Post Go back to editing

ADGM1304/ADGM1004 matching to 50 Ohm

Category: Datasheet/Specs
Product Number: ADGM1304

Hi, I am looking for components for a RF system design. I am new to MEMS switches, but I think either the ADGM1304 or the ADGM1004 could be a good switch in the design because of the low insertion loss and 4 ports to switch between.

I am working with a 50 Ohm system and need to either find components that are internally matched to 50 Ohm, or match the components to 50 Ohm myself. 

My questions:

  • Can I use the RF ports with other components matched to 50 Ohm as is, or does the RF ports of the MEMS switch need to be matched to 50 Ohm?
  • If not, is the impedance I need to match to R_on? Is this impedance purely resistive or does it have any reactive elements changing over frequency?
  • The datasheet says it supports the range DC - 14 GHz, is this before matching? I.e you can do matching within this band and expect similar results as in the datasheet, but the expected bandwidth after matching is a fraction of the "supported" bandwidth?
  • If this is not matched to 50 Ohm internally, do you have any other switches to recommend? It should have insertion loss under 1 dB, preferably work within the range DC to 6 GHz, have three or four ports to switch between, and be able to handle at least 30 dBm.

Thank you for your feedback

Parents
  • Hi Calle,  

    The ADGM switch ports are optimized for 50ohm terminated systems, no extra matching is required.  The switches RF performance parameters are all measured with 50ohm terminations, e.g. 50ohm VNA ports for IL etc, no matching. From an RF perspective its like a solid state RF switch, e.g. SOI or GaAs etc.  Note when the switch is "off" there are no absorptive 50ohm shunt resistors internal in the part, its a reflective open type switch.  The ADGM parts also perform at DC, that is why there are Ron specs in the datasheet to help with DC analysis, like a relay. But this DC Ron is not relevant for RF analysis. 

    If the ADGM isn't a fit you can search the regular solid state RF switches here:

    https://www.analog.com/en/parametricsearch/10723#/

    Eric.

Reply
  • Hi Calle,  

    The ADGM switch ports are optimized for 50ohm terminated systems, no extra matching is required.  The switches RF performance parameters are all measured with 50ohm terminations, e.g. 50ohm VNA ports for IL etc, no matching. From an RF perspective its like a solid state RF switch, e.g. SOI or GaAs etc.  Note when the switch is "off" there are no absorptive 50ohm shunt resistors internal in the part, its a reflective open type switch.  The ADGM parts also perform at DC, that is why there are Ron specs in the datasheet to help with DC analysis, like a relay. But this DC Ron is not relevant for RF analysis. 

    If the ADGM isn't a fit you can search the regular solid state RF switches here:

    https://www.analog.com/en/parametricsearch/10723#/

    Eric.

Children