In this article, a parallel‐feedback differential voltage‐controlled oscillator (VCO) with constantly low‐phase noise and frequency tuning range (FTR) of 1.72–2.12 GHz (20.8%) is presented. The presented differential VCO with differential outputs and low‐phase noise is achieved using a four‐pole tunable balanced bandpass filter (BAL‐BPF) with quasi‐elliptic frequency response as a frequency stabilization element. The low‐phase noise is obtained and maintained because of the high in‐band group delay and the constant absolute bandwidth (CABW) of the used tunable BAL‐BPF. For demonstration, an example is designed, fabricated, and measured. The measured oscillation frequency of the differential VCO can be tuned from 1.72–2.12 GHz (20.8%) and the phase noises keep better than −99 dBc/Hz @100 kHz and − 129.1 dBc/Hz @1 MHz over the FTR. In the meantime, the differential oscillating signals are generated at two outputs.

中文翻译：

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基于平衡可调准椭圆和恒定ABW BPF的恒定低相位噪声差分VCO

本文介绍了一种并行反馈差分压控振荡器（VCO），它具有恒定的低相位噪声和频率调谐范围（FTR）为1.72–2.12 GHz（20.8％）。提出的具有差分输出和低相位噪声的差分VCO是使用具有准椭圆频率响应的四极可调平衡带通滤波器（BAL-BPF）作为频率稳定元件来实现的。由于高带内群时延和所用可调BAL-BPF的恒定绝对带宽（CABW），获得并保持了低相位噪声。为了演示，设计，制造和测量了一个示例。可以在1.72–2.12 GHz（20.8％）的范围内对差分VCO的测量振荡频率进行调谐，并且在FTR上，相位噪声保持优于-99 dBc / Hz @ 100 kHz和− 129.1 dBc / Hz @ 1 MHz。同时，