Design Of 24-40GHz Frequency Divider Applied To Ultra-wideband Millimeter Wave Frequency Source

The frequency synthesizer is an important component of the RF transceiver whose role is to provide the transceiver with a high stability,low phase noise,and sufficient local driving signal.In a millimeter-wave frequency synthesizer based on a charge-pump phase-locked loop,since the operating frequency of the programmable frequency divider is limited,the system usually uses a frequency divider with a fixed frequency division ratio(for example,divide-by-2)to lower the frequency of signal which is from the voltage-controlled oscillator in order to further processed by the next stage.The structure,linear ization model and noise model of the charge pump frequency synthesizer are discussed briefly,and the effect of the divider on the loop noise performance is determined in this paper.And the pr inciple,structure and performance of the injection-locked,regenerative,and digital frequency dividers widely used in millimeter-wave frequency bands are summarized and compared.It can be known from the system's requirements for the divider that the wide operating temperature range,wide frequency range,and low phase noise characteristics are the main design goals.Based on the literature research,a regenerative frequency divider characterized by high operating frequency,large bandwidth,and low phase noise was finally identif ied as the main research direction.On the premise of ensuring good high-frequency performance of the circuit,the circuit structure of the traditional regenerative frequency divider has been simplified and improved.In order to minimize the chip area,the transimpedance amplifier and the peaking inductance are removed.And load node of the mixer was parallelled by a shunt capacitor in order to get better low frequency characteristics.In this paper,the transmission characteristics and frequency response characteristics of Gilbert's double-balanced mixer are analyzed in detail.And the circuit design,pre-simulation,layout design,post-simulation and electromagnetic simulation of a regenerative divider by two in 0.13?m SiGe BiCMOS process are completed.The electromagnetic field simulation results are as follows,in the worst case of the simulation result(SS process corner,125°C),the frequency division range is 20~50GHz,and the phase noise performance is-125.0dBc/Hz@1kHz,-142.7dBc/Hz@1MHz and the operating current is 43.7mA.The results show that the design meets the requirements and retains a certain design margin.The broadband high-speed divide-by-2 circuit designed in this paper has been applied to ultra-wideband millimeter-wave frequency synthesizer.