An RPSMA PCB connector is a Reverse Polarity SMA connector designed for direct mounting onto a printed circuit board, rather than for termination onto a length of cable. The center contact position is reversed compared to a standard SMA connector, while the outer threaded coupling remains unchanged, so the connector body threads onto standard SMA mating hardware but does not form a signal path with a standard SMA center contact. As a manufacturer of RF coaxial connectors since 1999, Yangzhou Jingcheng Electronics Co., Ltd (JC Company) produces RPSMA PCB connectors in several mounting styles for use on RF and wireless circuit boards.
Reverse Polarity Design Principle
In a standard SMA connector, the plug carries the center pin and the jack carries the center socket. In an RPSMA connector, this arrangement is reversed: the RPSMA plug contains a center socket, and the RPSMA jack contains a center pin. This reversal applies equally to PCB-mount versions, meaning the PCB footprint and center contact geometry of an RPSMA PCB connector differ from those of a standard SMA PCB connector even though the outer body and thread dimensions are compatible.
Mounting Types
RPSMA PCB connectors are produced in several mounting configurations, selected according to the board layout and mechanical requirement of the assembly.
| Mounting Type |
Description |
Typical Application |
| Edge mount |
Connector body is positioned at the board edge, with the center contact soldered to the board trace along the edge |
Boards with an accessible edge for connector placement |
| End launch |
Connector is mounted at the end of the board with the center contact aligned to the board microstrip or stripline |
RF boards requiring a controlled impedance transition at the board edge |
| Through-hole |
Connector pins pass through plated holes in the board and are soldered on the opposite side |
General purpose board mounting where vertical connector placement is acceptable |
| Surface mount (SMT) |
Connector is reflow soldered directly onto board pads without through-hole pins |
Automated assembly processes and space-constrained board layouts |
Panel and Bulkhead PCB Variants
In addition to direct board mounting, some RPSMA PCB connectors are supplied with a bulkhead or panel-mount body, allowing the connector to be fixed through an enclosure wall while the rear contact is connected to the board through a short internal cable or a direct board interface. This configuration is used where the connector must be externally accessible while remaining electrically connected to internal circuitry.
Typical Applications
RPSMA PCB connectors are used on circuit boards within RF and wireless systems that require a reverse polarity interface, including:
- Wi-Fi and wireless local area network (WLAN) modules
- Router and access point main boards with external antenna ports
- Machine-to-machine (M2M) and IoT communication boards
- Test fixtures and evaluation boards requiring a reverse polarity connection point
Key Technical Parameters
| Parameter |
General Reference Range |
| Impedance |
50 ohm |
| Frequency range |
DC to several GHz, depending on connector series and board transition design |
| Mating cycles |
Rated according to threaded coupling design, typically several hundred cycles |
| Mounting process |
Wave solder, hand solder, or reflow solder, depending on mounting type |
| Contact materials |
Brass or beryllium copper body with gold or other plating on contact areas |
Selection Considerations
When selecting an RPSMA PCB connector, the following factors are typically reviewed:
- Board thickness and edge accessibility, to determine edge mount or end launch suitability
- Assembly process used, such as wave soldering, hand soldering, or reflow, to determine through-hole or surface mount selection
- Required plug or jack polarity based on the mating cable or equipment interface
- Operating frequency range and impedance matching requirement of the RF trace
- Mechanical retention requirement, including whether the connector will experience repeated mating cycles
Frequently Asked Questions
What is the difference between RPSMA and standard SMA PCB connectors?
The outer thread coupling is the same, but the center contact position is reversed. This means the board footprint and mating behavior differ from a standard SMA PCB connector, even though both use the same thread interface.
Can an RPSMA PCB connector be soldered using an automated process?
Through-hole and surface mount RPSMA PCB connectors can generally be processed using wave soldering or reflow soldering, depending on the specific connector design and the assembly equipment used.
Is edge mount or end launch better for RF performance?
End launch designs are generally used where a controlled impedance transition to the board trace is required, while edge mount designs are used where board space and layout constraints take priority. The appropriate choice depends on the specific board design and frequency requirement.
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