For a given range of frequencies, the required capacitance Tuning Ratio (TR) can be calculated as:
1
\(\rm TR=\sqrt{\frac{fr(min)}{fr(max)} } \)
2
\(\rm TR=\sqrt{\frac{fr(max)}{fr(min)} } \)
3
\(\rm TR=\frac{f^2_r(max)}{f^2_r(min)} \)
4
\(\rm TR=\frac{fr(min)}{fr(max)} \)