This paper presents a 0.8-6 GHz inductor less low-noise amplifier (LNA) with an improved deep trench isolation (DTI) electrostatic discharge (ESD) diode. The improved DTI diodes reduce parasitic capacitance by up to 30% compared to conventional ones. This design includes a cascode amplifier with RC shunt feedback and an emitter follower. For the circuit design, a detailed port matching and gain flatness analysis are given. This work achieves a flat high S21 of 18±0.2 dB and an extremely low noise figure of 2.56-2.85 dB. The S11 and S22 are below -11 dB and -18 dB over the entire frequency band. The input third-order intermodulation point (IIP3) is -5.72 dBm at 2 GHz. Thanks to the inductor-less design, LNA core occupies only 0.05 mm2 area.