Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017		Sep. 24, 2016
Cash flows from operating activities:
Net income	$ 25,948		$ 950
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of microwave communications equipment business	278		4
Depreciation and amortization	6,731		8,089
Share-based compensation expense	5,336		5,291
Amortization of inventory step-up	1,404
Deferred income taxes	(932)		(1,111)
Mark to market adjustment to Kita contingent consideration liability	668
Changes in other accrued liabilities	427		716
Changes in other assets	572		(32)
(Gain) loss on disposal of assets	(22)		37
Changes in current assets and liabilities, excluding effects from acquisitions:
Accounts receivable	(9,013)		3,073
Inventories	(6,701)		3,551
Accounts payable	(3,620)		(2,109)
Other current assets	1,257		(411)
Income taxes payable	1,272		(2,451)
Deferred profit	(299)		1,970
Accrued compensation, warranty and other liabilities	303		980
Net cash provided by operating activities	23,609		18,547
Cash flows from investing activities, excluding effects from acquisitions:
Sales and maturities of short-term investments	39,315		13,654
Purchases of short-term investments	(23,665)		(31,453)
Cash paid for Kita, net of cash received	(11,716)
Purchases of property, plant and equipment	(4,739)		(2,797)
Cash received from sale of fixed assets	109		852
Net cash used in investing activities	(696)		(19,744)
Cash flows from financing activities:
Issuance (repurchases) of common stock, net	7,149		(1,325)
Cash dividends paid	(4,894)		(4,748)
Repayments of long-term debt	(1,280)
Net cash provided by (used in) financing activities	975		(6,073)
Effect of exchange rate changes on cash and cash equivalents	2,051		1,117
Net increase (decrease) in cash and cash equivalents	25,939		(6,153)
Cash and cash equivalents at beginning of period	96,045	[1]	115,370
Cash and cash equivalents at end of period	121,984		109,217
Supplemental disclosure of cash flow information:
Cash paid for income taxes	3,740		5,977
Inventory capitalized as property, plant and equipment	113		201
Dividends declared but not yet paid	1,683		1,603
Property, plant and equipment purchases included in accounts payable	$ 594		$ 118

[1] Derived from December 31, 2016 audited financial statements