Can anyone explain me the 4 diode Balanced modulator circuit

dexterdev

Hi,
Can anyone explain me the working of 4 diode DSBSC Balanced modulator circuit. ie how multiplication occurs when switching. The image is attached.
-Devanand T

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sophiecentaur

Noddy description:
The bridge will produce an output version of the input signal that is 'either way up', depending on the polarity of the (high level) 'control voltage' across the carrier input.The way I have always looked at it is that the Carrier signal reverses the polarity of the Modulation input signal twice every carrier cycle, so the resulting signal will appear as two symmetrical versions of the modulation signal; one inverted and one the right way up - i.e like conventional DSBAM but without any carrier to 'separate' the top and bottom halves of the envelope.

dexterdev

thank you sir

sophiecentaur

Did that make sense, then? I wasn't sure!

dexterdev

Sir, I got an explanation from Fresnel's Ppls of commn book...that was satisfactory... Thanks for your effort..In between I want to know any IRC channel for this forum (or any similar)so that I can ask doubts live (using windows 7 os). Not that comfortable with chating in IRC although

sophiecentaur

I don't know of any IRC on PF - but don't discount the possibility. Post a question of the Computing forum. You may get lucky.

dexterdev

thank you sir