Wideband matching of 300-j450 to 50 Ohms
时间：04-07
整理：3721RD
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Hello everyone!
I am designing an LNA for a radio telescope (1.42GHz) and i want to achieve the lowest possible noise figure... I am using the NEC NE3210S01 PHEMT. I have designed it for Noise Figure<0.5. My problem is that the source reflection coefficients associated with this NF are at the very right of the Smith Chart (i.e. they are associated with very large impedances). I want to achieve a BW of 100MHz.. I want to match 300-j450Ω to 50Ω. I have tried a Chebychev low-pass filter that does the job but i end up with a 20nH inductor that is very big and difficult to be realized with transmission lines... Any ideas? Is there any way to achieve this with practical element values or should i settle for a higher noise figure that provides easier matching?
Thank you
Georgios
I am designing an LNA for a radio telescope (1.42GHz) and i want to achieve the lowest possible noise figure... I am using the NEC NE3210S01 PHEMT. I have designed it for Noise Figure<0.5. My problem is that the source reflection coefficients associated with this NF are at the very right of the Smith Chart (i.e. they are associated with very large impedances). I want to achieve a BW of 100MHz.. I want to match 300-j450Ω to 50Ω. I have tried a Chebychev low-pass filter that does the job but i end up with a 20nH inductor that is very big and difficult to be realized with transmission lines... Any ideas? Is there any way to achieve this with practical element values or should i settle for a higher noise figure that provides easier matching?
Thank you
Georgios
Coilcraft 0402CS (1005) Wirewound Ceramic Chip Inductors