The ban is Armitage's fourth of 2011 following previous high-profile incidents for both club and country.
The most controversial of those suspensions came after a Premiership match on New Year's Day - ironically against Bath yet again - when he was found to have pushed and verbally abused an anti-doping official in the tunnel at the Madejski Stadium.
Armitage then received a three-week ban for a punch on Northampton outside-half Stephen Myler in April.
And having impressed for England at the World Cup after been chosen on the wing following Mark Cueto's back injury, the 27-year-old missed the quarter-final defeat to France having being sidelined for a single match for a dangerous tackle on Scotland's Chris Paterson.
Armitage's poor disciplinary record, as well as the International Rugby Board's recent clampdown on tip tackles, counted against him at his latest hearing with the initial length of his ban increased because of past misdemeanours and the need to follow international protocol.
However, a three-week ban for his clash with Attwood will run concurrently with his five-week suspension for the dangerous tackle meaning he will available to play again on December 9 rather than December 30.
"We accept that both these incidents were reckless and not malicious," said Rugby Football Union disciplinary officer Judge Jeff Blackett.
"However, in relation to the dangerous tackle on Tom Biggs there was the potential for significant injury and for that reason we believe that it was a mid-range entry level offence of six weeks. We increased it to eight because of concerns raised by the IRB about injuries caused by dangerous tackles and because of his poor disciplinary record.
"We then reduced the sanction to five weeks because of his guilty plea, his contrition and the impressive way he conducted himself at the hearing. In relation to the strike to which he also pleaded guilty, we
decided that this was a low end entry offence and for that we imposed a three-week suspension.
"Delon has unfortunately had several disciplinary issues this year and it is a shame that he once again finds himself not playing. However, we hope that he will learn from these events and we look forward to him resuming the game he quite clearly feels very passionate about."