Daily Archives: December 2, 2022

RF MEMS Switches for 5G Networks

For high-power RF designs like 5G networks, Menlo Micro has added an RF MEMS switch that contains an integrated driver circuit for a charge pump. The RF MEMS switch operates from DC to 6 GHz.

The new RF switch from Menlo Micro is one of a family of SP4T or single-pole/four-throw, DC-t0-6 GHz switch, and is meant for 5G infrastructure, measurement, and testing equipment involving high-power RF switching applications. Menlo Micro is using its own Ideal Switch technology for the high integration MM5140 SP4T switch. The technology gives the new switch power handling capability up to 25 W, an ultra-low insertion loss, and the highest linearity in the industry. The MM5140 SP4T switch easily outperforms all types of traditional solid-state switches and electromechanical relays.

The MM5140 SP4T switch performs RF operations at high power levels over a wide temperature range of -40 °C to +85 °C, delivering superb linearity from DC to 6 GHz. 5G RF applications demand significant reductions in distortion, which the switch’s IP3 of 95 dBm provides conveniently.

Menlo Micro has custom designed a built-in high-voltage charge pump or driver circuit and integrated it into the LGA package of the MM5140 SP4T switch. The charge pump circuit has both GPIO and SPI digital interfaces so that any test system or host processor can keep control over it.

Although the new module has the existing MM5130 at heart, it also has the CMOS charge pump driver ASIC, driver circuitry, and other peripheral passive components in its 5.2 X 4.2 mm package.

As the MM5140 SP4T switch is a single-pole four-throw device, the voltage must route over to each of the four gate lines. This requires the presence of either a MOSFET drive circuit or a dedicated multiplexer IC. Along with the integrated charge pump and the driver circuitry, the MM5140 SP4T switch saves board area and bill of materials.

The integrated passive components include a large capacitor that the charge pump requires for handling the high voltage that drives the MEMS. This helps reduce the BOM for passive components.

The difference between the MM5130 and the MM5140 is their operational speed. The MM5130 is a design meant to operate at higher frequencies, such as the microwave band. The design of the MM5140 is meant for a sub-6 GHz application. The MM5140 comes in an LGA package rather than the WLCSP of MM5130. That makes it easier for customers to design their boards, as the LGA package has a bigger pitch.

Moreover, Menlo Micro has eliminated some external components for the MM5140 design reduces its complexity. This helps in simplifying RF front-end development including receivers and transmitters, beamforming antennas, and RF filters. These are necessary for radar systems and advanced radio architectures.

5G base stations typically use RF/microwave solid-state switches and RF electromagnetic relays that the MM5140 SP4T switch can replace. The replacement offers significant improvements over the competing technologies, especially in the integrated capability, BOM count reduction, and real-estate savings on the board. Moreover, the MM5140 SP4T switch exhibits far better reliability over the other competing technologies.