Amphenol RF has developed several high power microwave relays for applying directly to a printed circuit board (PCB) utilizing the SMT process. These designs enable the user to move from a frame-mounted package design necessitating a labor-intensive final assembly into the supporting product. In addition to the physical mounting of these earlier designs, hand soldering of the solenoid power leads was required as well as cabling of the NC/C/NO contacts to the main PCB.

The new surface-mount coaxial relays feature a nominal characteristic impedance of 50 or 75 Ω depending on the cavity where internal switching occurs and based on the users’ application. The product can be supplied as either a single pole-double throw (SPDT) or single pole-single throw (SPST) design with fail-safe operation.

The SMT relays are designed for operation up to 3 GHz and feature maximum VSWRs of 1.15 from DC to 1 GHz, 1.2 from 1 to 2 GHz and 1.25 from 2 to 3 GHz. Insertion loss is 0.10, 0.15 and 0.20 dB maximum for the same frequency ranges, respectively, and isolation is 65, 60 and 50 minimum. The relays operate with a wide range of DV voltages and a power consumption of 2 to 3 W typical. They are designed to operate over a temperature range of –25° to +85°C and can operate for a minimum of 10,000 life cycles. Switching time for these mechanical relays is 10 ms maximum.

Using a gold-plated zinc die cast body and gold-plated beryllium copper or brass PC contacts, the construction of these relays allows for a SMT leaded or lead-free solder re-flow temperature of 260°C maximum for 10 seconds. In addition, there is a silicone rubber dust seal to protect the contact area.

Various FEA tools are utilized to optimize performance through analysis and then validate through extensive testing. Power handling is optimized by employing Ansoft ePhysics to accurately predict the thermal characteristics of the products and identify the ideal materials and configuration for each component. Currently offered products are rated for 50, 100 or 200 W continuous at up to 2 GHz.

With an understanding of the PCB characteristics, Amphenol RF can work with the user to develop a PCB footprint capable of optimizing RF performance at the launch area of the signals. These characteristics include PCB material, thicknesses and knowledge as to whether the PCB design represents a microstrip, coplanar or stripline configuration.

Special considerations have been taken to minimize overall package size and the comparative size benefit demonstrates a 50 percent savings of available real estate. This allows for denser packaging in all applications.

Each relay contains several features to withstand environmental conditioning. Highlights include a sealed construction with an IEC 529 rating of IP50 to ensure the RF switching cavity remains clean for error free operation in controlled office environments for extended lifecycles. A robust internal design ensures protection against industry standard vibration and mechanical and thermal shock conditions.

Strict quality control procedures are applied to production including 100 percent functional screening. Dedicated work cells and processes are configured to ensure cleanliness is maintained on critical switching components.

The products implement the latest technologies for cost reduction including zinc die casting, progressive die stamping, molding and selective plating. The product can be supplied in tape-and-reel for pick and place equipment resulting in significant total installed cost reduction. All internal components are designed to consider the necessary process temperatures for no-lead processes.

These products are backed by Amphenol’s global service and support team. A local representative is available to discuss specific applications.

Amphenol RF,
Danbury, CT (203) 743-9272,
RS No. 300