Low power dual transformer injection locked frequency divider using 0.5 μm GaAs E/D-Mode PHEMTs process

This letter proposes a new divide-by-2 injection locked frequency divider (ILFD) fabricated by 0.5 μm GaAs ED-Mode PHEMTs process and describes the operation principle of the dualtransformer ILFD. The first transformer is applied to replace two inductors of the cross-couple LC-tank oscillator circuit. The injection signal of the ILFD transmits into a transistor through a second transformer, which consisted of a bandpass filter achieving a high injection signal power and wide locking range. The measurement results show that the divider's free-running frequency were from 6.47 to 9.54 GHz (32.2%) with 3 V supply voltage. With an incident power of 0 dBm, the locking range is 3.07 GHz from the incident frequency 16.41 to 19.45 GHz (15.6%). The measured phase noise of free running VCO is -92.2 dBc/Hz at 1 MHz offset frequency at 9.45 GHz and this value of the locked ILFD is -128.4 dBc/Hz, which is 36.2 dB lower than the free running VCO. The core power consumption was 42 mW.