一款低附加相位噪声X波段四倍频MMIC的设计

Design of a Low Additive Phase Noise X-Band Frequency Quadrupler MMIC

基于GaAs异质结双极性晶体管（HBT）工艺设计了一款输出频率为8~10 GHz的X波段四倍频器单片微波集成电路（MMIC）。采用两级对管平衡倍频器级联结构,并在输出端设计了驱动放大器,实现了高变频增益和良好谐波抑制。基于GaAs HBT工艺优良的闪烁噪声（1/f）特性,优化了对管平衡电路拓扑和工作点的选取,达到低附加相位噪声的设计目标。对MMIC进行了在片微波探针测试,测试结果表明,当输入功率为-10 dBm时,在8~10 GHz输出频率内变频增益大于13 dB,二次谐波抑制大于18 dBc,其余各次抑制优于27 dBc。电路采用单电源5 V供电,工作电流为55 mA,芯片面积仅为1.3 mm×1.1 mm。介绍了附加相位噪声及其对频率源系统的影响,并分析了正交鉴相法测量相位噪声的原理,所设计的MMIC在输出频率为9 GHz、频偏100 kHz时附加相位噪声达到-143 dBc/Hz。

Based on GaAs heterojunction bipolar transistor （HBT） technology, an X-band frequen- cy quadrupler monolithic microwave integrated circuit （MMIC） operating at the output frequency of 8- 10 GHz was designed. Two-stage balanced doublers structure was adopted and the drive amplifier was designed at the output port, which realized high conversion gain and excellent harmonic suppression. Based on the excellent flick-noise （I/f） characteristic of GaAs HBT technology, the topology of the ba- lanced circuit and the selections of circuit operating point were optimized to achieve the design target of low additive phase noise. The on-wafer microwave prober measurement of the MMIC was carried out. The test results indicate that when the input power is -10 dBm, the conversion gain is greater than 13 dB in the output frequency range of 8-10 GHz, the second harmonic suppression is higher than 18 dBc and the other harmonics are superior to 27 dBc. The operating current of the circuit is 55 mA with a single 5 V supply voltage. The chip area is only 1.3 mmx 1.1 mm. The additive phase noise and the influence of the additive phase noise on the frequency generation system were introduced, and the principle of measuring the phase noise by orthogonal phase detecting method was analyzed. The proposed MMIC achieves excellent additive phase noise of -143 dBc/Hz at the output frequency of 9 GHz and 100 kHz offset.