Design Of 24~40GHz SiGe BiCMOS Broadband Divide-by-2 Frequency Divider

The millimeter wave(MMW)frequency divider(FD),as one of the key blocks in MMW frequency synthesizers(FSs),are usually working behind the Voltage Controlled Oscillator(VCO).On the one hand,this module derives signals with lower frequencies from the VCO.On the other hand,it delivers the signals disposed to the Phase Frequency Detector(PFD),making them compared with the reference signal.In conventional MMW FSs based on phase-locked loop(PLL)systems,FDs with fixed frequency division ratio are generally adopted to lower the frequency of the output of VCO for proper operation due to the speed limitation on the programmable FDs.For the system requirement,a divider by 2 with definite operation frequency range 24~40GHz acquired based on 0.13?m SiGe BiCMOS process was designed,besides low phase noise,power consumption and high sensitivity,as well as great reliability throughout a broad temperature range.Regenerative division scheme was first applied,otherwise broad-band match technology and output buffer amplifier were also included to enhance performance.For purpose of increasing the upper frequency limit further,trans-impedance amplifier(TIA)as the load of the core was utilized instead of the pure resistance.After that,pre-simulation,layout,post-simulation and electromagnetic simulation were accomplished.Finally,the last simulation results show that the regenerative frequency divider(RFD)by 2 acquires the operating range from 22 to 32GHz with 0dBm input power and the FD works with 42.43mA dc current while the power supply is 3.3V.All these results are obtained under the circumstance of-55~125?temperature range in tt corner.For broader working range and lower power consumption,a kind of injection-locked frequency dividers(ILFDs)was employed for improvement.This circuit has a simple construction and the number of devices in the core needed is much less than that in the RFD previously.Also,electromagnetic simulation for the ILFD was accomplished.The divider can operate properly in the range of 12~75GHz and the largest phase noise are about-118dBc/Hz@1kHz and-143dBc/Hz@1MHz when the frequency of input signal is 40GHz with 0dBm input power.The whole circuit consumes dc current about 17.9mA merely with 3.3V supply.All these results are obtained under the circumstance of-55~125?temperature range in tt corner.The die area is approximately560×645?m~2.Obviously,this kind of ILFDs by 2 has tremendous advantages in the working range and power consumption with all other performances satisfied for design requirements.In conclusion,the ILFD designed in this paper can be applied for the Millimeter Wave Frequency Synthesizer.