| 摘要 |
<p>A circuit topology is configured to flatten out a phase- and amplitude-response over a specified range of frequencies. The circuit topology also provides a large cumulative phase- shift. In one embodiment, the circuit topology cascades a plurality of all-pass sections, with the center-frequencies of each all-pass section staggered to create a substantially flat phase- response over a frequency range. Further, in one embodiment the plurality of all-pass sections has at least one all-pass section that is different from another all-pass section. Each all-pass section includes a tunable capacitor and has a center- frequency that can be varied by electronically tuning the capacitor. Each center frequency is selected to obtain substantially constant amplitude and phase response over a desired frequency range and capacitance tuning range.</p> |
