Agilent Technologies E4438C External burst envelope Composite modulation Simultaneous modulation

Specifications for Analog Modulation

External burst envelope

Composite modulation

Simultaneous modulation

Input voltage
RF On	0 V
RF Off	–1.0 V
Linear control range	0 to –1 V
On/off ratio1
Condition: Vin below –1.05 V
	≤ 4 GHz	> 75 dB
	> 4 GHz	(> 64 dB)
Rise/fall time1
Condition: With rectangular input
	(< 2 µs)
Minimum burst repetition frequency1
ALC on	(10 Hz)
ALC off	DC
Input port	External 1
Input impedance	50 Ω, nominal

AM, FM, and FM each consist of two modulation paths which are summed internally for composite modulation. The modulation sources may be any two of the following: Internal, External 1, External 2.

Multiple modulation types may be simultaneously enabled. For example, W-CDMA, AM, and FM can run concurrently and all will affect the output RF. This is useful for simulating signal impairments. There are some exceptions: FM and FM cannot be combined; AM and Burst envelope cannot be combined; Wideband AM and internal I/Q cannot be combined. Two modulation types cannot be generated simultaneously by the same modulation source.

1. Parentheses denote typical performance.

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