High-Performance 94-GHz Single-Balanced Diode Mixer Using Disk-Shaped GaAs Schottky Diodes

We present a high-performance 94-GHz single-balanced monolithic millimeter-wave integrated-circuit (MMIC) mixer using the disk-shaped GaAs Schottky diodes grown on an n/n+ epitaxial structure. Due to the superior characteristics of the GaAs diodes with high diode-to-diode uniformity, the mixer shows a conversion loss of 5.5 dB at 94 GHz, a 1-dB compression point (
P

<sub>1

-dB</sub>
) of 5 dBm, and high local-oscillator to radio-frequency isolation above 30 dB in an RF frequency range of 91-97 GHz. To our knowledge, the fabricated mixer shows the best performance in terms of conversion loss at 94 GHz and
P

<sub>1

-dB</sub>
among the W-band MMIC mixers without amplifier circuits.