Evaluation of LDMOS transistors for 10 Gbps switched mode applications and X-band power amplifier

Abstract

In this article we report on the capability of integrated LDMOS transistors for power amplifiers in 10 gigabit per second (Gbps) communication systems, smart power systems and X-band power amplifiers. The switched mode properties of the amplifier were evaluated using a 10.3125 Gbps pseudo random bit error sequence (PRBS) signal. A test mask according to the IEEE P802.3aq 10GBASE-LRM Ethernet standard was applied to evaluate the recorded eye diagram. No single hit was detected in the forbidden test mask regions after measuring 6 million data points. Load-pull measurements at 11 GHz show an operational gain of 16 dB, a maximum power added efficiency (PAE) of 30 % and a maximum drain efficiency (EFF) of 38 %. RF small signal scattering parameters of the LDMOS transistor were measured up to 67 GHz. A cutoff frequency of 27 GHz and a maximum oscillation frequency of 61 GHz were extracted. The investigated n-LDMOS transistor is modularly integrated into a 0.25 μm SiGe:C BiCMOS Technology.