Greetings,
I would like to ask you a question about the HMC253AQS24 SP8T switch. I am planning to use that integrated circuit to switch my 2.45 GHz patch antennas (Mostly my antennas have operatings bands between 2.4-2.5 GHz). I have realized a few studies to make this HMC253AQS24 to work on substrates such as FR4 and RO3210. But I could not make the circuit work. I believe its because of impedance matching problem. I investigated HMC253AQS24 SP8T evaluation circuit board that you presented but I did not understand the working mechanism. I would like to learn impedance matching logic behind this evaluation circuit board. When I examine HMC253AQS24 SP8T evaluation circuit board, I see that all the microstrip line widths are 0.3mms which are the same width of circuits output leg witdhs. It's also mentioned that as the evaluation circuit board substrate, Rogers 4350 (DK=3.48 h=1.52 mm) (I am not sure about the height of the substare since its not mentioned in there) is used which means this substrate 50 ohm impedance microstrip line width at least should be 3.45 mm according to classical microstrip line width calculation method. But all the microstrip line widths are thinner in this evaluation board obviously . So I would like to learn how this impedance matching realized in that evaluation circuit board without any impedance matching techniques. I also would like to learn the reason why using so many vias in this evaluation board. I appreciate if you help me to understand working mechanism behind this HMC253AQS24 SP8T evaluation circuit board.
Waiting for your reply.
Best Regards...
Gulden Gunay BULUT ONER
Research Assistant
Nevsehir Haci Bektas Veli University Departmant of Electrical and Electronics Engineering
