A low-power differential injection-locked frequency divider with output power flatness in 0.5 μm E/D-mode GaAs PHEMT

This study implemented an injection-locked frequency divider (ILFD) on Ka-band millimeter-wave communication systems in 0.5 μm enhancement/depletion-mode (E/D-mode) GaAs PHEMT technology. The ILFD presents a low-power design based on the differential-injection circuit topology without using any injectors. Compared with the conventional single-injection ILFD circuits, the proposed ILFD exhibits output power flatness and wide locking range characteristics with a power consumption of 0.9 mW under a 0.4 V supply. The self-oscillation frequency was chosen to be 20 GHz for divided-by-2 operation. The measured locking range is approximately 11.5 GHz ranging from 32.5 GHz to 44 GHz when the injection power level is 5 dBm. The locking range exhibiting a 3 dB power roll-off characteristic at output is 10.5 GHz ranging from 33 GHz to 42.5 GHz.