Two-Terminal InGaAs Microwave Amplifier

The feasibility of using a two-terminal InGaAs planar Gunn structure as a microwave amplifier is proposed and verified. By achieving a pronounced negative differential resistance with a peak-to-valley current ratio of 1.20, our devices are able to amplify microwaves at a high gain of 17 dB. Compared to commonly used three-terminal transistor-based microwave amplifiers, the proposed devices not only have a simple structure but also are capable of achieving high operating frequencies even with relatively large feature sizes. The device with a channel length of 4 μm has a positive gain up to about 77 GHz, and the 2-μm device is able to amplify microwaves well beyond 110 GHz. Furthermore, the planar Gunn amplifier shows a good linearity over a wide input power range from -45 to about 0 dBm. A good operation stability has also been demonstrated despite having no substrate thinning and heat sink.