bicmos8hp Class E amplifier

Hi,

I'm designing class E amplifier.It is working fine with ideal components (inductance and capacitance).When I replaced the ideal components with practical instances the efficiency is dropping to 42 %(above 80% with ideal components).The class E design is attached below.The capacitance c21 is causing the problem.The current is dissipating more in it.Can anyone help me to modify my circuit.I used bicmos8hp technology.I tried with ncap and MIM capacitors but both of them results in same efficiency.

while calculating the efficiency I took rms values of the output and DC values of the supply.Is it correct?.

I biased the circuit at 400mv and signal is 800mv.

Can anyone help me in this regard.