High-power III-Nitride Integrated Microwave Switch with capacitively-coupled contacts

We fabricated novel monolithically integrated microwave switch using AlGaN/GaN heterojunction field-effect transistors (HFET) without ohmic contacts. All three electrodes: source, gate and drain, formed by capacitively coupled contacts (C3) to the 2D channel. The C3HFETs do not require annealed contacts and hence can be fabricated using alignment-free technology. This makes them ideally suitable for microwave ICs. C³HFETs have much higher RF switching powers. In the frequency range 1...10 GHz the switch IC shows -1 dB insertion loss, the isolation -30 dB and the switching powers +39 dBm (limited by the available RF power source).