Ka-band pHEMT quadrupler with injection and extraction from oscillator frequency doubling points

A Ka-band injection-locked quadrupler MMIC is demonstrated using 0.15-µm pseudomorphic high electron mobility transistor (pHEMT) technology. pHEMT technology is suitable to the millimeter wave quadrupler by using the topology of high-order sub-harmonic injection lock based on a cross-coupled oscillator. Furthermore, thanks to the semi-insulating GaAs substrate, it is easy to implement microwave/millimeter wave passive components to achieve accurate balanced signals. As a result, the measured output power of the quadrupler is 8 dBm for frequency of 30 GHz and the locking bandwidth reaches 300 MHz.