优化耦合方式的低相位噪声宽带正交压控振荡器设计

An Optimally Coupled Low Phase Noise Wideband Quadrature Voltage-Controlled Oscillator

本文对传统正交压控振荡器(QVCO)耦合方式进行了改进,提出了在耦合管的源端引入相移网络的方法,从而改善了QVCO电路的相位噪声性能以及减小输出相位失配,并依此设计了一个低相位噪声,输出相位关系稳定的宽带正交压控振荡器.QVCO电路采用TSMC 0.13 μm CMOS工艺进行设计,输出频率范围为3.4～5.48 GHz,即调谐范围达46.8%.测试表明,输出频率4.2 GHz时在频偏1 MHz处,相位噪声为-120 dBc/Hz.在整个输出频率范围内电路FOM值介于179.5～185.2 dB,电路功耗为7.68～18mW.

An approach is presented to improve the traditional coupling method of quadrature voltage-controlled oscillator （QVCO）. Phase shifter is proposed to be added at the source of the coupling transistor to depress the phase noise and phase mismatch. A low phase noise QVCO with steady output phase relation is designed accordingly. The circuit is designed and fabricated with TSMC 0.13 btm CMOS technology. The output frequency ranges from 3. 4 to 5. 48 GHz and the tuning range is 46. 80//00. The measured results show phase noise --120 dBc/Hz at 1 MHz offset frequency of 4. 2 GHz carrier frequency. The corresponding Figure of Merit （FOM） of this oscillator ranges from 179. 5 dB to 185 dB while the power consumption is between 7. 68 mW and 18 mW.