中文摘要：

为了满足教学和科研的需要，基于负阻原理设计了一款工作于ISM频段2.45 GHz低成本微带压控振荡器。振荡电路采用双电源供电和共基极连接方式，利用双极性晶体管和变容二极管等分立元件制作。借助于ADS软件对电路参数及主要指标进行仿真优化，并进行了实物的加工和测试。实测结果表明，设计的压控振荡器在输入调频电压为0~6V时，输出振荡频率覆盖2.4-2.5 GHz，输出功率大于9.2 dBm，相位噪声在偏离移中心频率100 kHz处为-90 dBc/Hz。该振荡器调谐频带线性度好，输出功率平坦度高。

英文摘要：

In order to satisfy the need of teaching and scientific research,a low？cost 2.45 GHz microstrip voltage controlled oscillator（VCO）working in ISM band was designed based on the principle of negative resistance. The dual power supply and common base connection modes are adopted in the oscillating circuit composed of discrete components such as bipolar transistor and varactor. The circuit parameters and specifications are simulated and optimized with the help of ADS software. The prototype circuit was fabricated and tested. Experimental results demonstrate that,when the input voltage is 0~6 V,its output frequency coverage is 2.4~2.5 GHz,output power is more than 9.2 dBm,and phase noise is ？90 dBc/Hz at 100 kHz of departing from the central frequency. The designed oscillator has fine tuning band linearity and high output power flatness.