — the cables have to survive repeated assembly and user handling.
High-speed test and measurement. Lab probes, network analyzer cables, oscilloscope active probes. These demand the tightest impedance tolerance and lowest VSWR. Frequencies often run into millimeter-wave ranges.
Smartphone and tablet camera modules. Many premium camera modules use micro-coax for data off-loading. The cable routing between the module and the SoC passes through very tight spaces near the battery and display.
Industrial RF and IoT sensor networks. Factory-floor sensor nodes, industrial WiFi, and smart metering use micro-coax antenna leads. Here the mechanical spec (IP ratings, chemical resistance, operating temperature) often becomes more demanding than the pure RF spec.
Why SZFRS for Micro-Coaxial Cable Work
Micro-coax work has a small margin for error. A cable that passes continuity can still fail VSWR testing. Our approach:
RF-specific first article verification. Every new micro-coax program gets return loss (S11) and VSWR testing on first article samples. We can match the spec your device qualification requires — typically -15 dB to -25 dB return loss at the target frequency.
I-PEX MHF series experience at volume. Roughly 60% of our micro-coax work involves MHF 4 or MHF 4L connectors. Our operators are trained specifically on MHF mating and on the extremely compact termination process.
Medical-grade capability. For endoscope cable and other medical imaging work, we run ISO 13485 process on dedicated production lines. Biocompatible jacket material sourcing and traceability extend to the raw material level. See our quality and certifications page for the full medical compliance scope.
Cross-reference expertise. Many clients need to substitute an I-PEX part for a Hirose U.FL or vice versa when one vendor has a stock-out. We maintain cross-reference tables and can quickly identify mechanically and electrically equivalent parts.
IPC/WHMA-A-620 trained operators. Class 2 default, Class 3 on request. See the capabilities page for equipment and testing details.
Our Micro-Coaxial Cable Manufacturing Process
- Drawing review and RF spec check. Impedance target, frequency range, connector series, and length reviewed. We flag any inconsistencies before quoting.
- Material sourcing. Coax wire selected to match the target impedance and frequency range. Connectors from authorized I-PEX, Hirose, or Murata distribution.
- Precision stripping. Semi-automatic strippers handle the layered construction — outer jacket, braid, dielectric, center conductor — without nicking inner layers. This step is where most quality issues originate, so we staff experienced operators only.
- Connector termination. Crimp or solder depending on connector family. MHF and U.FL are crimp-type; SMA and SMP can be either. Crimp force and height verified per IPC/WHMA-A-620.
- Shield grounding. Braid termination to connector shell. Done correctly, this is invisible; done wrong, it ruins RF performance at high frequencies.
- Electrical testing. 100% continuity. VSWR and insertion loss sampling per the quality plan. TDR for impedance verification on programs that require it.
- Visual and dimensional inspection. Cable length, connector position, and overall cosmetic inspection.
- ESD packaging. Anti-static bag, moisture barrier where specified.
Frequently Asked Questions
What’s the difference between MHF, MHF II, MHF III, and MHF 4?
All four are I-PEX micro-coax connectors. MHF I (original) works to 6 GHz and is older. MHF II supports up to 15 GHz. MHF III has improved mating reliability at similar frequencies. MHF 4 and MHF 4L are the newest, with ultra-compact footprints for modern smartphones and WiFi 6/6E modules. MHF 4L specifically is the low-profile version. For new designs, MHF 4 or MHF 4L is almost always the right choice.
Are MHF and U.FL interchangeable?
Mechanically similar but not identical. Some MHF and U.FL products mate with each other based on shared footprint, but the manufacturers officially specify compatibility per individual part number. We can build to either standard or cross-reference equivalent parts if your design calls for flexibility.
Can you build micro-coax for frequencies above 20 GHz?
Yes, with appropriate connector selection. W.FL (Hirose) is rated to 40 GHz and commonly used in 5G millimeter-wave applications. Murata MM8430 targets similar frequency ranges. For specific designs, send us the target frequency and we’ll recommend cable-connector combinations that hit the spec.
Do you provide VSWR and S-parameter test reports?
Yes. First article return loss and VSWR testing is standard for RF programs. We can provide per-lot test reports as part of the quality package if your qualification process requires it.
Can you build medical-grade micro-coax for endoscopes?
Yes. Medical endoscope cable is one of our core application areas. We run ISO 13485 workflow, biocompatible jacket material selection (PFA, FEP, silicone variants), and lot traceability to the raw material level. Send us your device class and sterilization method — we’ll match the material spec.
What’s the minimum cable length you can produce?
30 mm from connector to connector is achievable. Shorter is possible but harder to produce reliably — the stripping and termination process needs more space than the finished cable. Below 20 mm, we work with you on custom tooling.
Can you reproduce an older micro-coax cable from a sample?
Yes. Send the old cable. We measure diameter, identify dielectric material, characterize the connector, and verify impedance. For micro-coax, older OEM samples often use connector variants that have since gone EOL — we cross-reference to current production parts and match the electrical spec.
What’s your MOQ and lead time for custom micro-coax?
100 sets for production. Prototype batches of 10–50 pieces available with modest NRE. First samples ship 7–10 days from drawing approval. Repeat production in 10–14 days.
Related Cable Products
If you’re comparing cable options for an RF, antenna, or imaging application:
- Cable Assembly — full overview of our cable assembly capabilities.
- RF Cable Assembly (U.FL / MHF) — standard-diameter RF cable for antenna and instrumentation.
- Medical Cable Assembly — ISO 13485 compliant cables for medical imaging and devices.
- LVDS Cable — differential-pair cable for display interfaces.
- MIPI Cable — mobile processor interface for displays and cameras.
Ready to Quote Your Micro-Coax Project? – A Micro Coaxial Cable Manufacturer
Send us a drawing, the target frequency, or the application description. If you have an old sample that needs matching, mail it to us. Quote back in 24 hours, first sample in 7–10 days. Whether it’s a 100-piece prototype for an AR/VR research project or 50,000 WiFi antenna cables for a production program, we build both.