what's meant by coupling - RF Cafe Forums

RF Cafe Forums closed its virtual doors in late 2012 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2012, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. Regardless, there are still lots of great posts in the archive that ware worth looking at. Below are the old forum threads, including responses to the original posts. Here is the full original RF Cafe Forums on Archive.org

-- Amateur Radio

-- Anecdotes, Gripes, & Humor

-- Antennas

-- CAE, CAD, & Software

-- Circuits & Components

-- Employment & Interviews

-- Miscellany

-- Swap Shop

-- Systems

-- Test & Measurement

-- Webmaster

guest

Post subject: what's meant by coupling Posted: Mon Sep 12, 2005 4:58 am

i m an undergraduate and starting out in circuit analysis and design and hope to go on to do something in rf field 'cause i like it a lot. i've a very basic question to ask...when people talk about ac coupling capacitor, what they do really mean? exactly, what does coupling exactly mean? i know blocking cap blocks dc signal, bypass cap open circuits the dc signal but i'm not exactly sure what's meant by dc coupling or ac coupling.

any explanation w/ or w/o example will help a lot! thanx

Top

IR

Post subject: Posted: Mon Sep 12, 2005 6:03 am

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Coupling means how much the signal will pass forward from one point to another. AC coupling is done by means of series capacitor. As the frequency increases the reactance of the capacitor drops, according to the ratio of Xc=1/2*pi*f*C.

_________________

Best regards,

- IR

Top

guest

Post subject: Posted: Mon Sep 12, 2005 6:37 pm

hi IR, this means that a series capacitor that is used for ac coupling is then also a dc block??

Top

IR

Post subject: Posted: Mon Sep 12, 2005 11:30 pm

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Exactly!!

_________________

Best regards,

- IR

Top

YZ-israel

Post subject: Posted: Wed Sep 14, 2005 1:33 am

you can say DC coupling is the same as High Pass Filter.

It will blocked the DC and the lower Freq. and pass the higher freq.

the 3 dB point for this filter depend on the capacitor and the impedance.[/img]

Posted  11/12/2012