Intangible Assets

Intangible assets, net consist of the following (in thousands):



	December 28, 2013			December 29, 2012
Cost
Patents	$	18,750		$	15,645
Customer relationships	7,669			7,669
Acquired technology	5,580			5,580
Trademarks	3,338			3,116
Capitalized software development costs	1,612			1,612
Other	969			656
Total cost	37,918			34,278
Accumulated amortization
Patents	(5,679		)	(4,591		)
Customer relationships	(1,086		)	(320		)
Acquired technology	(834		)	(305		)
Trademarks	(653		)	(464		)
Capitalized software development costs	(1,270		)	(1,085		)
Other	(292		)	(150		)
Total accumulated amortization	(9,814		)	(6,915		)
Net carrying amount	$	28,104		$	27,363

For the years ended December 28, 2013, December 29, 2012 and December 31, 2011, total amortization expense was $2.7 million, $2.1 million and $1.6 million, respectively.

Estimated amortization expense for each of the fiscal years is as follows (in thousands):



Fiscal year	Amount
2014	$	2,922
2015	2,808
2016	2,513
2017	2,448
2018	2,254
Thereafter	15,159
Total	$	28,104

During the year ended December 29, 2012, the Company acquired $14.6 million of intangible assets as part of acquisitions. The acquired intangibles are comprised of $7.2 million of customer relationships, $5.3 million of acquired technology, $1.1 million of trademarks and $1.0 million of patents. All of these acquired intangible assets have a 10 year weighted average amortization period.