The SMP interface provides an ideal interconnect solution for high frequency PCB board-to-board applications and cable-to-board applications.

The SMP interface is a subminiature interface in the same scale as MMCX connectors but offers a frequency range of DC to 40 GHz. It is commonly used in miniaturized high frequency coaxial modules and is offered in both a push-on and snap-on mating styles. The receptacles are available in surface mount, end launch and vertical configurations.

In addition to RF applications, the product is used to carry shielded high data signals typically up to 20 gigabits such as those common in optical transmission systems.

The interface is an excellent choice for PC board-to-board interconnects. For these applications, the interface series utilizes a male connector on each of the PC boards and a female-to-female adapter mounted in between to complete the connection. The female adapter is often called a bullet and is necessary to provide a flexible link between the male connectors. This flexible link allows .020 inches of radial float and .010 inches of axial float. Utilized in this manner the SMP product can provide multiple RF connections between stacking boards. The floating bullets used can be supplied in a variety of heights.

In the board-to-board application one male connector will be specified as a snap-on interface and the other as a push-on. This ensures that the bullet adapter remains fixed in the same male connector if the PC boards are separated.

In its snap-on configuration, the SMP interface is available in two levels of detent each with different mating and de-mating forces. The two levels are full detent and limited detent. In board mount applications, the lower level of detent (limited detent) is typically selected, as it is only required to retain the bullet. Full detent is often used for discreet cable connections where higher forces are desirable.

When specifying requirements for a board-to-board application the user should provide the required PC board connector configurations, the board-to-board spacing, and the tolerances associated. With this information, Amphenol can suggest a package of connectors to suit the application.

The SMP is of particular importance due to its significant role within the mission-critical systems of military aerospace applications. Learn more within the Microwave Journal Cable and Connector Supplement coming in March 2004.