Monolithic integration of vertical-oriented schottky diode using 0.5×200 μm2 GaAs pHEMT for microwave limiter applications

In this paper, the development and implementation of vertical-oriented monolithic microwave ICs (MMICs) in Schottky diode structure are discussed. The Schottky diode is configured by shorting the drain and source contacts of a prefabricated pseudomorphic HEMT (pHEMT) in vertical arrangement to minimise the utilisation of chip area. Smaller forward voltage drop is observed from the Schottky diode which designed for microwave rectification. Measured S-parameters show good agreement with the simulated analysis. To investigate the feasibility of this approach, the Schottky diode is used in designing a limiter circuit. A very low insertion loss of less than 1.89 dB is observed at 3 GHz. It is also revealed the ability of limiter circuit to block high power level signal at 20 dBm of input power. This vertical-oriented approach provides promising solution to the integration of active and passive components in MMIC on a single chip.