Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018		Jun. 24, 2017
Cash flows from operating activities:
Net income	$ 19,770		$ 17,193
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Loss on disposal of microwave communications equipment business			278
Depreciation and amortization	4,874		4,339
Share-based compensation expense	3,617		3,476
Deferred income taxes	486		(986)
Adjustment to contingent consideration liability	428
Changes in other accrued liabilities	(294)		308
Changes in other assets	(322)		90
(Gain) loss on disposal of assets	40		(21)
Changes in current assets and liabilities, excluding effects from acquisitions:
Accounts receivable	(21,289)		(23,106)
Inventories	(1,396)		(9,557)
Accounts payable	3,853		7,034
Other current assets	(2,432)		(1,773)
Income taxes payable	1,728		822
Deferred profit	(3,653)		(610)
Accrued compensation, warranty and other liabilities	505		(279)
Net cash provided by (used in) operating activities	5,915		(2,792)
Cash flows from investing activities, excluding effects from acquisitions:
Purchases of short-term investments	(27,374)		(20,477)
Sales and maturities of short-term investments	24,838		30,657
Cash paid for Kita, net of cash received			(11,716)
Purchases of property, plant and equipment	(1,860)		(2,415)
Cash received from sale of fixed assets	4		109
Net cash used in investing activities	(4,392)		(3,842)
Cash flows from financing activities:
Issuance (repurchases) of common stock, net	(2,638)		4,420
Cash dividends paid	(3,484)		(3,221)
Payment of contingent consideration for Kita	(823)
Repayments of long-term debt	(686)		(840)
Net cash provided by (used in) financing activities	(7,631)		359
Effect of exchange rate changes on cash and cash equivalents	(1,170)		2,702
Net decrease in cash and cash equivalents	(7,278)		(3,573)
Cash and cash equivalents at beginning of period	134,286	[1]	96,045
Cash and cash equivalents at end of period	127,008		92,472
Supplemental disclosure of cash flow information:
Cash paid for income taxes	2,608		3,761
Inventory capitalized as property, plant and equipment	149		122
Dividends declared but not yet paid	1,733		1,673
Property, plant and equipment purchases included in accounts payable	$ 166		$ 348

[1] Derived from December 30, 2017 audited financial statements