Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Apr. 30, 2011	Apr. 30, 2010	Apr. 30, 2011	Apr. 30, 2010	Jul. 31, 2010
Number of reportable operating segments			3
Amortization of stock-based compensation	$ 1,118,000	$ 2,332,000	$ 3,977,000	$ 5,758,000
Merger termination fee, net	0	0	12,500,000	0
Net sales	131,081,000	216,303,000	472,052,000	521,251,000
Operating Income (loss)	21,918,000	36,026,000	87,263,000	78,389,000
Interest income and other (expense)	557,000	315,000	1,877,000	728,000
Interest expense	2,135,000	1,980,000	6,288,000	5,913,000
Depreciation and amortization	7,023,000	7,046,000	20,393,000	19,821,000
Expenditure for long-lived assets, including intangibles	1,418,000	1,162,000	10,271,000	4,315,000
Total assets	979,534,000	1,013,910,000	979,534,000	1,013,910,000	1,066,562,000
Telecommunications Transmission [Member]
Net sales	62,443,000	56,536,000	173,852,000	161,661,000
Operating Income (loss)	15,447,000	12,757,000	39,217,000	34,868,000
Interest income and other (expense)	12,000	37,000	99,000	43,000
Interest expense	159,000	42,000	399,000	130,000
Depreciation and amortization	2,831,000	2,716,000	8,483,000	8,133,000
Expenditure for long-lived assets, including intangibles	1,037,000	623,000	8,909,000	2,392,000
Total assets	257,720,000	256,218,000	257,720,000	256,218,000
Mobile Data Communications [Member]
Net sales	45,588,000	134,064,000	228,461,000	272,388,000
Operating Income (loss)	9,127,000	27,529,000	48,510,000	52,509,000
Interest income and other (expense)	9,000	12,000	33,000	36,000
Interest expense	0	0	0	0
Depreciation and amortization	1,874,000	786,000	4,357,000	2,354,000
Expenditure for long-lived assets, including intangibles	140,000	353,000	768,000	1,134,000
Total assets	28,587,000	78,314,000	28,587,000	78,314,000
R F Microwave Amplifiers [Member]
Net sales	23,050,000	25,703,000	69,739,000	87,202,000
Operating Income (loss)	1,197,000	2,480,000	2,241,000	7,904,000
Interest income and other (expense)	(3,000)	31,000	(5,000)	13,000
Interest expense	0	0	0	0
Depreciation and amortization	1,140,000	1,159,000	3,383,000	3,422,000
Expenditure for long-lived assets, including intangibles	241,000	159,000	547,000	745,000
Total assets	102,754,000	105,395,000	102,754,000	105,395,000
Unallocated [Member]
Net sales	0	0	0	0
Operating Income (loss)	(3,853,000)	(6,740,000)	(2,705,000)	(16,892,000)
Interest income and other (expense)	539,000	235,000	1,750,000	636,000
Interest expense	1,976,000	1,938,000	5,889,000	5,783,000
Depreciation and amortization	1,178,000	2,385,000	4,170,000	5,912,000
Expenditure for long-lived assets, including intangibles	0	27,000	47,000	44,000
Total assets	590,473,000	573,983,000	590,473,000	573,983,000
Telecommunications Transmissions Sales to Mobile Data Communications [Member]
Intersegment sales	5,976,000	44,575,000	20,285,000	75,170,000
Telecommunications Transmission Sales to RF Microwave Amplifiers [Member]
Intersegment sales	729,000	1,023,000	2,591,000	6,064,000
RF Microwave Amplifiers Sales to Telecommunications Transmission [Member]
Intersegment sales	$ 1,000	$ 264,000	$ 32,000	$ 264,000