Temperature-compensated lumped element tunable bandpass filter
Temperature-compensated lumped element tunable bandpass filter
复制标题
温度补偿集总元件可调谐带通滤波器
DOI：
10.1109/mwsym.2016.7539990
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
D. Peroulis
中科院分区：
文献类型：
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作者：
M. Abu Khater;Kaiyuan Zeng;D. Peroulis
本文介绍并比较了两种在基于变容二极管的集总元件可调谐带通滤波器 (BPF) 中补偿温度影响的技术。温度补偿依赖于首先测量温度，然后根据预先计算的查找表重新偏置滤波器的变容二极管。查找表使用两种不同的方法进行校准：a) 恒定变容二极管电容，b) 恒定滤波器响应。当过滤器承受 -40 至 100°C 的温度范围时，对这两种方法进行评估。在第一种方法中，每个滤波器变容二极管的电容保持恒定在室温下产生所需滤波器响应的值。另一方面，第二种方法利用全局优化方案，重新偏置所有变容二极管，直到滤波器产生所需的传递函数。针对可在 226 MHz 至 333 MHz 范围内调谐的三阶 BPF，对两种方法的结果进行了测量和比较。虽然第一种方法更容易实现并且可能看起来很直观，但它实际上会导致更严重的温度引起的漂移，因为它忽略了基板和电感器的影响。具体而言，第一种方法产生的中心频率温度漂移为 4.3%，而未应用补偿时为 3.2%。第二种方法可实现最佳结果，其中滤波器的中心频率在 -40 至 100°C 的温度范围内保持恒定在 0.1% 以内。
This paper presents and compares two techniques for compensating temperature effects in varactor diode-based lumped element tunable bandpass filters (BPFs). Temperature compensation relies on first measuring the temperature and subsequently re-biasing the varactors of the filter based on pre-calculated lookup table. The lookup table is calibrated using two different methods: a) constant varactor capacitance, and b) constant filter response. Both approaches are evaluated when the filter is subjected to temperatures ranging from -40 to 100°C. In the first approach the capacitance of each of the filter's varactors is held constant at the value found to yield the desired filter response at room temperature. On the other hand, the second approach utilizes a global optimization scheme that re-biases all varactors until the filter yields the desired transfer function. The results from both methods are measured and compared for a third-order BPF tunable from 226 MHz to 333 MHz. While the first method is simpler to implement and may appear intuitive, it actually causes a worse temperature-induced drift because it ignores substrate and inductor effects. Specifically, the resulting temperature drift of the center frequency with the first method is 4.3% as compared to 3.2% when no compensation is applied. Optimal results are achieved with the second approach where the filter's center frequency remains constant to within 0.1% over the -40 to 100°C temperature range.