A Fully Integrated X-Band Multifunction Core Chip in 0.25 µm GaN HEMT Technology

This paper presents the design of a wide band and highly compact multifuction core chip Monolithic Microwave Integrated Circuit (MMIC) using WIN Semiconductor’s 0.25 µm Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) process design kit for the first time. The core chip is designed for use in GaN based X-band Transmit Receive (T/R) modules of Active Electronically Scanned Antenna (AESA) radars. Core chip operates in the frequency band of 9 to 11 GHz and provides multiple functions that includes 6-bit Digital Phase Shifter (DPS) for beam steering, 6-bit Digital Step Attenuator (DSA) for amplitude correction, interstage Low Noise Amplifiers (LNAs) and Single Pole Double Throw (SPDT) T/R switches. The Electromagnetic Simulation (EM) shows that MMIC exhibits a transmit gain of 19 dB and receive gain of 17 dB at 9 GHz. Transmit path Root Mean Square (RMS) gain and phase error are better than 1.15 dB and 4.7◦ respectively. The RMS attenuation and insertion phase shift error are also better than 0.75 dB and 7.25◦ respectively. The receive path has a maximum noise figure of 5.8 dB at 11 GHz. This core chip occupies die area of 15.36 mm2 (6.65 mm x 2.31 mm). The compact size, low receiver noise figure and high transmit/receive gain makes this core chip suitable for integration in T/R modules of X-band AESA radars.