amplifier design and trouble shooting in Cadence

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Joined Feb 26, 2020
I am new to the circuit design and troubleshooting. My project is to design a trans-impedance amplifier using Cadence that can amplify a signal coming from a photodiode. I started out with the regulated cascode configuration as shown in the circuit below. I look at the frequency repsonse using AC simulation and it looks like a high pass (/net 5 Vac_info.png). I checked that all the transistors are in saturation mode, and we are looking for a low pass response like that of most amplifiers.
ALso there is no gain between the input an dthe output isgnals plotted from the transient analysis.
But I dont know why the response doesnot show gain and roll-off like a low pass. I would appreciate how to work over to improve the design

-Rakesh.Operating points RGC.pngResults.png