I'm developing a HPF to attenuate frequencies below 30KHz.
My input voltage is a sinusoidal voltage from 0V to + 5V with a frequency of 30KHz.
My objective is to attenuate frequencies below 30KHz including the DC component.
In the end I want to have a sinusoidal voltage from -2.5V to +2.5V and with a frequency of 30KHz.
My HPF is a passive RC circuit. C is equal to 10nF and R is 510 Ohms. The cutoff frequency therefore equals 30KHz. I used this site to help me with component values: sim.okawa-denshi.jp/en/CRhikeisan.htm
But in some simulations that I'm doing with Proteus my signal comes out with attenuations:
What happened? What is the correct cutoff frequency and why? Tks!