Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

RF Switching with DC Pass

Status
Not open for further replies.

Xenobius

Member level 5
Joined
Feb 25, 2019
Messages
84
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
850
Hi, I have an application whereby I need to switch between 2 RF signals. Both signals carry DC with them and this must be switched too not blocked. Also both signals are between 0 and 2.4Ghz
Can you please help me identify an IC which can be controlled using a microcontroller or perhaps even a name of what-these-ICs-are-called so that I can look and further my research.

Something I need to explain is that some existing switches have "DC Pass" marked on them and some don't and in my case it needs to have "DC Pass". What exactly is this?

Thanks for your help
 

Voltage and current rating? Permitted signal attenuation? Required isolation?
 

Solid-State RF switches have not been designed being as passing DC because DC voltage changes the OP of FET devices in it.Also, if the switch absorbing type, termination resistors may be burned..
I suggest to search mechanical RF relays for that frequency.
 

Simulation, switching an AC signal by turning on a diode to conduct it.

By itself the audio signal cannot pass through the diode, until mixed with a control voltage of sufficient level to overcome the diode threshold. Output is AC riding a DC voltage.

View attachment 156942

If you need to increase the voltage range it can be changed by placing sufficient diodes (led's, zener diodes) in series.
 

Right so clearly there is a lot to learn as I don't have much knowledge here. The mechanical relay solution sounds simple enough to me! Thanks all much appreciated!
 

Coaxial SPDT relays are available on the market, also non-absorptive GaAs SPDT switches can switch DC if driver bias is setup respectively. You didn't yet specify voltage and current rating.
 

Coaxial SPDT relays are available on the market, also non-absorptive GaAs SPDT switches can switch DC if driver bias is setup respectively. You didn't yet specify voltage and current rating.

Hi, Yes so I haven't yet specified because I have no clue. Both signals are from 2 different TV companies, one is a cable provider and one is an antenna based provider and I have just 1 wire to pass both. I managed to deduce that they use 75ohm connectors and that with a switch of 2400Mhz I could work but would need to constantly screw and un screw the coaxial on both ends which is tedious.
 

Both signals are from 2 different TV companies, one is a cable provider and one is an antenna based provider

You mentioned that the signals are between 0Hz (which is DC) and 2.4Ghz.

My questions are: How a cable provider is transmitting a DC signal? How a DC signal is propagating through the air, between two antennas?
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top