All About MMCX Cable Assemblies
Key Takeaways
- MMCX (Micro-Miniature Coaxial) connectors are compact RF coax connectors similar to MCX but about 30 % smaller, ideal for high-density and space-critical designs.
- MMCX cable assemblies typically operate up to 6 GHz and are available in 50 Ω and 75 Ω versions, making them suitable for a wide range of RF and microwave applications.
- The snap-on coupling mechanism allows quick, reliable connections with 360° rotation, facilitating easy assembly and deployment in compact systems.
- MMCX assemblies are commonly used in antenna systems, Wi-Fi modules, GPS receivers, embedded RF boards, and test equipment, thanks to their small size, low loss, and vibration resistance.
- These cable assemblies can be built on a variety of coax types, such as RG-174, RG-316, and RG-178, providing flexibility in design and performance.
What Are MMCX Cable Assemblies?
MMCX cable assemblies are compact RF interconnect solutions that use Micro-Miniature Coaxial (MMCX) connectors terminated to flexible or semi-flexible coaxial cables. Designed for applications where space is limited, MMCX assemblies provide reliable signal transmission while maintaining a small footprint. These assemblies are commonly used to connect RF modules, antennas, and test points in systems operating across low to mid microwave frequency ranges. Due to their miniature size and snap-on coupling mechanism, MMCX cable assemblies are ideal for high-density electronic designs where frequent connections and disconnections may be required.
Key Features and Design of MMCX Connectors
MMCX connectors are approximately 30 percent smaller than MCX connectors, making them well-suited for compact and lightweight RF designs. They feature a snap-on interface rather than a threaded coupling, allowing for quick installation and removal without specialized tools. One of the defining design characteristics of MMCX connectors is their 360-degree rotational capability, which reduces cable strain and improves flexibility during assembly. Electrically, MMCX connectors are typically available in 50-ohm and 75-ohm impedance options and are designed to support frequencies up to approximately 6 GHz, depending on cable type and construction. Their robust contact design also offers good vibration resistance for mobile and embedded applications.
Micro Miniature Coaxial (MMCX) connectors are a type of blind-mate or snap-on style coaxial interface based on the MCX connector type. MMCX Cable Assemblies along with MCX cable assemblies are often used as an easily replaceable cable assembly between antennas and transceivers/receivers, Wi-Fi cards, TV tuners, GPS receivers, video transmitters for first-person view (FPV) radio control piloting systems, in-ear monitors, budget oscilloscopes, budget signal generators, and budget signal analyzers. MMCX connectors are very similar to MCX connectors but are smaller in dimension and are typically rated for 500 mating cycles. The outer diameter of an MMCX connector is 2.4 mm, which allows for very tight pitch installations compared to threaded coaxial connectors and even other lock-snap connectors.
MCX connectors are generally designed to conform to the European CECC 22000 specification. These connectors are meant to be vibration and shock resistant and are intended to operate in rugged environments with minimal wear or chance of disconnecting. Most MMCX are made of brass or stainless steel as the base metal with a thin gold plating or nickel plating, which makes these connectors extremely resistant to environmental damage for corrosive chemicals.
MMCX connectors are made to allow for 360-degree rotation about the coaxial axis, though excessive rotation can cause damage to the connector interface. Most MMCX cable assemblies are made to be 50 Ohms, though there are 75-ohm varieties. Standard MMCX cable assemblies are designed to operate to 6 GHz, though precision MMCX could potentially reach higher operating frequencies. MMCX cable assemblies and connectors are often used because they are much easier to remove and replace than U.FL, MHF4, and W.FL connectors.
MMCX cable assemblies are frequency made from crimping RG 178, RG 316, or RG 174 coaxial cables to a variety of MMCX cables.
MMCX cables are most often used for low-power and cost-sensitive RF/microwave applications but can also be used for high-speed digital and sensitive analog signals that benefit from being carried over a coaxial interface due to noise immunity and low loss. Given the diverse uses of MMCX both as internal and external interconnect, MMCX adapter cable assemblies are commonly available with SMA, SMB, SMC, SSMC, MCX, BNC, and SMA connectors on the opposite side. There are also MMCX adapter cables with right angle (RA) connectors to aid with insertion in tight spots.
FAQs (Frequently Asked Questions)
Q1: What does MMCX stand for?
A: MMCX stands for Micro-Miniature Coaxial, a type of RF connector that is smaller than MCX connectors but maintains similar broadband performance.
Q2: What frequency range do MMCX cable assemblies support?
A: Standard MMCX assemblies typically support frequencies up to about 6 GHz, suitable for many RF and microwave systems.
Q3: What impedance are MMCX cables?
A: Most MMCX cable assemblies are designed with 50 Ω impedance, although 75 Ω versions are also available.
Q4: How many mating cycles can MMCX connectors handle?
A: MMCX connectors are generally rated for around 500 mating cycles, making them suitable for repeated connections in testing and field applications.
