Effective Design of a 3×4 Two Dimensional Distributed Amplifier Based on Gate Line Considerations

In this paper two dimensional wave propagation is used for power combining in drain nodes of a distributed amplifier (DA). The proposed two dimensional DA uses an electrical funnel to add the currents of drain nodes. The proposed structure is modified due to gate lines considerations. Total gain improvement is achieved by engineering the characteristic impedance of gate lines and also make appropriate variation in the output of gain cells. All variations are done with respect to input and output reflection loss considerations. Analytical expression for the gain of the proposed DA is presented and design considerations for electrical funnel are discussed. Based on two dimensional power combining a wide band DA is simulated using TSMC 0.18 CMOS model in ADS which consumes 49.42 mw from 1.2V power supply. Good agreement between the proposed DA gain and calculated value is achieved. Although one stage DA is used, the final results yield a high figure of merit (FOM) in 0.18 CMOS technology. The final design shows 11.1 dB gain from near DC to 23.6 GHz, noise figure between 3 to 5.2dB and maximum output power of 7.1dBm at 1-dB output compression point (OP1dB).