Segment Information (Details) (USD $)	3 Months Ended												12 Months Ended
	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2009	Apr. 30, 2009	Jan. 31, 2009	Oct. 31, 2008	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Number of reportable operating segments													3
Net sales	$ 140,327,000	$ 131,081,000	$ 162,811,000	$ 178,160,000	$ 256,954,000	$ 216,303,000	$ 171,132,000	$ 133,816,000	$ 122,026,000	$ 128,545,000	$ 143,886,000	$ 191,915,000	$ 612,379,000	$ 778,205,000	$ 586,372,000
Operating Income (loss)													107,798,000	103,980,000	76,927,000
Interest income and other (expense)													2,421,000	1,210,000	2,738,000
Interest expense													8,415,000	7,888,000	6,396,000
Depreciation and amortization													27,701,000	27,783,000	37,392,000
Expenditure for long-lived assets, including intangibles													12,641,000	8,865,000	197,238,000
Total assets	937,509,000				1,066,562,000				938,671,000				937,509,000	1,066,562,000	938,671,000
Merger termination fee, net													12,500,000	0	0
Amortization of stock-based compensation													5,357,000	8,716,000	9,576,000
Impairment of goodwill													0	13,249,000	0
Telecommunications Transmission Segment [Member]
Net sales													231,957,000	219,701,000	254,266,000
Operating Income (loss)													49,913,000	47,493,000	55,489,000
Interest income and other (expense)													89,000	73,000	104,000
Interest expense													562,000	171,000	141,000
Depreciation and amortization													11,241,000	10,821,000	15,684,000
Expenditure for long-lived assets, including intangibles													10,607,000	3,490,000	133,955,000
Total assets	252,839,000				253,212,000				270,596,000				252,839,000	253,212,000	270,596,000
Impairment of goodwill														0
Mobile Data Communications Segment [Member]
Net sales													288,449,000	446,545,000	177,007,000
Operating Income (loss)													64,945,000	75,506,000	31,348,000
Interest income and other (expense)													43,000	47,000	1,000
Interest expense													10,000	0	0
Depreciation and amortization													6,282,000	3,403,000	3,352,000
Expenditure for long-lived assets, including intangibles													922,000	3,887,000	10,923,000
Total assets	31,265,000				105,698,000				53,105,000				31,265,000	105,698,000	53,105,000
Impairment of goodwill														13,249,000
R F Microwave Amplifiers Segment [Member]
Net sales													91,973,000	111,959,000	155,099,000
Operating Income (loss)													1,063,000	9,808,000	14,266,000
Interest income and other (expense)													(8,000)	15,000	68,000
Interest expense													0	0	0
Depreciation and amortization													4,576,000	4,630,000	8,567,000
Expenditure for long-lived assets, including intangibles													1,069,000	1,288,000	52,282,000
Total assets	98,261,000				101,290,000				112,709,000				98,261,000	101,290,000	112,709,000
Impairment of goodwill														0
Unallocated [Member]
Net sales													0	0	0
Operating Income (loss)													(8,123,000)	(28,827,000)	(24,176,000)
Interest income and other (expense)													2,297,000	1,075,000	2,565,000
Interest expense													7,843,000	7,717,000	6,255,000
Depreciation and amortization													5,602,000	8,929,000	9,789,000
Expenditure for long-lived assets, including intangibles													43,000	200,000	78,000
Total assets	555,144,000				606,362,000				502,261,000				555,144,000	606,362,000	502,261,000
Telecommunications Transmissions Sales to Mobile Data Communications [Member]
Intersegment sales													36,959,000	7,172,000	14,643,000
Telecommunications Transmission Sales to RF Microwave Amplifiers [Member]
Intersegment sales													3,810,000	82,170,000	52,970,000
RF Microwave Amplifiers Sales to Telecommunications Transmission [Member]
Intersegment sales													$ 90,000	$ 436,000	$ 145,000