Generating time varying sinusoidal function

Hello

I need to generate time varying sinusoidal signal, I used linearly varying frequency with time but the resulting signal was not matching with the desired frequency.

Could you kindly help me generate sinusoidal signal that had time varying frequency with the band of 0.10 - 2 hz.

Thank you

[Azzi Abdelmalek]

what is the desired frequency? what is the desired signal?