Hybrid SPST Switch Delivers High Isolation Over an Ultra-wide Bandwidth

Abstract

Researchers at the University of California, Davis have developed a hybrid, complementary metal-oxide semiconductor (CMOS) mm-wave, single-polar single-throw (SPST) switch that combines the wide bandwidth features of a distributed structure and the compact implementation of coupled lump elements for an area-efficient layout.

Full Description

Within millimeter wave (mm-wave) applications, including passive imaging, short-range communications, and sensing applications, switches are essential components for transmitting/receiving, signal-routing, and modulation. Different from the traditional series-shunt switch architecture in radio frequency ranges, most published mm-wave switches remove the series switch to reduce insertion loss. However, without these series switches, isolation performance is degraded.

Researchers at the University of California, Davis have developed a hybrid, complementary metal-oxide semiconductor (CMOS) mm-wave, single-polar single-throw (SPST) switch that combines the wide bandwidth features of a distributed structure and the compact implementation of coupled lump elements for an area-efficient layout. This SPST switch achieves over 35 dB in isolation across an ultra-wide frequency range (from 54 GHz to 84 GHz), a minimum of 1.7 dB insertion loss, and less than -10 dB return loss with a 0.012 mm² chip area in 65 nm CMOS. Compared to other designs, this switch achieves an enhancement of more than 10 dB of isolation while maintaining similar insertion loss.

Applications

• Passive imaging
• Short-range communication
• Sensing applications

Features/Benefits

• Higher isolation compared with silicon optical amplifiers over a wide frequency range with small insertion loss
• Hybrid technique allows for the chip area is be conserved

Patent Status